Antibiotic treatment of preterm labor with intact membranes: a multicenter, randomized, double-blinded, placebo-controlled trial. Antibiotic treatment in preterm labor and intact membranes: a randomized, double-blinded, placebo-controlled trial. A randomized trial of intrapartum versus immediate postpartum treatment of women with intra-amniotic infection. Randomized trial of antibiotics in addition to tocolytic therapy to treat preterm labor. Anaerobic coverage for intra-amnionic infection: maternal and perinatal impact. Administration of antibiotics to patients with rupture of membranes at term: a prospective, randomized, multicentric study. Collaborative Group on PROM. Randomized trial of prophylactic antibiotic therapy after preterm amnion rupture. Antibiotic therapy in preterm premature rupture of membranes: a randomized, prospective, double-blind trial. Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
Although an association between subclinical intrauterine infection and preterm birth is well established, there is conflicting evidence regarding the benefits of antibiotic administration to women in preterm labor with intact membranes. We attempted to determine the effect of ampicillin-amoxicillin and erythromycin treatment on prolongation of pregnancy, the rate of preterm birth, and neonatal morbidity in patients with preterm labor and intact membranes.
                A multicenter, randomized, double-blinded, placebo-controlled trial was designed and implemented by the Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development. Two hundred seventy-seven women with singleton pregnancies and preterm labor with intact membranes (24 to 34 weeks) were randomly allocated to receive either antibiotics or placebos.
                Of the 2373 patients screened for participation in this study in six medical centers, 277 women were enrolled (n = 133 for antibiotics group vs n = 144 for placebo group). In each study group, 60% of patients completed all the study medications. The overall prevalence of microbial invasion of the amniotic cavity was 5.8% (14/239). No significant difference between the antibiotic group and the placebo group was found in maternal outcomes, including duration of randomization-to-delivery interval, frequency of preterm delivery (< 37 weeks), frequency of preterm premature rupture of membranes, clinical chorioamnionitis, endometritis, and number of subsequent admissions for preterm labor. Similarly, no significant difference in neonatal outcomes could be detected between the two groups including respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage, sepsis, and admission and duration of newborn intensive special care unit hospitalization.
                The results of this study do not support the routine use of antibiotic administration to women in preterm labor with intact membranes. Although an association between microbial invasion of amniotic cavity and preterm birth has been extensively demonstrated, there is conflicting evidence regarding the benefits of antibiotic therapy in patients with preterm labor and intact membranes. We attempted to assess the efficacy of amoxicillin and erythromycin on pregnancy outcome in those patients. A randomized, double-blinded, placebo-controlled trial was designed and implemented. A total of 196 patients with singleton pregnancies and preterm labor with intact membranes (22-36 weeks) were randomly allocated to receive either antibiotics or placebo, plus adjunctive parenteral tocolysis, and 173 patients (antibiotics group n = 83 vs. placebo group n = 90) completed the treatment. The overall prevalence of microbial invasion of the amniotic cavity was 5.2% (9/173). No significant difference between both groups was found in maternal outcomes, including duration of randomization-to-delivery interval, frequency of preterm delivery, and frequency of clinical chorioamnionitis and endometritis. Rate of cesarean section was significantly higher in the placebo group (28% vs. 12%). Regarding neonatal outcome, no significant difference was detected between both groups in neonatal death, respiratory distress syndrome, proven sepsis, and birthweight. Suspected sepsis was significantly more frequent in the placebo group (6/90 vs. 0/78). The results of this trial indicate that amoxicillin and erythromycin do not prolong pregnancy in patients with preterm labor and intact membranes. A significant reduction in the rate of cesarean section was observed in patients receiving antibiotics. A significant reduction in the rate of neonatal suspected sepsis was also demonstrated. A randomized trial of intrapartum versus postpartum antibiotic treatment of women with intra-amniotic infection was conducted. Intra-amniotic infection was treated with ampicillin and gentamicin during labor (at the time of diagnosis) in 26 women and immediately after umbilical cord clamping in 19 women. Intrapartum treatment led to a lower incidence of neonatal sepsis (0 versus 21%; P = .03) and a shorter neonatal hospital stay (3.8 versus 5.7 days; P = .02) when compared with postpartum treatment. There were no significant differences in the microbiologic results, the gestational age, or the birth weight between the groups. Intrapartum-treated mothers had a shorter mean postpartum stay, a lower mean number of febrile days, and a lower mean peak postpartum temperature than did postpartum-treated mothers; these differences were all statistically significant (P = .05). The treatment of clinical intra-amniotic infection during labor results in improved outcome. The objective of this study was to assess whether antibiotic therapy plus tocolysis given to women in preterm labor would prolong pregnancy compared with tocolysis alone.
                A randomized, double-blind trial of intravenous mezlocillin and oral erythromycin therapy vs. placebo was used in addition to tocolysis among women in preterm labor < or =34 weeks gestation with intact membranes. Amniocentesis was performed, and chorioamnionic membranes were examined histologically and cultured for microorganisms after delivery.
                Clinical characteristics including gestational age at enrollment, frequency of contractions, cervical Bishop's score, and white blood cell count on admission were similar in the 2 groups. Antibiotic therapy was well tolerated. No significant differences in the interval to delivery, birth weight, and neonatal outcomes were observed between the 2 groups. Women in the antibiotic group had a significantly lower incidence of postpartum infections compared with women in the placebo group. Patients with evidence of upper genital tract infection in either group had a significantly shorter interval to delivery, lower gestational age at delivery, lower mean birth weight, and increased neonatal hospitalization time.
                Lack of an antibiotic effect on the gestational age at delivery may be due to the low prevalence of upper genital tract infection among unselected women in preterm labor, to advanced preterm labor unresponsive to antibiotic therapy, or to an inability of antibiotics given alone to inhibit the cytokine response. Further work is needed to identify markers of upper genital tract infection among women in preterm labor and to evaluate other potential therapeutic interventions. Although intrapartum antibiotics are beneficial to both the mother and newborn, there is no consensus as to the most efficacious antibiotic regimen in the treatment of intra-amnionic infection, especially with regard to anaerobic coverage. We randomized pregnant women with intra-amnionic infection to receive either dual agent therapy (ampicillin and gentamicin) or triple agent therapy (ampicillin, gentamicin, and clindamycin). The frequency of vaginal and cesarean delivery was similar in both groups. There was no significant difference in the incidence of endometritis between the two groups (10 of 69 versus 5 of 64; p = NS). There were no significant differences in either neonatal morbidity or mortality. The addition of clindamycin to provide anaerobic coverage for intra-amnionic infection does not significantly alter the incidence of endometritis in women delivered by cesarean section, although it may have an impact on women delivering vaginally. To assess whether antibiotic administration changes the rate of materno-fetal infectious morbidity in premature rupture of membranes occurring later than 35 weeks of gestation.
                A prospective, randomized and multicentric study in the Perinatology Units of eleven hospitals in Spain. Women were randomized to either antibiotic administration or control group. All were induced, if labor had not started spontaneously after 12 hours of ruptured membranes. Main outcome measures were maternal infection (chorioamnionitis and endometritis) and neonatal infectious morbidity (neonatal sepsis, meningitis and bronchopneumonia).
                Seven hundred and thirty-three patients were enrolled in the study, 371 in the antibiotics group and 362 in the control group. The incidence of chorioamnionitis and puerperal endometritis were reduced but the differences are statistically nonsignificant. However, the incidence of neonatal sepsis was significantly lower in newborns to mothers who had received antibiotics, 1 vs. 7 cases (Fisher's exact test, p<0.007).
                The study strongly suggests that prophylactic use of antibiotics in premature rupture of membranes occurring at 36 or more weeks of gestation reduces the risk of neonatal sepsis and probably maternal endometritis. Our purpose was to determine whether maternal administration of prophylactic ampicillin or erythromycin after preterm amnion rupture is associated with maternal or neonatal benefits.
                Women with singleton pregnancies between 24 and 33 weeks 6 days of gestation were eligible if they had no immediate indication for delivery. After giving informed consent, patients were randomized either to receive ampicillin (erythromycin if penicillin allergic) until delivery or to enter a control group. Women whose cervical cultures were positive for either group B streptococci or Neisseria gonorrhoeae received treatment. Tocolytics and corticosteroids were not used.
                From January 1990 to February 1992 117 patients (antibiotics 59, control 58) were recruited and analyzed. Prophylactic antibiotics were associated with a longer latent phase (mean 12 vs 7.0 days, p = 0.004) and fewer maternal infectious complications (29% vs 60%, p = 0.001). A higher incidence of neonatal necrotizing enterocolitis was observed in the treatment group (14% vs 3.5%, p = 0.05). Other neonatal complications, including death, were lower in the treatment group, but none attained statistical significance (p = 0.09 to 0.33).
                The use of prophylactic antibiotics in selected patients after preterm amnion rupture appears to have a demonstrable maternal benefit. Large, multicenter trials may demonstrate a significant neonatal benefit or confirm any adverse outcomes. The use of antibiotics in the management of preterm, premature rupture of membranes remains controversial. By use of a prospective randomized double-blind design we investigated the maternal-fetal benefits associated with antibiotic therapy in 85 women with premature rupture of membranes at 34 weeks' estimated gestational age. In the treatment group 40 patients received intravenous mezlocillin for 48 hours followed by oral ampicillin until delivery. In the control group 45 patients received intravenous and oral placebo. Patients who received antibiotics had chorioamnionitis and endometritis less frequently than the control group (p less than 0.01 and p less than 0.05). Pathologic examination of the placentas showed a lower incidence of chorioamnionitis in the treatment group (p less than 0.05). The period from premature rupture of membranes to delivery (latency) was prolonged with antibiotics (p less than 0.05) and resulted in significant weight gain in the infants in the antibiotic group (p less than 0.0001). These infants also had higher 1- and 5-minute Apgar scores. Clinically suspected sepsis, respiratory distress syndrome, intraventricular hemorrhage, perinatal death rate, and prolonged hospitalization (greater than 30 days) were also increased in the control group. Intrauterine infection is thought to be one cause of preterm premature rupture of the membranes (PPROM). Antibiotic therapy has been shown to prolong pregnancy, but the effect on infant morbidity has been inconsistent.
                To determine if antibiotic treatment during expectant management of PPROM will reduce infant morbidity.
                Randomized, double-blind, placebo-controlled trial.
                University hospitals of the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
                A total of 614 of 804 eligible gravidas with PPROM between 24 weeks' and 0 days' and 32 weeks' and 0 days' gestation who were considered candidates for pregnancy prolongation and had not received corticosteroids for fetal maturation or antibiotic treatment within 1 week of randomization.
                Intravenous ampicillin (2-g dose every 6 hours) and erythromycin (250-mg dose every 6 hours) for 48 hours followed by oral amoxicillin (250-mg dose every 8 hours) and erythromycin base (333-mg dose every 8 hours) for 5 days vs a matching placebo regimen. Group B streptococcus (GBS) carriers were identified and treated. Tocolysis and corticosteroids were prohibited after randomization.
                The composite primary outcome included pregnancies complicated by at least one of the following: fetal or infant death, respiratory distress, severe intraventricular hemorrhage, stage 2 or 3 necrotizing enterocolitis, or sepsis within 72 hours of birth. These perinatal morbidities were also evaluated individually and pregnancy prolongation was assessed.
                In the total study population, the primary outcome (44.1 % vs 52.9%; P=.04), respiratory distress (40.5% vs 48.7%; P=.04), and necrotizing enterocolitis (2.3% vs 5.8%; P=.03) were less frequent with antibiotics. In the GBS-negative cohort, the antibiotic group had less frequent primary outcome (44.5% vs 54.5%; P=.03), respiratory distress (40.8% vs 50.6%; P=.03), overall sepsis (8.4% vs 15.6%; P=.01), pneumonia (2.9% vs 7.0%; P=.04), and other morbidities. Among GBS-negative women, significant pregnancy prolongation was seen with antibiotics (P<.001).
                We recommend that women with expectantly managed PPROM remote from term receive antibiotics to reduce infant morbidity.
The conclusions that can be drawn from this meta-analysis are limited due to the small number of studies. For none of the outcomes was a statistically significant difference seen between the different interventions. Current consensus is for the intrapartum administration of antibiotics when the diagnosis of intraamniotic infection is made; however, the results of this review neither support nor refute this although there was a trend towards improved neonatal outcomes when antibiotics were administered intrapartum. No recommendations can be made on the most appropriate antimicrobial regimen to choose to treat intraamniotic infection.
[Note: The six citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]