Antibiotics in the management of PROM and preterm labor

A significant fraction of preterm birth results from subclinical intrauterine infection. It is presumed that ascending bacterial colonization of the decidua results and either uterine contractions or membrane weakening that results in the clinical presentation of preterm labor or PROM. Those with overt infection require delivery. However, it is plausible that adjunctive antibiotic treatment during therapy for preterm labor and PROM remote from term could result in pregnancy prolongation and reductions in gestational age-dependent and infectious newborn morbidities. Data support adjunctive antibiotic treatment during conservative management of PROM remote from term. Such treatment should include broad-spectrum agents, typically intravenous therapy initially, and continue for up to 7 days if undelivered. Such treatment should be reserved for women presenting remote from term where significant improvement in neonatal outcomes can be anticipated with conservative management. Alternatively, current evidence suggests that antibiotic treatment in the setting of preterm labor with intact membranes does not consistently prolong pregnancy or improve newborn outcomes. Given this, and the concerning findings from the ORACLE II trial of antibiotics for preterm labor, this treatment should not be offered in the setting of preterm labor with intact membranes. Although one could speculate that women with preterm labor and with either a short cervical length for a positive fetal fibronectin screen might benefit from antibiotic therapy, no well-designed, randomized, controlled trials addressing this issue have been completed. Therefore, antibiotic therapy for women in preterm labor should be reserved for usual clinical indications, including suspected bacterial infections, GBS prophylaxis, and chorioamnionitis.