Missed abortion, and later spontaneous abortion, in pregnancies clinically normal at 7-12 wk.

One thousand nine hundred and thirty-eight mothers were examined by ultrasound at 7-12 wk gestation. Eighty-three (4.28%) were found to have a dead fetus or an empty gestation sac. Twenty-five (1.29%) had a live fetus at that scan but spontaneously aborted 1-13 wk later. The earlier in pregnancy the ultrasound was carried out the more likely was the pregnancy to be dead or subsequently to abort. Mothers aged 35 or over were more likely than other women to have dead pregnancies at the initial ultrasound or subsequently to abort: those of 19 or less were likely than other age groups to have a missed abortion but they had a rate of spontaneous abortion similar to those of 35 or more.