Ultrasound and circulating placental protein measurements in complications of early pregnancy.

Maternal serum levels of human chorionic gonadotrophin (hCG), Schwangerschaftsprotein 1 (SP1) and pregnancy-associated plasma protein A (PAPP-A) were measured in an unselected group of 624 women presenting with amenorrhoea and vaginal bleeding with or without abdominal pain to an emergency gynaecological ultrasound clinic. Abdominal sector scanning was used to assess uterine contents. Pregnancy was confirmed by ultrasound in 406 pregnancies. Histological confirmation was obtained in each case of pregnancy failure. A live fetus was demonstrated in 259 women of whom six subsequently miscarried; one of these had markedly depressed serum hCG and PAPP-A, but normal SP1 levels, and two had oligohydramnios. Of the 147 women without ultrasound evidence of fetal heart action 67 had a correct ultrasound diagnosis of anembryonic pregnancy. The predictive value of a depressed serum hCG level was 70% in this group, and 31% in samples taken at less than or equal to 7 weeks. The predictive value of a normal hCG level was 96%. In 34 women missed miscarriage was diagnosed readily by ultrasound; all but five had depressed hCG and PAPP-A levels. A clinical diagnosis of a complete or incomplete miscarriage was made in 45 women and easily confirmed by ultrasound. All of them had depressed hCG, SP1 and PAPP-A levels. These results indicate that the diagnostic value of ultrasound in threatened miscarriage is often better than that of biochemical tests.