A G2P1 at 36 weeks with gestational diabetes mellitus is undergoing scheduled weekly fetal surveillance testing. Which test is used?

A G2P1 at 36 weeks with gestational diabetes mellitus is undergoing scheduled weekly fetal surveillance testing. Which test is used?

• A. Contraction Stress Test
• B. Nonstress Test (NST)
• C. Biophysical Profile
• D. Umbilical artery Doppler

Answer: (B)

Nonstress testing is the standard way to screen fetal well‑being in late pregnancy, especially in pregnancies affected by diabetes. It monitors the fetal heart rate in response to fetal movements, without stressing the fetus. A reactive NST—typically two or more accelerations of the heart rate of about 15 beats per minute for 15 seconds within a 20-minute window (guidelines vary slightly by gestational age)—suggests adequate fetal oxygenation and autonomic function. For a 36-week gestation with gestational diabetes, weekly NSTs are a practical, quick, noninvasive way to detect potential fetal distress early. If the NST is reactive, surveillance can continue as planned. If it’s nonreactive, additional testing like a comprehensive biophysical profile or a contraction stress test may be pursued to gather more information about fetal status. The other tests are used less routinely for simple weekly surveillance: a contraction stress test introduces contractions and more risk; umbilical artery Doppler focuses on placental blood flow and is primarily used when growth restriction or placental insufficiency is suspected; a biophysical profile is more thorough but is typically reserved for equivocal NST results or specific concerns.

Nonstress testing is the standard way to screen fetal well‑being in late pregnancy, especially in pregnancies affected by diabetes. It monitors the fetal heart rate in response to fetal movements, without stressing the fetus. A reactive NST—typically two or more accelerations of the heart rate of about 15 beats per minute for 15 seconds within a 20-minute window (guidelines vary slightly by gestational age)—suggests adequate fetal oxygenation and autonomic function.

For a 36-week gestation with gestational diabetes, weekly NSTs are a practical, quick, noninvasive way to detect potential fetal distress early. If the NST is reactive, surveillance can continue as planned. If it’s nonreactive, additional testing like a comprehensive biophysical profile or a contraction stress test may be pursued to gather more information about fetal status. The other tests are used less routinely for simple weekly surveillance: a contraction stress test introduces contractions and more risk; umbilical artery Doppler focuses on placental blood flow and is primarily used when growth restriction or placental insufficiency is suspected; a biophysical profile is more thorough but is typically reserved for equivocal NST results or specific concerns.