Sometimes the protective bag of fluid around an unborn baby (the membranes) break when the baby is due without the onset of labour (regular uterine contractions). This is called PROM or prelabour rupture of the membranes. When this happens there is a risk of infection entering the womb (uterus) and affecting the mother and her baby. Newborn infections are rare but have the potential to cause serious harm requiring neonatal intensive care. Giving a pregnant woman antibiotics when she has PROM may reduce the risk of infections for the woman and her baby. Most women spontaneously start labour within 24 hours, so delaying induction of labour and waiting for spontaneous onset of labour (expectant management) may be a possibility. Another treatment for term PROM is to induce labour with oxytocin or prostaglandins. Women are often given antibiotics to prevent infection, but there are concerns about possible side-effects of antibiotics, and that overuse of antibiotics can cause resistance to antibiotics so that they become less effective.
Our review questions
Do antibiotics given to women with PROM when they are at or near term (more than 36 weeks' gestation) but not in labour reduce the risk of infection for the baby and the mother? Are there adverse effects from the antibiotics?
What the studies showed
This review included four randomised controlled studies involving 2639 pregnant women at 36 weeks' gestation or more. The evidence showed that routine antibiotics for term PROM did not reduce the risk of infection for pregnant women or their babies when compared to the control group which received a placebo or no antibiotics. There was not enough strong evidence about other outcomes including death, allergic reactions for the woman or complications for the baby, which rarely occurred in the included studies. The quality of the evidence using GRADE was judged to be low to very low.
The conclusions from this review are limited by the low number of women who developed an infection across the studies overall. There is not enough information in this review to assess the possible side-effects from the use of antibiotics for women or their infants, particularly for any possible long-term harms. Because we do not know enough about side-effects and because we did not find strong evidence of benefit from antibiotics, they should not be routinely used for pregnant women with ruptured membranes prior to labour at term, unless a woman shows signs of infection.