Double-blind; placebo-controlled trial of piperacillin prophylaxis in preterm membrane rupture

Efficacy of prophylactic antibiotics for preterm premature rupture of membranes: a systematic review and network meta-analysis

OBJECTIVE

Various prophylactic antibiotic regimens are used in the management of preterm premature rupture of membranes. We investigated the efficacy and safety of these regimens in terms of maternal and neonatal outcomes.

DATA SOURCES

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to July 20, 2021.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials involving pregnant women with preterm premature rupture of membranes before 37 weeks of gestation and a comparison of ≥2 of the following 10 antibiotic regimens: control/placebo, erythromycin, clindamycin, clindamycin plus gentamicin, penicillins, cephalosporins, co-amoxiclav, co-amoxiclav plus erythromycin, aminopenicillins plus macrolides, and cephalosporins plus macrolides.

METHODS

Two investigators independently extracted published data and assessed the risk of bias with a standard procedure following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Network meta-analysis was conducted using the random-effects model.

RESULTS

A total of 23 studies that recruited a total of 7671 pregnant women were included. Only penicillins (odds ratio, 0.46; 95% confidence interval, 0.27-0.77) had significantly superior effectiveness for maternal chorioamnionitis. Clindamycin plus gentamicin reduced the risk of clinical chorioamnionitis, with borderline significance (odds ratio, 0.16; 95% confidence interval, 0.03-1.00). By contrast, clindamycin alone increased the risk of maternal infection. For cesarean delivery, no significant differences were noted among these regimens.

CONCLUSION

Penicillins remain the recommended antibiotic regimen for reducing maternal clinical chorioamnionitis. The alternative regimen includes clindamycin plus gentamicin. Clindamycin should not be used alone.

Antibiotic prophylaxis in pregnant with premature rupture of ovular membranes: systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of randomized clinical trials that compared the use of antibiotics versus placebo in premature rupture of membranes preterm and evaluated maternal, fetal and neonatal outcomes in pregnant women with premature rupture of ovular membranes at a gestational age between 24 and 37 weeks.

METHODS

A search was conducted using keywords in PubMed, Cochrane, Biblioteca Virtual em Saúde and Biblioteca Digital de Teses e Dissertações da USP between August 2018 and December 2021. A total of 926 articles were found. Those included were randomized clinical trials that compared the use of antibiotics versus placebo in the premature rupture of preterm membranes. Articles referring to antibiotics only for streptococcus agalactiae prophylaxis were excluded. The retrieved articles were independently and blindly analyzed by two reviewers. A total of 24 manuscripts met the inclusion criteria and 21 articles were included for quantitative analysis.

RESULTS

Among the maternal outcomes analyzed, there was a prolongation of the latency period that was ≥7 days. In addition, we observed a reduction in chorioamnionitis in the group of pregnant women who used antibiotics. As for endometritis and other maternal outcomes, there was no statistically significant difference between the groups. Regarding fetal outcomes, antibiotic prophylaxis worked as a protective factor for neonatal sepsis. Necrotizing enterocolitis and respiratory distress syndrome showed no statistically significant differences.

CONCLUSION

The study showed positive results in relation to antibiotic prophylaxis to prolong the latency period, new randomized clinical trials are needed to ensure its beneficial effect.

PROSPERO DATABASE REGISTRATION

(www.crd.york.ac.uk/prospero) under number CRD42020155315.

Developing a Core Outcome Set for the Evaluation of Antibiotic Use in Prelabor Rupture of Membranes: A Systematic Review and Semi-Structured Interview

Background: Prelabor rupture of membranes (PROM) is associated with maternal and neonatal infections. Although guidelines suggest prophylactic antibiotics for pregnant women with PROM, the optimal antibiotic regimen remains controversial. Synthesizing the data from different studies is challenging due to variations in reported outcomes. Objective: This study aimed to form the initial list of outcomes for the core outcome set (COS) that evaluates antibiotic use in PROM by identifying all existing outcomes and patients' views. Methods: Relevant studies were identified by searching PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang, and VIP databases. We also screened the references of the included studies as a supplementary search. We extracted basic information from the articles and the outcomes. Two reviewers independently selected the studies, extracted the data, extracted the outcomes, and grouped them into domains. Then, semi-structured interviews based on the potential factors collected by the systematic review were conducted at West China Second Hospital of Sichuan University. Pregnant women who met the diagnostic criteria for PROM were enrolled. Participants reported their concerns about the outcomes. Two researchers identified the pregnant women's concerns. Results: A total of 90 studies were enrolled in this systematic review. The median outcomes in the included studies was 7 (1-31), and 109 different unique outcomes were identified. Pre-term PROM (PPROM) had 97 outcomes, and term PROM (TPROM) had 70 outcomes. The classification and order of the core outcome domains of PPROM and TPROM were consistent. The physiological domain was the most common for PPROM and TPROM outcomes. Furthermore, 35.1 and 57.1% outcomes were only reported once in PPROM and TPROM studies, respectively. Thirty pregnant women participated in the semi-structured interviews; 10 outcomes were extracted after normalized, and the outcomes were reported in the systematic review. However, studies rarely reported pregnant women's concerns. Conclusion: There was considerable inconsistency in outcomes selection and reporting in studies about antibiotics in PROM. An initial core outcomes set for antibiotics in PROM was formed.

Pregnancy latency after preterm premature rupture of membranes: oral versus intravenous antibiotics

BACKGROUND

Following the destruction of pharmaceutical production facilities in Puerto Rico by Hurricane Maria in September 2017, a shortage of small-volume bags of sterile intravenous fluid for infusion led to a decreased ability to administer intravenous azithromycin and ampicillin efficiently for use in the treatment of patients with preterm premature rupture of membranes.

OBJECTIVE

This study aimed to assess pregnancy latency after preterm premature rupture of membranes following treatment with oral-only antibiotics compared with treatment with intravenous antibiotics followed by oral antibiotics.

STUDY DESIGN

This is a retrospective historic control study comparing women with preterm premature rupture of membranes who were initiated on a 7-day oral-only regimen of azithromycin and amoxicillin (modified regimen) during a 12-month period beginning December 2017 (during which time there was a shortage of small-volume bags of intravenous fluid) to women with preterm premature rupture of membranes who were initiated on a 2-day regimen of intravenous ampicillin and azithromycin followed by 5 days of oral amoxicillin and azithromycin (standard regimen) from December 2016 to December 2018. Women were included in the study if they were diagnosed with preterm premature rupture of membranes at <34 weeks' gestation and were started on latency antibiotics, and women were excluded from the study if they had a contraindication to expectant management, a cerclage, or suspected fetal anomalies. The primary outcome was pregnancy latency, defined as time from the first dose of antibiotics to delivery.

RESULTS

The 37 women who received the modified regimen and the 79 women who received the standard regimen had similar baseline characteristics. Mean (standard deviation) gestational age at time of preterm premature rupture of membranes was similar between the modified (30.5 weeks' gestation [±3.1]) and standard regimen groups (30.2 weeks' gestation [±3.2]), and the rate of group B streptococcus rectovaginal colonization was similar for both groups (27% vs 24%; P=.95). Pregnancy latency did not differ in the modified vs standard regimen (mean difference, -0.15 days; 95% confidence interval, -4.87 to 4.58) There was no statistically significant difference in the relative risk of composite maternal infection (relative risk, 0.43; 95% confidence interval, 0.05-3.53) or composite neonatal infection (relative risk, 0.43; 95% confidence interval, 0.05-3.52).

CONCLUSION

Although limited by small sample size, our study suggested that adoption of an oral-only antibiotic regimen for pregnancy latency following preterm premature rupture of membranes is worthy of further study.

Antibiotics for Prophylaxis in the Setting of Preterm Prelabor Rupture of Membranes

"For many years, providers have been using antibiotics to prevent infection in women who present with preterm prelabor rupture of membranes (PPROM). Given the polymicrobial nature of intra-amniotic infection, the recommended regimen includes a 7-day course of ampicillin and erythromycin, although many substitute of azithromycin. This regimen is used from viability to 34 weeks, independent of the number of fetuses present. Meta-analyses have shown that antibiotics for this indication are associated with lower rates of maternal and fetal infection, as well as longer pregnancy latency. Thus, latency antibiotics are recommended for all women with PPROM through 34 weeks of gestation."

Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes

BACKGROUND

Preterm prelabor rupture of the membranes (PPROM) is frequently complicated by intraamniotic inflammatory processes such as intraamniotic infection and sterile intraamniotic inflammation. Antibiotic therapy is recommended to patients with PPROM to prolong the interval between this complication and delivery (latency period), reduce the risk of clinical chorioamnionitis, and improve neonatal outcome. However, there is a lack of information regarding whether the administration of antibiotics can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with PPROM.

OBJECTIVE

The first aim of the study was to determine whether antimicrobial agents can reduce the magnitude of the intraamniotic inflammatory response in patients with PPROM by assessing the concentrations of interleukin-6 in amniotic fluid before and after antibiotic treatment. The second aim was to determine whether treatment with intravenous clarithromycin changes the microbial load of Ureaplasma spp DNA in amniotic fluid.

STUDY DESIGN

A retrospective cohort study included patients who had (1) a singleton gestation, (2) PPROM between 24+0 and 33+6 weeks, (3) a transabdominal amniocentesis at the time of admission, and (4) intravenous antibiotic treatment (clarithromycin for patients with intraamniotic inflammation and benzylpenicillin/clindamycin in the cases of allergy in patients without intraamniotic inflammation) for 7 days. Follow-up amniocenteses (7th day after admission) were performed in the subset of patients with a latency period lasting longer than 7 days. Concentrations of interleukin-6 were measured in the samples of amniotic fluid with a bedside test, and the presence of microbial invasion of the amniotic cavity was assessed with culture and molecular microbiological methods. Intraamniotic inflammation was defined as a bedside interleukin-6 concentration ≥745 pg/mL in the samples of amniotic fluid. Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity.

RESULTS

A total of 270 patients with PPROM were included in this study: 207 patients delivered within 7 days and 63 patients delivered after 7 days of admission. Of the 63 patients who delivered after 7 days following the initial amniocentesis, 40 underwent a follow-up amniocentesis. Patients with intraamniotic infection (n = 7) and sterile intraamniotic inflammation (n = 7) were treated with intravenous clarithromycin. Patients without either microbial invasion of the amniotic cavity or intraamniotic inflammation (n = 26) were treated with benzylpenicillin or clindamycin. Treatment with clarithromycin decreased the interleukin-6 concentration in amniotic fluid at the follow-up amniocentesis compared to the initial amniocentesis in patients with intraamniotic infection (follow-up: median, 295 pg/mL, interquartile range [IQR], 72-673 vs initial: median, 2973 pg/mL, IQR, 1750-6296; P = .02) and in those with sterile intraamniotic inflammation (follow-up: median, 221 pg/mL, IQR 118-366 pg/mL vs initial: median, 1446 pg/mL, IQR, 1300-2941; P = .02). Samples of amniotic fluid with Ureaplasma spp DNA had a lower microbial load at the time of follow-up amniocentesis compared to the initial amniocentesis (follow-up: median, 1.8 × 104 copies DNA/mL, 2.9 × 104 to 6.7 × 108 vs initial: median, 4.7 × 107 copies DNA/mL, interquartile range, 2.9 × 103 to 3.6 × 107; P = .03).

CONCLUSION

Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation. Moreover, treatment with clarithromycin was related to a reduction in the load of Ureaplasma spp DNA in the amniotic fluid of patients with PPROM <34 weeks of gestation.

Effect on perinatal outcome of prophylactic antibiotics in preterm prelabor rupture of membranes: network meta-analysis of randomized controlled trials

OBJECTIVES

Prophylactic antibiotics are recommended routinely for preterm prelabor rupture of membranes (PPROM), but there is an abundance of potential treatments and a paucity of comparative information. The aims of this network meta-analysis were to compare the efficiency of different antibiotic regimens on perinatal outcomes and to assess the quality of the current evidence.

METHODS

This was a network meta-analysis of randomized controlled trials comparing prophylactic antibiotics, or regimens of antibiotics, with each other or with placebo/no treatment, in women with PPROM. MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, US Registry of Clinical Trials ( www.ClinicalTrials.gov) and gray literature sources were searched. The primary outcomes were neonatal mortality and chorioamnionitis; secondary outcomes included other measures of perinatal morbidity. Relative effect sizes were estimated using risk ratios (RR) and the relative ranking of the interventions was obtained using cumulative ranking curves. The quality of evidence for the primary outcomes was assessed according to GRADE guidelines, adapted for network meta-analysis.

RESULTS

The analysis included 20 studies (7169 participants randomized to 15 therapeutic regimens). For the outcome of chorioamnionitis, clindamycin + gentamycin (network RR, 0.19 (95% CI, 0.05-0.83)), penicillin (RR, 0.31 (95% CI, 0.16-0.6)), ampicillin/sulbactam + amoxicillin/clavulanic acid (RR, 0.32 (95% CI, 0.12-0.92)), ampicillin (RR, 0.52 (95% CI, 0.34-0.81)) and erythromycin + ampicillin + amoxicillin (RR, 0.71 (95% CI, 0.55-0.92)) were superior to placebo/no treatment. Erythromycin was the only effective drug for neonatal sepsis (RR, 0.74 (95% CI, 0.56-0.97)). Clindamycin + gentamycin (RR, 0.32 (95% CI, 0.11-0.89)) and erythromycin + ampicillin + amoxicillin (RR, 0.83 (95% CI, 0.69-0.99)) were the only effective regimens for respiratory distress syndrome, whereas ampicillin (RR, 0.42 (95% CI, 0.20-0.92)) and penicillin (RR, 0.49 (95% CI, 0.25-0.96)) were effective in reducing the rates of Grade-3/4 intraventricular hemorrhage. None of the antibiotics appeared significantly more effective than placebo/no treatment in reducing the rates of neonatal death, perinatal death and necrotizing enterocolitis. No network RR could be estimated for neonatal intensive care unit admission. The overall quality of the evidence, according to GRADE guidelines, was moderate to very low, depending on the outcome and comparison.

CONCLUSIONS

Several antibiotics appear to be more effective than placebo/no treatment in reducing the rate of chorioamnionitis after PPROM. However, none of them is clearly and consistently superior compared to other antibiotics, and most are not superior to placebo/no treatment for other outcomes. The overall quality of the evidence is low and needs to be updated, as microbial resistance may have emerged for some antibiotics, while others are underrepresented in the existing evidence. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

[Antibiotic prophylaxis in preterm premature rupture of membranes: CNGOF preterm premature rupture of membranes guidelines]

OBJECTIVE

To analyse benefits and risks of antibiotic prophylaxis in the management of preterm premature rupture of membranes.

METHODS

PubMed and Cochrane Central databases search.

RESULTS

Streptoccoccus agalactiae (group B streptococcus) and Escherichia coli are the two main bacteria identified in early neonatal sepsis (EL3). Antibiotic prophylaxis at admission is associated with significant prolongation of pregnancy (EL2), reduction in neonatal morbidity (EL1) without impact on neonatal mortality (EL2). Co-amoxiclav could be associated with an increased risk for neonatal necrotising enterocolitis (EL2). Antibiotic prophylaxis at admission in women with preterm premature rupture of the membranes is recommended (Grade A). Monotherapy with amoxicillin, third generation cephalosporin and erythromycin can be used as well as combination of erythromycin and amoxicillin (Professional consensus) for 7 days (GradeC). Shorter treatment is possible when initial vaginal culture is negative (Professional consensus). Co-amxiclav, aminoglycosides, glycopeptides, first and second generation cephalosporin, clindamycin and metronidazole are not recommended (Professional consensus).

CONCLUSIONS

Antibiotic prophylaxis against Streptoccoccus agalactiae (group B streptococcus) and E. coli is recommended in women with preterm premature of the membranes (Grade A). Monotherapy with amoxicillin, third generation cephalosporin or erythromycin, as well as combination of erythromycin and amoxicillin are recommended (Professional consensus).

A new antibiotic regimen treats and prevents intra-amniotic inflammation/infection in patients with preterm PROM

OBJECTIVES

To determine whether a new antibiotic regimen could reduce the frequency of intra-amniotic inflammation/infection in patients with preterm PROM.

STUDY DESIGN

This retrospective cohort study was conducted to evaluate the effect of antibiotics on the frequency of intra-amniotic inflammation/infection based on the results of follow-up transabdominal amniocenteses from 89 patients diagnosed with preterm PROM who underwent serial amniocenteses. From 1993-2003, ampicillin and/or cephalosporins or a combination was used ("regimen 1"). A new regimen (ceftriaxone, clarithromycin and metronidazole) was used from 2003-2012 ("regimen 2"). Amniotic fluid was cultured and matrix metalloproteinase-8 (MMP-8) concentrations were measured.

RESULTS

(1) The rates of intra-amniotic inflammation and intra-amniotic inflammation/infection in patients who received regimen 2 decreased during treatment from 68.8% to 52.1% and from 75% to 54.2%, respectively. In contrast, in patients who received regimen 1, the frequency of intra-amniotic inflammation and infection/inflammation increased during treatment (31.7% to 55% and 34.1% to 58.5%, respectively); and (2) intra-amniotic inflammation/infection was eradicated in 33.3% of patients who received regimen 2, but in none who received regimen 1.

CONCLUSION

The administration of ceftriaxone, clarithromycin and metronidazole was associated with a more successful eradication of intra-amniotic inflammation/infection and prevented secondary intra-amniotic inflammation/infection more frequently than an antibiotic regimen which included ampicillin and/or cephalosporins in patients with preterm PROM.

A new anti-microbial combination prolongs the latency period, reduces acute histologic chorioamnionitis as well as funisitis, and improves neonatal outcomes in preterm PROM

OBJECTIVE

Antibiotic administration is a standard practice in preterm premature rupture of membranes (PROM). Specific anti-microbial agents often include ampicillin and/or erythromycin. Anaerobes and genital mycoplasmas are frequently involved in preterm PROM, but are not adequately covered by antibiotics routinely used in clinical practice. Our objective was to compare outcomes of PROM treated with standard antibiotic administration versus a new combination more effective against these bacteria.

STUDY DESIGN

A retrospective study compared perinatal outcomes in 314 patients with PROM <34 weeks receiving anti-microbial regimen 1 (ampicillin and/or cephalosporins; n = 195, 1993-2003) versus regimen 2 (ceftriaxone, clarithromycin and metronidazole; n = 119, 2003-2012). Intra-amniotic infection/inflammation was assessed by positive amniotic fluid culture and/or an elevated amniotic fluid MMP-8 concentration (>23 ng/mL).

RESULTS

(1) Patients treated with regimen 2 had a longer median antibiotic-to-delivery interval than those with regimen 1 [median (interquartile range) 23 d (10-51 d) versus 12 d (5-52 d), p < 0.01]; (2) patients who received regimen 2 had lower rates of acute histologic chorioamnionitis (50.5% versus 66.7%, p < 0.05) and funisitis (13.9% versus 42.9%, p < 0.001) than those who had received regimen 1; (3) the rates of intra-ventricular hemorrhage (IVH) and cerebral palsy (CP) were significantly lower in patients allocated to regimen 2 than regimen 1 (IVH: 2.1% versus 19.0%, p < 0.001 and CP: 0% versus 5.7%, p < 0.05); and (4) subgroup analysis showed that regimen 2 improved perinatal outcomes in pregnancies with intra-amniotic infection/inflammation, but not in those without intra-amniotic infection/inflammation (after adjusting for gestational age and antenatal corticosteroid administration).

CONCLUSION

A new antibiotic combination consisting of ceftriaxone, clarithromycin, and metronidazole prolonged the latency period, reduced acute histologic chorioamnionitis/funisitis, and improved neonatal outcomes in patients with preterm PROM. These findings suggest that the combination of anti-microbial agents (ceftriaxone, clarithromycin, and metronidazole) may improve perinatal outcome in preterm PROM.

Antibiotics for preterm rupture of membranes

BACKGROUND

Premature birth carries substantial neonatal morbidity and mortality. Subclinical infection is associated with preterm rupture of membranes (PROM). Prophylactic maternal antibiotic therapy might lessen infectious morbidity and delay labour, but could suppress labour without treating underlying infection.

OBJECTIVES

To evaluate the immediate and long-term effects of administering antibiotics to women with PROM before 37 weeks, on maternal infectious morbidity, neonatal morbidity and mortality, and longer-term childhood development.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2013).

SELECTION CRITERIA

Randomised controlled trials comparing antibiotic administration with placebo that reported clinically relevant outcomes were included as were trials of different antibiotics. Trials in which no placebo was used were included for the outcome of perinatal death alone.

DATA COLLECTION AND ANALYSIS

We extracted data from each report without blinding of either the results or the treatments that women received. We sought unpublished data from a number of authors.

MAIN RESULTS

We included 22 trials, involving 6872 women and babies.The use of antibiotics following PROM is associated with statistically significant reductions in chorioamnionitis (average risk ratio (RR) 0.66, 95% confidence interval (CI) 0.46 to 0.96, and a reduction in the numbers of babies born within 48 hours (average RR 0.71, 95% CI 0.58 to 0.87) and seven days of randomisation (average RR 0.79, 95% CI 0.71 to 0.89). The following markers of neonatal morbidity were reduced: neonatal infection (RR 0.67, 95% CI 0.52 to 0.85), use of surfactant (RR 0.83, 95% CI 0.72 to 0.96), oxygen therapy (RR 0.88, 95% CI 0.81 to 0.96), and abnormal cerebral ultrasound scan prior to discharge from hospital (RR 0.81, 95% CI 0.68 to 0.98). Co-amoxiclav was associated with an increased risk of neonatal necrotising enterocolitis (RR 4.72, 95% CI 1.57 to 14.23).One study evaluated the children's health at seven years of age (ORACLE Children Study) and found antibiotics seemed to have little effect on the health of children.

AUTHORS' CONCLUSIONS

Routine prescription of antibiotics for women with preterm rupture of the membranes is associated with prolongation of pregnancy and improvements in a number of short-term neonatal morbidities, but no significant reduction in perinatal mortality. Despite lack of evidence of longer-term benefit in childhood, the advantages on short-term morbidities are such that we would recommend antibiotics are routinely prescribed. The antibiotic of choice is not clear but co-amoxiclav should be avoided in women due to increased risk of neonatal necrotising enterocolitis.

Antibiotic Therapy for Premature Rupture of Membranes and Preterm Labor and Effect on Fetal Outcome

In Germany almost 10 % of children are born before the end of 37th week of gestation. In at least one quarter of these cases, ascending infection of the vagina plays a causative role, particularly during the early weeks of gestation. If, in addition to the decidua, the amniotic membrane, amniotic fluid and the umbilical cord are also affected, infection not only triggers uterine contractions and premature rupture of membranes but also initiates a systemic inflammatory reaction on the part of the fetus, which can increase neonatal morbidity. Numerous studies and meta-analyses have found that antibiotic therapy prolongs pregnancy and reduces neonatal morbidity. No general benefit of antibiotic treatment was found for premature uterine contractions. But it is conceivable that a subgroup of pregnant women would benefit from antibiotic treatment. It is important to identify this subgroup of women and offer them targeted treatment. This overview summarizes the current body of evidence on antibiotic treatment for impending preterm birth and the effect on neonatal outcomes.

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.

Antibiotics for preterm rupture of membranes

BACKGROUND

Premature birth carries substantial neonatal morbidity and mortality. Subclinical infection is associated with preterm rupture of membranes (PROM). Prophylactic maternal antibiotic therapy might lessen infectious morbidity and delay labour, but could suppress labour without treating underlying infection.

OBJECTIVES

To evaluate the immediate and long-term effects of administering antibiotics to women with PROM before 37 weeks, on maternal infectious morbidity, neonatal morbidity and mortality, and longer-term childhood development.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (29 April 2010).

SELECTION CRITERIA

Randomised controlled trials comparing antibiotic administration with placebo that reported clinically relevant outcomes were included as were trials of different antibiotics. Trials in which no placebo was used were included for the outcome of perinatal death alone.

DATA COLLECTION AND ANALYSIS

We extracted data from each report without blinding of either the results or the treatments that women received. We sought unpublished data from a number of authors.

MAIN RESULTS

We included 22 trials, involving 6800 women and babies.The use of antibiotics following PROM is associated with statistically significant reductions in chorioamnionitis (average risk ratio (RR) 0.66, 95% confidence interval (CI) 0.46 to 0.96, and a reduction in the numbers of babies born within 48 hours (average RR 0.71, 95% CI 0.58 to 0.87) and seven days of randomisation (average RR 0.79, 95% CI 0.71 to 0.89). The following markers of neonatal morbidity were reduced: neonatal infection (RR 0.67, 95% CI 0.52 to 0.85), use of surfactant (RR 0.83, 95% CI 0.72 to 0.96), oxygen therapy (RR 0.88, 95% CI 0.81 to 0.96), and abnormal cerebral ultrasound scan prior to discharge from hospital (RR 0.81, 95% CI 0.68 to 0.98). Co-amoxiclav was associated with an increased risk of neonatal necrotising enterocolitis (RR 4.72, 95% CI 1.57 to 14.23).One study evaluated the children's health at seven years of age (ORACLE Children Study) and found antibiotics seemed to have little effect on the health of children.

AUTHORS' CONCLUSIONS

The decision to prescribe antibiotics for women with PROM is not clearcut. Benefits in some short-term outcomes (prolongation of pregnancy, infection, less abnormal cerebral ultrasound before discharge from hospital) should be balanced against a lack of evidence of benefit for others, including perinatal mortality, and longer term outcomes. If antibiotics are prescribed it is unclear which would be the antibiotic of choice.Co-amoxiclav should be avoided in women at risk of preterm delivery due to increased risk of neonatal necrotising enterocolitis.

Antibiotics for pre-term pre-labour rupture of membranes: prevention of neonatal deaths due to complications of pre-term birth and infection

Background In high-income countries, it is standard practice to give antibiotics to women with pre-term, pre-labour rupture of membranes (pPROM) to delay birth and reduce the risk of infection. In low and middle-income settings, where some 2 million neonatal deaths occur annually due to complications of pre-term birth or infection, many women do not receive antibiotic therapy for pPROM.

Objectives To review the evidence for and estimate the effect on neonatal mortality due to pre-term birth complications or infection, of administration of antibiotics to women with pPROM, in low and middle-income countries.

Methods We performed a systematic review to update a Cochrane review. Standardized abstraction forms were used. The quality of the evidence provided by individual studies and overall was assessed using an adapted GRADE approach.

Results Eighteen RCTs met our inclusion criteria. Most were from high-income countries and provide strong evidence that antibiotics for pPROM reduce the risk of respiratory distress syndrome [risk ratio (RR) = 0.88; confidence interval (CI) 0.80, 0.97], and early onset postnatal infection (RR = 0.61; CI 0.48, 0.77). The data are consistent with a reduction in neonatal mortality (RR = 0.90; CI 0.72, 1.12).

Conclusion Antibiotics for pPROM reduce complications due to pre-term delivery and post-natal infection in high-income settings. There is moderate quality evidence that, in low-income settings, where access to other interventions (antenatal steroids, surfactant therapy, ventilation, antibiotic therapy) may be low, antibiotics for pPROM could prevent 4% of neonatal deaths due to complications of prematurity and 8% of those due to infection.

Preterm prelabour amniorrhexis

Preterm delivery occurs in less than 10% of pregnancies but accounts for more than 60% of all neonatal deaths. Approximately one third of preterm deliveries are associated with preterm prelabour amniorrhexis and in a high proportion of such cases the underlying cause may be ascending infection from the lower genital tract. The causes of neonatal death in pregnancies with amniorrhexis are prematurity, pulmonary hypoplasia and sepsis. In the management of pregnancies with preterm prelabour amniorrhexis it is essential to distinguish between those with and without intrauterine infection. If there is no infection at presentation it is unlikely that this will develop and in such cases there is no benefit from hospitalisation, bed rest, prophylactic tocolytics or antibiotics. The group with evidence of intrauterine infection go into spontaneous labour within a few days of amniorrhexis; in this group the main determinant for the appropriate management is the gestation at amniorrhexis.

The NICHD-MFMU antibiotic treatment of preterm PROM study: impact of initial amniotic fluid volume on pregnancy outcome

OBJECTIVE

The purpose of this study was to evaluate the associations between measured amniotic fluid volume and outcome after preterm premature rupture of membranes (PROM).

STUDY DESIGN

This was a secondary analysis of 290 women, with singleton pregnancies, who participated in a trial of antibiotic therapy for preterm PROM at 24(0) to 32(0) weeks. Each underwent assessment of the 4 quadrant amniotic fluid index (AFI) and a maximum vertical fluid pocket (MVP) before randomization. The impact of low AFI (< 5.0 cm) and low MVP (< 2.0 cm) on latency, amnionitis, neonatal morbidity, and composite morbidity (any of death, RDS, early sepsis, stage 2-3 necrotizing enterocolitis, and/or grade 3-4 intraventricular hemorrhage) was assessed. Logistic regression controlled for confounding factors including gestational age at randomization, GBS carriage, and antibiotic study group.

RESULTS

Low AFI and low MVP were identified in 67.2% and 46.9% of women, respectively. Delivery occurred by 48 hours, 1 and 2 weeks in 32.4%, 63.5% and 81.7% of pregnancies, respectively. Both low AFI and low MVP were associated with shorter latency (P < .001), and with a higher rate of delivery at 48 hours, 1, and 2 weeks (P = .02 for each). However, neither test offered significant additional predictive value over the risk in the total population. Low AFI and low MVP were not associated with increased amnionitis. After controlling for other factors, both low MVP and low AFI were associated with shorter latency (P < or = .002), increased composite morbidity (P = .03), and increased RDS (P < or = .01), but not with increased neonatal sepsis (P = .85) or pneumonia (P = .53). Alternatively, after controlling for fluid volume, gestational age, and GBS carriage, the antibiotic study group had longer latency, and suffered less common primary outcomes and neonatal sepsis.

CONCLUSION

Oligohydramnios should not be a consideration in determining which women will be candidates for expectant management or antibiotic treatment when it is identified at initial assessment of preterm PROM remote from term.

Effect of antenatal corticosteroid and antibiotics in pregnancies complicated by premature rupture of membranes between 24 and 28 weeks of gestation

The aim of this study was to assess the effectiveness of active intervention with antenatal maternal corticosteroid and antibiotics therapy in infants delivered between 24 and 28 weeks of gestation after premature rupture of membrane. This retrospective study included pregnant women complicated by preterm delivery at the Dong-A University Hospital from 1998 to 2002. Patients were divided into labor induction group 1 (n=20), observation group 2 (n=19), and medication group 3 (n=20). We evaluated the effects of prolongation of pregnancy and intervention with maternal corticosteroids and antibiotics therapy on perinatal and neonatal outcomes. Each group did not have a significant difference (p<0.05) in neonatal outcomes, such as respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, pneumonia, bronchopulmonary dysplasia, and sepsis. The mean latency period was 4.7 days and 7.6 days in groups 2 and 3, respectively. Therefore, this study was unable to demonstrate any beneficial effects of corticosteroids in improving neonatal outcomes and prolongation of the latency period with antibiotics.

Antibiotics for preterm rupture of the membranes: a systematic review

OBJECTIVE

We sought to evaluate the administration of antibiotics to pregnant women with preterm rupture of membranes (PROM).

DATA SOURCES

We collected data by using the Cochrane Controlled Trials Register and MEDLINE.

METHODS OF STUDY SELECTION

We included randomized controlled comparisons of antibiotic versus placebo (14 trials, 6,559 women).

TABULATION, INTEGRATION, AND RESULTS

Antibiotics were associated with a statistically significant reduction in maternal infection and chorioamnionitis. There also was a reduction in the number of infants born within 48 hours and 7 days and with the following morbidities: neonatal infection (relative risk [RR] 0.67, 95% confidence interval [CI] 0.52-0.85), positive blood culture (RR 0.75, 95% CI 0.60-0.93), use of surfactant (RR 0.83 95% CI 0.72-0.96), oxygen therapy (RR 0.88, 95% CI 0.81-0.96), and abnormal cerebral ultrasound scan before discharge from hospital (RR 0.82, 95% CI 0.68-0.99). Perinatal mortality was not significantly reduced (RR 0.91, 95% CI 0.75-1.11). A benefit was present both in trials where penicillins and erythromycin were used. Amoxicillin/clavulanate was associated with a highly significant increase in the risk of necrotizing enterocolitis (RR 4.60, 95% CI 1.98-10.72).

CONCLUSION

The administration of antibiotics after PROM is associated with a delay in delivery and a reduction in maternal and neonatal morbidity. These data support the routine use of antibiotics for women with PROM. Penicillins and erythromycin were associated with similar benefits, but erythromycin was used in larger trials and, thus, the results are more robust. Amoxicillin/clavulanate should be avoided in women at risk of preterm delivery because of the increased risk of neonatal necrotizing enterocolitis. Antibiotic administration after PROM is beneficial for both women and neonates.

An Evidence-Based Approach to the Evaluation and Treatment of Premature Rupture of Membranes: Part II

Preterm premature rupture of membranes (PPROM) occurs in 3% of pregnancies and is responsible for one third of all preterm births. In part I of this series, the definition, pathophysiology, and diagnosis of PPROM was reviewed. In this part, treatment is discussed. Adjunctive antibiotic and corticosteroid therapy has the strongest evidence for improving neonatal outcome. Treatment is gestational age-dependent and will be influenced by local neonatal intensive-care unit (NICU) survival statistics. This review presents the available evidence and grades it according to the U.S. Preventative Task Force recommendations.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to summarize the data on the use of labor inhibition in the setting of PPROM, list potential antibiotics regimens that are recommended for prophylaxis in patients with PPROM, to describe the benefits of corticosteroid administration in patients with PPROM, and to outline potential management strategies for patients with PPROM based on gestational age.

The effect of antibiotic therapy on intrauterine infection-induced preterm parturition in rabbits

OBJECTIVE

The purpose of this study was to determine whether early antibiotic administration to pregnant rabbits with intrauterine infection could prevent preterm delivery and perinatal mortality.

STUDY DESIGN

Under hysteroscopic guidance, pregnant rabbits at 70% gestation (21 days) were allocated to three groups: (1) control group, transcervical inoculation of 0.2 ml phosphate-buffered saline (n = 16); (2) infection group, transcervical inoculation of 0.2 ml of 10(5) colony-forming units (CFU) of Escherichia coli (n = 21); (3) infection and antibiotics group, transcervical inoculations of 0.2 ml of 10(5) CFU of E. coli and ampicillin-sulbactam 150 mg/kg every 8 h intramuscularly (n = 32). To examine the consequences of treatment delay, animals in the latter group were subdivided to receive antibiotics at different time intervals of 0, 6, 11 and 18 h after bacterial inoculation. The intervals from bacterial inoculation to delivery and litter survival were documented. Systemic (rectal) temperatures were recorded at 4 h intervals through the first 36 h and every 12 h until delivery. A p value of < 0.05 was considered significant.

RESULTS

All rabbits inoculated with E. coli without antibiotic treatment delivered prematurely. The median inoculation-to-delivery interval was significantly shorter in the infected group than in the control group (median 32 h, range 14.9-76.5 h vs. median 219 h, range 173-246 h, respectively; p < 0.0001). Antibiotic administration within 12 h of inoculation, but not after 18 h, increased duration of pregnancy (by reducing the rate of preterm delivery) and neonatal survival (0% vs. 71%; p < 0.0001). The mean temperatures at delivery of animals whose treatments began at 6 and 11 h post-inoculation were significantly lower than those untreated with antibiotics or those treated at 18 h post-inoculation (p < 0.0001 for each comparison).

CONCLUSIONS

Antibiotic administration can prolong pregnancy and reduce perinatal mortality if administered early (within 12 h of microbial inoculation) in a rabbit model of ascending intrauterine infection.

Duration of antibiotic therapy after preterm premature rupture of fetal membranes

OBJECTIVE

This study was undertaken to compare the efficacy of 3 days versus 7 days of ampicillin in prolonging gestation for at least 7 days in women with preterm premature rupture of membranes (PPROM).

STUDY DESIGN

We performed a randomized clinical trial comparing 3 days of ampicillin with 7 days ampicillin in patients with PPROM. Our primary outcome was the prolongation of pregnancy for at least 7 days. Secondary outcomes included rates of chorioamnionitis, postpartum endometritis, and neonatal morbidity and mortality.

RESULTS

Forty-eight patients were randomly selected. There was no statistically significant difference in the ability to achieve a 7-day latency (relative risk 0.83, 95% CI 0.51-1.38). In addition, there was no statistically significant difference in the rates of chorioamnionitis, endometritis, and our composite neonatal morbidity.

CONCLUSION

In patients with PPROM, length of antibiotic therapy does not change the rate of a 7-day latency or affect the rate of chorioamnionitis, postpartum endometritis, or neonatal morbidity.

What we have learned regarding antibiotic therapy for the reduction of infant morbidity after preterm premature rupture of the membranes

Preterm premature rupture of the membranes (pPROM) is responsible for approximately one third of the over 450,000 preterm births occurring in the United States annually. In this manuscript, we summarize the outcomes and analyses related to the National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network (NICHD-MFMU) network multicenter trial of antibiotics to reduce infant morbidity after pPROM. Based on evident reduction in gestational age dependent and infectious infant morbidity, we provide the rationale for aggressive intravenous and oral, broad spectrum Ampicillin/Amoxicillin, and Erythromycin therapy during conservative management of pPROM before 32 weeks' gestation. We further review the histopathologic correlates to pPROM, to antibiotic treatment, and to perinatal outcome, and discuss the relationships between maternal and neonatal cytokine levels intercellular adhesion molecule, and other clinical and plasma markers regarding perinatal morbidity. The use and limitations of ultrasound and vaginally collected amniotic fluid pulmonary maturity assessment are discussed.

Antibiotics for preterm rupture of membranes

BACKGROUND

Premature birth carries substantial neonatal morbidity and mortality. One cause, associated with preterm rupture of membranes (pROM), is often subclinical infection. Maternal antibiotic therapy might lessen infectious morbidity and delay labour, but could suppress labour without treating underlying infection.

OBJECTIVES

To evaluate the immediate and long-term effects of administering antibiotics to women with pROM before 37 weeks, on maternal infectious morbidity, fetal and neonatal morbidity and mortality, and longer term childhood development.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (January 2003) and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2002).

SELECTION CRITERIA

Randomised controlled trials comparing antibiotic administration with placebo that reported clinically relevant outcomes, were included. In addition, trials, in which no placebo was used, were included for the outcome of perinatal death alone.

DATA COLLECTION AND ANALYSIS

Data were extracted from each report without blinding of either the results or the treatments that women received. Unpublished data were sought from a number of authors.

MAIN RESULTS

Nineteen trials involving over 6000 women and their babies were included. The use of antibiotics following pROM is associated with a statistically significant reduction in chorioamnionitis (relative risk (RR) 0.57, 95% confidence interval (CI) 0.37 to 0.86). There was a reduction in the numbers of babies born within 48 hours (RR 0.71, 95% CI 0.58 to 0.87) and seven days of randomisation (RR 0.80, 95% CI 0.71 to 0.90). The following markers of neonatal morbidity were reduced: neonatal infection (RR 0.68, 95% CI 0.53 to 0.87), use of surfactant (RR 0.83, 95% CI 0.72 to 0.96), oxygen therapy (RR 0.88, 95% CI 0.81 to 0.96), and abnormal cerebral ultrasound scan prior to discharge from hospital (RR 0.82, 95% CI 0.68 to 0.98). Co-amoxiclav was associated with an increased risk of neonatal necrotising enterocolitis (RR 4.60, 95% CI 1.98 to 10.72).

REVIEWER'S CONCLUSIONS

Antibiotic administration following pROM is associated with a delay in delivery and a reduction in major markers of neonatal morbidity. These data support the routine use of antibiotics in pPROM. The choice as to which antibiotic would be preferred is less clear as, by necessity, fewer data are available. Co-amoxiclav should be avoided in women at risk of preterm delivery because of the increased risk of neonatal necrotising enterocolitis. From the available evidence, erythromycin would seem a better choice.

Infection, antibiotics, and preterm delivery

The relationship between genital tract infection and preterm delivery has been established on the basis of biochemical, microbiological, and clinical evidence. In theory, pathogenic bacteria may ascend from the lower reproductive tract into the uterus, and the resulting inflammation leads to preterm labor, rupture of the membranes, and birth. A growing body of evidence suggests that preterm labor and/rupture of the membranes are triggered by micro-organisms in the genital tract and by the host response to these organisms, ie, elaboration of cytokines and proteolytic enzymes. Epidemiologic and in vitro studies do not prove a cause-and-effect relationship between infection and preterm birth. However, the preponderance of evidence indicates that treatment of asymptomatic bacteriuria and symptomatic lower genital tract infections such as bacterial vaginosis (BV), trichomoniasis, gonorrhea, and chlamydia will lower the risk of preterm delivery. Based on current evidence, pregnant women who note an abnormal vaginal discharge should be tested for BV, trichomonas, gonorrhea, and chlamydia. Those who test positive should be treated appropriately. A 3- to 7-day course of antibiotic treatment for asymptomatic bacteriuria during pregnancy is clinically indicated to reduce the risk of pyelonephritis and preterm delivery. Routine screening for chlamydia and gonorrhea should be performed for women at high risk of acquiring sexually transmitted diseases. The practice of routine screening for BV in asymptomatic women who are at low risk for preterm delivery cannot be supported based on evidence from the literature. Routine screening for asymptomatic bacteriuria during pregnancy is cost-effective, particularly in high-prevalence populations. The results of antibiotic trials for the treatment of preterm labor have been inconsistent. In the absence of reasonable evidence that antimicrobial therapy leads to significant prolongation of pregnancy in the setting of preterm labor, antibiotics should be used only for protecting the neonate from group B streptococci sepsis. They should not be used for the purpose of prolonging pregnancy. Multiple investigations have shown that, in patients with preterm premature rupture of the membranes, prophylactic antibiotics are of value in prolonging the latent period between rupture of the membranes and onset of labor and in reducing the incidence of maternal and neonatal infection. The most extensively tested effective antibiotic regimen for prophylaxis involves erythromycin alone or in combination with ampicilln. Controversy still exists regarding the appropriate length and route of antibiotic prophylaxis.

Place of amniocentesis in the assessment of preterm labour

OBJECTIVE

To evaluate the benefits and indications for amniocentesis in cases of preterm labor with or without preterm rupture of membranes.

METHOD

A review of the literature on amniocentesis in cases of intra-amniotic infection.

RESULTS

Amniocentesis is an invasive method that allows the diagnosis of intra-amniotic infection. However, no randomized trials have been performed from which we can assess the benefits and complications of amniocentesis in preterm labor.

CONCLUSION

The published data do not justify the routine practice of amniocentesis in preterm labor. More data are needed to evaluate the benefits and complications of this practice. Only randomized trials of patients in preterm labor, comparing those who undergo amniocentesis with those who do not, will clarify the indications for this procedure.

Prophylactic augmentin in prelabor preterm rupture of the membranes

OBJECTIVE

To determine whether the use of prophylactic Augmentin in PPROM prolongs gestation and reduces neonatal and maternal morbidity due to sepsis.

METHOD

Study setting was Harare Maternity Hospital, Zimbabwe. Women with PPROM between 26 and 36 weeks' gestation were randomly allocated either to a group given a course of prophylactic oral Augmentin or another receiving no prophylactic antibiotic treatment. The calculated sample size was 72 women per group. Data were analyzed using the EPI INFO program.

RESULTS

A total of 171 women were recruited into the study, 84 in the Augmentin group and 87 in the No Treatment group. The group receiving prophylactic Augmentin had a significantly longer latency period between rupture of membranes and delivery. There was a trend towards increased neonatal and maternal morbidity due to sepsis in the No Treatment group although no statistical significance was reached.

CONCLUSION

The use of prophylactic Augmentin in PPROM significantly prolongs gestation. It appears to decrease neonatal and maternal morbidity due to sepsis.

Antibiotic therapy in preterm premature rupture of membranes

Good quality evidence supports the use of antibiotic therapy in women with preterm PROM for whom expectant management is planned. The best evidence supports the choice of an extended-spectrum agent or combination administered intravenously for 2 days followed by an extended spectrum or combination of oral agents for several more days. Despite the effectiveness of antimicrobial therapy in this setting, the potential risks of systemic antibiotic administration, such as allergic reactions, overgrowth of commensal organisms, and emergence of resistant pathogens, much always be kept in mind. Nevertheless, in the majority of cases, assuming the patient is a good candidate for expectant management, the benefits of antibiotic therapy outweigh the risks.

Antibiotic therapy for preterm premature rupture of membranes

Antibiotic treatment of the patient with preterm premature rupture of membranes remote from term significantly prolongs pregnancy and reduces amnionitis without increasing the risk of cesarean delivery. Antibiotic treatment reduces perinatal infectious morbidity including neonatal sepsis, GBS sepsis, and pneumonia. Stratified analysis of the currently available prospective trials also demonstrates a significant reduction in gestational-dependent morbidity, specifically respiratory distress and intraventricular hemorrhage with treatment. This is supported by a reduction in composite infant morbidity and other gestational age-dependent morbidities in the NICHD-MFMU trial. Although the optimal treatment regimen has not been determined, limited duration broad spectrum antibiotic treatment is justified in the setting of conservative management of pPROM remote from term. The patient with pPROM and documented pulmonary maturity near term may benefit more from expeditious delivery than from expectant management with antibiotics.

Concomitant use of glucocorticoids: a comparison of two metaanalyses on antibiotic treatment in preterm premature rupture of membranes

OBJECTIVE

This study was performed to investigate whether the demonstrated beneficial effects of antibiotics on maternal and neonatal morbidity are altered when glucocorticoids are part of the treatment of preterm premature rupture of membranes.

STUDY DESIGN

We performed a metaanalysis of five published, randomized trials of antibiotic treatment in preterm premature rupture of membranes in which glucocorticoids were used as additional treatments and compared the results with those of a previously published metaanalysis of antibiotic treatment in preterm premature rupture of membranes, which excluded studies with concomitant glucocorticoids. Primary outcomes included chorioamnionitis, postpartum endometritis, neonatal sepsis, respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and neonatal mortality. A logistic regression analysis was performed to test whether glucocorticoids significantly influenced the effect of antibiotic treatment.

RESULTS

Among the 509 patients from five trials on antibiotic and glucocorticoid treatment published between 1986 and 1993 antibiotic therapy did not show any significant effect on any of the outcomes analyzed. In contrast, antibiotic therapy without concomitant use of glucocorticoids significantly reduced the odds of chorioamnionitis, postpartum endometritis, neonatal sepsis, and intraventricular hemorrhage by 62%, 50%, 68%, and 50%, respectively. The logistic regression analysis showed that glucocorticoids significantly diminished the effect of antibiotic treatment on chorioamnionitis and neonatal sepsis.

CONCLUSION

Glucocorticoids appear to diminish the beneficial effects of antibiotics in the treatment of preterm premature rupture of membranes. A careful selection of patients who are likely to benefit from both therapies is therefore recommended.

Preterm labor and preterm premature rupture of the membranes. Diagnosis and management

Preterm delivery due to preterm labor and pPROM is responsible for most infant morbidity and mortality in the United States. The patient who presents with suspicious symptoms should undergo a thorough evaluation to confirm the diagnosis of either entity and identify a treatable cause. Determination of gestational age, fetal well-being, and the presence of intrauterine infection is a crucial step in subsequent management. Corticosteroid therapy has been demonstrated to be one of the most effective antenatal interventions to reduce infant morbidity and should be administered to patients with preterm labor, if feasible, when fetal pulmonary maturity is absent or undocumented. We recommend a similar protocol regarding gravidas with pPROM remote from term but recognize the need for further study in this area. Acute tocolytic therapy has been demonstrated to offer short-term benefit to enhance corticosteroid effect. However, all of the available tocolytic agents carry significant risks to the mother and fetus. As such, administration of these agents should be given only when the potential benefits outweigh the risks of administration. Evaluation for fetal pulmonary maturity and intrauterine infection, in concert with evaluation of gestational age-dependent risks of prematurity, may be helpful in determining whether tocolysis should be attempted. Adjunctive antibiotic administration has not been shown to reduce maternal or infant morbidity in the face of preterm labor. However, such treatment offers a reduction of chorioamnionitis, prolongation of latency, and a possible reduction of neonatal infectious and gestational age-dependent morbidity in the setting of pPROM remote from term. Finally, current guidelines recommend the administration of intrapartum GBS prophylaxis when preterm birth or prolonged membrane rupture is anticipated if GBS carrier status is unknown or positive. Intrapartum treatment with intravenous penicillin or ampicillin is appropriate.

Antibiotic therapy for preterm premature rupture of the membranes

Amniotic fluid studies and placental histopathological evaluation have confirmed the association between intrauterine infection and preterm premature rupture of the membranes (pPROM). This association is increasingly strong with pPROM at early gestational ages. The organisms associated with pPROM include a broad spectrum of aerobic and anaerobic gram-positive and gram-negative bacteria. In many cases, the patient presenting with pPROM will have overt intrauterine infection necessitating delivery. For those amenable to expectant management, the clinical course is usually of brief latency between membrane rupture and delivery. A number of well-designed prospective clinical trials have evaluated the utility of antibiotic treatment during the expectant management of pPROM. Taken together, these studies suggest broad spectrum antibiotic treatment of this population to enhance pregnancy prolongation, and to reduce maternal and neonatal infectious morbidity. There are some data suggesting the potential for a reduction in neonatal gestational age-dependent morbidity. We recommend aggressive adjunctive antibiotic treatment to prolong pregnancy and reduce morbidity in patients with pPROM, at gestations remote from term, when a significant improvement in neonatal outcome can anticipated with expectant management.

Premature rupture of the membranes: neonatal consequences

Premature rupture of the membranes (PROM), membrane rupture before the onset of labor, occurs in 2% to 18% of pregnancies. The time from PROM to delivery (latency) is usually less than 48 hours in term pregnancy. Therefore, the risks of PROM at term are related to fetal distress, prolapsed cord, abruptio placenta, and rarely, infection. Preterm PROM (pPROM), PROM before 37 weeks' gestation, accounts for 20% to 40% of PROM, and the incidence is doubled in multiple gestations. The latency period in pPROM is inversely related to the gestational age thereby increasing the risks of oligohydramnios and infection in very premature infants and their mothers. Because pPROM is associated with 30% to 40% of premature births, pPROM is also responsible for the neonatal problems resulting from prematurity. This review examines the impact of PROM on the neonate including fetal distress, prematurity, infection, pulmonary hypoplasia, and restriction deformations.

Group B Streptococcus and preterm premature rupture of membranes: a randomized, double-blind clinical trial of antepartum ampicillin

OBJECTIVE

Our purpose was to determine whether ampicillin prolongs the latency period after preterm premature rupture of membranes in patients colonized with group B Streptococcus.

STUDY DESIGN

Sixty patients presenting at < or = 35 weeks' gestation with preterm premature rupture of membranes were included in the study. Cervical, vaginal, and perianal cultures for group B premature rupture were obtained. The participants then were randomized to receive either ampicillin or placebo intravenously for 24 hours and then orally until hospital discharge or delivery. All patients were treated without the use of tocolytic drugs. The chi(2) test, Fisher exact test, Student t test, and Wilcoxon signed-rank test were used for statistical analysis when appropriate.

RESULTS

Fifteen patients had cultures positive for group B Streptococcus. Patients with cultures positive for group B Streptococcus who received ampicillin (n = 8) were more likely not to have been delivered of their infants 48 hours after preterm premature rupture of membranes than patients who received placebo (n = 7), a statistically significant difference (100% vs 43%; p = 0.01; relative risk 2.3; 95% confidence interval 1.2 to 4.5). Seven days after preterm premature rupture of membranes, however, there was no significant difference in percentage of patients with cultures positive for group B Streptococcus who remained undelivered (63% vs 29%; p = 0.19; relative risk, 2.2; 95% confidence interval 0.7 to 7.1). Among patients with cultures negative for group B Streptococcus, there was a trend for patients who received ampicillin to remain undelivered 48 hours after preterm premature rupture of membranes compared with those who received placebo, but the difference was not statistically significant (87% vs 64%; p = 0.07; relative risk, 1.4; 95% confidence interval 1.0 to 1.9). There also was no difference in percentage of patients with cultures negative for group B Streptococcus who remained undelivered 7 days after preterm premature rupture of membranes 39% vs 27%; p = 0.40; relative risk, 1.4; 95% confidence interval 0.61 to 3.3). There were no differences between the treatment and placebo arms of the group B Streptococcus positive and negative cohorts in incidence of cesarean section, chorioamnionitis, postpartum endometritis, or neonatal infectious morbidity.

CONCLUSION

Use of antibiotics increases the percentage of patients with cultures positive for group B Streptococcus who remain undelivered 48 hours after preterm premature rupture of membranes. Antibiotic therapy may provide a window of opportunity for maternal treatment with corticosteroids to decrease the risk for neonatal morbidity among these preterm gestations.

Urinary trypsin inhibitor: a new drug to treat preterm labor: a comparative study with ritodrine

Prevention of preterm delivery is one of the difficult problems facing obstetricians. beta Adrenergic agonists, especially ritodrine, are commonly used in these cases.

OBJECTIVES

The aim of this research was to study and compare the effect of urinary trypsin inhibitor (UTI) which has anti-inflammatory anti-cytokine effects with ritodrine in treating preterm labor.

STUDY DESIGN

Patients in preterm delivery were randomly selected to be treated either by ritodrine or UTI. In the ritodrine group, uterine contractions were initially suppressed by high doses of ritodrine (up to 300 micrograms/min) and then a maintenance dose was given until 35 weeks of gestation. In the UTI group one vaginal suppository (5000 U) was used daily for 2 weeks. Patients with recurrent preterm uterine contraction during the initial 14 days of treatment, who needed course of other drugs to suppress the contractions, were excluded from the study. Patients responding to the drugs were followed until delivery. Tocolytic index and elastase concentration in the cervical mucus was calculated. Recurrence rate of uterine contraction and time of elongation of pregnancy since the beginning of treatment was calculated.

RESULTS

UTI was more effective than ritodrine in inhibition of recurrent uterine contraction and elongation of pregnancy. No side effects could be observed after treatment with UTI for the mother or the fetus.

CONCLUSION

UTI may be a new therapeutic method for the inhibition of preterm delivery through suppression of cytokines and inflammatory mediators.

Prophylactic administration of amoxicillin and clavulanic acid in pregnant women with premature rupture of the membranes

Seventy-five pregnant women (mean gestational age 32.26 weeks, range 20-36 weeks) with premature rupture of the membranes (PROM) were admitted in our department during 1989 and the first 6 months of 1990. Amoxicillin and clavulanic acid was initially administered at a dose of 1.2 g i.v. every 8 hours for 3-4 days and was followed by oral administration of 625 mg every 8 hours until labor. Sixty-one patients (mean gestational age 32.6 +/- 2.3 weeks, range 26-36 weeks) achieved an uncomplicated course of their pregnancies with a mean time of 11.4 +/- 5.7 days (range 3-27 days), from rupture to delivery. Fourteen women (mean gestational age 30.8 +/- 5 weeks, range 20-36 weeks) developed chorioamnionitis 3.5 +/- 0.9 days (range 1.4-5.6 days) after the rupture with several degrees of leukocyte infiltration of the membranes, placenta and the umbilical cord. Five women (mean gestational age 23.8 +/- 2.3 weeks, range 20-26 weeks) had complications resulting in fetal/infant death, three of them because of fetal sepsis (Escherichia coli, Pseudomonas aeroginosa, Staphylococcus aureus). The newborns were followed up 6 months from delivery and had no signs of drug influence. Few side effects were observed with the chief complaints involving the gastrointestinal tract (4%). No one discontinued the drug. It seems therefore, that the prophylactic administration of amoxicillin and cluvalanic acid in women with PROM is associated with a significant prolongation of pregnancy and with a reduction in the incidence of fetal/maternal infections.

Utility of antibiotic therapy in preterm premature rupture of membranes: a meta-analysis

The optimal management of preterm premature rupture of membranes (PROM) is controversial. Maternal risks must be weighed against fetal benefit when expectant management is considered. Despite concerns about maternal harm, protocols of expectant management seem to afford the best perinatal outcomes. Given that infection often is the common pathway for delivery in preterm PROM, recent reports have explored the utility of maternal administration of antibiotics. In this paper we will summarize these results using meta-analytic techniques and assess the impact of antibiotic therapy on maternal and perinatal outcomes.

Antibiotic treatment in preterm premature rupture of membranes and neonatal morbidity: a metaanalysis

OBJECTIVE

We performed a metaanalysis of seven published randomized clinical trials to estimate more precisely the effect of prophylactic antibiotics on neonatal mortality, clinical sepsis of the neonate, respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis.

STUDY DESIGN

To evaluate the effect of antibiotic treatment unaffected by other forms of treatment such as tocolytics or corticosteroids, investigations in which these additional measures were used were not included. We analyzed study patients and methods and abstracted quantitative outcome data. For each outcome both odds ratios and 95% confidence intervals were calculated.

RESULTS

Among the 657 patients from seven trials published between 1989 and 1994, antibiotic therapy significantly reduced the risk of neonatal sepsis by 68% (odds ratio 0.32, 95% confidence interval 0.16 to 0.65, p=0.001) and that of intraventricular hemorrhage by 50% (odds ratio 0.50, 95% confidence interval 0.28 to 0.89, p=0.019). In contrast, no significant effect of antibiotics on overall neonatal mortality (odds ratio 0.92, 95% confidence interval 0.46 to 1.81), respiratory distress syndrome (odds ratio 0.84, 95% confidence interval 0.58 to 1.22), or necrotizing enterocolitis (odds ratio 1.27, 95% confidence interval 0.61 to 2.62) was found.

CONCLUSION

This metaanalysis supports an improvement of neonatal morbidity in mothers with preterm premature rupture of membranes treated prenatally with different antibiotic regimens.

Antimicrobial therapy in expectant management of preterm premature rupture of the membranes

We review the impact of antimicrobial treatment on maternal and fetal outcome during expectant management of preterm premature rupture of the membranes. Relevant studies were retrieved from Medline (1966 to August, 1994) with the search term fetal-membrane-premature-rupture and antibiotics or antimicrobial, Excerpta Medica (1972 to August, 1994) with the search term premature fetus, membrane rupture, and antibiotic or antimicrobial therapy, and the Cochrane database of systemic reviews with the criterion antibiotics and prelabour rupture of membranes. We also obtained unpublished data from a randomised clinical trial of ceftizoxime versus placebo. The selected studies were randomised controlled trials of systemic antimicrobial therapy for prolongation of gestation in non-labouring women after preterm premature rupture of the membranes. Data extraction was done by a single reviewer. Studies were evaluated for post-randomisation exclusion and other confounding variables that might introduce analytical bias. Analysis was done with SAS statistical software by a blinded investigator. Antimicrobial therapy after preterm premature rupture of the membranes is associated with a reduced number of women delivering within 1 week (62 vs 76%; OR 0.51, 95% CI 0.41-0.68), and reduced diagnosis of maternal morbidity including chorioamnionitis (12 vs 23%; 0.45, 0.33-0.60) and postpartum infection (8 vs 12%; 0.63, 0.41-0.97). Fetal morbidity, including confirmed sepsis (5 vs 9%; 0.57, 0.36-0.88), pneumonia (1 vs 3%; 0.32, 0.11-0.96), and intraventricular haemorrhage (9 vs 14%; 0.65, 0.45-0.92) were less often diagnosed after antimicrobial therapy. Separate analysis of the six placebo-controlled trials revealed similar or improved odds of pregnancy prolongation, chorioamnionitis, neonatal sepsis, postpartum infection, positive infant blood cultures, and pneumonia. Antimicrobial therapy, when used in the expectant management of preterm premature rupture of the membranes is associated with prolongation of pregnancy and a reduction in the diagnosis of maternal and infant morbidity. Further study should be directed towards determination of optimal antimicrobial therapy, increasing pregnancy prolongation, and enhancement of corticosteroid therapy for induction of pulmonary maturity after preterm premature rupture of the membranes.