Ultrasonic assessment of complications during first trimester of pregnancy.

624 women were referred to an emergency gynaecological ultrasound clinic with a provisional diagnosis of threatened miscarriage based on a history of amenorrhoea and vaginal bleeding with or without abdominal pain. High-resolution abdominal sector scanning was used to assess fetal size and viability, as well as uterine and placental size, to identify features which might indicate imminent fetal death. In 158 women there was no evidence of pregnancy; 60 women had an ectopic pregnancy. In the remaining 406 women ultrasound examination correctly identified the underlying cause of vaginal bleeding at first presentation in all but the 6 who subsequently aborted. 3.9% of the patients had a second empty sac and 5.4% had an intrauterine haematoma; none of these women subsequently aborted. 2 patients had early-onset oligohydramnios and spontaneous abortion occurred in both.