The outcome of pregnancy after threatened abortion.

A prospectively collected group of 93 pregnancies complicated by threatened abortion was carefully monitored throughout pregnancy, during birth and in the perinatal period, and any deviation from a completely uneventful course was registered. Comparison was made with a selected group of 282 non-risk pregnant women. A significant association was found between threatened abortion and the overall number of complications in the second half of pregnancy requiring medical intervention and/or admission to hospital, impending pre-term birth requiring betamimetics, pre-term birth, retention of the placenta, birth weight below 2000 g, light-for-dates infants in case of pre-term birth or birth weight below 2000 g, and hyperbilirubinemia in infants with birth weight below 2000 g. The incidences of perinatal mortality and congenital malformations did not differ significantly from those of the control group. Pregnancies complicated by threatened abortion constitute a risk group requiring careful obstetric and perinatal supervision and follow-up.