The role of infection in necrotising enterocolitis:

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 We sought unpublished data from a number of authors.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.

Probiotics and the mechanism of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a severe intestinal inflammatory disorder in newborns. Although the pathogenesis of NEC is not completely understood, we reviewed the literature and our previous studies to explore the mechanism of NEC and to evaluate the role for probiotics in this disease. NEC may be associated with an inappropriate innate immune and excessive inflammatory response of the immature intestine. Probiotics are widely used in promoting human health and adjunctive therapy of human disease. There are growing clinical trials and research studies that support a beneficial role for probiotics for NEC. We have reviewed the literature associated with the use of probiotics in NEC.

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.

Comparison between killed and living probiotic usage versus placebo for the prevention of necrotizing enterocolitis and sepsis in neonates

The aim of the study is to compare the role of killed (KP) Lactobacillus acidophilus with living (LP) in reducing incidence of sepsis (NS) and necrotizing enterocolitis (NEC) in neonates. Randomized double blind placebo study, included 150 neonates admitted to NICU at day 1, sixty received oral (LP) and 60 received (KP) and 30 received placebo. One gram of stools was collected on admission, at day 7, at end of the study, as well as on suspected NEC or NS and was sent for culture.

RESULTS

LP and KP were preventive factors for NEC with absolute risk reduction (AAR) 16, 15%, respectively and 18% for NS compared to placebo. Incidence of NEC and NS did not differ significantly between neonates supplemented with LP and those with KP. Preterm neonates supplemented with KP showed significantly lower incidence of NEC compared to placebo, while incidence of NS showed no significant difference between both groups. There is significant reduction in NS and NEC among neonates with positive Lactobacillus colonization of gut compared to those none colonized at day 7 (27.9 vs. 85.9%, 0 vs. 7.8%) and at day 14 (48.7 vs. 91.7% for NS and 0 vs. 20.8% for NEC). Overall comparison between the three groups showed statistical significant reduction in the incidence of NEC. Present conclusions are that early gut colonization with beneficial bacteria lowers the incidence of NEC and NS. KP retained similar benefits to live bacteria.

Clinical parameters do not adequately predict outcome in necrotizing enterocolitis: a multi-institutional study

OBJECTIVE

Necrotizing enterocolitis (NEC) remains a major cause of neonatal morbidity and mortality. Some infants recover uneventfully with medical therapy whereas others develop severe disease (that is, NEC requiring surgery or resulting in death). Repeated attempts to identify clinical parameters that would reliably identify infants with NEC most likely to progress to severe disease have been unsuccessful. We hypothesized that comprehensive prospective data collection at multiple centers would allow us to develop a model which would identify those babies at risk for progressive NEC.

STUDY DESIGN

This prospective, observational study was conducted at six university children's hospitals. Study subjects were neonates with suspected or confirmed NEC. Comprehensive maternal and newborn histories were collected at the time of enrollment, and newborn clinical data were collected prospectively, thereafter. Multivariate logistic regression analysis was used to develop a predictive model of risk factors for progression.

RESULT

Of 455 neonates analyzed, 192 (42%) progressed to severe disease, and 263 (58%) advanced to full feedings without operation. The vast majority of the variables studied proved not to be associated with progression to severe disease. A total of 12 independent predictors for progression were identified, including only 3 not previously described: having a teenaged mother (odds ratio, OR, 3.14; 95% confidence interval, CI, 1.45 to 6.96), receiving cardiac compressions and/or resuscitative drugs at birth (OR, 2.51; 95% CI, 1.17 to 5.48), and having never received enteral feeding before diagnosis (OR, 2.41; 95% CI, 1.08 to 5.52).

CONCLUSION

Our hypothesis proved false. Rigorous prospective data collection of a sufficient number of patients did not allow us to create a model sufficiently predictive of progressive NEC to be clinically useful. It appears increasingly likely that further analysis of clinical parameters alone will not lead to a significant improvement in our understanding of NEC. We believe that future studies must focus on advanced biologic parameters in conjunction with clinical findings.

Effects of probiotics on enteric flora and feeding tolerance in preterm infants

BACKGROUND

Probiotics are live microbes that colonize the gastrointestinal tract and benefit the host. Preterm infants develop abnormal patterns of bowel colonization, and only a few clinical trials have reported the outcomes of preterm infants treated with probiotics.

PURPOSE

We investigated the rate of colonization of Lactobacillus and the clinical variables affecting the colonization in preterm infants.

METHODS

Infants with gestational age less than 37 weeks treated at Ewha Womans University Hospital between March 2003 and July 2004 were eligible. Lactobacillus acidophilus (containing 10(8) CFU) was supplemented orally, mixed with breast milk or formula divided into three doses a day. Stool samples were collected before and 14 days after supplementation of the probiotic. Stool samples were anaerobically cultured on Rogosa agar and identified by Gram stain, catalase test and glucose fermentation test. Clinical characteristics were analyzed.

RESULTS

Seventy-three patients with an average gestational age of 33.0 +/- 2.5 weeks were studied. Meconium was cultured in 46 patients and Lactobacillus was not detected. Probiotic supplementation began on 3.4 +/- 6.8 days, and after 14 days of supplementation, Lactobacillus was cultured in an average of 3.01 x 10(8) CFU in the stool of 37.0% (27/73) of the patients. There was a tendency towards an increased incidence of sepsis in the Lactobacillus- group (p = 0.082). In the Lactobacillus+ group, a striking increase in feeding tolerance was detected.

CONCLUSION

In preterm infants, with the administration of probiotics, 37% of the preterm infants had Lactobacillus colonized in the gastrointestinal tract and improved feeding tolerance. A double-blind study is in progress for further investigation into the effect on other systemic diseases in premature infants.

Clostridium difficile and Clostridium perfringens species detected in infant faecal microbiota using 16S rRNA targeted probes

Clostridium perfringens and Clostridium difficile are pathogenic clostridia potentially associated with gastrointestinal infections and allergy in infants. To enable the molecular detection and quantification of these species in the infant gut, two 16S rRNA oligonucleotide probes were developed: Cdif198 for C. difficile and Cperf191 for C. perfringens. We defined the probes in silico using the RDP sequence database. The probes were then validated using FISH combined with flow cytometry and a collection of target and non-target strains, and faecal samples inoculated with dilutions of C. difficile and C. perfringens strains. These new probes were used to assess the composition of the intestinal microbiota of 33 infants of 1.5 to 18.5 months of age, associated with a panel of 8 probes targeting the predominant faecal bacterial groups of humans. The probes designed allowed detection and quantification of the relative proportions of C. difficile (0.5+/-1.0%) and C. perfringens (2.1+/-2.3%) in the microbiota of infants.

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.

Pro- and pre-biotics administration in preterm infants: colonization and influence on faecal flora

Prolonged administration of probiotic in preterm babies induce a rise of specific IgA and IgM antibodies against probiotic. This fact explains why presence of living germs in stools almost disappeared in spite of continuous administration. However some positive influences were observed: decreased ratio of aerobic/anaerobic. Increased ratio of gram +/gram - germs. Prebiotic administration induces after 28 days a significant increase of faecal bifidobacteria and frequency and consistency of stools were more similar to those observed in subjects fed with human milk.

ORACLE--antibiotics for preterm prelabour rupture of the membranes: short-term and long-term outcomes

Preterm prelabour rupture of the foetal membranes (pPROM) is the most common antecedent of preterm birth and can lead to death, neonatal disease and long-term disability. Previous small trials of antibiotics for pPROM suggested some health benefits for the neonate, but the results were inconclusive. A large, randomized, multicentre trial was undertaken to try to resolve this issue. In total, 4826 women with pPROM were randomized to one of four treatments: 325 mg co-amoxiclav plus 250 mg erythromycin, co-amoxiclav plus erythromycin placebo, erythromycin plus co-amoxiclav placebo, or co-amoxiclav placebo plus erythromycin placebo, four times daily for 10 d or until delivery. The primary outcome measure was a composite of neonatal death, chronic lung disease or major cerebral abnormality on ultrasonography before discharge from hospital. The analysis was undertaken by intention to treat. Indications of short-term respiratory function, chronic lung disease and major neonatal cerebral abnormality were reduced with the prescription of erythromycin. In contrast, the use of co-amoxiclav was associated with a significant increase in the occurrence of neonatal necrotizing enterocolitis.

CONCLUSION

Prophylactic antibiotics can play a role in preterm prelabour rupture of the membranes in reducing infant morbidity.

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.