Prenatal Care & Risk Assessment Flashcards

Per current ACOG guidance, universal Group B Streptococcus vaginal-rectal culture screening is recommended at what gestational age?

Answer: 36 0/7 to 37 6/7 weeks

ACOG (2020) recommends GBS screening at 36 0/7 to 37 6/7 weeks so results stay valid through 41 weeks.

A client with no risk factors asks when routine screening for gestational diabetes is typically performed. What is the best answer?

Answer: Between 24 and 28 weeks

Routine GDM screening is done at 24-28 weeks, when placental insulin resistance becomes evident.

An Rh-negative, antibody-negative client with an Rh-positive partner should routinely receive Rh immune globulin prophylaxis at about what gestational age?

Answer: 28 weeks

Antepartum RhIG is given at about 28 weeks, with a postpartum dose within 72 hours if the newborn is Rh-positive.

According to CDC criteria, anemia in the second trimester of pregnancy is defined as a hemoglobin below which value?

Answer: 10.5 g/dL

The CDC threshold is Hgb <11.0 g/dL in the first and third trimesters and <10.5 g/dL in the second, reflecting peak hemodilution.

Cell-free DNA (NIPT) screening for fetal aneuploidy can be performed starting at what gestational age?

Answer: 10 weeks

Cell-free DNA screening is valid from about 10 weeks, when the fetal fraction is usually adequate.

The maternal serum quad screen is drawn during which gestational window?

Answer: 15-22 weeks

The quad screen (AFP, hCG, estriol, inhibin A) is done at 15-22 weeks, ideally 16-18.

An elevated maternal serum alpha-fetoprotein on a second-trimester screen is most often explained by which finding?

Answer: Underestimated gestational age

Wrong dating is the most common cause of an abnormal MSAFP, so ultrasound dating is the first step.