Normal Pregnancy And Antepartum Care Flashcards
What is the goal of preconception care?
To reduce risk of adverse effects for the woman, fetus or neonate by optimizing the pt’s health before conception
What are examples of preconception care?
Starting folic acid supplementation at least 1 month before conception reduces the incidence of neural tube defects; adequate glucose control in diabetic pt’s before conception and throughout the pregnancy can decrease maternal morbidity, SAB’s, fetal malformations, fetal macrosomia, and IUFD
What is gravidity (G)?
Refers to the number of times a woman has been pregnant
What is parity (P)?
Refers to the number of pregnancies led to a birth at or beyond 20 weeks or an infant weighing more than 500g; can be broken into FPAL
What is FPAL?
Full term (37-42 weeks), preterm (20-36+6); abortions (include all pregnancy losses prior to 20 weeks including ectopic and abortions); living
What are normal PE findings associated with pregnancy?
Systolic murmurs (exaggerated splitting and S3), palmar erythema, spider angiomas, dark linea nigra, striae gravidarum, Chadwick’s sign
What prenatal labs are usually done at the first visit?
CBC, type and screen (Rh negative pts receive Rhogam at 28 weeks), rubella (vaccinate postpartum if not immune), syphilis, Hep B, HIV, cervical cytology, gonorrhea and chlamydia, screen for DM based RFs, urine culture
What is a common lab finding in pregnancy?
Anemia
What is additional information that is obtained during the first prenatal visit?
Confirm pregnancy and viability, estimate gestational age and due date, provide genetic counseling as necessary, discuss teratology (meds), advice on decreasing early pregnancy sx (N/V, cramping)
How is gestational age calculated?
It is the # of weeks that have elapsed between the first day of the LMP and the date of delivery
When can hCG first be detected in serum?
6-8 days after ovulation
In the first 30 days of a normal pregnancy hCG doubles how frequently?
Every 2.2 days (used to evaluate for early IUP vs ectopic pregnancies)
How is pregnancy and viability confirmed with transvaginal US?
Gestational sac seen around 5 weeks with mean hCG of 1500-2000*; fetal pole seen at 6 weeks; cardiac activity at 7 weeks
What is Naegels rule?
Expected date of delivery = minus 3 months + 7 days of LMP; only useful in pts with regular 28 day cycles
Crown rump length (CRL) between 6-11 weeks can determine what?
Due date within 7 days
What can be used to determine due date at 12-20 weeks?
Measuring femur length, biparietal diameter, and abd circumference can determine due to date within 10 days
In the third trimester the due date can be off by how much?
Up to +/- 3 weeks
Which pts should get genetic counseling?
Advanced maternal age (>35), previous child/family hx of birth defects or known genetic disorder, previous child with undiagnosed mental retardation, previous baby who died in neonatal period, multiple fetal losses, abnormal serum marker screening, consanguinity, maternal conditions, exposure to teratogens, abn US findings, parent who is a known carrier of genetic disorder
When should chromosomal studies (karyotype) be performed on a couple?
After 3 or more spontaneous abortions; 3-5% of them will be dx with a balanced translocation; should receive genetic counseling and be offered prenatal dx (chorionic villus sampling/amniocentesis)
What is the MC class of spontaneous abortions?
Autosomal trisomies (with trisomy 16 being the MC)
What is the MC single chromosomal abnormality found in SAB’s?
45 XO (turner syndrome)
Carrier screening programs focus on what?
High risk populations because the frequency of heterozygotes is greater than that of the general population
What is the MC gene carried in North America whites?
Cystic fibrosis
Who is offered CF screening?
All pregnant women, people with FHx, partners of known CF carriers, parents with US findings of echogenic bowel, sperm donors and any pt who requests screening
What is the MC form of inherited mental retardation?
Fragile X syndrome; also the 2nd MC form of mental retardation after trisomy 21
Many sex linked disorders can be diagnosed prenatally by what?
Chorionic villus sampling or amniocentesis
What are multifactorial disorders?
Both genetic and environmental factors
What are examples of multifactorial disorders?
Cleft lips or palates, congenital heart defects, pyloric stenosis, and neural tube defects (i.e. spina bifida or anencephaly)
First and second trimester screening can be performed in order to screen for what?
Fetal aneuploidy
Review
First and second trimester screening
What is noninvasive prenatal testing of cell free fetal DNA?
9-10 weeks (can be performed in the 1st or 2nd trimester); tests cell free fetal DNA, thought to be derived apoptosis of trophoblastic cells that have entered the maternal circulation; 90% detection rates for trisomies and sex chromosome abn; doesnt test for open neural fetal defects
Cell free fetal DNA should only be ordered in high risk pts including what?
Advanced maternal age, Hx of prior pregnancy with a trisomy, FHx of chromosomal abnormalities, fetal US abnormalities suggestive of aneuploidy, positive serum screening test including first trimester, triple or quad screen
What is a teratogen?
Any agent or factor that can cause abnormalities of form or function in an exposed fetus; can lead to fetal loss, intrauterine growth restriction, malformations due to abn growth, abn CNS performance
What are the categories for the pregnancy and lactation labeling rule?
Pregnancy, lactation, and females and males of reproductive age
What does the pregnancy subsection of PLLR include?
Pregnancy exposure registry risk summary and clinical considerations
What does the lactation subsection of PLLR include?
Provides information about the use of drugs while breastfeeding such as amount of drug in breast milk and potential effects to breastfed infants
What does the female and males of reproductive age subsection of PLLR include?
Includes information about the need for pregnancy testing, contraception recommendations and information about infertility as it relates to the drug
What are the principles of teratology?
Fetal susceptibility, dose, timing and nature of the teratogenic agent
Efficacy of a teratogen is dependent on what?
The genetic makeup of mother and fetus as well as on a number of factors related to the maternal-fetal environment (multifactorial)
How does the dose of a teratogen affect the fetus?
No apparent affect at low dose; organ malformation at intermediate dose; spontaneous abortion at high dose; may have different effects if taking med in large single dose vs smaller doses over several days
What is the most vulnerable stage of development?
From day 17 to day 56 post conception which is known as organogenesis; determines which organ or organ systems are affected
From the 4th month to the end of gestation, development consists primarily of what?
Increasing organ size; with the exception of brain and gonads-teratogenic exposure after the 4th month usually results in delayed growth and not in a malformation
What are 3 categories of teratogenic agents?
Drugs, infectious agents, radiation
What is the MC teratogen to which a fetus is exposed?
Alcohol —> fetal alcohol syndrome
Which anti-anxiety meds have teratogenic affects?
Data is conflicting; exposure to meprobamate (D) or chlordiazepoxide (D) has been associated with a 4 fold increase in severe congenital anomalies; fluoxetine drug of choice during pregnancy
Which anti-neoplastic agents are teratogens?
Aminopterin (X) and MTX (D) are both folic acid antagonists and are teratogens; exposure before 40 days is lethal to embryo; later exposure causes IUGR, craniofacial abn, mental retardation, miscarriage, stillbirth and neonatal death
What are alkylating anti-neoplastic agents that are teratogens?
Busulfan, chlorambucil, cyclophosphamide; may result in IUGR, fetal death, cleft lip/palate, microphthalmia and limb reduction anomalies
Which anticoagulants cross the placenta and are therefore teratogens?
Coumadin (warfarin); spontaneous abortion, IUGR, CNS defects like mental retardation, still birth, craniofacial features known as fetal warfarin syndrome
Which anticoagulant does not cross the placenta?
Heparin
What is fetal hydantoin syndrome?
Exposure to diphenylhydantoin (dilantin; an anticonvulsant) in utero; craniofacial abn, limb reduction defects, prenatal onset growth restriction, mental deficiency, CV abn
What affects does valproic acid have as a teratogen?
1-2% risk of open spina bifida; some association with cardiac defects, skeleton defects and craniofacial abn
What affects does carbamazepine have as a teratogen?
Also increased risk for spina bifida as well as minor craniofacial defects, fingernail hypoplasia, and developmental delay
Which drug has been removed as a teratogen by the FDA?
OCPs
Which drug can result in a T shaped uterus?
DES; among other abn
What malformations are associated with retinoids?
CNS (hydrocephaly, facial N palsies, cortical blindness), CV, craniofacial defects (microcephaly with severe ear abn, microtia, cleft palate); risk of SAB or congenital malformations is as high as 50% in women who take isoretinoids in 1st trimester
How does tobacco smoking affect development?
Interferes with fetal growth (weight, length, head circumference); IUGR and low brith weight; increased risk of SAB, fetal death, neonatal death and prematurity
Which infectious agents can cause growth restrictions, fetal death and mental retardation?
Viruses, bacteria, and parasites can all result in congenital malformations
How does radiation affect development?
Dose dependent; effects include teratogenesis, mutagenesis, carcinogenesis; critical period between 2-6 weeks post conception; rule of thumb: less than 5 rads of exposure = no risk; if exposure before 2 weeks effect is lethal or no effect at all
What are recommendations for the unpleasant sx of N/V during pregnancy?
Eat small but frequent meals, avoid greasy and fried foods, room temperature sodas and saltine crackers, acupuncture, meds (antihistamines, vitamin B6, antiemetics)
What are recommendations for the unpleasant sx of heartburn during pregnancy?
Due to relaxation of esophageal sphincter by progesterone; dont lie down immediately after meals, elevate head of bed, eat smaller more frequent meals throughout the day, antacids, cimetidine or famotidine
What are recommendations for the unpleasant sx of constipation during pregnancy?
Due to decrease in colonic activity; dietary changes (increase water, fiber, fruits and veggies), stool softeners
What are recommendations for the unpleasant sx of hemorrhoids during pregnancy?
Due to increase in venous pressure in the rectum; rest, stool softeners, stir baths, elevation of legs, avoid constipation
What are recommendations for the unpleasant sx of leg cramps during pregnancy?
More common in last half of pregnancy and more frequent in calves at night; massage and stretching
What are recommendations for the unpleasant sx of backache during pregnancy?
Common esp in late pregnancy; avoid excess wt gain, exercise/stretching, comfortable shoes, strategic use of pillows while sleeping, heat and massage
What is the frequency of prenatal visits?
Every 4 weeks until 28 weeks; every 2 weeks from 28-36 weeks; weekly until delivery
What occurs at routine prenatal office visits?
BP, weight, urine protein, measurement of uterine size (20 weeks at the umbilicus), fetal heart rate
What else occurs during prenatal office visits?
Address fetal movement/kick counts (first sensation occurs on avg at 20 weeks); educate on preterm and term labor, rupture of membranes, preeclampsia, and address any other identified potential complications with the pregnancy; discuss lifestyle situations (exercise, work and travel); near term evaluate fetal lie (longitudinal, oblique or transverse) and evaluate fetal position
What screening occurs at 20 weeks?
Obtain fetal survey US
What screening occurs at 28 weeks?
Screening for gestational DM and repeat H&H; Rhogam injection to Rh negative patients; Tdap given between 27-36 weeks
What screening occurs at 36 weeks?
Screening for group B strep carrier with vaginal culture; treat in labor if positive
What is used to assess fetal well being?*
Kick counting (monitor fetal movement; 10 movements in 2 hours), nonstress test (NST), contraction stress test (CST)
What is a reactive nonstress test?
2 accelerations of at least 15 beats above baseline lasting at least 15 seconds during 20 minutes of monitoring
What happens if a NST is non-reactive?
Further evaluation is warranted with a contraction stress test or biophysical profile
What is a contraction stress test?
Give oxytocin to establish at least 3 contractions in a 10 min period; if late decelerations are noted with the majority of contractions the test is positive and delivery is warranted
What is late deceleration?
Fetal HR lags behind contractions with little or no variability in line
What are the components of the reassuring biophysical profile?
Each category gets 2 points; categories include NST, fetal breathing movements, fetal movement, fetal tone, amniotic fluid volume
What does a total biophysical profile of 8-10 points indicate?
Reassuring
What does a total biophysical profile of 6 points indicate?
Equivocal; deliver if pt is at term gestation
What does a total biophysical profile of 4 or less points indicate?
Non reassuring; consider delivery
What is the incidence of stillbirth occurring within 1 week of a reactive NST?*
1.9 per 1000
What is the incidence of stillbirth occurring within 1 week of a negative CST?*
0.3 per 1000
What is the incidence of stillbirth occurring within 1 week of a biophysical profile?*
0.8 per 1000
