Fetal loss following ultrasound diagnosis of a live fetus at 6-10 weeks of gestation.

OBJECTIVE To examine prospectively the value of demographic characteristics and ultrasound findings in the prediction of subsequent fetal loss in pregnancies with live fetuses at 6-10 weeks of gestation. METHODS Transvaginal ultrasound examination was performed in 866 pregnancies at 6-10 weeks of gestation. The relation of demographic data and ultrasound findings at the time of the initial assessment to subsequent fetal loss was examined. RESULTS In the 668 singleton pregnancies with live fetuses and complete follow-up there were 50 (7.5%) fetal losses. The incidence of fetal loss increased significantly with maternal age and decreased with gestation. In the pregnancies resulting in fetal loss, compared to those with live births, the incidence of vaginal bleeding and cigarette smoking was higher, the fetal heart rate was significantly lower and the gestation sac diameter was smaller but the yolk sac diameter was not significantly different. CONCLUSION In pregnancies with a live fetus at 6-10 weeks' gestation the rate of subsequent fetal loss is related to maternal age, gestation, cigarette smoking, history of vaginal bleeding and the ultrasound findings of small gestation sac diameter and fetal bradycardia, relative to crown-rump length.