Outcome of subsequent pregnancies following antibiotic therapy after primary or multiple spontaneous abortions

The course of the subsequent pregnancy and the maternal and fetal complications were evaluated in 254 couples who were seen in an infertility clinic after primary or multiple spontaneous abortions. The 100 couples who were treated with antibiotics after pregnancy loss showed a significantly better chance of achieving a subsequent pregnancy. The outcome of pregnancy was significantly better in the antibiotic treated group and the rate of spontaneous abortion recurrence was significantly lower (10 versus 38 per cent). The number of maternal complications was significantly less in the treated group--premature rupture of membranes, three (4 per cent) versus 30 (46 per cent), and postpartum fever, three (4 per cent) versus 23 (35 per cent), respectively. The untreated group experienced a significantly lower percentage of vaginal delivery (56 versus 69 per cent) (p less than 0.001). In the antibiotic treated group, there were significantly lower rates of fetal complications, including fetal distress, meconium, respiratory distress syndrome, neonatal infection and hyperbilirubinemia. The mean birth weight of infants in the antibiotic treated group was significantly higher (3,529 versus 3,090 grams; p less than 0.001). Prematurity and postdatism were significantly less frequent in the antibiotic treated group, and the corresponding Apgar scores were significantly better. We, thus, postulate that certain spontaneous abortions may be caused by bacteria present in the genital tract at the time of conception. These bacteria may have an adverse effect on the course of pregnancy and result in increased maternal and fetal complications.