Prophylactic antibiotic administration in pregnancy to prevent infectious morbidity and mortality

Abstract

Background: Some previous studies suggested that prophylactic antibiotics given during pregnancy improved maternal and perinatal outcomes, some did not show any benefit and some even reported adverse effects.

Objectives: To determine the effect of prophylactic antibiotics during second and third trimester of pregnancy on maternal and perinatal outcomes.

Search strategy: The Cochrane Pregnancy and Childbirth Group trials register (April 2002), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002) and reference lists of articles were searched.

Selection criteria: Randomized controlled trials comparing prophylactic antibiotic treatment with placebo or no treatment for women in the second or third trimester of pregnancy before labour.

Data collection and analysis: Trial quality assessment and data extraction were done by the reviewers.

Main results: There were six randomized controlled trials which recruited 2184 women to detect the effect of prophylactic antibiotic administration in the second or third trimester on pregnancy outcomes. Antibiotic prophylaxis in unselected pregnant women reduced the risk of prelabour rupture of membranes (Peto odds ratio (OR) 0.32, 95% confidence interval (CI) 0.14 to 0.73). In women with a previous preterm birth there was a risk reduction in low birth weight (OR 0.48, 95% CI 0.27 to 0.84) and postpartum endometritis (OR 0.46, 95% CI 0.24 to 0.89). There was a risk reduction in preterm delivery (OR 0.48, 95% CI 0.28 to 0.81) in pregnant women with a previous preterm birth associated with bacterial vaginosis (BV) during the current pregnancy but there was no risk reduction in pregnant women with previous preterm birth without BV during pregnancy (OR 1.06, 95% CI 0.68 to 1.64). However, vaginal antibiotic prophylaxis during pregnancy did not prevent infectious pregnancy outcomes and there is a possibility of adverse effects such as neonatal sepsis (OR 8.07, 95% CI 1.36 to 47.77).

Reviewer's conclusions: Antibiotic prophylaxis given during the second or third trimester of pregnancy reduces the risk of prelabour rupture of the membranes when given routinely to pregnant women. Beneficial effects on birth weight and the risk of postpartum endometritis were seen for high risk women.