A randomised controlled trial of metronidazole for the prevention of preterm birth in women positive for cervicovaginal fetal fibronectin: the PREMET Study. A randomized trial of management of pre-labor rupture of membranes at term in multiparous women using vaginal prostaglandin gel. Induction of labor compared with expectant management for prelabor rupture of the membranes at term. TERMPROM Study Group. Controlled comparison of induction versus expectant care for prelabor rupture of the membranes at term.
To determine whether metronidazole reduces early preterm labour in asymptomatic women with positive vaginal fetal fibronectin (fFN) in the second trimester of pregnancy.
                Randomised placebo-controlled trial.
                Fourteen UK hospitals (three teaching).
                Pregnancies with at least one previous risk factor, including mid-trimester loss or preterm delivery, uterine abnormality, cervical surgery or cerclage.
                Nine hundred pregnancies were screened for fFN at 24 and 27 weeks of gestation. Positive cases were randomised to a week's course of oral metronidazole or placebo.
                Primary outcome was delivery before 30 weeks of gestation. Secondary outcomes included delivery before 37 weeks.
                The Trial Steering Committee (TSC) recommended the study be stopped early; 21% of women receiving metronidazole (11/53) delivered before 30 weeks compared with 11% (5/46) taking placebo [risk ratio 1.9, 95% confidence interval (CI) 0.72-5.09, P = 0.18]. There were significantly more preterm deliveries (before 37 weeks) in women treated with metronidazole 33/53 (62%) versus placebo 18/46 (39%), risk ratio 1.6, 95% CI 1.05-2.4. fFN was a good predictor of early preterm birth in these asymptomatic women; positive and negative predictive values (24 weeks of gestation) for delivery by 30 weeks were 26% and 99%, respectively (positive and negative likelihood ratios 15, 0.35).
                Metronidazole does not reduce early preterm birth in high risk pregnant women selected by history and a positive vaginal fFN test. Preterm delivery may be increased by metronidazole therapy. To compare conservative management of pre-labor spontaneous rupture of membranes (SROM) with the use of prostaglandin (PG) E2 in healthy parous women at term (gestational age at least 37 weeks).
                An open randomized study was conducted with 100 parous women; 50 were treated conservatively for 24 hours, and 50 were managed actively using PGE2 gel (1 mg), administered at admission and repeated 6 hours later if labor was not established. Both groups received intravenous oxytocin if labor did not start within 24 hours after admission.
                The use of PGE2 gel led to a significant reduction in the mean interval (+/- standard error of the mean) from SROM to onset of labor: 17.26 +/- 1.51 hours in the conservative group versus 6.50 +/- 1.23 in the PGE2 group. A significantly smaller proportion of subjects required oxytocin in the PGE2 group (12 versus 38%, P < .02). The two groups were comparable with respect to analgesic requirements. Within 24 hours of SROM, 80% of the women in the PG group and 56% in the conservative group had delivered (P < .02). Most women delivered vaginally, 96% of those managed conservatively and 100% of those managed actively with PGE2.
                Active management using PGE2 gel in parous women with pre-labor SROM significantly improves the time to delivery without influencing the cesarean rate or fetal-maternal infective morbidity. As the interval between rupture of the fetal membranes at term and delivery increases, so may the risk of fetal and maternal infection. It is not known whether inducing labor will reduce this risk or whether one method of induction is better then another.
                We studied 5041 women with prelabor rupture of the membranes at term. The women were randomly assigned to induction of labor with intravenous oxytocin; induction of labor with vaginal prostaglandin E2 gel; or expectant management for up to four days, with labor induced with either intravenous oxytocin or vaginal prostaglandin E2 gel if complications developed. The primary outcome was neonatal infection. Secondary outcomes were the need for cesarean section and women's evaluations of their treatment.
                The rates of neonatal infection and cesarean section were not significantly different among the study groups. The rates of neonatal infection were 2.0 percent for the induction-with-oxytocin group, 3.0 percent for the induction-with-prostaglandin group, 2.8 percent for the expectant-management (oxytocin) group, and 2.7 percent for the expectant-management (prostaglandin) group. The rates of cesarean section ranged from 9.6 to 10.9 percent. Clinical chorioamnionitis was less likely to develop in the women in the induction-with-oxytocin group than in those in the expectant-management (oxytocin) group (4.0 percent vs. 8.6 percent, P<0.001), as was postpartum fever (1.9 percent vs. 3.6 percent, P=0.008). Women in the induction groups were less likely to say they liked "nothing" about their treatment than those in the expectant-management groups.
                In women with prelabor rupture of the membranes at term, induction of labor with oxytocin or prostaglandin E2 and expectant management result in similar rates of neonatal infection and cesarean section. Induction of labor with intravenous oxytocin results in a lower risk of maternal infection than does expectant management. Women view induction of labor more positively than expectant management. This randomized clinical trial compared oxytocin induction of labor with expectant care for 48 hours after prelabor rupture of the membranes at term. Women at term with prelabor rupture of the membranes for at least 8 hours were assigned at random to induction with oxytocin or to expectant management for 48 hours followed by induction if necessary. Of 168 eligible women, 123 (73%) agreed to participate. More women in the induction group (23%) than in the expectant group (10%) had operative delivery, either cesarean section or instrumental vaginal delivery. In the induction group 41% received analgesia versus 24% in the expectant group (p < 0.005). There was no difference in the rate of maternal and neonatal infection between groups and sepsis was not observed. The active policy of oxytocin induction exposed the mother to a higher risk of operative delivery and a less comfortable labor than the 48 hours expectant care option.
Although FFN is commonly used in labor and delivery units to help in the management of women with symptoms of preterm labor, currently there is not sufficient evidence to recommend its use. Since this review found an association between knowledge of FFN results and a lower incidence of preterm birth before 37 weeks, further research should be encouraged.