Introduction to Midwifery History of Midwifery
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The history of midwifery is a long and interesting one.
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Women of all countries have done noble work as midwives throughout the countries.
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Socrates Socrates mother was a midwife midwife and he considered it “a most respected respected profession”.
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According to Aristotle, a midwife is a most necessary and honourable office, being a helper of nature.
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Midw Midwif ifee carr carrie iess a huge huge resp respon onsi sibi bili lity ty in help helpin ing g wome women n duri during ng childbirth.
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Biblical references to midwives have always been to their honour. There are instances in the Old Testament to show that midwives play vital role.
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Until the end of the sixteenth century, midwifery was practiced entirely by women. Men could be severely punished for attending women in childbirth.
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In the seventeenth century male midwives began to take up midwifery.
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By the middle of the eighteenth century the number of male midwives had increased, though there was great opposition and competition from the midwives and from the general public.
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In English the word midwife means “With woman” (the person with the woman who is in labour).
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Midw Midwiv ives es hold hold an impo import rtan antt key key to posi positi tive ve care care at the the time time of childbirth that will contribute to a good start for the baby and parents. The midwife is able to do so only by virtue of her expert knowledge. The education of the midwife is designed to enable her to fulfill her wide and varied role.
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During the last 25 years of the nineteenth century, several hospitals began to train midwives and to issue certificates.
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In 1902 Midwives Act in United Kingdom entitled an act to secure better training and supervision of midwives.
Terminology
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the know knowle ledg dgee nece necess ssar ary y to perf perfor orm m the the duti duties es of Midwifery is the midwife.
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branch of medicine, ne, which deal dealss with the Obstetrics is that bra management of pregnancy, labour and puerperium.
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By the middle of the eighteenth century the number of male midwives had increased, though there was great opposition and competition from the midwives and from the general public.
•
In English the word midwife means “With woman” (the person with the woman who is in labour).
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Midw Midwiv ives es hold hold an impo import rtan antt key key to posi positi tive ve care care at the the time time of childbirth that will contribute to a good start for the baby and parents. The midwife is able to do so only by virtue of her expert knowledge. The education of the midwife is designed to enable her to fulfill her wide and varied role.
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During the last 25 years of the nineteenth century, several hospitals began to train midwives and to issue certificates.
•
In 1902 Midwives Act in United Kingdom entitled an act to secure better training and supervision of midwives.
Terminology
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the know knowle ledg dgee nece necess ssar ary y to perf perfor orm m the the duti duties es of Midwifery is the midwife.
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branch of medicine, ne, which deal dealss with the Obstetrics is that bra management of pregnancy, labour and puerperium.
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Gynaecology is that branch of medical science, which treats diseases of
the female genital organs. •
Reproduction means process by which a fully developed offspring of
its kind is produced. •
Pregnancy is a state of carrying fetus inside the uterus by a woman
from conception to birth. •
Gestation means pregnancy.
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Gravidae is state of pregnancy irrespective of its duration.
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Multipara refers to woman who has given birth more than once
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Nullipara is the woman who has not given birth before.
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Primigravidae is a woman carrying first pregnancy.
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Multigravidae is a woman carrying pregnancy more than once.
Maternal and Child Health Indicators
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Birth rate: The number of births per 1,000 population.
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Fert Fertil ilit ity y rate rate:: The The numb number er of preg pregna nanc ncie iess per per 1,00 1,000 0 wome women n of childbearing age.
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Fetal death rate: The number of fetal deaths (over 500 g) per 1,000 live births.
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Neonatal death rate: The number of deaths per 1,000 live births occurring at birth or in the first 28 days of life.
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Perinatal death rate: The number of deaths of fetuses more than 500 g and in the first 28 days of life per 1,000 live births.
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Maternal Mortality Rate: The number of maternal deaths per 100,000 live births that occur as a direct result of the reproductive process.
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Infant Mortality Rate: The number of deaths per 1,000 live births occurring at birth or in the first 12 months of life.
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Childhood Childhood Mortality Rate: The number of deaths per 1,000 population population in children, 1 to 14 years of age.
Role of Nurse in Midwifery Definition of Midwife
In 1992, The World Health Organization defined that “A midwife is a person who, having been regularly admitted to a midwifery educational programme, duly recognized in the country in which it is located, has successfully completed the prescribed courses or studies in midwifery and has acquired the requisite qualifications to be registered and or legally licensed to practise midwifery”.
Roles of Midwife
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The midwife has a unique role in care of mothers and babies.
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To give the necessary supervision, care and advice to women during pregnancy, labour and the postpartum period.
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To conduct deliveries on her own responsibility and to care for the mother and the newborn.
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To promote normal birth and detect complications in mother and child, access to medical or other appropriate assistance and the carry out emergency measures.
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To involve in health counselling and education, not only for the woman, but also within the family and community.
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To involve antenatal education and preparation for parenthood.
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To promote women's health, sexual or reproductive health and childcare.
TERMINOLOGY USED IN MIDWIFERY •
Gestation-pregnancy or maternal condition of having a developing
fetus in the body. •
Embryo-human conceptus up to the 10th week of gestation (8th week
postconception). •
Fetus-human conceptus from 10th week of gestation (8th week
postconception) until delivery.
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Viability-capability of living, usually accepted as 24 weeks, although
survival is rare. •
Gravida (G)-woman who is or has been pregnant, regardless of
pregnancy outcome. •
Nulligravida-woman who is not now and never has been pregnant.
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Primigravida-woman pregnant for the first time.
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Multigravida-woman who has been pregnant more than once.
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Para (P)-refers to past pregnancies that have reached viability.
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Nullipara-woman who has never completed a pregnancy to the period
of viability. The woman may or may not have experienced an abortion. •
Primipara-woman who has completed one pregnancy to the period of
viability regardless of the number of infants delivered and regardless of the infant being live or stillborn. •
Multipara-woman who has completed two or more pregnancies to the
stage of viability. •
Living children-refers to the number of living children a woman has
delivered regardless of whether they were live births or stillborn births.
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GPLAM
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In some institutions, a woman's obstetric history can also be summarized as GPLAM.
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G-represents gravida.
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P-represents preterm deliveries, 20 to less than 37 completed weeks.
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L-represents the number of children living. If a child has died,
further explanation is needed for clarification.
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A-represents abortions, elective or spontaneous loss of a pregnancy
before the period of viability.
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M-represents the number of Multiple pregnancy/ Medical
Termination of Pregnancy done.
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A woman who delivered one fetus carried to the period of viability
and who is pregnant again is described as Gravida 2, Para 1.
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A woman with two pregnancies ending in abortions and no viable
children is Gravida 2, Para 0.
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A woman who is pregnant for the first time is a primigravida and is
described as Gravida 1 Para 0 (or G1P0).
TRENDS IN THE MIDWIFERY AND OBSTETRICAL NURSING
Changes in social structure, variations in family lifestyle It has altered health care priorities for maternal and child health nurses. Today, client advocacy, an increased focus on health education, and new nursing roles are ways in which nurses have adapted to these changes. •
Cost Containment Cost containment refers to systems of health care delivery that focus on reducing the cost of health care by closely monitoring the cost of personnel, use and brands of supplies, length of hospital stays, number of procedures carried out, and number of referrals requested. •
Expanded roles for nurses Increasing nursing responsibility for assessment and professional judgment and providing expanded roles for nurse practitioners, such as the nurse-midwife. •
Family Centered Care More natural childbirth environment where partners, family members may remain in a homelike environment, and participate in the childbirth experience By adopting a view of pregnancy, childbirth as a family event, nurses can be instrumental in including family members in care and consult •
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family members about a plan of care and provide clear health teaching so that family members can monitor their own care
Access to Health Care Strong predictors of access to quality health care include having health insurance, a higher income level, and a regular primary care provider or other source of ongoing health care. Use of clinical preventive services, such as early prenatal care, can serve as indicators of access to quality health care services. The objectives selected to measure progress in this area are: Increase the proportion of persons with health insurance. •
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Increase the proportion of persons who have a specific source of ongoing care. Increase the proportion of pregnant women who begin prenatal care in the first trimester of pregnancy
Shortening Hospital Stays Women who have begun preterm labor stay in the hospital while labor is halted and then are allowed to return home on medication with continued monitoring. Routine hospital stay for mothers and newborns after an uncomplicated birth is now 2 days or less. •
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Short-term hospital stays require intensive health teaching by the nursing staff and follow-up by home care or community health nurses.
Increased Use of Alternative Treatment Modalities There is a growing tendency to consult alternative forms of therapy, such as acupuncture or therapeutic touch, in addition to, or instead of, traditional health care providers. Nurses have an increasing obligation to be aware of complementary or alternative therapies. •
Increased Use of Technology The field of assisted reproduction (e.g., in vitro fertilization), seeking information on the Internet, and monitoring fetal heart rates by Doppler ultra sonography are other examples. In addition to learning these technologies, maternal and child health nurses must be able to explain their use and their advantages to clients. Otherwise, clients may find new technologies more frightening than helpful to them. •
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PRE-CONCEPTION CARE AND COUNSELING INTRODUCTION Concept of preconception care has evolved over the last several decades J.W. Ballantyne - originated concept of prenatal care • •
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Preconception and prenatal care are forms of primary care and prevention
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Opportunities exist in many settings
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Should target all women of reproductive age
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Education and preparation are key
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Worldwide maternal mortality approaches one million women annually
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Risk of maternal death in the is 1 in 10,000 live births
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Unintended pregnancy rate approaches 40% annually
COMPONENTS OF PRECONCEPTION CARE Risk assessment Education • •
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Intervention or modification
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Counseling
GOALS OF PRECONCEPTION CARE To identify pre-existing conditions that may affect an anticipated pregnancy This may allow for intervention(s) that could lead to more favorable outcome • •
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Goal should be realistic
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Identification process involves mother and fetus
CONTRACEPTION Good preconception care begins with appropriate contraception!! Should be addressed at each visit, including primary care visits, emergency room visits, and well woman appointments • •
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Should be appropriate as regards patient’s lifestyle and medical condition
MATERNAL RISK ASSESSMENT Family and genetic history (maternal and paternal) Medical history • •
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Medication use
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Environmental exposures (home and work)
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Obstetric and reproductive history
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Domestic abuse
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Emotional preparedness
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Infectious disease
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HIV
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Immunization history
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Sexually transmitted diseases
REPRODUCTIVE HISTORY Conditions with recurrence risk: Premature delivery • •
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Preeclampsia/eclampsia
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Placenta previa/abruption
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Gestational diabetes
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Preterm premature rupture of membranes
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Certain birth defects/genetic disorders
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Prior uterine surgery or anomalies
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Good time to discuss trial of labor
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Prior pregnancy losses
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Habitual abortion
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Must also deal with associated emotional issues
FAMILY HISTORY Coagulation disorders Mental retardation • •
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Other conditions (congenital adrenal hyperplasia, neurofibromatosis, inborn errors of metabolism)
Anueploidy Risk Risk of any type of aneuploidy increases with maternal age Offer genetics consultation • •
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Important to obtain family pedigree
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Risk increases with increasing maternal age
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Risk of Trisomy 21 at age 35 is 1/378 and that of all aneuploidy is 1/192
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Risk increases to 1/30 and 1/21 respectively, at age 45
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Risk with increased paternal age probably small
RISK ASSESSMENT - MEDICAL HISTORY Possible effects of pregnancy on disease Possible effects of disease on pregnancy, mother and fetus • •
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Evaluate for any possible interventions
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Assess for possibility of teratogenic effects of medications
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Evaluate for presence of microvascular disease and level of glucose control
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Frequency of malformations 6-10 %
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Periconceptual control can significantly decrease malformation rate
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Hemoglobin A1C crude marker of glucose control/ ? Association with anomaly rate
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Hypertension - assess for microvascular disease, severity, underlying etiology
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Hyperthyroidism
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Hypothyroidism
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Previous treatment for cancer
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History of organ transplantation
RISK ASSESSMENT - MEDICAL HISTORY
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Connective tissue disorders Inflammatory bowel disease
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Asthma
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Neurological and psychiatric disorders
SPECIAL RISKS Primary Pulmonary Hypertension Chronic Renal Disease • •
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Complicated coarctation of the aorta
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Sever mitral or aortic stenosis
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Vasculitis syndromes
RISK ASSESSMENT - IMMUNIZATIONS Rubella - should wait 3 months before conceiving Hepatitis B • •
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Tetanus
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Mantoux skin test
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Influenza, pneumovax as indicated
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Varicella
RISK ASSESSMENT - STD’S Assess for high risk behaviors and counsel appropriately HIV - treatment can decrease transmission to fetus from 30% to 8% • •
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Gonorrhea
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Chlamydia
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Trichomonas
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Bacterial Vaginosis - presence associated with increased risk of premature labor and delivery Group B beta streptococcus - ? HPV - human papillomavirus/PAP/possible colposcopy in select cases/neonatal infection possible
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HSV - as indicated
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congenital syphilis can occur at any stage of maternal disease
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Toxoplasmosis - cat owners or if handle raw meat
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Cytomegalovirus
SOCIAL HISTORY •
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Illicit substance use and abuse major public health problem Alcohol Most common preventable cause of mental retardation No proven safe level of ingestion
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Tobacco use
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Associated with numerous pregnancy complications
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One of most common preventable cause of fetal growth restriction
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Increased risk of other health problems
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Illicit drug use
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Usually associated with other high risk behaviors
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Possible teratogen
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Increased pregnancy complications
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Associated with sudden death, infarction, hypertension
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Prescription drug dependency
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Evaluate for life stressors that may predispose to substance abuse
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Encourage counseling and rehabilitation prior to pregnancy
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May have co-existing psychological disorders
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Seen in all social classes
DOMESTIC VIOLENCE Incidence of abuse increases during pregnancy Physicians do a poor job of screening • •
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Look for: vague complaints; substance abuse; insomnia; injuries to central b ody areas; multiple ER visits
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Develop emergency plan/referral numbers
TERATOGENS Evaluate home environment Work exposure (plastics, vinyl monomers, heavy metals, viral agents) • •
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Medication or drug use
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Alcohol - fetal alcohol syndrome
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ACE - inhibitors - fetal renal dysfunction
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Coumarin derivatives - effects seen in up to 2 5% exposed
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Tegretol - craniofacial abnormalities; limb defects; growth and mental retardation
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Dilantin - fetal hydantoin syndrome
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Valproic acid - neural tube defects (1-2%)
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Lithium – congenital anomaly
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Tetracycline - deposition in fetal long bones
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Vitamin A derivatives - associated with numerous severe defects;
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X-Rays/radioactive isotopes
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DES - reproductive tract abnormalities
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Folic acid antagonists
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Thalidomide - limb defects
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Should consult specialist, poison control center or teratogen centers
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Some medications have different safety periods between cessation and conception
NUTRITIONAL ASSESSMENT Assess optimal nutritional needs Risk factors • •
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Low income
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Substance abuse
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Fad dieting/vegans
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Depression/mental illness
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Gastrointestinal disease
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Chronic disorders
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Must also assess for existence of eating disorders
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Folic acid supplementation beginning one month prior to conception can greatly reduce incidence of neural tube defects
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Utilize nutritionist for full evaluation
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Obesity
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Adolescence
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Pre-existing conditions - iron deficiency anemia, hyperlipidemia
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Evaluate exercise regimen
FINANCIAL AND EMOTIONAL CONCERNS Couples should be aware of maternity coverage provided by their insurance Leave benefits • •
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Stress importance of good family support
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May consult social services
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Emotional issues addressed
SUMMARY Thorough history taking Complete physical exam • •
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Necessary consultations
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Counseling
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Instruct on accurate menstrual history and on con traception
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Necessary laboratory evaluation
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Adequate preconception counseling can decrease risk of pregnancy complications
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Education can lead to healthy habits and realistic expectations
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Can lead to more efficient and less costly pregnancy care
Physiology of Reproduction
Function of the female reproductive system. At puberty the ova begins to mature. At the follicular phase, an ovum matures within a cyst called “Graafian follicle” until it reaches the surface of the ovary where rupture occurs. The ovum is discharged into the peritoneal cavity. This periodic liberation of matured ovum into the peritoneal cavity is referred to as ovulation. This ovum finds its way into the fimbriated end of the fallopian tube. On its way to the uterus, if it meets a spermatozoan, the male gamete and union occurs and conception or fertilization takes place. The empty Graafian follicle, after ovulation is called as corpus luteum (yellow body), which secretes progesterone, a hormone that prepares the uterus for receiving the fertilised ovum. Female hormones: The ovaries produce steroid hormones, estrogen and progesterone. Oestrogen: It is responsible for development and maintenance of the female reproductive organs and the secondary sexual characteristics associated with the adult female. Estrogen also plays an important role in breast development and in monthly cyclic changes (menstrual cycle) in the uterus. Progesterone: Progesterone regulates the changes that occur in the uterus during the menstrual cycle. It is secreted by the corpus luteum. Progesterone is important for conditioning the endometrium in preparation for implantation of the fertilised ovum. If the pregnancy occurs, progesterone is essential for maintaining a normal pregnancy. In addition, it works along with oestrogen in preparing the breast for secretion of milk. Physiology of reproduction: Menstrual cycle or uterine cycle: It is a series of changes in the uterus resulting in the discharge of blood from the vagina each month. Menstruation can be defined as, “sloughing and discharge of the lining of the uterus if conception does not take place.” This time varies in different women and also from time to time-in same woman. The first day of the cycle is the first day when bleeding begins. The ovarian
hormones control the menstrual cycle. There are three main phases and they affect the tissue structures of the endometrium. The average time of menstrual cycle is 28 days and recurs regularly from puberty to menopause except in pregnancy. The three phases are: 1. Proliferative phase: Follicular stimulating hormonal level increases in blood, stimulating oestrogen secretion, which causes the endometrium to thicken and become more vascular. This phase follows menstruation and lasts until ovulation. 2. Secretary phase: The secretary phase follows ovulation and is under the influence of progesterone and oestrogen from the corpus luteum. Leutinising hormone level increases in blood. Under the combined stimulus of estrogen and progesterone, the endometrium reaches the peak of its thickening and vascularisation. 3. Menstrual phase: It is characterised by vaginal bleeding, lasts for 3 – 5 days. On absence of fertilization, the thickened endometrium is shedded. Two Gonadotrophic hormones are released by the anterior pituitary gland. They are: -Follicular stimulating hormone:FSH is primarily responsible for stimulating the ovaries to secrete oestrogen and for maturation of ovum. -Luteinising Hormone (LH): LH is primarily responsible for stimulating the corpus luteum for productoin of progesterone. 3. Puberty: This is the period in which, the reproductive organs develop and reach maturity. The first signs are breast development and appearance of pubic hair. The body grows considerably and takes on the female contour. Puberty culminates in the onset of menstruation, the first period being called menarche. The first few cycles are not accompanied by ovulation. Puberty usually occurs between 12 and 14 years. Menopause: It is the end of a woman’ s reproductive life, characterised by the gradual cessation of menstruation. The period first becomes irregular and then ceases altogether. This occurs between the ages of 45 to 50. It is the normal part of aging and maturation. Menstruation ceases because the ovaries
are no longer active. No more ovarian hormones are produced. The reproductive organs become atrophied. Fertilization: Following ovulation, the ovum about (0.15 mm) in diameter passes into the fallopian tube and moves towards uterus. If coitus takes place at this time, the alkaline mucus attracts the spermatozoa. About 300 million sperms are deposited in the posterior fornix of the vagina. Those which are propelled by the cervical mucus reach the fallopian tube and others are destroyed by the acid medium of the vagina.
The matured sperm is capable of producing the enzyme hyaluronidase, which allows the sperm to penetrate the cell membrane, surrounding the ovum. Many sperm are needed for this, but only one will enter into the ovum and fertilisation occurs. After this, the membrane is sealed to prevent the entry of any further sperm and the nuclei of the two cells fuse. The sperm and the ovum each contribute half the complement of chromosomes to make a total of 46. The sperm and ovum are known as the male and female gametes. The fertilized ovum is known as the zygote. Implantation of the fertilised ovum (embedding) into the uterine cavity (endometrium) is called as nidation or nesting. Normally this occurs by the 11th day after ovulation and the endometrium closes over it completely. Development of the fertilised ovum: Fertilised ovum reaches the uterus by 3-4 days. Cell division takes place as 2 into 4,8,16, etc, till a cluster of cells formed known as morula (mulberry). Next a fluid filled cavity, a blastocele appears in the morula and it is known as blastocyst. Outside of blastocyst there is a single layer of cells known as trophoblast, while the remaining cells are clumped together forming an inner cell mass. The trophablast forms the placenta and chorion while the inner cell mass become fetus and amnion. Formation of fetal membrane and placenta:
The trophoblast has two layers, • Outer syncitiotrophoblast, which erodes the endometrium in the process of embedding.
The inner cytotrophoblast produces a hormone called human chorionic gonadotrophin (HCG) which reacts on corpus lutuem to continue the pregnancy by producing oestrogen and progesterone.The trophoblast develops as placenta which will nourish the fetus until delivery. The inner cell mass differentiates into three layers. •
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From the ectoderm skin and nervous system are formed. From the mesoderm bones and muscles, heart and blood vessels and certain internal organs are formed.
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From the endoderm mucous membranes and glands are formed.
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During the first three weeks following conceptual the fertilised ovum is termed as zygote. From 3-8 weeks, it is termed as embryo. The organs and systems are developed by 7 th week. After 8 weeks, till birth it is termed as fetus.
FETAL GROWTH AND DEVELOPMENT
Previously, methods used to determine how well the fetus was growing and maturing consisted of evaluating uterine growth and listening to fetal heart sounds. Advances in knowledge and technology have provided newer methods for assessing fetal well-being and maturity. Improved methods for assessment and diagnosis enable early intervention for improved outcome.
Stages of Growth and Development
The growth and development of the fetus is typically divided into three stages.
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Preembryonic Stage: Fertilization to 2 to 3 Weeks o
Rapid cell division and differentiation
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Develop embryonic membranes and germ layers
Embryonic Stage: 4 to 8 Weeks' Gestation o
Most critical stage of physical development
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Organogenesis
Fetal Stage: 9 Weeks to Birth o
Every organ system and external structure present.
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Refinement of fetus and organ function occurs.
Development by Month
First Lunar Month •
Fertilization to 2 weeks of embryonic growth.
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Implantation is complete.
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Primary chorionic villi forming.
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Embryo develops into two cell layers (trophoblast and blastocyst).
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Amniotic cavity appears.
Second Lunar Month •
3 to 6 weeks of embryonic growth.
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At the end of 6 weeks of growth, the embryo is approximately ½ inch (1.2 cm) long.
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Arm and leg buds are visible; arm buds are more developed with finger ridges beginning to appear.
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Rudiments of the eyes, ears, and nose appear.
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Lung buds are developing.
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Primitive intestinal tract is developing.
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Primitive cardiovascular system is functioning.
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Neural tube, which forms the brain and spinal cord, closes by the 4th week.
Third Lunar Month •
7 to 10 weeks of growth.
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The middle of this period (9 weeks) marks the end of the embryonic period and the beginning of the fetal period.
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At the end of 10 weeks of growth, the fetus is approximately 2 ½ inches (6.3 cm) from crown to rump and weighs ½ oz (14 g).
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Appearance of external genitalia.
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By the middle of this month, all major organ systems have formed.
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The membrane over the anus has broken down.
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The heart has formed four chambers (by 7th week).
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The fetus assumes a human appearance.
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Bone ossification begins.
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Rudimentary kidney begins to secrete urine.
Fourth Lunar Month •
11- to 14-week-old fetus.
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At the end of 14 weeks of growth, the fetus is approximately 4 ¾ inches (12 cm) crown-rump length and 3 ¾ oz (110 g).
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Head erect; lower extremities well developed.
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Hard palate and nasal septum have fused.
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External genitalia of male and female can now be differentiated.
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Eyelids are sealed.
Fifth Lunar Month •
15- to 18-week-old fetus.
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At the end of 18 weeks of growth, the fetus is approximately 6 ¼ inches (16 cm) crown-rump length and 11 ¼ oz (320 g).
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Ossification of fetal skeleton can be seen on x-ray.
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Ears stand out from head.
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Meconium is present in the intestinal tract.
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Fetus makes sucking motions and swallows amniotic fluid.
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Fetal movements may be felt by the mother (end of month).
Sixth Lunar Month •
19- to 22-week-old fetus.
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At the end of 22 weeks of growth, the fetus is approximately 8 ¼ inches (21 cm) crown-rump length and 1 lb 6 ¼ oz (630 g).
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Vernix caseosa covers the skin.
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Head and body (lanugo) hair visible.
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Skin is wrinkled and red.
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Brown fat, an important site of heat production, is present in neck and sternal area.
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Nipples are apparent on the breasts.
Seventh Lunar Month •
23- to 26-week-old fetus.
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At the end of 26 weeks of growth, the fetus is approximately 10 inches (25 cm) crown-rump length and 2 lb 3 ¼ oz (1,000 g).
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Fingernails present.
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Lean body.
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Eyes partially open; eyelashes present.
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Bronchioles are present; primitive alveoli are forming.
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Skin begins to thicken on hands and feet.
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Startle reflex present; grasp reflex is strong.
Eighth Lunar Month •
27- to 30-week-old fetus.
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At the end of 30 weeks of growth, the fetus is approximately 11 inches (28 cm) crown-rump length and 3 lb 12 oz (1,700 g).
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Eyes open.
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Ample hair on head; lanugo begins to fade.
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Skin slightly wrinkled.
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Toenails present.
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Testes in inguinal canal, begin descent to scrotal sac.
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Surfactant coats much of the alveolar epithelium.
Ninth Lunar Month •
31- to 34-week-old fetus.
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At the end of 34 weeks of growth, the fetus is approximately 12 ½ inches (32 cm) crown-rump length and 5 lb 8 oz (2,500 g).
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Fingernails reach fingertips.
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Skin pink and smooth.
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Testes in scrotal sac.
Tenth Lunar Month •
35- to 38-week-old fetus; end of this month is also 40 weeks from onset of last menstrual period.
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End of 38 weeks of growth, fetus is approximately 14 ½ nches (36 cm) crown-rump length and 7 lb 8 oz (3,400 g).
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Ample subcutaneous fat.
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Lanugo almost absent.
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Toenails reach toe tips.
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Testes in scrotum.
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Vernix caseosa mainly on the back.
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Breasts are firm.
Fetal circulation
During intra uterine life placenta is the sourse of nutrition and site of elimination of waste. There are several structure in addition to the placenta and umbilical cord. The umbilical vein : leads from umbilical cord to the underside of the liver and carries blood rich in oxygen and nutrients. It has branch that joins the portal vein and supply the liver. •
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Ductus venosus (from vein to vein) this connects the umbilical vein to the inferior vena cava. At this point the blood mixes with the deoxygenated blood returning from the lower parts of the body. •
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The foramen ovale: temporary opening between the atria that allows the majority of the blood to pass across the left atrium (no respiration) •
The ductus arteriosis (from artery to an artery) this leads from the bifurcation of the pulmonary artery to the descending aorta,entering it just beyond the point where the carotid and subclavian arteries leave. •
The hypogastric arteries: these arteries off from the internal iliac arteries and become umbilical arteries when they enter the umbilical cord they return blood to the placenta. From placenta the blood passes along the umbilical vein through the abdominal wall to the undersurface of the liver, •
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gives off branches to the left lobe of the liver and receives deoxygenated blood from the portal vein,. (unmixed blood) The ductus venosus carries blood to the inferior vena cava which mixes with the blood from the lower body. From here the blood passes into the right atrium Most of it is directed across through the foramen ovale in to the left atrium. Following its normal route it enters left ventricle and passes into aorta. The heart and brain gets a supply relatively well oxygenated. (coronary and carotid arteries are early branches of aorta.) Blood collected from the upper parts of the body returns to the right atrium in the superior vena cava. This blood is depleated of oxygen and nutrients. This stream of blood crosses the stream enteringfrom the inferior vena cava and passes into the right ventricle. the two streams remain separate because of the shape of the atrium. But there is a mixing of 25 % of the blood allowing a little oxygen and food to be taken into the lungs through pulmonary arteries. (necessary for the development)
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Adaptation to the extra uterine life At birth the baby breath and blood is drawn to the lungs through the pulmonary arteries. It is then collected and returned to the left atrium via pulmonary veins. The placental circulation ceases soon after birth. (less blood returns to the right side of the heart.) Pressure in the left side is greater This result in the closure of flap over foramen ovale. (stops blood flow from right to left) Establishment of pulmonary respiration result in the rise of oxygen concentration in the blood stream. Causes the ductus arteriosus to constrict and close. The cessation of the placental circulation result in collapse of the umbilical vein, ductus venosus and hypogastric arteries.
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Umbilical vein-ligamentum teres.
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D V- ligamentum venosum
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D A- ligamentum arteriosum
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Hypogastric arteries -obliterated hypogastric arteries
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F O-fossa ovalis
Closure of : umbilical artery-functional closure-instantaneous….anatomical closure 2 to 3 months U V-obliteration little later than U A •
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D A fun -soon after establishing pul circulation
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F O- fun soon after birth
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Anatomical 1 year
Anatomy and Functions of Placenta Gross Anatomy of the Placenta
It consists of two surfaces: 1. Fetal surface 2. Maternal surface Maternal Surface
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Placenta is attached to the upper side of the fundus
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15-20cm in diameter
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30% of uterus covered by the placenta
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Center part is 2.5cm in thickness
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Thickness reduced at the periphery
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Convex polygonal areas called Cotilidons
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16-20 cotilidons in a placenta
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Grayish areas are calcium deposits
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Greyish tinge is due to placental separation
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Each cotilidon has fissures which contain decidual septum Fetal Surface
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Fetal surface is grey and glistening
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Cord is the continuation of the mesoderm
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It is also called funis (50-100cm)
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It consists of two arteries and one vein
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At the cut end of the cord, vein appears collapsed and arteries are protruded and down.
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Cord is 50-100cm in length
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White jelly life substance called Wharton’s jelly present on the cord
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Inner layer is amnion and the outer layer is the chorion
Functions of the Placenta
1. The fetus obtains amino acids, glucose, vitamins, calcium, phosphorus, iron and other minerals from the maternal blood through the placenta. 2. The placenta also stores glucose in the form of glycogen. It also stores iron and fats soluble vitamins. 3. The waste products such as carbon dioxide, bilirubin and urea are excreted from the fetus through the placenta. 4. The placenta prevents passing of microorganisms from the mother to the fetus to some extent. 5. The placenta also produces hormones like the human chorionic gonadotrophic hormone, oestrogen, progesterone and human placental lactogen (HPL).
Amniotic fluid
The fluid medium in which the fetus grows and develops inside the uterus.
Functions of amniotic fluid
During pregnancy
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Acts as a shock absorber protecting the fetus from the possible extraneous injury
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Maintains even temperature
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Fluid distends the amniotic sac and there by allows for growth and free movement of the fetus
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It helps to prevent adhesion between the fetal parts and Amniotic sac.
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Its nutritive value is negligible as there is only small amount of protein and salt. (water supply is quite adequate)
During labour •
Amnion and chorion combined to form hydrostatic wedge which helps in the dilation the uterine os and effacement of cervix.
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During U C it prevent marked interferance with the placental circulation so long as the membranes remains intact.
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Cont….
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Flushes the birth canal at the end of the first stage of labour.
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Antiseptic and bactericidal action protects the fetus from the ascending infection.
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origin
Fetal and maternal.
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It is secreted by amnion especially the part covering the placenta and umbilical cord.
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Transudate from maternal serum across the fetal membranes or from the maternal circulation.
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Cont…
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Transudate of fetal plasma through highly permeable fetal skin before it is keratinized at 20th week.
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Fetal urine also contributes to the volume from 10 th week. (water of the A F is exchanged every 3 hrs.)
Clinical importance •
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As a measure of fetal wellbeing Normal amount at term approximately 1000ml
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If more than 2000-polyhydramnios
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If less than 200 ml- oligohydramnios
Volume of A F •
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50 ml at 12th week. 400 ml at 20th week.
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Reaches the peak amount at 36 to 38th week –that is approximately 1000ml.
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Thereafter amount diminishes at term the it measures about600 to 800 ml.
Chemical property •
Faintly alkaline with low specific gravity.of 1.010.
Colour •
Straw coloured(exfoliated epidermal cells and lanugo)
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Turbid (presence of vernix caseosa)
Abnormal colours •
Green coloured
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Golden coloured
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Greenish yellow (saffron)
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Dark coloured
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Dark brown
Anatomical variation of placenta and cord
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Succenturiate lobe of placenta
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Circumvallate placenta
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Battledore insertion of the cord
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Velamentous insertion of the cord.
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Bipartite
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tripartite
The Umbilical Cord Anatomy •
Origin : It develops from the connecting stalk.
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Length: At term, it measures about 50 cm.
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Diameter: 2 cm.
Structure:
It consists of mesodermal connective tissue called Wharton's jelly, covered by amnion. It contains: •
One umbilical vein carries oxygenated blood from the placenta to the foetus
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Two umbilical arteries carry deoxygenated blood from the foetus to the placenta,
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Remnants of the yolk sac and allantois.
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Most of the cord consists of a loose mesenchyme with intercellular ground substance (Wharton's jelly).
Insertion: •
The cord is inserted in the foetal surface of the placenta near the center "eccentric insertion" (70%)
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Or at the center "central insertion" (30%).
Abnormalities of the Umbilical Cord
(A) Abnormal cord insertion: •
Marginal insertion : in the placenta ( battledore insertion).
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Velamentous insertion: in the membranes and vessels connect the cord to the edge of the placenta.
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Vasa praevia: If these vessels pass at the region of the internal os , the condition is called " Vasa praevia".
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Vasa praevia can occur also when the vessels connecting a succenturiate lobe with the main placenta pass at the region of the internal os
(B) Abnormal cord length:
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Short cord which may lead to : o
i-Intrapartum haemorrhage due to premature separation of the placenta,
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ii-Delayed descent of the foetus druing labour,
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iii-Inversion of the uterus.
Long cord which may lead to: o
i-Cord presentation and cord prolapse,
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ii-Coiling of the cord around the neck,
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iii-True knots of the cord.
(C) Knots of the cord:
1.True knot: •
when the foetus passes through a loop of the cord.
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If pulled tight, foetal asphyxia may result.
2. False knot: •
localized collection of Wharton’s jelly containing a loop of umbilical vessels.
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A long umbilical cord may more easily become twisted, or even form a knot
(D) Torsion of the cord:
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may occur particularly in the portion near the foetus where the Wharton's jelly is less abundant.
(E) Haematoma : •
Due to rupture of one of the umbilical vessels.
(F) Single umbilical artery : •
may be associated with other foetal congenital anomalies Abnormalities of the Placenta
The placenta develops from
the chorion frondosum (foetal origin) and
decidua basalis (maternal origin).
Anatomy At Term •
Shape
: discoid.
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Diameter : 15-20 cm.
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Weight : 500 gm.
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Thickness: 2.5 cm at its center and gradually tapers towards the periphery.
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Position : in the upper uterine segment (99.5%), either in the posterior surface (2/3) or the anterior surface (1/3).
Surfaces
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Foetal surface
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Maternal surface
Foetal surface •
Smooth, glistening and is covered by the amnion which is reflected on the cord.
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The umbilical cord is inserted near or at the center of this surface and its radiating branches can be seen beneath the amnion.
Maternal surface •
Dull greyish red in colour and is divided into 15-20 cotyledons.
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Each cotyledon is formed of the branches of one main villus stem covered by decidua basalis
Abnormalities of the Placenta
(A) Abnormal Shape:
1. Placenta Bipartite 2. Placenta Succenturiata 3. Placenta Circumvallata 4. Placenta Fenestrata The placenta consists of two equal lobes connected by placental tissue
1. Placenta Bipartite: •
The placenta consists of two equal parts connected by membranes.
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The umbilical cord is inserted in one lobe and branches from its vessels cross the membranes to the other lobe.
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Rarely, the umbilical cord divides into two branches, each supplies a lobe.
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The placenta consists of a large lobe and a smaller one connecting together by membranes.
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The umbilical cord is inserted into the large lobe and branches of its vessels cross the membranes to the small succenturiate (accessory) lobe.
2. Placenta Succenturiata: •
The accessory lobe may be retained in the uterus after delivery leading to postpartum haemorrhage.
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This is suspected if a circular gap is detected in the membranes from which blood vessels pass towards the edge of the main placenta.
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A whitish ring composed of decidua, is seen around the placenta from its foetal surface.
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This may result when the chorion frondosum is two small for the nutrition of the foetus, so the peripheral villi grow in such a way splitting the decidua basalis into a superficial layer ( the whitish ring) and a deep layer.
3. Placenta Circumvallata: •
It can be a cause of :
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Abortion,
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Ante partum haemorrhage,
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Preterm labour
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Intrauterine foetal death.
and
4. Placenta Fenestrata:
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A gap is seen in the placenta covered by membranes giving the appearance of a window.
5. Placenta membranacea: •
A great part of the chorion develops into placental tissue.
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The placenta is large, thin and may measure 30-40 cm in diameter.
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It may encroach on the lower uterine segment i.e. placenta praevia.
(B) Abnormal Weight:
The placenta increases in size and weight as in : •
Congenital syphilis,
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Hydrops foetalis
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Diabetes mellitus.
Placenta Praevia
The placenta is partly or completely attached to the lower uterine segment In this gravid uterus, the placenta implanted over the os. This is called placenta
previa.
Implantation in this low lying position can lead to extensive hemorrhage as the dilation of the cervix disrupts the placenta.
(C) Abnormal Adhesion: •
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Placenta Accreta:The chorionic villi penetrate deeply into the uterine wall to reach the myometrium,due to deficient decidua basalis. Placenta increta:When the villi penetrate deeply into the myometrium, it is called "placenta increta" Placenta percreta: When they reach the peritoneal coat it is called "placenta percreta".
(D) Placental Lesions
Seen in placenta at term, mainly in hypertensive states with pregnancy. •
White infracts: due to excessive fibrin deposition. (Normal placenta may contain white infracts in which calcium deposition may occur).
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Red infarcts : due to haemorrhage from the maternal vessels of the decidua. (Old red infarcts finally become white due to fibrin deposition).
(E) Placental Tumour:
