Physician Assistant Exam: The Normal Pregnancy

Pregnancy is an important topic for Physician Assistant Exam questions. You will need to know about the standard of care for pregnant women as well as about normal labor and delivery.

Prenatal screening

You can find many guidelines for prenatal screening. For the PANCE, think of the screening recommendations in terms of each trimester of the pregnancy. The focus is on the big-ticket items, such as screening for Down syndrome. If the pregnancy is high-risk (because of advanced age, significant family history), a closer follow-up with an OB/GYN is needed, but here’s a general rundown of prenatal screenings by gestation week:

• Initial visit: The initial visit to the obstetrician is a complex one, which includes a thorough history and physical. Start the woman on folic acid/prenatal vitamins if she’s not taking them already, because they reduce the fetus’s risk of neural tube defects like spina bifida.

  After the initial visit, assuming that she has an uncomplicated pregnancy, you usually schedule follow-up visits at 4-week intervals until 28 weeks, at 2- to 3-week intervals between 28 and 36 weeks, and weekly thereafter.

• At 10 to 12 weeks gestation: If the parents have a family history of certain genetic disorders, you may do a chorionic villus sampling (CVS) to look for chromosomal or genetic disorders in the fetus. The chorionic villus sampling doesn’t look for neural tube defects, which is done with an amniocentesis.

• At 14 to 18 weeks gestation: Order a genetic screen, often referred to as a triple screen. It includes testing for alpha-fetoprotein (AFP), β-hCG, and estradiol (E2):

  • AFP: Low levels of AFP may mean that the fetus is at risk of developing Down syndrome. AFP levels may be elevated for a number of reasons; elevated levels are associated with spina bifida.

  • β-hCG: Low hCG levels indicate a risk that the fetus may develop Trisomy 18 (T18).

  • Estradiol: Low levels of estradiol increase the risk of developing Down syndrome and/or Trisomy 18.

  Perform an amniocentesis between 15 to 18 weeks if you find an abnormality on the triple screen, such as high levels of AFP in the maternal serum. An amniocentesis allows you to further evaluate the fetal amniotic fluid. An older maternal age is another indication to have an amniocentesis performed.

• At 20 weeks gestation: You’ll usually have ordered a fetal ultrasound to look at Junior and to make sure all the parts are intact and that they’re developing okay.

• At 24 to 28 weeks gestation: Rh testing is done. If the mom is Rh negative and hasn’t been previously sensitized, then give her Rh immune globulin (RhoGAM). The oral glucose tolerance test is given during this time to screen for gestational diabetes.

• At 35 to 37 weeks gestation: Testing for Group B Strep via vaginal culture occurs late in the third trimester, between 35 and 37 weeks of gestation — just prior to expected delivery.

The stages of labor and delivery

Labor and delivery (L&D) is the process by which the baby (along with the placenta) comes out of the mom. Labor and delivery involves four stages.