We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014) and reference lists of retrieved articles.
SELECTION CRITERIA: We assessed trial quality and extracted data.
MAIN RESULTS: The review included seven randomised controlled trials. Approximately 2100 women were recruited to detect the effect of prophylactic
antibiotic administration on pregnancy outcomes. Primary outcomesAntibiotic prophylaxis did not reduce the risk of preterm prelabour
rupture of membranes (risk ratio (RR) 0.31; 95% confidence interval (CI) 0.06 to 1.49 (one trial, 229 women) low quality evidence) or preterm delivery (RR 0.85; 95% CI 0.64 to 1.14 (five trials, 1480 women) low quality evidence). However, preterm delivery was reduced in the subgroup of pregnant women with a previous
preterm birth who had
bacterial vaginosis (BV) during the current pregnancy (RR 0.64; 95% CI 0.47 to 0.88 (one trial, 258 women), but there was no reduction in the subgroup of pregnant women with previous
preterm birth without BV during the pregnancy (RR 1.08; 95% CI 0.66 to 1.77 (two trials, 500 women)). A reduction in the risk of postpartum
endometritis (RR 0.55; 95% CI 0.33 to 0.92 (one trial, 196 women)) was observed in high-risk pregnant women (women with a history of
preterm birth, low
birthweight,
stillbirth or early
perinatal death) and in all women (RR 0.53; 95% CI 0.35 to 0.82 (three trials, 627 women) moderate quality evidence). There was no difference in low birth weight (RR 0.86; 95% CI 0.53 to 1.39 (four trials; 978 women) or
neonatal sepsis (RR 11.31; 95% CI 0.64 to 200.79); and blood culture confirming
sepsis was not reported in any of the studies. Secondary outcomesAntibiotic prophylaxis reduced the risk of prelabour
rupture of membranes (RR 0.34; 95% CI 0.15 to 0.78 (one trial, 229 women) low quality evidence) and gonococcal
infection (RR 0.35; 95% CI 0.13 to 0.94 (one trial, 204 women)). There were no differences observed in other secondary outcomes (
congenital abnormality; small-for-gestational age; perinatal mortality), whilst many other secondary outcomes (e.g. intrapartum
fever needing treatment with
antibiotics) were not reported in included trials.Regarding the route of
antibiotic administration, vaginal antibiotic prophylaxis during pregnancy did not prevent infectious pregnancy outcomes. The overall risk of bias was low except that incomplete outcome data produced high risk of bias in some studies. The quality of the evidence using GRADE was assessed as low for preterm prelabour
rupture of membranes, low for preterm delivery, moderate for postpartum
endometritis, low for prelabour
rupture of membranes, and very low for
chorioamnionitis. Intrapartum
fever needing treatment with
antibiotics was not reported in any of the included studies.
AUTHORS' CONCLUSIONS:
Antibiotic prophylaxis did not reduce the risk of preterm prelabour
rupture of membranes or preterm delivery (apart from in the subgroup of women with a previous
preterm birth who had
bacterial vaginosis).
Antibiotic prophylaxis given during the second or third trimester of pregnancy reduced the risk of postpartum
endometritis, preterm
rupture of membranes and gonococcal
infection when given routinely to all pregnant women. Substantial bias possibly exists in the review's results because of a high rate of loss to follow-up and the small numbers of studies included in each of our analyses. There is also insufficient evidence on possible harmful effects on the baby. Therefore, we conclude that there is not enough evidence to recommend the use of routine
antibiotics during pregnancy to prevent infectious adverse effects on pregnancy outcomes.