Objective: To report the utility of the ultrasonographic biophysical profile, which includes all the components of a biophysical profile minus the nonstress test, in women with maternal indications for antepartum surveillance.
Methods: We conducted a case series reviewing the records of all women at 32 weeks of gestation or greater with at least one indication for antenatal testing (per the American College of Obstetricians and Gynecologists) delivered by a single maternal-fetal medicine practice between 2006 and 2018. Indications included diabetes, hypertension, lupus, antiphospholipid syndrome, sickle cell disease, renal disease, heart disease, hyperthyroidism, isoimmunization, inherited thrombophilia, and prior intrauterine fetal demise. Weekly ultrasonographic biophysical profiles were initiated at 32 weeks of gestation. We calculated the test-positive rate, the percentage of women delivered for an abnormal ultrasonography biophysical profile, and the intrauterine fetal demise rate (false-negative rate).
Results: Nine hundred eighty-five women underwent 3,981 ultrasonographic biophysical profiles (four per woman; range 1-11). Sixteen women had an abnormal ultrasonographic biophysical profile, for a test positive rate of 1.6% (95% CI 1.0-2.6%) per woman, or 0.4% (95% CI 0.3-0.7%) per ultrasonographic biophysical profile. Of the 16 women with abnormal ultrasonographic biophysical profiles, 13 were delivered with good outcomes and three women had normal follow-up testing and uncomplicated deliveries at a later date. There were three women with intrauterine fetal demise (false-negative rate of 0.3%, 95% CI 0.1-0.9%). One woman with intrauterine fetal demise had a factor V Leiden mutation, fetal ventriculomegaly, and fetal growth restriction. The second woman with intrauterine fetal demise had advanced maternal age, a factor V Leiden mutation, and fetal growth restriction. The third woman with intrauterine fetal demise had class B diabetes. All three intrauterine fetal demises were diagnosed antepartum with an interval from normal ultrasonographic biophysical profile to intrauterine fetal demise of 7, 7, and 6 days, respectively.
Conclusion: The use of ultrasonographic biophysical profile in a high-risk cohort is associated with a very low test-positive rate and a very low incidence of intrauterine fetal demise. In women with preexisting medical conditions that place them at higher risk for intrauterine fetal demise, ultrasonographic biophysical profile can be used for antenatal testing.