BIOMETRIC MEASUREMENTS IN FETUSES OF DIFFERENT RACE AND GENDER

Sonographic fetal biometric measurements on 6082 low-risk patients wer e compared in the second and third trimesters of pregnancy with respec t to fetal race and gender. Ultrasonic measurements were obtained from fetuses of women participating in the Routine Antenatal Diagnostic Im aging with Ultrasound Study (RADIUS), who underwent both an early sono graphic evaluation between 15 and 22 weeks' gestation and a later scan between 31 and 35 weeks' gestation. In the 16-21-week scans, male fet uses had significantly larger biparietal diameter measurements compare d to female fetuses (estimated difference 0.852 mm, 95% CI 0.737-0.967 ). There was only minimal difference in biparietal diameter between Bl ack and White fetuses. Femur length was similar in both female and mal e fetuses, but longer in Black compared to White fetuses (estimated di fference 0.808 mm, 95% CI 0.539-1.078). During the 31-35-week scans, m ale fetuses continued to have larger biparietal diameter measurements compared to female fetuses (estimated difference 1.22 mm, 95% CI 1.04- 1.40), and femur lengths were persistently longer in Black compared to White fetuses (estimated difference 0.563 mm, 95% CI 0.234-0.893). Fu rther investigation is necessary to evaluate the effect of these sligh t differences in morphometric fetal measurements between races and gen ders, so that we can determine how best to use them for optimizing pre natal care.