FETAL WEIGHTS AND MEASUREMENTS AS DETERMINED BY POSTMORTEM EXAMINATION AND THEIR CORRELATION WITH ULTRASOUND EXAMINATION

Two hundred fifty fetuses from healthy singleton pregnancies terminate d other than on health grounds at 21 to 26 weeks gestation were examin ed by ultrasound in utero and by autopsy. No significant maturational difference between male and female fetuses was noted, although larger biparietal distances (0.2 cm) and smaller femur lengths (0.2 cm) were seen in female fetuses at 23 weeks gestation, and heavier body weights were also noted (80 g). No maturational difference was noted between white and nonwhite populations. Maternal age was not a significant var iable. Organ weights and fetal anthropometric measurements are provide d. Biparietal diameter as determined by ultrasound examination of the fetus in utero is an excellent predictor of gestational age and correl ated well with actual caliper measurements on the fetus (coefficient o f variation [CV] < 5%). Femur length determined by ultrasound examinat ion of the fetus in utero is significantly low compared with actual le ngth (CV = 23%) and is not a reliable indicator of fetal development. A large CV (17%) was also seen for calculated fetal weight. (Arch Path ol Lab Med. 1995;119:179-180)