Evaluation of biophysical fetal assessment in high-risk pregnancy to assess ultrasound parameters suitable for screening in the low-risk population.

Abstract

During a 1-year period, 662 pregnant women at 24-43 weeks' gestation were referred to the Department of Obstetrics and Gynaecology, at the Queens University Belfast, for fetal assessment because they were clinically suspected to be at high risk of perinatal complications. The results of our investigations were made available to the referring obstetricians who undertook the further management of the pregnancies. Subsequently six pregnancies resulted in perinatal deaths and 97 (14.7%) in the delivery of small-for-gestational-age infants. We restrospectively analyzed the data from ultrasonographic evaluation of the fetus and subjective and objective assessments of the amniotic fluid volume to determine their value in the prediction of adverse perinatal outcome. A fetal abdominal circumference < 10th centile for gestation or a subjectively reduced amniotic fluid volume identified 87 (90%) of small-for-gestational-age infants and five of the six perinatal deaths. When comparing the abdominal circumference and subjective liquor volume, both were sensitive in predicting delivery of a small-for-gestational-age fetus (sensitivity 86% vs. 53%, respectively) and perinatal death (sensitivity 50% vs. 83%, respectively). We suggest that, since assessments of these two factors are complementary in evaluating a high-risk pregnancy and can be measured in under 5 min, they now warrant consideration for screening in a prospective randomized trial in an unselected low-risk population.