OB 1 Kenobi Flashcards
What is the “count to 10 method?”
Perception of 10 fetal movements over 2 hours
or
Perception of 4 fetal movements over 1 hour (while mother is at rest)
What testing should be done at 15-20 weeks gestation? (during 2nd trimester)
Invasive Dx Testing
- Amniocentesis (genetic material from amniotic fluid is extracted, risk of miscarriage is 0.6%)
When does the baby drop in fundal height?
36-38 weeks
Describe Hegar’s Sign
(normal pregnancy PE finding)
Softening of uterine isthmus
6-8 weeks gestation

What is Nagele’s rule?
Used to calculate Expected Date of Confinement (EDC)
- Add 7 days to LMP
- Subtract 3 months
Define 3rd trimester
29-40 weeks (12 weeks)
When should a woman start taking prenatal vitamins?
3 months prior to conceiving
Define post-term infant
Live born birth AFTER 42 weeks gestation
(perinatal mortality (death of fetus or neonate) increases as gestation advances beyond due date)
At 12 weeks, what anatomical landmark is the fundal height?
pubic symphysis
An US completed at the initial OB visit can do what 2 things?
- Establish/Confirm EDC
- Detect fetal heart activity at 5-6 weeks gestation
How is gestational age calculated?
Age of fetus calculated from 1st day of LMP
(includes 2 weeks when woman is not pregnant)
What murmur is seen in pregnancy and totally normal for pregnancy?
Systolic ejection murmur
What is the total weight gain for pregnancy?
25-35 lbs
Define neonate
Live born birth –> 28 days old
Describe Goodell’s sign
(normal pregnancy PE finding)
Softening of cervix
4-6 weeks
Define 2nd trimester
13 - 28 weeks (16 weeks)
- Most home pregnancy tests are + by the time of a missed menses (+/- 1 week), HCG is approximately what??
- HCG is produced by what? Rises exponentially for how many weeks before it plateaus?
- Corpus luteum produces what hormone until how many weeks post-fertilization?
- 25
- placenta / 10 weeks
- progesterone till 6 weeks, then placenta takes over
What happens to Tidal Volume, PO2, Expiratory Reserve, and PCO2 in pregnancy?
↑ TV & PO2
↓ Exp Reserve & PCO2
What are 4 visible sxs of pregnancy?
- Linea nigra
- Melasma (>16 weeks = mask of preg)
- Leukorrhea
- Stretch marks
How is Fetal age calculated?
Age of fetus calculated from time of implantation
(2 weeks less than gestational age) = actual fetus age
How much folic acid supplementation is needed for low risk vs. high risk?
Most prenatal vitamins contain how much folic acid?
- Low risk: 0.4 mg
- High risk: 4 mg
- Vitamins: 1 mg
Define 1st trimester
1 - 12 weeks (12 weeks)
What happens to gastric motility, gallbladder empyting, GFR, plasma volume, and WBCs in pregnancy?
↓ gastric motility & delayed gallbladder emptying
↑ GFR, plasma volume, WBCs
Define preterm infant
Born prior to 37 weeks gestation
Define a fetus
9th week –> birth
Define an embryo
Fertilization –> 8th week
When is fundal height measured?
When do cervical exams begin?
Fundal H: 20 weeks gestation
Cervical: 37 weeks gestation
What testing should be done at 16-18 weeks gestation (during 2nd trimester)?
Genetic Screening
-
Quad screen: maternal blood testing of AFP, HCG, Estriol, Inhibin A
- ↑ AFP = neural tube defects or multiple gestation
- Abnormal levels of AFP, HCG, Estriol, AND Inhibin A (all 4 tests) = Trisomy 18 or 21
What happens to CO, SV, and systemic vascular resistance in pregnancy?
↑ CO & SV
↓ SVR
What testing is done at 10-12 weeks gestation (during 1st trimester)?
Invasive Dx Testing
- Chorionic Villus Sampling (risk of miscarriage is 1%, extracts cells from placenta)
What is “quickening” and how many weeks gestation does it occur?
First perception of fetal movement
- Primigravida (18-20 weeks)
- Multigravida (16-20 weeks)
What are the frequencies of prenatal care visits?
(4)
- Initial visit 6-8 weeks after LMP
- Monthly until 28 weeks gestation
- Bimonthly 28 weeks - 36 weeks gestation
- Weekly 36 weeks until delivery
Define an infant
Live born birth –> 1 year old
What are 2 abnormal findings on a UA for pregnancy?
Proteinuria
Glucosuria
What testing should be done at 11-13 weeks gestation (end of 1st trimester)?
Genetic Screening for Down Syndrome
- US to assess nuchal translucency w/ ↑ fluid/thickening and absence of fetal nasal bone
-
Maternal Blood Testing:
- ↑ HCG levels
- ↓ PAPP-A (pregnancy associated plasma protein A
In which trimester is the fetus most sensitive to teratogens?
1st trimester
Fetal heart tones begin at what weeks gestation?
What is used to evaluate them?
How many bpm?
10-12 weeks gestation
Hand held doppler
120-160 WNL
What are 6 sxs of pregnancy?
- Amenorrhea
- N/V (↑HCG, multiple gestation, molar preg)
- Breast tenderness
- Fatigue
- Urinary freq/nocturia
- ↑ incidence of UTIs
How do you measure fundal height after 20 weeks gestation (from the umbilicus)
1 cm for each week
Describe Chadwick’s sign
(normal pregnancy PE finding)
Bluish cervix
8-12 weeks gestation

At 20 weeks, what anatomical landmark is the fundal height?
Umbilicus
What time is fetal movement greatest?
Night
- beta HCG levels do what in a normal pregnancy?
- What causes sxs in the 1st trimester?
- Double every 48 hours (normal)
- Increase in HCG & progesterone causes nausea/vomiting