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OBGYN COMAT Review Questions and
Answers
When can fetal heart tones be detected w/doppler?
Ans: 10-12 weeks
When is fetal movement appreciated?
Ans: 17-18 weeks
When should you get a "quantitative" beta-hCG
Ans: -to diagnose & follow ectopic pregnancy
-monitor trophoblastic dz
-screen for fetal aneuploidy
What supplement is given in pregnancy to decrease neural tube
defects for all reproductive-age women?
Ans: Folic acid supplements
What additional supplements are given for complete vegeterians
Ans: vitamin D & vitamin B12
What kind of immunoglobulins can cross the placenta?
Ans: IgG
Prenatal screening at the initial visit
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, 2 | Page
Ans: Heme= CBC, Rh factor, Type & Screen
ID= UA & culture, rubella Ab titer, HBsAg, RPR/VDRL, cervical G/C, PPD,
IV, Pap smear (to check for dysplasia).
If indicated: HbA1C, Sickle cell screening. Can also discuss genetic
screening (Tay-Sachs dz, Cystic Fibrosis).
When are prenatal visits conducted?
Ans: Weeks 0-28= every 4 weeks (7*4=28)
Weeks 29-35= every 2 weeks
Weeks 36-birth= every week
When is a quad screen conducted?
Ans: 15-22 weeks
When's an ultrasound for full anatomic screen done?
Ans: 18-20 weeks
When is the 1 hr glucose challenge test for gestational DM done?
Ans: 24-28 weeks
When is RhoGAM given to Rh- women?
Ans: 28-30 weeks
When's GBS culture done?
(and cervical culture for N gonorrhoeae & Chlamydia in selected
populations).
Ans: 35-40 weeks or 32-37 weeks
when can a nuchal transparency test be ordered?
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, 3 | Page
Ans: 9-14 weeks
4 elements of the Quad Screen
Ans: maternal serum AFP
B-hCG
Estradiol
Inhibin A
What's associated with ELEVATED maternal serum AFP (MSAFP)?
(<2.5 MoMs)
Ans: Open neural tube defects (spina bifida, anencephaly)
Abdominal wall defects (gastroschisis, omphalocele)
Multiple gestation
Incorrect gestational dating
Fetal death
Placental abnormailities (like rupture)
What's associated with REDUCED maternal serufm AFP (MSAFP)
(<0.5 MoM)
Ans: Trisomy 21 & 18
Fetal demise
Inaccurate gestational dating
Quad screen in trisomy 18
Ans: all are decreased
(still "UNDERage" at age 18)
Quad screen in Trisomy 21
© 2025 All rights reserved
OBGYN COMAT Review Questions and
Answers
When can fetal heart tones be detected w/doppler?
Ans: 10-12 weeks
When is fetal movement appreciated?
Ans: 17-18 weeks
When should you get a "quantitative" beta-hCG
Ans: -to diagnose & follow ectopic pregnancy
-monitor trophoblastic dz
-screen for fetal aneuploidy
What supplement is given in pregnancy to decrease neural tube
defects for all reproductive-age women?
Ans: Folic acid supplements
What additional supplements are given for complete vegeterians
Ans: vitamin D & vitamin B12
What kind of immunoglobulins can cross the placenta?
Ans: IgG
Prenatal screening at the initial visit
© 2025 All rights reserved
, 2 | Page
Ans: Heme= CBC, Rh factor, Type & Screen
ID= UA & culture, rubella Ab titer, HBsAg, RPR/VDRL, cervical G/C, PPD,
IV, Pap smear (to check for dysplasia).
If indicated: HbA1C, Sickle cell screening. Can also discuss genetic
screening (Tay-Sachs dz, Cystic Fibrosis).
When are prenatal visits conducted?
Ans: Weeks 0-28= every 4 weeks (7*4=28)
Weeks 29-35= every 2 weeks
Weeks 36-birth= every week
When is a quad screen conducted?
Ans: 15-22 weeks
When's an ultrasound for full anatomic screen done?
Ans: 18-20 weeks
When is the 1 hr glucose challenge test for gestational DM done?
Ans: 24-28 weeks
When is RhoGAM given to Rh- women?
Ans: 28-30 weeks
When's GBS culture done?
(and cervical culture for N gonorrhoeae & Chlamydia in selected
populations).
Ans: 35-40 weeks or 32-37 weeks
when can a nuchal transparency test be ordered?
© 2025 All rights reserved
, 3 | Page
Ans: 9-14 weeks
4 elements of the Quad Screen
Ans: maternal serum AFP
B-hCG
Estradiol
Inhibin A
What's associated with ELEVATED maternal serum AFP (MSAFP)?
(<2.5 MoMs)
Ans: Open neural tube defects (spina bifida, anencephaly)
Abdominal wall defects (gastroschisis, omphalocele)
Multiple gestation
Incorrect gestational dating
Fetal death
Placental abnormailities (like rupture)
What's associated with REDUCED maternal serufm AFP (MSAFP)
(<0.5 MoM)
Ans: Trisomy 21 & 18
Fetal demise
Inaccurate gestational dating
Quad screen in trisomy 18
Ans: all are decreased
(still "UNDERage" at age 18)
Quad screen in Trisomy 21
© 2025 All rights reserved
