CM- Obstetrics Flashcards
What are the 3 pieces of definitive evidence that a woman is pregnant?
- Fetal heart rate
- transvaginal US probe @ 4-5wks
- transabdominal US @ 6wks
- auscultation with Doppler @12wks
- auscultation with stethoscope @ 16-20 - Fetal movement
- detected by the mother [quickening]
- examination with physicians hand
- sonography [MOST DEFINITIVE] - Visualizing the fetus
- Sonogram = gold standard
- Xray [NEVER done as diagnostic because fetus is susceptible to radiation injury 8-15wks]
What are 3 pieces of probable evidence that a woman is pregnant?
- abdominal enlargement
- Uterine changes
- McDonald = flexion of uterine body on cervix
- Hegar = lower uterus softening
- Chadwick’s = blue discoloration of cervix/vagina
- Goodell = cervical softening - Endocrine tests
- Serum hCG at 5mlIU produced by syncitiotrophoblast as early as 2 days post implantation
- Urine test is sensitive to 25ml
What are the pieces of presumptive evidence that a woman is pregnant?
- cessation of period
- tender/sore breasts
- skin/vagina changes like Chloasma facial pigment
- nausea [morning sickness]
- bladder irritability
- fatigue
- perception of movement [quickening]
What are the general markers used to estimate gestational age?
- weeks since LMP [Nageles rule]
- quickening
- fundal height
What is Nagele’s rule for estimating gestational age and to calculate the due date?
- Add 7 to the first day of the last menstrual period
2. subtract 3 months
When does quickening usually occur?
It is a feeling of butterflies in the stomach and is the perception of fetal movement.
It occurs at approx. 16-20 wks
How can fundal height help you estimate gestational age?
fundal height is measured in cm and can provide a rough estimate of age between gestational weeks 20-32.
20cm = 20wks
32 cm = 32wks
If it is off with other calculations, the baby may be too small, too big or there is not enough amniotic fluid
How does the accuracy of sonography for determining gestational age change as the pregnancy progresses?
1st trimester it is accurate to a week
2nd trimester it is accurate to 2 wks
3rd trimester it is accurate to 3 wks
so it gets less and less accurate for gestational age
What are the routine laboratory tests required at the initial prenatal visit?
A Prenatal RUSHHH, CC
- ABo-Rh typing/antibody screen
- Pap smear
- Rubella
- Urinalysis and cultures
- Syphilis screen [RPR]
- Hb and Hct
- Hep B virus screening
- HIV [1st visit, and 3rd trimester or at delivery]
- CF carrier test
- Cultures of gonorrhea/chlamydia
In addition to the initial prenatal screening, what other tests are done throughout the pregnancy to ensure a healthy baby?
- 1st trimester screening [nuchal translucency, biochemical markers]
- 2nd trimester [ maternal alpha fetoprotein]
- genetic evaluations {chorionic villus sampling}
- Glucose tolerance test
- repeat RPR, HIV, Hb and Hct at 32 weeks
What are medical complications that make a pregnancy “high risk”?
- Diabetes
- Hypertension
- advanced maternal age [>35]
- Prior poor pregnancy outcome
- perinatal mortality
- preterm delivery
- fetal growth restriction
- malformations
- placental accidents - Psychological or Environmental risks
What are nine psychological or environmental risks for a pregnancy?
- smoking [placental separation]
- alcohol [FAS]
- drugs [placental separation]
- employment [standing in one place]
- family/domestic abuse
- maternal anxiety/stress/undernutrition
- unpasteurized cheese/meat [listeria] and high mercury fish
- exercise
How is fetal growth monitored for the first 1/2 of the pregnancy? Second half?
1st half = manual examination of the size of the uterus
2nd half = rate-of-growth sonograms
What are the 5 indications for antepartum surveillance?
[risk factors for uteroplacental insufficiency]
- hypertension
- diabetes
- clinical intrauterine growth restriction
- history of previous stillbirth
- post date [42wks gestation]
What are the 5 techniques to assess fetal wellbeing in utero?
- Fetal kick counts [10 in 2 hrs is good]
- non-stress test
- contraction stress test
- biophysical profile via sonography
- fetal acoustic stimulation
What is a non-stress test?
It is based on the premise that the heart rate of a non-acidotic fetus will accelerate at random intervals spontaneously or in response to rubbing, sound etc.
A fetus is reactive if the heart rate accelerates to >15 BPM for 15 seconds twice within a 20 minute period
What is a contraction stress test?
How does it differ from non-stress test?
Non-stress test evaluates the fetus well-being.
Stress tests evaluates utero-placental function.
Uterine contractions increase myometrial/amniotic pressure great enough to collapse the myometrial blood vessels temporarily cutting off oxygen exchange from mom to baby.
If the fetus tolerates this well, it will have early decelerations of HR or no decelerations. If the deceleration is “late” after the contraction, it means there is placental insufficiency.
In what 5 ways can fetal maturation be evaluated?
- amniotic fluid L/S ratio
- phosphatidylglycerol
- foam stability index
- fetal lung maturity
- Ultrasound
What L/S ratio in the anmiotic fluid is a sign that there is low likelihood of RDS?
> 2
What are the 2 indications on pelvic ultrasound that correlate with <1% risk of RDS?
- BPD [biparietal diameter] of over 9.3 cm
2. femur length of over 7.4 cm
What is the recommended weight gain during pregnancy for a woman with a BMI:
- under 18.5
- 18.5 -24.9
- 25-29.9
- over 30
- 28-40lbs
- 25 to 35 lbs
- 15-25 lbs
- 11-20 lbs
What are the energy requirements in terms of calories for a pregnant woman?
- 300 Kcal increase /day
2. 500 Kcal increase/day postpartum if breast-feeding
What are the 4 vitamins that need to be added prenatally or during pregnancy?
- Iron [7mg/day]
- Folate - add before pregnancy because it is needed to close the neural tube
- calcium- 1200mg/day
- vit D - 10 microns/day
What are class A, B, C, D, and X drugs? What are examples of meds in each cateorory?
A - safe- prenatal vitamins
B - presumed safe- antibiotics [penicillin, cephalosporin, macrolides]
C- uncertain safety - 2/3 of all medicines, asthma, HIV meds, antihypertensives
D- unsafe - systemic corticoids, seizure meds
X -teratogenic - alcohol, thalidomide, mercury, aminopterin/methotrexate, isotretinoin [Vit a], DES
What are the 6 most common teratogens?
- Alcohol
- thalidomide
- DES
- mercury
- isotretinoin
- aminopterin/methotrexate
On examination of a baby you note craniofacial abnormalities like:
- absent philtrum
- flattened nasal bridge
- maxillary hypoplasia
- short palpebral fissures
What is the likely cause?
What other problems will the child have growing up?
It is the presentation of FAS.
The child will also have mental retardation and behavioral disturbances.
They may also have cardiac and spinal defects.
What is the recommendation for alcohol consumption during pregnancy?
NONE. complete abstinence is recommended
A baby presents with bilateral limb reduction [phocomelia], facial hemangioma, esophageal/duodenal atresia, external ear anomalies and cardiac and renal problems.
What was the likely teratogen? What does it typically treat?
Thalidomide - treats leprosy and HIV wasting syndromes
A baby in a Japanese village has mental retardation, neurological impairment, growth retardation and some limb defects. What was the likely teratogen?
Mercury- ingesting fish high in mercury
A mother being treated for cancer gives birth to a baby with hydrocephalus, cleft palate, meningomycele, IUGR and ossification defects in the skull.
What was the likely teratogen?
Methotrexate/aminopterin are folate antagonists used to treat cancer, psoriasis, and connective tissue disorders [RA, etc]
A baby has microtia, micrognathia, cleft palate, small eyes, heart defects, and CNS anomalies.
What teratogen presents this way?
Isotretinoin [vit A derivative used to treat acne]
What are the 8 major cause of discomfort during pregnancy?
What pathophysiology causes each?
- syncope
- ankle edema
- breathlessness
- nausea/vomiting
- ptyalism [salivating too much]
- heartburn
- constipation
- urinary urgency/frequency
What is the pathophysiology behind why pregnant women will get ankle swelling?
Increased venous pressure due to the enlarging uterus impinging on the IVC.
Treatment: lift lower extremities and recline in LL decubitis
What is the pathophys for why pregnant women experience breathlessness?
Increased progesterone levels in the maternal serum increase the maternal minute ventilation giving the feeling of “having to catch ones breath”
What causes nausea/vomiting in pregnant women?
increased levels of B-hCG and estrogen.
Treat by eating smaller more frequent meals
What causes ptyalism in pregnancy?
stimulation of the salivary glands by ingestion of starch
What causes heartburn in pregnancy?
- Upward displacement and compression of the stomach by the gravid uterus
- delayed gastric emptying and relaxation of LES due to the effects of progesterone
What causes constipation/hemorrhoids in pregnant women?
Constipation = prolonged transit time and smooth muscle relaxation of the bowel
Hemorrhoids = increased pressure in the rectal veins by the gravis uterus
