! 1!
Chapter 3 Genetics, Conception, Fetal Development, and Reproductive Technology
! Genetics " study of heredity
! Genomics " addresses all genes and their interrelationships in order to identify their combined influence on growth and
development of the organism
o Providing better methods for preventing disease and abnormalities, diagnosing diseases, predicting health risks,
personalizing treatment plans
! 30,000 genes in the human genome (organism’s complete set of DNA)
! 46 chromosomes; 22 homologous pairs of chromosomes and one pair of sex chromosomes
! genotype " person’s genetic makeup
! phenotype " how genes are outwardly expressed (eye color, hair color, height)
! recessive genetic disorders " sickle cell anemia, cystic fibrosis, thalassemia, Tay-Sachs disease
! carrier testing " identify individuals who carry one copy of a gene mutation that, when present in two copies causes a
genetic disorder; used when there is a family history of genetic disorder
! preimplantation testing/preimplantation genetic diagnosis " used to detect genetic changes in embryos that are created
using assisted reproductive techniques
! prenatal testing " early detection of genetic disorders
! risks for conceiving child with genetic disorder " maternal age older than 35, man/woman who has genetic disorder;
family history of genetic disorder, history of previous pregnancy resulting in a genetic disorder or newborn
abnormalities
! refer to support group whether they wish to terminate/continue with pregnancy
! sickle cell anemia
o most common of African ancestry
o sickle-cell hemoglobin forms rigid crystals that distort and disrupt RBCs; oxygen-carrying capacity of blood is
diminished
! cystic fibrosis
o most common genetic disease of European ancestry
o production of thick mucus clogs in bronchial tree and pancreatic ducts
o most severe effects are chronic respiratory infections and pulmonary failure
! Tay-Sach disease
o Most common among Jewish ancestry
o Degeneration of neurons and nervous system results in death by the 2 years old
! PKU
o Lack of enzyme to metabolize the amino acid phenylalanine " leads to severe mental and physical retardation
o Effects may be prevented by use of a diet at beginning of birth that limits phenylalanine
! Huntington’s Disease
o Uncontrollable muscle contractions between 30-50 years followed by memory loss and personality
o No treatment that can delay mental deterioration
! Hemophilia (X-linked)
o Lack of factor 8
o Can be controlled with factor 8 from donated blood
! Duchenne’s Musclular Dystrophy
o Replacement of muscle by adipose or scare tissue with progressive loss of muscle function; often fatal before age
20 due to involvement of cardiac muscle
! teratogens " any drugs, viruses, infections, or other exposures that can cause embryonic/fetal developmental
abnormality
! degree or types of malformation vary on length of exposure, amount of exposure, and when it occurs during human
development
! developing human is most vulnerable to effects of teratogens within first 8 weeks of gestation (organogenesis)" can
cause gross structural defects
! exposure after 13 weeks may cause fetal growth restriction or reduction of organ size
! toxoplasma is a protozoan parasite found in cat feces and uncooked/rare beef and lamb
o can cause fetal demise, mental retardation, blindness when fetus is exposed
o avoid contact with cat feces and eating rare beef or lamb if pregnant or attempting pregnancy
! rubella " increased risk for heart defects, deafness and/or blindness, mental retardation, fetal demise
! cytomegalovirus " increased risk for hydrocephaly, microcephaly, cerebral calcification, mental retardation, hearing loss
! herpes varicella/chicken pox " increased risk for hypoplasia of hands and feet, blindness/cataracts, mental retardation
! syphilis " increased risk for skin, bone and/or teeth defects, fetal demise
! cocaine " increased risk for heart, limbs, face, GI/GU tract defects, cerebral infarctions, placental abnormalities
Chapter 4 Physiological Aspects of Antepartum Care
,! 2!
! G/P System
o Gravida: # times a woman has been pregnancy including current pregnancy
o Para: # of births after 20 weeks’ gestation whether live or stillbirths
o Abortions are not accounted for in this system
! GTPAL
o G: # times pregnancy
o T: # of term infants born after 37 weeks
o P: # of preterm infants between 20 and 37 weeks
o A: # of abortions either spontaneous or induced before 20 weeks
o L: # of living children
! Nulligravida: woman who has never been pregnant or given birth
! Primigravida: woman who is pregnant for the first time
! Multigravida: someone who is pregnant for at least the second time
! Prenatal period " entire time period during which a woman is pregnant through birth of baby
! Nurse places emphasis on health education and health promotion
! Family-centered maternity care is a model of obstetrical care based on a view of pregnancy and childbirth as a normal life
event, a life transition that is not primarily medical but rather developmental
! Low-risk population should have approximately 14-16 prenatal visits per pregnancy
! First trimester
o Woman learns frequency of follow-up visits and what to expect from pregnancy visits as pregnancy progresses
during initial visit
o Comprehensive health and risk assessment; currently pregnancy history; complete physical and pelvic examination;
nutrition assessment; psychosocial assessment; assessment for intimate partner violence
o Fetal heart tones are auscultated with US Doppler, initially by 10 and 12 weeks
o At end of first trimester, fetus is 3 inches in length and weights 1-2 ounces, all organ systems are present
o Assessment of uterine growth after 10-12 weeks is measured by height of fundus with centimeter measuring tape;
zero point of tape is placed on the symphysis pubis and tape is extended to top of fundus; MEASUREMENT
SHOULD EQUAL # OF WEEKS PREGNANT
o Certain types of fish (king mackerel, shark, swordfish, tilefish) should be avoided due to high levels of
methylmercury
! Second trimester
o Chart review; interval history; focused physical assessment; pelvic exam/sterile vaginal exam if indicated; confirm
EDD
o Triple/quad screen (neural tube defect); US; screening for gestational diabetes; hemoglobin and hematocrit;
antibody screen if Rh-negative (Administration of RhoGAM if Rh-negative and anti-body screen negative)
# Administered prophylactically at 28 weeks to prevent isoimmunization from potential exposure to Rh-
positive fetal blood during normal course of pregnancy
# Adverse reaction " pain at IM site; fever
o Slight decrease in blood pressure toward end of second trimester
o Assess for quickening " when the woman feels baby move for first time
o Leopold’s maneuvers to identify position of fetus
o Slight lower body edema is normal due to decreased venous return
o At 20 weeks, fetus is 8 inches long and weights 1 pound
o Increase in calorie intake by 340 kcal/day
! Third trimester
o Chart review; interval history; nutrition follow-up; focused physical assessment; pelvic exam/sterile vaginal exam if
indicated
o Group B Strept at 35-37 weeks; H&H if not done in second trimester; repeat GC, chlamydia, RPR, HIV HbSAg; 1-
hour glucose challenge test at 24-28 weeks
o Record fetal movement count " 10 distinct fetal movements within 2 hours is considered reassuring OR 4
movements in 1 hour
o At term, fetus is 17-20 inches long, 6-8 pounds
o Increase in calorie intake by 452 kcal/day
Chapter 6 Antepartal Tests
! Chorionic villus sampling " aspiration of a small amount of placental tissue for chromosomal, metabolic, or DNA testing
o Between 10 and 12 weeks to detect fetal abnormalities caused by genetic disorders
o Tests for cystic fibrosis but not neural tube defects
o Supine position for transabdominal aspiration with US to guide placement
o Lithotomy for transvaginal aspiration with US to guide placement
o Small biopsy of chorionic (placental) tissue is removed
o Assess fetal and maternal well-being post-procedure; FHR is auscultated twice in 30 minutes
, ! 3!
o Instruct woman to report abdominal pain/cramps, leaking of fluid, bleeding, fever, chills
o Results within 1 week
! Amniocentesis
o Needle is inserted through maternal abdominal wall into uterine cavity to obtain amniotic fluid
o Genetic testing, fetal lung maturity, assessment of hemolytic disease in fetus or for intrauterine disease
# Fetal lung maturity, monitor for L/S RATIO, PG, LBC
o Usually performed 14-20 weeks gestation
o Results within 2 weeks
o FULL BLADDER MAY BE REQUIRED FOR ULTRASOUND VISULIZATION IF WOMAN IS LESS THAN 20
WEEKS
! Delta OD 450
o Evaluation of amniotic fluid obtained via amniocentesis to predict life-threatening anemia in fetus during second and
third trimester
o Used in a lab to determine if there is a deviation of optical density at 45 nm
! Fetal blood sampling/percutaneous umbilical blood sampling (CORDOCENTESIS)
o Removal of fetal blood from umbilical cord " used to test for metabolic and hematological disorders, fetal infection,
fetal karyotyping
o may be done as early as 11 weeks but usually done in second trimester
o results within 48 hours
o POSITION WOMAN IN LATERAL/WEDGED POSITION TO AVOID SUPINE HYPOTENSION DURING FETAL
MONITORING TESTS
o Have terbutaline ready as ordered in case uterine contractions occur during procedure
o Assess fetal well-being post-procedure 1-2 hours via external fetal monitoring
! Alpha-fetoprotein (AFP)
o Done at 15-20 weeks gestation
o Assessed in maternal blood to screen for certain developmental defects in the fetus (NTD, ventral abdominal wall
defects)
o Increased levels associated with NTDs, anencephaly, omphalocele, gastroschisis
o Decreased levels associated with Down syndrome
o Abnormal findings require additional testing " amniocentesis, VNS, US
! Multiple marker screen
o Combination of AFP, human chorionic gonadotropin (hCG), estriol levels
o Detects for some trisomies and NTDs
o done at 15-16 weeks gestation
o maternal blood is drawn and sent to lab
o low levels of maternal serum alpha-fetoprotein and unconjugated estriol levels suggest an abnormality
o hCG and inhibin-A levels are twice as high in pregnancies with trisomy 21 (Down’s Syndrome)
o decreased estriol levels are an indicator of NTDs
! Daily fetal movement
o Proposed as primary method of fetal surveillance after 28 weeks gestation
o Instruct woman to palpate abdomen and track fetal movements daily for 1-2 hours
o 10 distinct fetal movements within 2 hours is normal
# once movement is achieved, counts can be d/c for the day
o 4 movements in 1 hour is reassuring
# if decreased, have woman eat, rest and focus on fetal movement for 1 hour
o FEWER THAN 4 FETAL MOVEMENTS IN 2 HOURS SHOULD BE REPORTED
o LIE ON SIDE WHILE COUNTING MOVEMENTS
! Non-stress test
o Uses electronic fetal monitoring to assess fetal condition/well-being
o Looking for accelerations; baby is nice and active
o Used in women with complications such as HTN, diabetes, multiple gestation, trauma and/or bleeding, woman’s
report of lack of fetal movement, placental abnormalities
o Heart rate of normal fetus with adequate oxygenation and intact autonomic nervous system accelerates in
response to movement
o Monitored with external FHR until reactive (up to 40 minutes) while running FHR contraction strip for interpretation
o Considered reactive when FHR increases 15 beats above baseline for 15 seconds twice or more in 20
minutes
o In fetuses less than 32 weeks, two accelerations peaking at least 10 bpm above baseline and lasting 10
seconds in a 20-minute period is reactive
o Nonreactive NST is one without sufficient FHR accelerations in 40 minutes " followed up for further testing
Chapter 3 Genetics, Conception, Fetal Development, and Reproductive Technology
! Genetics " study of heredity
! Genomics " addresses all genes and their interrelationships in order to identify their combined influence on growth and
development of the organism
o Providing better methods for preventing disease and abnormalities, diagnosing diseases, predicting health risks,
personalizing treatment plans
! 30,000 genes in the human genome (organism’s complete set of DNA)
! 46 chromosomes; 22 homologous pairs of chromosomes and one pair of sex chromosomes
! genotype " person’s genetic makeup
! phenotype " how genes are outwardly expressed (eye color, hair color, height)
! recessive genetic disorders " sickle cell anemia, cystic fibrosis, thalassemia, Tay-Sachs disease
! carrier testing " identify individuals who carry one copy of a gene mutation that, when present in two copies causes a
genetic disorder; used when there is a family history of genetic disorder
! preimplantation testing/preimplantation genetic diagnosis " used to detect genetic changes in embryos that are created
using assisted reproductive techniques
! prenatal testing " early detection of genetic disorders
! risks for conceiving child with genetic disorder " maternal age older than 35, man/woman who has genetic disorder;
family history of genetic disorder, history of previous pregnancy resulting in a genetic disorder or newborn
abnormalities
! refer to support group whether they wish to terminate/continue with pregnancy
! sickle cell anemia
o most common of African ancestry
o sickle-cell hemoglobin forms rigid crystals that distort and disrupt RBCs; oxygen-carrying capacity of blood is
diminished
! cystic fibrosis
o most common genetic disease of European ancestry
o production of thick mucus clogs in bronchial tree and pancreatic ducts
o most severe effects are chronic respiratory infections and pulmonary failure
! Tay-Sach disease
o Most common among Jewish ancestry
o Degeneration of neurons and nervous system results in death by the 2 years old
! PKU
o Lack of enzyme to metabolize the amino acid phenylalanine " leads to severe mental and physical retardation
o Effects may be prevented by use of a diet at beginning of birth that limits phenylalanine
! Huntington’s Disease
o Uncontrollable muscle contractions between 30-50 years followed by memory loss and personality
o No treatment that can delay mental deterioration
! Hemophilia (X-linked)
o Lack of factor 8
o Can be controlled with factor 8 from donated blood
! Duchenne’s Musclular Dystrophy
o Replacement of muscle by adipose or scare tissue with progressive loss of muscle function; often fatal before age
20 due to involvement of cardiac muscle
! teratogens " any drugs, viruses, infections, or other exposures that can cause embryonic/fetal developmental
abnormality
! degree or types of malformation vary on length of exposure, amount of exposure, and when it occurs during human
development
! developing human is most vulnerable to effects of teratogens within first 8 weeks of gestation (organogenesis)" can
cause gross structural defects
! exposure after 13 weeks may cause fetal growth restriction or reduction of organ size
! toxoplasma is a protozoan parasite found in cat feces and uncooked/rare beef and lamb
o can cause fetal demise, mental retardation, blindness when fetus is exposed
o avoid contact with cat feces and eating rare beef or lamb if pregnant or attempting pregnancy
! rubella " increased risk for heart defects, deafness and/or blindness, mental retardation, fetal demise
! cytomegalovirus " increased risk for hydrocephaly, microcephaly, cerebral calcification, mental retardation, hearing loss
! herpes varicella/chicken pox " increased risk for hypoplasia of hands and feet, blindness/cataracts, mental retardation
! syphilis " increased risk for skin, bone and/or teeth defects, fetal demise
! cocaine " increased risk for heart, limbs, face, GI/GU tract defects, cerebral infarctions, placental abnormalities
Chapter 4 Physiological Aspects of Antepartum Care
,! 2!
! G/P System
o Gravida: # times a woman has been pregnancy including current pregnancy
o Para: # of births after 20 weeks’ gestation whether live or stillbirths
o Abortions are not accounted for in this system
! GTPAL
o G: # times pregnancy
o T: # of term infants born after 37 weeks
o P: # of preterm infants between 20 and 37 weeks
o A: # of abortions either spontaneous or induced before 20 weeks
o L: # of living children
! Nulligravida: woman who has never been pregnant or given birth
! Primigravida: woman who is pregnant for the first time
! Multigravida: someone who is pregnant for at least the second time
! Prenatal period " entire time period during which a woman is pregnant through birth of baby
! Nurse places emphasis on health education and health promotion
! Family-centered maternity care is a model of obstetrical care based on a view of pregnancy and childbirth as a normal life
event, a life transition that is not primarily medical but rather developmental
! Low-risk population should have approximately 14-16 prenatal visits per pregnancy
! First trimester
o Woman learns frequency of follow-up visits and what to expect from pregnancy visits as pregnancy progresses
during initial visit
o Comprehensive health and risk assessment; currently pregnancy history; complete physical and pelvic examination;
nutrition assessment; psychosocial assessment; assessment for intimate partner violence
o Fetal heart tones are auscultated with US Doppler, initially by 10 and 12 weeks
o At end of first trimester, fetus is 3 inches in length and weights 1-2 ounces, all organ systems are present
o Assessment of uterine growth after 10-12 weeks is measured by height of fundus with centimeter measuring tape;
zero point of tape is placed on the symphysis pubis and tape is extended to top of fundus; MEASUREMENT
SHOULD EQUAL # OF WEEKS PREGNANT
o Certain types of fish (king mackerel, shark, swordfish, tilefish) should be avoided due to high levels of
methylmercury
! Second trimester
o Chart review; interval history; focused physical assessment; pelvic exam/sterile vaginal exam if indicated; confirm
EDD
o Triple/quad screen (neural tube defect); US; screening for gestational diabetes; hemoglobin and hematocrit;
antibody screen if Rh-negative (Administration of RhoGAM if Rh-negative and anti-body screen negative)
# Administered prophylactically at 28 weeks to prevent isoimmunization from potential exposure to Rh-
positive fetal blood during normal course of pregnancy
# Adverse reaction " pain at IM site; fever
o Slight decrease in blood pressure toward end of second trimester
o Assess for quickening " when the woman feels baby move for first time
o Leopold’s maneuvers to identify position of fetus
o Slight lower body edema is normal due to decreased venous return
o At 20 weeks, fetus is 8 inches long and weights 1 pound
o Increase in calorie intake by 340 kcal/day
! Third trimester
o Chart review; interval history; nutrition follow-up; focused physical assessment; pelvic exam/sterile vaginal exam if
indicated
o Group B Strept at 35-37 weeks; H&H if not done in second trimester; repeat GC, chlamydia, RPR, HIV HbSAg; 1-
hour glucose challenge test at 24-28 weeks
o Record fetal movement count " 10 distinct fetal movements within 2 hours is considered reassuring OR 4
movements in 1 hour
o At term, fetus is 17-20 inches long, 6-8 pounds
o Increase in calorie intake by 452 kcal/day
Chapter 6 Antepartal Tests
! Chorionic villus sampling " aspiration of a small amount of placental tissue for chromosomal, metabolic, or DNA testing
o Between 10 and 12 weeks to detect fetal abnormalities caused by genetic disorders
o Tests for cystic fibrosis but not neural tube defects
o Supine position for transabdominal aspiration with US to guide placement
o Lithotomy for transvaginal aspiration with US to guide placement
o Small biopsy of chorionic (placental) tissue is removed
o Assess fetal and maternal well-being post-procedure; FHR is auscultated twice in 30 minutes
, ! 3!
o Instruct woman to report abdominal pain/cramps, leaking of fluid, bleeding, fever, chills
o Results within 1 week
! Amniocentesis
o Needle is inserted through maternal abdominal wall into uterine cavity to obtain amniotic fluid
o Genetic testing, fetal lung maturity, assessment of hemolytic disease in fetus or for intrauterine disease
# Fetal lung maturity, monitor for L/S RATIO, PG, LBC
o Usually performed 14-20 weeks gestation
o Results within 2 weeks
o FULL BLADDER MAY BE REQUIRED FOR ULTRASOUND VISULIZATION IF WOMAN IS LESS THAN 20
WEEKS
! Delta OD 450
o Evaluation of amniotic fluid obtained via amniocentesis to predict life-threatening anemia in fetus during second and
third trimester
o Used in a lab to determine if there is a deviation of optical density at 45 nm
! Fetal blood sampling/percutaneous umbilical blood sampling (CORDOCENTESIS)
o Removal of fetal blood from umbilical cord " used to test for metabolic and hematological disorders, fetal infection,
fetal karyotyping
o may be done as early as 11 weeks but usually done in second trimester
o results within 48 hours
o POSITION WOMAN IN LATERAL/WEDGED POSITION TO AVOID SUPINE HYPOTENSION DURING FETAL
MONITORING TESTS
o Have terbutaline ready as ordered in case uterine contractions occur during procedure
o Assess fetal well-being post-procedure 1-2 hours via external fetal monitoring
! Alpha-fetoprotein (AFP)
o Done at 15-20 weeks gestation
o Assessed in maternal blood to screen for certain developmental defects in the fetus (NTD, ventral abdominal wall
defects)
o Increased levels associated with NTDs, anencephaly, omphalocele, gastroschisis
o Decreased levels associated with Down syndrome
o Abnormal findings require additional testing " amniocentesis, VNS, US
! Multiple marker screen
o Combination of AFP, human chorionic gonadotropin (hCG), estriol levels
o Detects for some trisomies and NTDs
o done at 15-16 weeks gestation
o maternal blood is drawn and sent to lab
o low levels of maternal serum alpha-fetoprotein and unconjugated estriol levels suggest an abnormality
o hCG and inhibin-A levels are twice as high in pregnancies with trisomy 21 (Down’s Syndrome)
o decreased estriol levels are an indicator of NTDs
! Daily fetal movement
o Proposed as primary method of fetal surveillance after 28 weeks gestation
o Instruct woman to palpate abdomen and track fetal movements daily for 1-2 hours
o 10 distinct fetal movements within 2 hours is normal
# once movement is achieved, counts can be d/c for the day
o 4 movements in 1 hour is reassuring
# if decreased, have woman eat, rest and focus on fetal movement for 1 hour
o FEWER THAN 4 FETAL MOVEMENTS IN 2 HOURS SHOULD BE REPORTED
o LIE ON SIDE WHILE COUNTING MOVEMENTS
! Non-stress test
o Uses electronic fetal monitoring to assess fetal condition/well-being
o Looking for accelerations; baby is nice and active
o Used in women with complications such as HTN, diabetes, multiple gestation, trauma and/or bleeding, woman’s
report of lack of fetal movement, placental abnormalities
o Heart rate of normal fetus with adequate oxygenation and intact autonomic nervous system accelerates in
response to movement
o Monitored with external FHR until reactive (up to 40 minutes) while running FHR contraction strip for interpretation
o Considered reactive when FHR increases 15 beats above baseline for 15 seconds twice or more in 20
minutes
o In fetuses less than 32 weeks, two accelerations peaking at least 10 bpm above baseline and lasting 10
seconds in a 20-minute period is reactive
o Nonreactive NST is one without sufficient FHR accelerations in 40 minutes " followed up for further testing
