A prospective study of 200 pregnancies complicated by threatened abortion was undertaken. Pregnancy outcome was compared with that in a selected group of 415 non-risk pregnant women. There was a significant association between threatened abortion and the following complications of pregnancy: impending preterm delivery, preterm delivery, preterm rupture of membranes, low birth weight, abruptio placentae, and perinatal mortality. No significant association was found between threatened abortion and placenta previa, pregnancy-induced hypertension, malpresentation, small-for-gestational-age infants, congenital anomalies, and postpartum hemorrhage. Preterm delivery rate and abruptio placentae constituted the most frequently observed complications for those cases in which there was more than one episode of bleeding. Pregnancies complicated by threatened abortion represent a high risk and need careful antepartum, intrapartum, and pediatric care. Abortion. 1990; 10(6): 593-597 Threatened abortion complicating early pregnancy is known to be associated with suboptimal pregnancy outcome. Many studies have shown an increase in the risk of preterm delivery [1][2][3][4][5][6][7], low birth weight [2][3][4][5]8], and small-for-gestational-age infants [2][3][4][5], as well as increased perinatal mortality [2][3][4]6,7,9], though a more recent study failed to show this increase [5]. Other complications were also shown to be increased, including congenital anomalies [9,10], abruptio placentae [4], malpresentations [2], and retention of placenta [5], RAS Tikreeti, ZAH Al-Saadi, The Outcome of Pregnancies Complicated by ThreatenedThe purpose of this prospective study was to assess the complications that can result from threatened abortion and compare our findings with those in a control group of non-risk pregnant women. The complication that caused the greatest concern is preterm delivery (before 37 completed weeks), as the mortality of preterm infants is high in developing countries because of lack of facilities and skilled personnel essential for effective neonatal intensive care. Materialand Methods Study groupsFrom January 1987 to November 1988, 200 women whose pregnancies were complicated by threatened abortion (vaginal bleeding with or without cramping and the absence of cervical dilatation before 20 weeks' gestation) and who continued pregnancy until at least the 28th week of pregnancy were studied. These 200 women were referred to as the "threatened abortion (TA) index group." All were scheduled to deliver at the Department of Obstetrics and Gynaecology, Medical City Teaching Hospital, Baghdad. Women were included in the study if they