Ampicillin and metronidazole treatment in preterm labour: a multicentre, randomised controlled trial

Abstract

Objective: To ascertain whether adjuvant ampicillin and metronidazole given to women in preterm labour with intact membranes would prolong pregnancy and decrease the perinatal mortality and morbidity.

Design: A multicentre, prospective, randomised controlled trial.

Setting: Three perinatal centres serving an indigent population.

Subjects: Eighty-one women in active preterm labour with otherwise uncomplicated singleton pregnancies between 26 and 34 weeks gestation or an ultrasound fetal weight estimate of 800 g to 1500 g.

Interventions: The study group received ampicillin and metronidazole for five days. The control group received no antibiotics. In all women contractions were suppressed with hexoprenaline and indomethacin for 24 h, and betamethasone was given for fetal lung maturity.

Main outcome measures: Days gained and perinatal mortality and morbidity.

Results: The study (n = 43) and control groups (n = 38) were comparable at entry. In those receiving ampicillin and metronidazole the pregnancy was significantly prolonged (median 15 days versus 2.5 days, P = 0.04) with significantly more women still pregnant after seven days (63% versus 37%, P = 0.03, OR 0.34 95% CI 0.13-0.94). Significantly more infants in the control group developed necrotising enterocolitis than in the study group (5 versus 0, P = 0.02).

Conclusion: Adjuvant ampicillin and metronidazole in the management of women in preterm labour with intact membranes significantly prolonged the pregnancy and decreased neonatal morbidity.