The Normal Pregnancy: Antepartum Care Flashcards
What is the goal for preconception care?
- Reduce risk of adverse effects for the woman, fetus, or neonate by optimizing the patients health before conception
What is recommended for anyone considering getting pregnant?
- Identify risks and promote preconception health
- Risk assessment: smoking cessation, ETOH, illicit drugs
- Health promotion: nutrition, folic acid supplement, weight issues)
- Medical interventions: diabetes management
- Psychosocial intervention: stress reduction
What are some 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 patients before conception and throughout the pregnancy can decrease maternal morbidity, SABs, fetal malformation, fetal macrosomia, and IUFD
What is Gravidity?
- Number of times a woman has been pregnant
What is Parity?
- Number of pregnancies led to a birth at or beyond 20 weeks or an infant weight more than 500 grams
How can parity be broken down?
- Full term (37-40 weeks)
- Preterm (20-36+6)
- Abortions (include all pregnancy losses prior to 20 weeks including ectopic and spontaneous
- Living
What is the gravidity and parity of a women who has given birth to 1 set of twins at term and both are living?
- G1P1002
What is the gravidity and parity of a women who has given birth to one term infant, one set of preterm twins, and has had 1 miscarriage and 1 ectopic pregnancy. She has 3 living children?
- G4P1123
What is done at the first prenatal visit?
- Obtain a thorough history including:
- Medical (DM, HTN)
- Reproductive (PTD, pre-e, stillbirth)
- Family (DM)
- Nutritional (folic acid, weight gain)
- Social (ETOH, drugs)
- Psychosocial (depression, anxiety)
What are normal findings on a PE associated with pregnancy?
- Systolic murmurs, exaggerated splitting and S3
- Palmar erythema
- Spider angiomas
- Linea nigra
- Striae gravidarum
- Chadwicks sign
What are some prenatal labs done at 1st visit?
- CBC
- Type and screen
- Rubella (vaccinate postpartum if not)
- Syphilis
- Hep B surface Ag
- HIV
- Cervical cytology and gonorrhea and chlamydia
- Screen for diabetes
- Urine cultures
What are some common lab values in pregnancy?
- Albumin: decreased
- Calcium: grandual fall
- Chloride: no change
- Creatinine: decreased by 20 weeks
- Fibrinogen: increased
- Fasting glucose: gradual fall
- Potassium: Fall by 20 weeks
- Protein: fall by 20 week then stable
- Sodium: decreased by 20 week then stable
- Urea nitrogen: decreased in first trimester
- Uric acid: decreased in first trimester then rise at term
What does urine chemistries show in pregnancy?
- Creatinine: no change
- Protein: increased from 150mg/day to 250-300mg
- Creatinine clearance: decreased 40-50%
What are the serum enzymatic activity in pregnancy?
- Amylase: increased
- Transaminases: no change
- Hematocrit: decreased
- Hemoglobin: decreased
- Leukocyte count: increased
- Platelets: slight decrease
- Factors 7-10 increase
What additional information is discussed at the first prenatal visit?
- Confirm pregnancy and viability
- Estimate gestational age and due date
- Provide genetic counseling if needed
- Discuss teratology
- Advice on decreasing early pregnancy symptoms
What does a pregnancy test do?
- Detect hCG in the serum or urine
- hCG can first be detected in serum 6 to 8 days after ovulation
- Most urine tests detect a level of 25 IU/L
What are the different levels of hCG and what do they mean?
- Less than 5 IU/L is negative
- Above 25 IU/L is positive
- Above 100 IU/L is reached by time of expected menses
How much does hCG rise in the first 30 days?
- Doubles every 2.2 days
What is seen on transvaginal ultrasound and what are the corresponding hCG levels?
- Gestational sac is seen around 5 weeks (hCG is 1500-200 IU/L)
- Fetal pole seen at 6 weeks (hCG of 5200 IU/L)
- Cardiac activity seen at 7 weeks (hCG at 17500 IU/L)
What is Naegels rule?
- Minus 3 months + 7 days is expected date of delivery
- Only useful in patients with regular 28 day cycles`
What are some ways to estimate gestational age and due date?
- Last menstrual period
- Physical exam
- Ultrasound
How can physical exam be used to estimate gestational age and due date?
- Size of uterus
How can ultrasound be used to estimate gestational age and due date?
- Crown rump length (CRL) between 6-11 weeks can determine due date within 7 days
- At 12-20 weeks measuring femur length, biparietal diameter and abdominal circumferences can determine due date within 10 days
- In third trimester, due date can be off up to 3 weeks
What is crown rump length?
- Length from head to toe
Who is assessed for genetic counseling?
- Advanced maternal age (35 or older)
- Previous child/family history of birth defects or known genetic disorder
- Previous child with mental retardation
- Previous baby who died in neonatal period or multiple fetus loss
- Abnormal serum marker screening or ultrasound
- Consanguinity
- Maternal conditions
- Exposure to teratogens
- Parent who is known carrier of genetic disorder
What are some common chromosomal disorders?
- Turners
- Klinefelter’s
- Balanced robertsonian translocations
- Autosomal trisomies
How is maternal age related to chromosomal disorders?
- Women that are age 35 and older are at increased risk of autosomal trisomies or sex chromosome abnormalities
What is the leading cause of down syndrome?
- Due to meiotic nondisjunctional events leading to 47 chromosomes with an extra copy of chromosome 21
- Some are due to an unbalanced translocation
How much of a risk is it for a couple to have another child with a chromosomal abnormality?
- 1%
What should be done to couples after 3 or more spontaneous abortions?
- Chromosomal studies (karyotyping)
- In 3-5% of these couples, there will be a diagnosis of a balanced translocation
What should balanced translocation couples receive?
- Counseling regarding possibility of having a child with an unbalanced translocation and therefore be offered prenatal diagnosis (chorionic villus sampling/amniocentesis)
What are some examples of autosomal dominant disorders?
- Tuberous sclerosis
- Neurofibromatosis
- Achondroplasia
- Craniofacial synostosis
- Adult onset polycystic kidney disease
- Muscular dystrophy
What are some examples of autosomal recessive disorders?
- Tay-Sachs
- Sickle cell disorders
- Alpha and beta thalassemia
- Cystic fibrosis
What is done for high risk populations?
- Carrier screening programs because the frequency of heterozygotes is greater than that of the general population
Why is genetic counseling important for cystic fibrosis?
- 15% of carriers go undetected
- CF is most common in North American whites
Who is offered screening for CF?
- All pregnant women
- People with family history
- Partners of known CF carriers
- Parents with ultrasound findings of echogenic bowel
- Sperm donors and any patient who requests screening
What are some examples of sex linked disorders?
- Duchenne muscular dystrophy
- Fragile X syndrome
What is fragile x syndrome?
- Most common form of inherited mental retardation
- Second most common form of mental retardation after down syndrome
How can sex linked disorders be diagnosed prenatally?
- By chorionic villus sampling or amniocentesis
What does someone look like with fragile x syndrome?
- Normal structure
- Elongated face
- Broad forehead
- Large prominent ears
- Strabismus
- Highly arched palate
- Hyperextensible joints
- Hand calluses
- Pectus excavatum
- Mitral valve prolapse
- Enlarged testicles
- Hypotonia
- Soft fleshy skin
- Flat feet
- Seizures
What are multifactorial disorders? Example?
- Birth defects that are inherited due to both genetic and environmental factors
- Examples: Cleft lips/palates, congenital heart defects, pyloric stenosis, and neural tube defects
What are some details about neural tube defects?
- Incidence is 1 per 1000 births
- Folic acid supplementation has been shown to lower risk for NTD
- Women with affected child should take 4 mg in subsequent pregnancies before conception since neural tube closure is complete at 28 days post conception
What does the first trimester screening include?
- Maternal age
- Fetal nuchal translucency thickness
- Maternal serum b-hCG
- Pregnancy associated plasma protein A (PAPP-A)
What does the fetal nuchal translucency thickness tell?
- It is the echo free area at the back of the neck between 10 and 14 weeks
- Increased thickness associated with both chromosomal and congenital anomalies
What in the first trimester screening would lead to a suspicion of Down’s syndrome?
- Elevated b-hCG and low PAPP-A
- Nasal bone assessment (absence of) can increase detection
What does the second trimester include?
- Triple screen: b-hCG, estriol, and maternal serum alpha fetoprotein biochemical markers
- Quadruple screen: b-hCG, estriol, AFP, and inhibin A
When does the triple screen in the second trimester take place? What is detection rate of trisomy 21?
- Takes place between weeks 16 and 20
- 70% detection week
What is the detection rate of trisomy 21 in the quadruple screen?
- 80%
What is the noninvasive prenatal testing (cell free fetal DNA)?
- Tests cell free fetal DNA, thought to be derived apoptosis of trophoblastic cells that have entered maternal circulation
What is noninvasive prenatal testing good at detecting?
- Trisomy 21 = 99.4%
- Trisomy 18 = 99.1%
- Trisomy 16 = 91.7%
- Sex chromosomes = 96.2%
What does noninvasive prenatal testing good at detecting?
- Open neural fetal defects
Who is the cell free fetal DNA test ordered in?
- High risk patients such as:
- Advanced maternal age
- History of prior pregnancy with a trisomy
- Family history of chromosomal abnormalities
- Fetal ultrasound abnormalities suggestive of aneuploidy
- Positive serum screening test including first trimester, triple or quad screen
When is an amniocenteisis done?
- 16-20 weeks
- 0.3% miscarriage rate
When is a chorionic villus sampling done?
- 11 weeks
- 1% miscarriage rate
What is teratology?
- Study of abnormal fetal development
What is a teratogen?
- Any agent or factor that can cause abnormalities of form or function in an exposed fetus
What are some abnormalities caused by teratogens?
- Fetal loss
- Intrauterine growth restriction
- Malformations due to abnormal growth
- Abnormal CNS performance
What is fetal susceptibility of teratogens?
- Efficacy of teratogen is dependent on the genetic makeup of mother and fetus as well as on a number of factors related to the fetal-maternal environment
How does the dose of a teratogen affect its effects?
- Low dose: no apparent effect
- Intermediate dose: Organ malformation
- High dose: spontaneous abortion
- May have different effect if taking one large dose or many small doses over days
How is timing important in teratogens?
- Most vulnerable stage is from day 17 to day 56 post conception (called organogenesis)
- Determines which organ or organ systems are affected
- From fourth month to end of gestation, development is mainly just increasing organ size
Why does the nature of the teratogenic agent matter?
- Under the right set of circumstances, agents can cause malformations
- Large doses during organogenesis, susceptible fetus
- Some agent are only teratogenic when combined with other agents
What are some examples of teratogenic agents?
- Drugs
- Alcohol
- Infectious agents
- Radiation
What is the most common teratogen a fetus is exposed to?
- Alcohol
- Causes fetal alcohol syndrome
What antineoplastic agents are teratogens?
- Aminopterin (X) and methotrexate (D) are both folic acid antagonists
- Exposure before 40 days is lethal to embryo
- Later exposures causes IUGR, craniofacial abnormalities, mental retardation, miscarriage, stillbirth and neonatal death
What does fetal alcohol syndrome look like?-
- Growth restriction (prenatal or postnatal)
- Facial abnormalities: low set ear, smooth philtrum, thin upper lip, shortened palpebral fissures, flat midface
- CNS dysfunction: Microcephaly, mental retardation, and behavior disorders
What alkylating antineoplastic agents are teratogenic?
- Busulfan, chlorambucil, and cyclophosphamide
- May result in IUGR, fetal death, cleft lip/palate, microphthalmia and limb reduction anomalies, and poorly developed external genitalia
What anticoagulants are considered teratogenic?
- Coumadin (crosses placenta)
- Causes spontaneous abortion, IUGR, CNS defects like mental retardation, stillbirth, and craniofacial features known as fetal warfarin syndrome
- Heparin (does not cross placenta)
What anticonvulsants are considered teratogenic?
- Diphenylhydantoin: fetal hydantoin syndrome
- Valproic acid: 1-2% risk of open spina bifida, some association with cardiac defects, skeleton defects, and craniofacial abnormalities
- Carbamazepine: increased risk for spina bifida, minor craniofacial defects, fingernail hypoplasia, and developmental delay
What is seen with phenobarbital in neonates?
- Usually in combination with other drugs and true teratogenic potential is difficult to access
- Can see neonatal withdrawal and hemorrhage
What abnormality is seen with estrogen-progesterone combinations?
- Masculinization of female external genitalia
What is diethylstilbestrol (DES) used for?
- Threatened abortion
What does DES cause?
- Risk for cervical abnormalities and uterine malformations
- Female offspring are at greater risk of vaginal cell cancer and male offspring are at risk of testicular abnormalities
- T shaped uterus
What malformations does accutane/retinoids cause?
- CNS (hydrocephaly, facial nerve palsies, and cortical blindness)
- Cardiovascular
- Craniofacial defects
What does tobacco smoking do to the fetus?
- Interferes with fetal growth- weight, length, and head circumference
- Increased risk of spontaneous abortion, fetal death, neonatal death, and prematurity
What do illicit drugs do to a fetus?
- Often unrecognized due to lack of overt symptoms or structural anomaly following birth
- Opiate- may experience withdrawal
- Behavioral abnormalities
How can infectious agents affect a fetus?
- Growth restriction
- Fetal death
- Mental retardation
How does radiation affect a fetus?
- Dose dependent
- Critical period is between 2 and 6 weeks post conception (if before 2 weeks, could be lethal or have no effect)
What is the rule of thumb with radiation in pregnancy?
- Less than 5 rads of exposure is no risk
How can nausea and vomiting be controlled during pregnancy?
- Eat small but frequent meals
- Avoid greasy, fried foods
- Room temperature sodas and saltine crackers
- Acupuncture
- Meds
How can heartburn be controlled during pregnancy?
- Do not lie down after meals
- Elevate head of bed
- Eat smaller but frequent meals
- Antacids
- H2 blockers
How can constipation be controlled during pregancy?
- Dietary changes like increasing water, fiber, fruits and veggies
- Stool softener
How can hemorrhoids be controlled during pregnancy?
- Rest, stool softeners, sitz baths
- Elevation of legs
- Avoid constipation
How can leg cramps be controlled during pregancy?
- More common in last half of pregnancy
- More frequent in calves at night
- Massage or stretching to treat
How can backache be controlled during pregancy?
- Common in late pregnancy
- Avoid excess weight gain
- Exercise/stretching
- Comfortable shoes
- Strategic use of pillows while sleeping
- Heat
- Massage
What is the frequency of prenatal office visits?
- Every 4 weeks until 28 weeks
- Then every 2 weeks from 28 to 36 weeks
What occurs at a prenatal office visit?
- BP
- Weight
- Urine proteins
- Measurement of uterine size
- Fetal heart rate
- Address fetal movement and kick counts
- Discuss lifestyle situations
- Educate on preterm and term labor, rupture of membranes, preeclampsia, and any other complications
What is the first sensation of movement called? When does it occur?
- Quickening and occurs near 20 weeks
What is evaluated near term?
- Fetal lie and fetal position
What screening is done at 20 weeks?
- Obtain fetal survey ultrasound
What screening is done at 28 weeks?
- Screening for gestational diabetes and repeat hemoglobin and hematocrit
- Rhogam injections to Rh- patients
- Tdap given between 27-36 weeks
What screening is done at 36 weeks?
- Screening for group B strep carriers with vaginal culture- treat if positive
What is a part of the assessment of fetal well being?
- Kick counting (10 movements in 2 hours)
- Nonstress test
- Contraction stress test
What is a nonstress test?
- Reactive- 2 accelerations of at least 15 beats above baseline lasting at least 15 seconds during 20 minutes of monitoring
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 warrented
