Background & Aims: This study aimed to evaluate the pregnancy outcomes in pregnancies with threatened abortion (miscarriage).

Materials & Methods: A prospective cohort study was performed on 1000 pregnant women. 500 women (case group), had a history of vaginal bleeding during the first half of pregnancy and the other 500 women (control group), did not have this history.  Both groups of women were followed from 20 weeks of pregnancy up to delivery.

Results: The women both groups did not have any significant differences according to age, parity, or body mass index (BMI). Spontaneous preterm delivery was in 126 cases (25.2%) vs.  47 cases (9.4%), P=0.001, [ADJ RR=1.4, CI 95%=1.2-1.5], premature rupture of membrane  were 51 cases (10.2%) vs.  24 cases (4.8%), P=0.02, [ADJ RR=2.1, CI95%= 1.2- 2.3], placental abruption were 20 cases (4%) vs. 7 cases (1.4%) P=0.01, [ADJ RR= 1.1, CI 95%= 1.01-1.2], were more in the case group.  There were no differences between the two groups regarding preeclampsia, small for gestational age (SGA), and cesarean deliveries. Neonatal weight (in term pregnancies) in the case group was lower than the control group (3046.4± 560.8 gram vs. 3317.6± 432 gram, P=0.001). There was a significant relationship between the number of bleeding episodes, spontaneous preterm delivery, and placental abruption and there was also a significant relationship between the amount of bleeding and placental abruption

Conclusion: Threatened abortion increases the rate of spontaneous preterm delivery, premature rupture of membrane and placental abruption, and decreases the neonatal weight. Therefore threatened abortion makes a pregnancy as high risk and demands more serious prenatal care.   

SOURCE: URMIA MED J 2012: 23(3): 349 ISSN: 1027-3727