Prophylactic antibiotics in women with a history of pelvic inflammatory disease undergoing first-trimester abortion.

In a double-blind controlled trial the effect of prophylactic metronidazole on postabortal infection in women with a history of pelvic inflammatory disease (PID) was assessed. One hundred and thirty-five women were eligible for randomization, of whom 17 were excluded. The regimen consisted of oral metronidazole 400 mg 1 h before the abortion and again 4 and 8 h after, or else placebo. In the placebo group the rate of postabortal PID was 13.0% (7/54) and in the metronidazole group 10.9% (7/64), a nonsignificant difference (p greater than 0.7). Women in gestational weeks 11-12 had a significantly increased rate of postabortal PID compared with women in weeks 6-10 (p less than 0.005), but this rate was not influenced by the treatment (p greater than 0.2). Women with parity 1 had a significantly increased rate of postabortal PID compared with women with parity 0 (p less than 0.05), but again the treatment did not influence this rate significantly (p greater than 0.2). The number of hospital days for women in the metronidazole group did not differ significantly from that in the placebo group (p less than 0.1). The amount of metronidazole administered for prophylactic and postabortal treatment was significantly greater in the metronidazole group (p less than 0.001). The amounts of other antibiotics prescribed showed non-significant differences between the two groups (all p-values greater than 0.3).