General obstetrics: A randomised controlled trial of metronidazole for the prevention of preterm birth in women positive for cervicovaginal fetal fibronectin: the PREMET Study

Pregnancy outcomes in pregnant women taking oral probiotic undergoing cerclage compared to placebo: two blinded randomized controlled trial

AIM

The purpose of this study is to evaluate the oral probiotic effect on pregnancy outcomes in pregnant women undergoing cerclage compared to placebo.

METHODS

This study was a double-blind randomized clinical trial undertaken in Yasuj, Iran. 114 eligible participants who have undergone cerclage were randomly divided to either receive probiotic adjuvant or 17α-OHP (250 mg, IM) with placebo from the 16th -37th week of pregnancy by "block" randomization method. Our primary outcomes were preterm labor (PTB) (late and early) and secondary outcomes were other obstetrical and neonatal outcomes included preterm pre-labor rupture of membranes (PPROM), pre-labor rupture of membranes (PROM), mode of delivery, and neonatal outcomes including anthropometric characterize and Apgar score (one and fifth-minute).

RESULTS

Results show that there are no statistically significant differences between the two groups in terms of PTB in < 34th (15.51% vs. 17.86%; P = 0.73) and 34-37th weeks of pregnancy (8.7% vs. 16.1%; P = 0.22), and mode of delivery (P = 0.09). PPROM (8.7% vs. 28.5%; P = 0.006) PROM (10.3% vs. 25%; P = 0.04) was significantly lower in patients receiving probiotic adjuvant compared to the control group. After delivery, the findings of the present study showed that there were no significant differences in newborn's weight (3082.46 ± 521.8vs. 2983.89 ± 623.89), head circumstance (36.86 ± 1.53vs. 36.574 ± 1.52), height (45.4 ± 5.34 vs. 47.33 ± 4.92) and Apgar score in one (0.89 ± 0.03 vs. 0.88 ± 0.05) and five minutes (0.99 ± 0.03vs. 0.99 ± 0.03) after birth.

CONCLUSION

Our result has shown that the consumption of Lactofem probiotic from the 16th week until 37th of pregnancy can lead to a reduction of complications such as PPROM and PROM.

Prevalence of Bacterial Vaginosis and Its Association With Preterm Birth in a Tertiary Care Hospital in Chennai: A Cross-Sectional Study

Background The most common preventive cause of premature labour is ascending infections. This study was conducted to evaluate the association between bacterial vaginosis (BV) and preterm labour in antenatal women and determine the significance of using the Amsel criteria to screen for BV. Methods This was a hospital-based cross-sectional study conducted among 100 antenatal mothers in the second trimester attending the antenatal OPD at a tertiary care hospital in Chennai from October 2019 to September 2021 after obtaining clearance from the institutional ethics committee and written informed consent from the study participants. Data were entered in Excel (Microsoft Corporation, Redmond, WA) and analysed in SPSS (IBM Corp., Armonk, NY). Results According to the Amsel criteria, BV was detected in 21 women (21%). Neither maternal age nor parity had an effect on the study group. There was a statistically significant relationship (p < 0.05) between the mode of delivery, preterm labour, and the study group. Of the 21 positive BV cases, 95% were positive for clue cells and only 5% were positive for gram-negative bacteria. Consequently, BV was found to be associated with early labour. There is no association between BMI and BV (p > 0.005). Conclusion In the current study, BV was shown to be associated with preterm labour. Our study underscores the significance of the Amsel criteria as a valuable tool for screening BV in antenatal women.

Antenatal interventions to reduce risk of low birth weight related to maternal infections during pregnancy

BACKGROUND

Maternal infections during pregnancy have been linked to increased risk of adverse birth outcomes, including low birth weight (LBW), preterm birth (PTB), small for gestational age (SGA), and stillbirth (SB).

OBJECTIVES

The purpose of this article was to summarize evidence from published literature on the effect of key interventions targeting maternal infections on adverse birth outcomes.

METHODS

We searched MEDLINE, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and CINAHL Complete between March 2020 and May 2020 with an update to cover until August 2022. We included randomized controlled trials (RCTs) and reviews of RCTs of 15 antenatal interventions for pregnant women reporting LBW, PTB, SGA, or SB as outcomes.

RESULTS

Of the 15 reviewed interventions, the administration of 3 or more doses of intermittent preventive treatment in pregnancy with sulphadoxine-pyrimethamine [IPTp-SP; RR: 0.80 (95% CI: 0.69, 0.94)] can reduce risk of LBW compared with 2 doses. The provision of insecticide-treated bed nets, periodontal treatment, and screening and treatment of asymptomatic bacteriuria may reduce risk of LBW. Maternal viral influenza vaccination, treatment of bacterial vaginosis, intermittent preventive treatment with dihydroartemisinin-piperaquine compared with IPTp-SP, and intermittent screening and treatment of malaria during pregnancy compared with IPTp were deemed unlikely to reduce the prevalence of adverse birth outcomes.

CONCLUSIONS

At present, there is limited evidence from RCTs available for some potentially relevant interventions targeting maternal infections, which could be prioritized for future research.

Exploration of Maternal and Fetal Toxicity Risks for Metronidazole-Related Teratogenicity and Hepatotoxicity through an Assessment in Albino Rats

Metronidazole is the primary antimicrobial drug for treating acute and chronic vaginal pathogens during pregnancy; however, there has been insufficient research on placental disorders, early pregnancy loss, and preterm birth. Here, the potential activity of metronidazole on pregnancy outcomes was investigated. 130 mg/kg body weight of metronidazole was orally given individually to pregnant rats on gestation days 0-7, 7-14, and 0-20. Pregnancy outcome evaluations were carried out on gestation day 20. It was demonstrated that metronidazole could induce maternal and fetal hepatotoxicity. There is a significant increase in the activities of maternal hepatic enzymes (ALT, AST, and ALP), total cholesterol, and triglycerides compared with the control. These biochemical findings were evidenced by maternal and fetal liver histopathological alterations. Furthermore, metronidazole caused a significant decrease in the number of implantation sites and fetal viability, whereas it caused an increase in fetal lethality and the number of fetal resorptions. In addition, a significant decrease in fetal weight, placental weight, and placental diameter was estimated. Macroscopical examination revealed placental discoloration and hypotrophy in the labyrinth zone and the degeneration of the basal zone. The fetal defects are related to exencephaly, visceral hernias, and tail defects. These findings suggest that the administration of metroniazole during gestation interferes with embryonic implantation and fetal organogenesis and enhances placental pathology. We can also conclude that metronidazole has potential maternal and fetal risks and is unsafe during pregnancy. Additionally, it should be strictly advised and prescribed, and further consideration should be given to the associated health risks.

Antibiotic treatment of bacterial vaginosis to prevent preterm delivery: Systematic review and individual participant data meta-analysis

BACKGROUND

Bacterial vaginosis (BV) increases preterm delivery (PTD) risk, but treatment trials showed mixed results in preventing PTD.

OBJECTIVES

Determine, using individual participant data (IPD), whether BV treatment during pregnancy reduced PTD or prolonged time-to-delivery.

DATA SOURCES

Cochrane Systematic Review (2013), MEDLINE, EMBASE, journal searches, and searches (January 2013-September 2022) ("bacterial vaginosis AND pregnancy") of (i) clinicaltrials.gov; (ii) Cochrane Central Register of Controlled Trials; (iii) World Health Organization International Clinical Trials Registry Platform Portal; and (iv) Web of Science ("bacterial vaginosis").

STUDY SELECTION AND DATA EXTRACTION

Studies randomising asymptomatic pregnant individuals with BV to antibiotics or control, measuring delivery gestation. Extraction was from original data files. Bias risk was assessed using the Cochrane tool. Analysis used "one-step" logistic and Cox random effect models, adjusting gestation at randomisation and PTD history; heterogeneity by I2 . Subgroup analysis tested interactions with treatment. In sensitivity analyses, studies not providing IPD were incorporated by "multiple random-donor hot-deck" imputation, using IPD studies as donors.

RESULTS

There were 121 references (96 studies) with 23 eligible trials (11,979 participants); 13 studies (6915 participants) provided IPD; 12 (6115) were incorporated. Results from 9 (4887 participants) not providing IPD were imputed. Odds ratios for PTD for metronidazole and clindamycin versus placebo were 1.00 (95% CI 0.84, 1.17), I2  = 62%, and 0.59 (95% CI 0.42, 0.82), I2  = 0 before; and 0.95 (95% CI 0.81, 1.11), I2  = 59%, and 0.90 (95% CI: 0.72, 1.12), I2  = 0, after imputation. Time-to-delivery did not differ from null with either treatment. Including imputed IPD, there was no evidence that either drug was more effective when administered earlier, or among those with a PTD history.

CONCLUSIONS

Clindamycin, but not metronidazole, was beneficial in studies providing IPD, but after imputing data from missing IPD studies, treatment of BV during pregnancy did not reduce PTD, nor prolong pregnancy, in any subgroup or when started earlier in gestation.

Pregnancy in Patients with Inflammatory Bowel Diseases-A Literature Review

In recent years, we have faced an increasing incidence of inflammatory bowel disease (IBD), especially among young people, affecting them during their reproductive years. The paucity of data and reduced knowledge regarding the evolution of the disease during pregnancy and the adverse effects of the therapy on the mother and infant increase voluntary childlessness in this group of patients. Depending on the type of IBD, severity and surgical or medical management, this can negatively affect the pregnancy. C-sections and the risk of low-birth-weight babies are higher in women with IBD, independent of active/inactive disease, while preterm birth, stillbirth and miscarriage are associated with disease activity. In the last period, medicinal therapy has evolved, and new molecules have been developed for better control of the lesions, but the effect on pregnancy and breastfeeding is still controversial. We conducted this review by studying the literature and recent research in order to have a better image of the practical management of IBD during pregnancy.

Investigating the efficacy and safety of metronidazole during pregnancy; A systematic review and meta-analysis

OBJECTIVE

We aimed to review and analyze studies focusing on the efficacy of metronidazole in reducing the risk of preterm birth and the safety of metronidazole taking into account the different doses, duration of treatment and routes of administration.

STUDY DESIGNS

Embase, Cochrane Library and PubMed were searched up to 29 July 2019 to identify studies assessing metronidazole exposure during pregnancy. Additional studies were identified from reference lists of retrieved papers. Measured outcomes were preterm births (<37 weeks of gestation) and associated delivery outcomes such as spontaneous abortions (≤ 20 weeks of gestation), stillbirths (≥20 weeks of gestation) and low birth weight (<2500 g) irrespective of the period of exposure and major malformations after first-trimester exposure. Overall effect estimates for RCTs and observational studies were calculated using the random-effects model and pooled using Risk Ratios (RR) and Odds Ratios (OR) respectively. ROB-2 and ROBINS-I tool were used to assess Risk of Bias for RCTs and observational studies, respectively.

RESULTS

Twenty-four studies (17 observational studies and 7 RCTs) were selected. Pooled RR was 1.10 (95 % CI 0.78-1.55; n = 7; I2 = 72 %) for preterm birth. Subgroup analysis found RR 1.67; 95 % CI 1.07-2.62; n = 3; I² = 32 %) for treatment duration of ≤3 days among women with a previous preterm delivery. Pooled OR for spontaneous abortion was 1.72 (95 % CI 1.40-2.12; n = 5; I2 = 72 %) and 1.15 (95 % CI 0.98-1.34; n = 12; I2 = 25 %) for major malformations. After exclusion of studies with critical risk of bias, pooled OR were 1.7 (1.42-2.04; n = 3; I2 = 19 %) and 1.13 (0.93-1.36; n = 9; I2 = 28 %) respectively. Among several specific malformations analyzed, only congenital hydrocephaly was significantly increased at 4.06 (95 % CI 1.75-9.42; n = 2; I² = 0%).

CONCLUSIONS

Data do not confirm the efficacy of metronidazole in reducing the risk of preterm birth and associated delivery outcomes. Further research is required to confirm the effect of high dose and short duration of metronidazole treatment on preterm birth among the high-risk group. Regarding the increased odds of spontaneous abortion, RCTs are required to assess the role of the underlying infection. The need for further studies to confirm the risk of congenital hydrocephaly is paramount.

Use of medications during pregnancy and breastfeeding for Crohn's disease and ulcerative colitis

Introduction: The peak age of diagnosis of inflammatory bowel disease (IBD) occurs during childbearing years, therefore management of IBD during pregnancy is a frequent occurrence. Maintenance of disease remission is crucial to optimize pregnancy outcomes, and potential maternal or fetal toxicity from medications must be balanced against the risks of untreated IBD.Areas covered: This review summarizes the literature on safety and use of medications for IBD during pregnancy and lactation.Expert opinion: 5-aminosalicylates, corticosteroids and thiopurines are safe for use during pregnancy, while methotrexate and tofacitinib should only be used with extreme caution. Anti-TNF agents (except certolizumab), vedolizumab, ustekinumab and tofacitinib readily traverse the placenta via active transport, therefore theoretically may affect fetal development. Certolizumab only undergoes passive transfer across the placenta, thus has markedly lower cord blood levels making it likely the safest biologic agent for infants. There is reasonable evidence to support the safety of anti-TNF monotherapy and combination therapy during pregnancy and lactation. Vedolizumab and ustekinumab are also thought to be safe in pregnancy and lactation, while tofacitinib is generally avoided due to teratogenic effects in animal studies.

Effect of metronidazole on placental and fetal development in albino rats

Metronidazole is an antiprotozoal and antibacterial used in gynecology and obstetrics for the treatment of parasitic infections. However, despite having clinical use for more than three decades, questions about the safety of its use during pregnancy is not well understood. Thus, the present study evaluated the effect of metronidazole on placental and fetal development in pregnant rats. Metronidazole was orally administered by gavage at a dosage of 130 mg/kg for 7 and 14 days. Morphological analysis, morphometry and immunohistochemistry were performed at the implantation sites and placentas with 14 days of development. The results showed that in the treated group there was a significant reduction in the number of implantation sites, total placental disc area and constituent elements of the labyrinth and spongiotrophoblast layers. Histochemical analysis revealed no significant changes in the content of collagen, elastic and reticular fibers. The TUNEL test showed apoptotic activity in the implantation sites and placentas with 14 days of development independent of the treatment. There was no evidence of malformation in the neonates. However, there was a significant reduction in the number and weight of neonates in the group treated with metronidazole when compared to the control group. Thus, it is concluded that the administration of 130 mg/kg of metronidazole during pregnancy in rats, in addition to interfering with the number of implanted embryos, promotes changes in placental structure and interferes with fetal development. This suggests that this drug should be used with caution during pregnancy.

Fetal fibronectin testing for reducing the risk of preterm birth

BACKGROUND

Fetal fibronectin (FFN) is an extracellular matrix glycoprotein localized at the maternal-fetal interface of the amniotic membranes, between chorion and decidua, where it is concentrated in this area between decidua and trophoblast. In normal conditions, FFN is found at very low levels in cervicovaginal secretions. Levels greater than or equal to 50 ng/mL at or after 22 weeks have been associated with an increased risk of spontaneous preterm birth. In fact, FFN is one of the best predictors of preterm birth in all populations studied so far, and can help in selecting which women are at significant risk for preterm birth. This is an update of a review first published in 2008.

OBJECTIVES

To assess the effectiveness of management based on knowledge of FFN testing results for preventing preterm birth.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register (7 September 2018), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (7 September 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials of pregnant women screened with FFN for risk of preterm birth. Studies included are based exclusively on knowledge of FFN results versus no such knowledge, and we have excluded studies including women with only positive or only negative FFN results.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We identified 16 trials, of which six were eligible for inclusion. The six included studies randomized 546 women with singleton gestations and threatened preterm labor (PTL) at 23 0/7 to 34 6/7 weeks. A total of 277 women were randomized to knowledge and 269 to no knowledge of FFN. No trials were identified on asymptomatic women or multiple gestations.The risk of bias of included studies was mixed. For selected important outcomes, preterm birth before 37, 34, and 32 weeks, and maternal hospitalization, we graded the quality of the evidence and created a 'Summary of findings' table. For these outcomes, the evidence was graded as mainly low quality due to the imprecision of effect estimates.Management based on knowledge of FFN results may reduce preterm birth before 37 weeks (21.6%) versus controls without such knowledge (29.2%) (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.52 to 1.01; 4 trials; 357 women; low-quality evidence). However, management based on knowledge of FFN results may make little or no difference to preterm birth before 34 (RR 1.09, 95% CI 0.54 to 2.18; 4 trials; 357 women; low-quality evidence) or maternal hospitalization (RR 1.06, 95% CI 0.79 to 1.43; 5 trials; 441 women; low-quality evidence). The evidence for preterm birth before 32 weeks is uncertain because the quality was found to be very low (average RR 0.79, 95% CI 0.16 to 3.96; 4 trials; 357 women; very low-quality evidence).For all other outcomes, for which there were available data (preterm birth less than 28 weeks; gestational age at delivery (weeks); birthweight less than 2500 g; perinatal death; tocolysis; steroids for fetal lung maturity; time to evaluate; respiratory distress syndrome; neonatal intensive care unit (NICU) admission; and NICU days), knowledge of FFN results may make little or no difference to the outcomes.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that management based on knowledge of FFN results may reduce preterm birth before 37 weeks. However, our confidence in this result is limited as the evidence was found to be of low quality. Effects on other substantive outcomes are uncertain due to serious concerns in study design, inconsistency, and imprecision of effect estimates. No trials were identified on asymptomatic women, or multiple gestations.Future studies are needed that include specific populations (e.g. singleton gestations with symptoms of preterm labor), a study group managed with a protocol based on the FFN results, and that report not only maternal but also important perinatal outcomes. Cost-effectiveness analyses are also needed.

No. 211-Screening and Management of Bacterial Vaginosis in Pregnancy

OBJECTIVE

To review the evidence and provide recommendations on screening for and management of bacterial vaginosis in pregnancy.

OPTIONS

The clinical practice options considered in formulating the guideline.

OUTCOMES

Outcomes evaluated include antibiotic treatment efficacy and cure rates, and the influence of the treatment of bacterial vaginosis on the rates of adverse pregnancy outcomes such as preterm labour and delivery and preterm premature rupture of membranes.

EVIDENCE

Medline, EMBASE, CINAHL, and Cochrane databases were searched for articles, published in English before the end of June 2007 on the topic of bacterial vaginosis in pregnancy.

VALUES

The evidence obtained was rated using the criteria developed by the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Guideline implementation will assist the practitioner in developing an approach to the diagnosis and treatment of bacterial vaginosis in pregnant women. Patients will benefit from appropriate management of this condition.

VALIDATION

These guidelines have been prepared by the Infectious Diseases Committee of the SOGC, and approved by the Executive and Council of the SOGC.

SPONSORS

The Society of Obstetricians and Gynaecologists of Canada.

RECOMMENDATIONS

There is currently no consensus as to whether to screen for or treat bacterial vaginosis in the general pregnant population in order to prevent adverse outcomes, such as preterm birth.

Association between preterm delivery and bacterial vaginosis with or without treatment

The relationship between bacterial vaginosis (BV) and preterm delivery has become well known in recent years, although there are few studies on: (i) the differences in test results during the early gestational (EGP) and middle gestational (MGP) periods; (ii) the significance of the intermediate (I) group that does not develop overt BV; or (iii) the therapeutic effects of metronidazole. We performed a retrospective study to analyze the relationship between the vaginal bacterial status and the preterm delivery rate. Without treatment, the preterm delivery rate was higher in the BV subgroup than in the I and normal (N) subgroups (p = 0.021) in the EGP, whereas the rates in the BV and I subgroups were higher than in the N subgroup in the MGP (p = 0.0003). Although treatment of BV by metronidazole vaginal tablets significantly increased the N subgroup in the MGP (p = 0.020), there was no significant improvement in the preterm delivery rate. Decreasing the rate of preterm delivery requires development of treatment methods that will further increase the percentage of patients who test N during the MGP after BV during the EGP.

The fetal fibronectin test: 25 years after its development, what is the evidence regarding its clinical utility? A systematic review and meta-analysis

Background: The identification of women at risk for preterm birth should allow interventions which could improve neonatal outcome. Fetal fibronectin, a glycoprotein which acts normally as glue between decidua and amniotic membranes could be a good marker of impending labour when its concentration in cervicovaginal secretions between 22 and 36 weeks of gestation is ≥50 ng/mL. Many authors worldwide have tested this marker with many different methodologies and clinical settings, but conclusions about its clinical use are mixed. It is time for a comprehensive update through a systematic review and meta-analysis.Methods: We searched PubMed, Cochrane Library, and Embase, supplemented by manual search of bibliographies of known primary and review articles, international conference papers, and contact with experts from 1-1990 to 2-2018. We have selected all type of studies involving fetal fibronectin test accuracy for preterm delivery. Two authors independently extracted data about study characteristics and quality from identified publications. Contingency tables were constructed. Reference standards were preterm delivery before 37, 36, 35, 34, and 32 weeks, within 28, 21, 14, or 7 d and within 48 h. Data were pooled to produce summary likelihood ratios for positive and negative tests results.Results: One hundred and ninety-three primary studies were identified allowing analysis of 53 subgroups. In all settings, none of the summary likelihood ratios were >10 or <0.1, thus indicating moderate prediction, particularly in asymptomatic women and in multiple gestations.Conclusions: The fetal fibronectin test should not be used as a screening test for asymptomatic women. For high-risk asymptomatic women, and especially for women with multiple pregnancies, the performance of the fetal fibronectin test was also too low to be clinically relevant. Consensual use as a diagnostic tool for women with suspected preterm labor, the best use policy probably still depends on local contingencies, future cost-effectiveness analysis, and comparison with other more recent available biochemical markers.

The effect of blood staining on cervicovaginal quantitative fetal fibronectin concentration and prediction of spontaneous preterm birth

OBJECTIVE

Spontaneous preterm birth is the leading cause of neonatal morbidity and mortality. Cervicovaginal fetal fibronectin (fFN) has enhanced prediction of preterm birth and, more recently, quantified results have become available so that management can planned more effectively and targeted to individual women. Manufacture guidelines stipulate that fetal fibronectin (fFN) samples should be discarded in the presence of moderate to heavy vaginal bleeding but there hasn't yet been any formal investigation into the effect of blood staining on fetal fibronectin concentration and subsequent preterm birth prediction. The objective for this study was to determine the impact of blood stained swabs on quantitative fetal fibronectin (qfFN) concentration and prediction of spontaneous preterm birth (sPTB) in asymptomatic high-risk women.

STUDY DESIGN

Predefined blinded sub-analysis of a larger prospective study of qfFN in asymptomatic women at high-risk of preterm labour. Women with and without blood stained swabs were matched for gestational age at testing and delivery, risk factors and cervical length measurement.

RESULTS

Median fFN concentration in blood stained swabs (n=58) was 66ng/ml vs. 7.5ng/ml in the controls (n=58) (p<0.0001). At ≥50ng/ml threshold the false positive ratio (FPR) in blood stained was 25/33 (75.8%) vs. 8/15 (53%) in controls, (risk difference 22.4; -6.8 to 51.6, p=0.18). At ≥50ng/ml threshold the false-negative ratio (FNR) in blood stained was 2/25 (8.0%) vs. 1/43 (2.3%) in controls (risk difference -5.7; -17.2 to 5.9, p=0.55). At each threshold 10, 50 and 200ng/ml blood stained swabs had higher sensitivity but lower specificity for predicting preterm birth. Receiver Operating Characteristic (ROC) curve, the strongest global measure of test performance, for prediction of delivery at <34 weeks gestation was similar in blood stained vs. control groups. (0.78 vs. 0.84) in blood stained vs. control groups respectively.

CONCLUSION

Blood stained swabs have elevated qfFN concentrations but may still have predictive value, and clinical utility. Very low fFN values (<10ng/ml) are especially reassuring and indicate lower risk of delivery than non-blood stained swabs. The higher false positive rate must be noted and explained to the patient.

[Bacterial vaginosis and spontaneous preterm birth]

OBJECTIVE

To determine if bacterial vaginosis is a marker for risk of spontaneous preterm delivery and if its detection and treatment can reduce this risk.

METHODS

Consultation of the database Pubmed/Medline, Science Direct, and international guidelines of medical societies.

RESULTS

Bacterial vaginosis (BV) is a dysbiosis resulting in an imbalance in the vaginal flora through the multiplication of anaerobic bacteria and jointly of a disappearance of well-known protective Lactobacilli. His diagnosis is based on clinical Amsel criteria and/or a Gram stain with establishment of the Nugent score. The prevalence of the BV extraordinarily varies according to ethnic and/or geographical origin (4-58 %), in France, it is close to 7 % in the first trimester of pregnancy (EL2). The link between BV and spontaneous premature delivery is low with an odds ratio between 1.5 and 2 in the most recent studies (EL3). Metronidazole or clindamycin is effective to treat BV (EL3). It is recommended to prescribe one of these antibiotics in the case of symptomatic BV (Professional Consensus). The testing associated with the treatment of BV in the global population showed no benefit in the prevention of the risk of spontaneous preterm delivery (EL2). Concerning low-risk asymptomatic population (defined by the absence of antecedent of premature delivery), it has been failed profit to track and treat the BV in the prevention of the risk of spontaneous preterm delivery (EL1). Concerning the high-risk population (defined by a history of preterm delivery), it has been failed profit to track and treat the VB in the prevention of the risk of spontaneous preterm delivery (EL3). However, in the sub population of patients with a history of preterm delivery occurred in a context of materno-fetal bacterial infection, there may be a benefit to detect and treat early and systematically genital infection, and in particular the BV (Professional Consensus).

CONCLUSION

The screening and treatment of BV during pregnancy in asymptomatic low-risk population is not recommended in the prevention of the risk of spontaneous preterm delivery (grade A). In the population at high risk with the only notion of antecedent of premature delivery, screening and treatment of the BV is not recommended (grade C).

The bacterial etiology of preterm birth

Preterm birth is the leading cause of infant morbidity and mortality. Very preterm births, those occurring before 32 completed weeks of gestation, are associated with the greatest risks. The leading cause of very preterm birth is intrauterine infection, which can lead to an inflammatory response that triggers labor or preterm premature rupture of membranes. How bacteria invade the uterine cavity, which is normally a sterile environment, and the reasons why different species vary in their capacity to induce inflammation and preterm birth are still incompletely understood. However, advanced techniques that circumvent the need for cultivating bacteria, deep sequence analysis that allows for the comprehensive characterization of the microbiome of a given body site and detection of low-prevalence species, and transcriptomics and metabolomics approaches that shed light on the host response to bacterial invasion are all providing a more complete picture of the progression from vaginal colonization to uterine invasion to preterm labor and preterm birth.

Advances in the Prevention of Infection-Related Preterm Birth

Infection-related preterm birth (PTB) is more common at early gestational ages and is associated with major neonatal mortality and morbidity. Abnormal genital tract microflora in early pregnancy predicts late miscarriage and early PTB. Accordingly, it is logical to consider antibiotics as an intervention. Unfortunately, the conclusions of systematic reviews and meta-analyses (SR&MAs) carried out in an attempt to explain the confusion over the heterogeneity of individual studies are flawed by the fact that undue reliance was placed on studies which: (a) had a suboptimal choice of antibiotic (mainly metronidazole) or used antibiotics not recommended for the treatment of bacterial vaginosis (BV) or BV-related organisms; (b) used antibiotics too late in pregnancy to influence outcome (23–27 weeks); and (c) included women whose risk of PTB was not due to abnormal genital tract colonization and hence unlikely to respond to antibiotics. These risks included: (a) previous PTB of indeterminate etiology; (b) low weight/body mass index; or (c) detection of fetal fibronectin, ureaplasmas, Group B streptococcus or Trichomonas vaginalis). While individual studies have found benefit of antibiotic intervention for the prevention of PTB, in meta-analyses these effects have been negated by large methodologically flawed studies with negative results. As a result, many clinicians think that any antibiotic given at any time in pregnancy to any woman at risk of PTB will cause more harm than good. Recently, a more focused SR&MA has demonstrated that antibiotics active against BV-related organisms, used in women whose risk of PTB is due to abnormal microflora, and used early in pregnancy before irreversible inflammatory damage has occurred, can reduce the rate of PTB. This review presents those data, the background and attempts to explain the confusion using new information from culture-independent molecular-based techniques. It also gives guidance on the structure of putative future antibiotic intervention studies.

Quantitative fetal fibronectin to predict preterm birth in asymptomatic women at high risk

OBJECTIVE

To evaluate the diagnostic accuracy of cervicovaginal fluid quantitative fetal fibronectin, measured by a bedside analyzer, to predict spontaneous preterm birth before 34 weeks of gestation.

METHODS

We conducted a prospective masked observational cohort study of cervicovaginal fluid quantitative fetal fibronectin concentration in asymptomatic women at high risk of spontaneous preterm birth (n=1,448; 22-27 6/7 weeks of gestation) measured using a rapid bedside analyzer. The routine qualitative result (positive-negative) was made available to clinicians at the time of testing, but the quantitative result remained blinded until after delivery.

RESULTS

Spontaneous preterm birth (less than 34 weeks of gestation) increased from 2.7%, 11.0%, 14.9%, 33.9%, and 47.6% with increasing concentration of fetal fibronectin (less than 10, 10-49, 50-199, 200-499, and 500 ng/mL or greater, respectively). A threshold of 200 ng/mL had a positive predictive value of 37.7 (95% confidence interval [CI] 26.9-49.4) with specificity 96% (95% CI 95.3-97.3). Women with a fetal fibronectin concentration of less than 10 ng/mL had a very low risk of spontaneous preterm birth at less than 34 weeks of gestation (2.7%), no higher than the background spontaneous preterm birth rate of the general hospital population (3.3%). The quantitative fetal fibronectin test predicted birth at less than 34 weeks of gestation with an area under the curve (AUC) of 0.78 (95% CI 0.73-0.84) compared with the qualitative test AUC 0.68 (95% CI 0.63-0.73). Quantitative fetal fibronectin discriminated risk of spontaneous preterm birth at less than 34 weeks of gestation among women with a short cervix (less than 25 mm); 9.5% delivered prematurely less than 10 ng/mL compared with 55.1% greater than 200 ng/mL (P<.001).

DISCUSSION

Alternative risk thresholds (less than 10 ng/mL and greater than 200 ng/mL) improve accuracy when using quantitative fetal fibronectin measurements to define risk of spontaneous preterm birth. This is particularly relevant for asymptomatic women with a short cervix.

LEVEL OF EVIDENCE

II.

Antibiotic prophylaxis during the second and third trimester to reduce adverse pregnancy outcomes and morbidity

BACKGROUND

Several studies have suggested that prophylactic antibiotics given during pregnancy improved maternal and perinatal outcomes, while others have shown no benefit and some have reported adverse effects.

OBJECTIVES

To determine the effect of prophylactic antibiotics on maternal and perinatal outcomes during the second and third trimester of pregnancy for all women or women at risk of preterm delivery.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2015) and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials comparing prophylactic antibiotic treatment with placebo or no treatment for women in the second or third trimester of pregnancy before labour.

DATA COLLECTION AND ANALYSIS

We assessed trial quality and extracted data.

MAIN RESULTS

The review included eight randomised controlled trials. Approximately 4300 women were recruited to detect the effect of prophylactic antibiotic administration on pregnancy outcomes. Primary outcomesAntibiotic prophylaxis did not reduce the risk of preterm prelabour rupture of membranes (risk ratio (RR) 0.31; 95% confidence interval (CI) 0.06 to 1.49 (one trial, 229 women), low quality evidence) or preterm delivery (RR 0.88; 95% CI 0.72 to 1.09 (six trials, 3663 women), highquality evidence). However, preterm delivery was reduced in the subgroup of pregnant women with a previous preterm birth who had bacterial vaginosis (BV) during the current pregnancy (RR 0.64; 95% CI 0.47 to 0.88 (one trial, 258 women)), but there was no reduction in the subgroup of pregnant women with previous preterm birth without BV during the pregnancy (RR 1.08; 95% CI 0.66 to 1.77 (two trials, 500 women)). A reduction in the risk of postpartum endometritis (RR 0.55; 95% CI 0.33 to 0.92 (one trial, 196 women)) was observed in high-risk pregnant women (women with a history of preterm birth, low birthweight, stillbirth or early perinatal death) and in all women (RR 0.53; 95% CI 0.35 to 0.82 (three trials, 627 women), moderate quality evidence). There was no difference in low birthweight (RR 0.86; 95% CI 0.53 to 1.39 (four trials; 978 women)) or neonatal sepsis (RR 11.31; 95% CI 0.64 to 200.79) (one trial, 142 women)); and blood culture confirming sepsis was not reported in any of the studies. Secondary outcomesAntibiotic prophylaxis reduced the risk of prelabour rupture of membranes (RR 0.34; 95% CI 0.15 to 0.78 (one trial, 229 women), low quality evidence) and gonococcal infection (RR 0.35; 95% CI 0.13 to 0.94 (one trial, 204 women)). There were no differences observed in other secondary outcomes (congenital abnormality; small-for-gestational age; perinatal mortality), whilst many other secondary outcomes (e.g. intrapartum fever needing treatment with antibiotics) were not reported in included trials.Regarding the route of antibiotic administration, vaginal antibiotic prophylaxis during pregnancy did not prevent infectious pregnancy outcomes. The overall risk of bias was low, except that incomplete outcome data produced high risk of bias in some studies. The quality of the evidence using GRADE was assessed as low for preterm prelabour rupture of membranes, high for preterm delivery, moderate for postpartum endometritis, low for prelabour rupture of membranes, and very low for chorioamnionitis. Intrapartum fever needing treatment with antibiotics was not reported in any of the included studies.

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis did not reduce the risk of preterm prelabour rupture of membranes or preterm delivery (apart from in the subgroup of women with a previous preterm birth who had bacterial vaginosis). Antibiotic prophylaxis given during the second or third trimester of pregnancy reduced the risk of postpartum endometritis, term pregnancy with pre-labour rupture of membranes and gonococcal infection when given routinely to all pregnant women. Substantial bias possibly exists in the review's results because of a high rate of loss to follow-up and the small numbers of studies included in each of our analyses. There is also insufficient evidence on possible harmful effects on the baby. Therefore, we conclude that there is not enough evidence to support the use of routine antibiotics during pregnancy to prevent infectious adverse effects on pregnancy outcomes.

Antibiotic prophylaxis during the second and third trimester to reduce adverse pregnancy outcomes and morbidity

BACKGROUND

Several studies have suggested that prophylactic antibiotics given during pregnancy improved maternal and perinatal outcomes, while others have shown no benefit and some have reported adverse effects.

OBJECTIVES

To determine the effect of prophylactic antibiotics on maternal and perinatal outcomes during the second and third trimester of pregnancy for all women or women at risk of preterm delivery.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014) and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials comparing prophylactic antibiotic treatment with placebo or no treatment for women in the second or third trimester of pregnancy before labour.

DATA COLLECTION AND ANALYSIS

We assessed trial quality and extracted data.

MAIN RESULTS

The review included seven randomised controlled trials. Approximately 2100 women were recruited to detect the effect of prophylactic antibiotic administration on pregnancy outcomes. Primary outcomesAntibiotic prophylaxis did not reduce the risk of preterm prelabour rupture of membranes (risk ratio (RR) 0.31; 95% confidence interval (CI) 0.06 to 1.49 (one trial, 229 women) low quality evidence) or preterm delivery (RR 0.85; 95% CI 0.64 to 1.14 (five trials, 1480 women) low quality evidence). However, preterm delivery was reduced in the subgroup of pregnant women with a previous preterm birth who had bacterial vaginosis (BV) during the current pregnancy (RR 0.64; 95% CI 0.47 to 0.88 (one trial, 258 women), but there was no reduction in the subgroup of pregnant women with previous preterm birth without BV during the pregnancy (RR 1.08; 95% CI 0.66 to 1.77 (two trials, 500 women)). A reduction in the risk of postpartum endometritis (RR 0.55; 95% CI 0.33 to 0.92 (one trial, 196 women)) was observed in high-risk pregnant women (women with a history of preterm birth, low birthweight, stillbirth or early perinatal death) and in all women (RR 0.53; 95% CI 0.35 to 0.82 (three trials, 627 women) moderate quality evidence). There was no difference in low birth weight (RR 0.86; 95% CI 0.53 to 1.39 (four trials; 978 women) or neonatal sepsis (RR 11.31; 95% CI 0.64 to 200.79); and blood culture confirming sepsis was not reported in any of the studies. Secondary outcomesAntibiotic prophylaxis reduced the risk of prelabour rupture of membranes (RR 0.34; 95% CI 0.15 to 0.78 (one trial, 229 women) low quality evidence) and gonococcal infection (RR 0.35; 95% CI 0.13 to 0.94 (one trial, 204 women)). There were no differences observed in other secondary outcomes (congenital abnormality; small-for-gestational age; perinatal mortality), whilst many other secondary outcomes (e.g. intrapartum fever needing treatment with antibiotics) were not reported in included trials.Regarding the route of antibiotic administration, vaginal antibiotic prophylaxis during pregnancy did not prevent infectious pregnancy outcomes. The overall risk of bias was low except that incomplete outcome data produced high risk of bias in some studies. The quality of the evidence using GRADE was assessed as low for preterm prelabour rupture of membranes, low for preterm delivery, moderate for postpartum endometritis, low for prelabour rupture of membranes, and very low for chorioamnionitis. Intrapartum fever needing treatment with antibiotics was not reported in any of the included studies.

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis did not reduce the risk of preterm prelabour rupture of membranes or preterm delivery (apart from in the subgroup of women with a previous preterm birth who had bacterial vaginosis). Antibiotic prophylaxis given during the second or third trimester of pregnancy reduced the risk of postpartum endometritis, preterm rupture of membranes and gonococcal infection when given routinely to all pregnant women. Substantial bias possibly exists in the review's results because of a high rate of loss to follow-up and the small numbers of studies included in each of our analyses. There is also insufficient evidence on possible harmful effects on the baby. Therefore, we conclude that there is not enough evidence to recommend the use of routine antibiotics during pregnancy to prevent infectious adverse effects on pregnancy outcomes.

VAGINAL MICROBIOME–PREGNANT HOST INTERACTIONS DETERMINE A SIGNIFICANT PROPORTION OF PRETERM LABOUR

Preterm birth (PTB) has a global prevalence of 11.1% accounting for almost 15 million babies born each year before 37 weeks of gestation. It is a risk factor in over 50% of all neonatal deaths, which amounts to 1.1 million deaths annually. Preterm birth, especially at early gestational ages is associated with a high risk of long-term morbidity in survivors. Despite much research effort, PTB rates continue to rise, placing immense financial and emotional burden on society. In the US, the annual societal economic cost associated with PTB is $26.2 billion with an average of $51,600 being spent per infant born preterm. Preterm labour (PTL) accounts for 70% of these births, of which 25% are preceded by preterm pre-labour rupture of membranes (PPROM).

Lipopolysaccharide-Induced Profiles of Cytokine, Chemokine, and Growth Factors Produced by Human Decidual Cells Are Altered by Lactobacillus rhamnosus GR-1 Supernatant

The aim of this study was to assess the effects of bacterial lipopolysaccharide (LPS) and Lactobacillus rhamnosus GR-1 supernatant (GR-1SN) on secretion profiles of cytokines, chemokines, and growth factors from primary cultures of human decidual cells. Lipopolysaccharide significantly increased the output of proinflammatory cytokines (interleukin [IL]-1B, IL-2, IL-6, IL-12p70, IL-15, IL-17A, interferon gamma [IFN-γ], and tumor necrosis factor [TNF]); anti-inflammatory cytokines (IL-1RN, IL-4, IL-9, and IL-10); chemokines (IL-8, eotaxin, IFN-inducible protein 10 [IP-10], monocyte chemoattractant protein 1 [MCP-1], macrophage inflammatory protein-1α [MIP-1α], macrophage inflammatory protein-1β [MIP-1β], and regulated on activation normal T cell expressed and secreted [RANTES]); and growth factors (granulocyte colony-stimulating factor [CSF] 3, CSF-2, and vascular endothelial growth factor A [VEGFA]). Lactobacillus rhamnosus GR-1SN alone significantly increased CSF-3, MIP-1α MIP-1β, and RANTES but decreased IL-15 and IP-10 output. The GR-1SN also significantly or partially reduced LPS-induced proinflammatory cytokines TNF, IFN-γ, IL-1β, IL-2 IL-6, IL-12p70, IL-15, IL-17, and IP-10; partially reduced LPS-induced anti-inflammatory cytokines IL-1RN, IL-4 and IL-10, and LPS-induced VEGFA output but did not affect CSF-3, MIP-1α, MIP-1β, MCP-1, IL-8, and IL-9. Our results demonstrate that GR-1SN attenuates the inflammatory responses to LPS by human decidual cells, suggesting its potential role in ameliorating intrauterine infection.

Urinary tract infection as a preventable cause of pregnancy complications: opportunities, challenges, and a global call to action

The urinary tract is a common site of infection in humans. During pregnancy, urinary tract infection (UTI) is associated with increased risks of maternal and neonatal morbidity and mortality, even when the infection is asymptomatic. By mapping available rates of UTI in pregnancy across different populations, we emphasize this as a problem of global significance. Many countries with high rates of preterm birth and neonatal mortality also have rates of UTI in pregnancy that exceed rates seen in more developed countries. A global analysis of the etiologies of UTI revealed familiar culprits as well as emerging threats. Screening and treatment of UTI have improved birth outcomes in several more developed countries and would likely improve maternal and neonatal health worldwide. However, challenges of implementation in resource-poor settings must be overcome. We review the nature of the barriers occurring at each step of the screening and treatment pipeline and highlight steps necessary to overcome these obstacles. It is our hope that the information compiled here will increase awareness of the global significance of UTI in maternal and neonatal health and embolden governments, nongovernmental organizations, and researchers to do their part to make urine screening and UTI treatment a reality for all pregnant women.

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.

Intakes of garlic and dried fruits are associated with lower risk of spontaneous preterm delivery

Several studies have found associations between microbial infections during pregnancy and preterm delivery (PTD). We investigated the influence of food with antimicrobial and prebiotic components on the risk of spontaneous PTD. A literature search identified microbes associated with spontaneous PTD. Subsequently, 2 main food types (alliums and dried fruits) were identified to contain antimicrobial components that affect the microbes associated with spontaneous PTD; they also contained dietary fibers recognized as prebiotics. We investigated intake in 18,888 women in the Norwegian Mother and Child Cohort (MoBa), of whom 950 (5%) underwent spontaneous PTD (<37 gestational weeks). Alliums (garlic, onion, leek, and spring onion) [OR: 0.82 (95% CI: 0.72, 0.94), P = 0.005] and dried fruits (raisins, apricots, prunes, figs, and dates) [OR: 0.82 (95% CI: 0.72, 0.94); P = 0.005] were associated with a decreased risk of spontaneous PTD. Intake of alliums was related to a more pronounced risk reduction in early spontaneous PTD (gestational weeks 28-31) [OR: 0.39 (95% CI: 0.19, 0.80)]. The strongest association in this group was with garlic [OR: 0.47 (95% CI: 0.25-0.89)], followed by cooked onions. Intake of dried fruits showed an association with preterm prelabor rupture of membranes (PPROM) [OR: 0.74 (95% CI: 0.65, 0.95)]; the strongest association in this group was with raisins [OR: 0.71 (95% CI: 0.56, 0.92)]. The strongest association with PPROM in the allium group was with garlic [OR: 0.74 (95% CI: 0.56, 0.97)]. In conclusion, intake of food with antimicrobial and prebiotic compounds may be of importance to reduce the risk of spontaneous PTD. In particular, garlic was associated with overall lower risk of spontaneous PTD. Dried fruits, especially raisins, were associated with reduced risk of PPROM.

Antibiotics for treating bacterial vaginosis in pregnancy

BACKGROUND

Bacterial vaginosis is an imbalance of the normal vaginal flora with an overgrowth of anaerobic bacteria and a lack of the normal lactobacillary flora. Women may have symptoms of a characteristic vaginal discharge but are often asymptomatic. Bacterial vaginosis during pregnancy has been associated with poor perinatal outcomes and, in particular, preterm birth (PTB). Identification and treatment may reduce the risk of PTB and its consequences.

OBJECTIVES

To assess the effects of antibiotic treatment of bacterial vaginosis in pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2012), searched cited references from retrieved articles and reviewed abstracts, letters to the editor and editorials.

SELECTION CRITERIA

Randomised trials comparing antibiotic treatment with placebo or no treatment, or comparing two or more antibiotic regimens in pregnant women with bacterial vaginosis or intermediate vaginal flora whether symptomatic or asymptomatic and detected through screening.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

We included 21 trials of good quality, involving 7847 women diagnosed with bacterial vaginosis or intermediate vaginal flora.Antibiotic therapy was shown to be effective at eradicating bacterial vaginosis during pregnancy (average risk ratio (RR) 0.42; 95% confidence interval (CI) 0.31 to 0.56; 10 trials, 4403 women; random-effects, T² = 0.19, I² = 91%). Antibiotic treatment also reduced the risk of late miscarriage (RR 0.20; 95% CI 0.05 to 0.76; two trials, 1270 women, fixed-effect, I² = 0%).Treatment did not reduce the risk of PTB before 37 weeks (average RR 0.88; 95% CI 0.71 to 1.09; 13 trials, 6491 women; random-effects, T² = 0.06, I² = 48%), or the risk of preterm prelabour rupture of membranes (RR 0.74; 95% CI 0.30 to 1.84; two trials, 493 women). It did increase the risk of side-effects sufficient to stop or change treatment (RR 1.66; 95% CI 1.02 to 2.68; four trials, 2323 women, fixed-effect, I² = 0%).In this updated review, treatment before 20 weeks' gestation did not reduce the risk of PTB less than 37 weeks (average RR 0.85; 95% CI 0.62 to 1.17; five trials, 4088 women; random-effects, T² = 0.06, I² = 49%).In women with a previous PTB, treatment did not affect the risk of subsequent PTB (average RR 0.78; 95% CI 0.42 to 1.48; three trials, 421 women; random-effects, T² = 0.19, I² = 72%).In women with abnormal vaginal flora (intermediate flora or bacterial vaginosis), treatment may reduce the risk of PTB before 37 weeks (RR 0.53; 95% CI 0.34 to 0.84; two trials, 894 women).One small trial of 156 women compared metronidazole and clindamycin, both oral and vaginal, with no significant differences seen for any of the pre-specified primary outcomes. Statistically significant differences were seen for the outcomes of prolongation of gestational age (days) (mean difference (MD) 1.00; 95% CI 0.26 to 1.74) and birthweight (grams) (MD 75.18; 95% CI 25.37 to 124.99) however these represent relatively small differences in the clinical setting.Oral antibiotics versus vaginal antibiotics did not reduce the risk of PTB (RR 1.09; 95% CI 0.78 to 1.52; two trials, 264 women). Oral antibiotics had some advantage over vaginal antibiotics (whether metronidazole or clindamycin) with respect to admission to neonatal unit (RR 0.63; 95% CI 0.42 to 0.92, one trial, 156 women), prolongation of gestational age (days) (MD 9.00; 95% CI 8.20 to 9.80; one trial, 156 women) and birthweight (grams) (MD 342.13; 95% CI 293.04 to 391.22; one trial, 156 women).Different frequency of dosing of antibiotics was assessed in one small trial and showed no significant difference for any outcome assessed.

AUTHORS' CONCLUSIONS

Antibiotic treatment can eradicate bacterial vaginosis in pregnancy. The overall risk of PTB was not significantly reduced. This review provides little evidence that screening and treating all pregnant women with bacterial vaginosis will prevent PTB and its consequences. When screening criteria were broadened to include women with abnormal flora there was a 47% reduction in preterm birth, however this is limited to two included studies.

Vaginal progesterone vs. cervical cerclage for the prevention of preterm birth in women with a sonographic short cervix, previous preterm birth, and singleton gestation: a systematic review and indirect comparison metaanalysis

OBJECTIVE

No randomized controlled trial has compared vaginal progesterone and cervical cerclage directly for the prevention of preterm birth in women with a sonographic short cervix in the mid trimester, singleton gestation, and previous spontaneous preterm birth. We performed an indirect comparison of vaginal progesterone vs cerclage using placebo/no cerclage as the common comparator.

STUDY DESIGN

Adjusted indirect metaanalysis of randomized controlled trials.

RESULTS

Four studies that evaluated vaginal progesterone vs placebo (158 patients) and 5 studies that evaluated cerclage vs no cerclage (504 patients) were included. Both interventions were associated with a statistically significant reduction in the risk of preterm birth at <32 weeks of gestation and composite perinatal morbidity and mortality compared with placebo/no cerclage. Adjusted indirect metaanalyses did not show statistically significant differences between vaginal progesterone and cerclage in the reduction of preterm birth or adverse perinatal outcomes.

CONCLUSION

Based on state-of-the-art methods for indirect comparisons, either vaginal progesterone or cerclage are equally efficacious in the prevention of preterm birth in women with a sonographic short cervix in the mid trimester, singleton gestation, and previous preterm birth. Selection of the optimal treatment needs to consider adverse events, cost and patient/clinician preferences.

Advances in medical diagnosis of intra-amniotic infection

INTRODUCTION

Intrauterine infection is a global problem and a significant contributor to morbidity and perinatal death. The host response to infection causes an inflammatory state that acts synergistically with microbial insult to induce preterm birth and fetal damage. Prompt and accurate diagnosis of intra-amniotic infection in the asymptomatic stage of the disease is critical for improved maternal and neonatal outcomes.

AREAS COVERED

This article provides an overview of the most recent progress, challenges, and opportunities for discovery and clinical implementation of various maternal serum, cervicovaginal, and amniotic fluid biomarkers in pregnancies complicated by intra-amniotic infection.

EXPERT OPINION

Clinically relevant biomarkers are critical to the accurate diagnostic of intrauterine infection. Front-end implementation of such biomarkers will also translate in lower incidence of early-onset neonatal sepsis (EONS) which is an important determinant of neonatal morbidity and mortality associated with prematurity. However, of the hundreds of differentially expressed proteins, only few may have clinical utility and thus function as biomarkers. The small number of validation studies along with barriers to implementation of technological innovations in the clinical setting are current limitations.

[Guidelines for the management of Crohn's disease]

Crohn's disease (CD) is a chronic inflammatory bowel disease (IBD) with uncertain etiopathogenesis. CD can involve any site of gastrointestinal tract from the mouth to anus and is associated with serious complications such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower than those of Western countries, but have been rapidly increasing during the past decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies are currently applied for diverse clinical situations of CD. However, a lot of decisions on the management of CD are made depending on the personal experiences and choices of physicians. To suggest preferable approaches to diverse problems of CD and to minimize the variations according to physicians, guidelines for the management of CD are needed. Therefore, IBD Study Group of the Korean Association for the Study of the Intestinal Diseases has set out to develop the guidelines for the management of CD in Korea. These guidelines were developed using the adaptation methods and encompass the treatment of inflammatory disease, stricturing disease, and penetrating disease. The guidelines also cover the indication of surgery, prevention of recurrence after surgery, and CD in pregnancy and lactation. These are the first Korean guidelines for the management of CD and the update with further scientific data and evidences is needed.

The Actim Partus test to predict pre-term birth in asymptomatic high-risk women

The Actim Partus test has been shown to be a useful predictor of pre-term birth in symptomatic women, but limited research has been carried out in high-risk asymptomatic women. This is a pilot study to evaluate the use of this test as a direct comparator with the fetal fibronectin test. All asymptomatic high-risk women attending a pre-term surveillance clinic over a 9-month period, took an Actim Partus and fetal fibronectin test, between 23(+0)-24(+6) weeks' gestation. A total of 45 women were eligible. The positive and negative predictive values of the Actim Partus test for delivery at ≤ 37 weeks' gestation were 0% and 70%, respectively, compared with the fetal fibronectin test, with values of 67% and 79%, respectively. It was concluded that the Actim Partus test did not perform well as a predictor of pre-term birth in high-risk asymptomatic women.

Obstetric management of moderate and late preterm labour

Moderate and late preterm births account for the majority of preterm babies. The common perception that birth at 32-36 weeks' gestation carries few risks is now being challenged, as these babies have increased risk of neonatal mortality and morbidity. However, spontaneous labour at this gestation frequently has no specific, easily identifiable precursor, although preterm birth per se has a number of epidemiological and clinical associations. Prediction and prevention of preterm birth is currently largely aimed at identifying women at high risk such as those with previous preterm birth, and targeting intervention at this group. Both cervical length assessment and fibronectin testing permit some modification of the likelihood of preterm birth in this group. Progesterone treatment for the prevention of preterm birth is currently being researched widely, and appears a potentially promising strategy. Babies born at 32-36 weeks' gestation need careful monitoring in labour, with modification of intervention in labour due to their prematurity.

TLR9 provokes inflammation in response to fetal DNA: mechanism for fetal loss in preterm birth and preeclampsia

Preterm birth, the major cause of neonatal mortality in developed countries, is associated with intrauterine infections and inflammation, although the exact mechanisms underlying this event are unclear. In this study, we show that circulating fetal DNA, which is elevated in pregnancies complicated by preterm labor or preeclampsia, triggers an inflammatory reaction that results in spontaneous preterm birth. Fetal DNA activates NF-κB, shown by IκBα degradation in human PBMCs resulting in production of proinflammatory IL-6. We show that fetal resorption and preterm birth are rapidly induced in mice after i.p. injection of CpG or fetal DNA (300 μg/dam) on gestational day 10-14. In contrast, TLR9(-/-) mice were protected from these effects. Furthermore, this effect was blocked by oral administration of the TLR9 inhibitor chloroquine. Our data therefore provide a novel mechanism for preterm birth and preeclampsia, highlighting TLR9 as a potential therapeutic target for these common disorders of pregnancy.

Antimicrobials for preterm birth prevention: an overview

OBJECTIVE

Preterm birth (PTB) remains a major cause of neonatal morbidity and mortality. The association between PTB and infection is clear. The purpose of this report is to present a focused review of information on the use of antibiotics to prevent PTB.

METHODS

We performed a search of the PubMed database restricted to clinical trials or meta-analyses published in English from 1990 through May 2011 using keywords "antibiotics or antimicrobials" and "preterm."

RESULTS

The search yielded 67 abstracts for review. We selected 31 clinical trials (n = 26) or meta-analysis (n = 5) for further full-text review. Discussion of each eligible clinical trial, its specific inclusion criteria, antibiotic regimen used, and study results are presented. Overall, trials evaluating antibiotic treatment to prevent preterm birth have yielded mixed results regarding any benefit.

CONCLUSION

Routine antibiotic prophylaxis is not recommended for prevention of preterm birth.

Bacterial vaginosis and preterm birth

Although it has been clear for more than 2 decades that bacterial vaginosis increases the risk for preterm birth in some women, it is not yet fully understood why this association exists or how best to modify the risk. Incomplete understanding of this polymicrobial condition and difficulties in classification contribute to the challenge. The relationship between altered vaginal microflora and preterm birth is likely mediated by host immune responses. Because treatment of bacterial vaginosis during pregnancy does not improve preterm birth rates, and may in fact increase them, screening and treatment of asymptomatic pregnant women is discouraged. Symptomatic women should be treated for symptom relief. This article reviews the pathophysiology of bacterial vaginosis and controversy surrounding management during pregnancy. Agents currently recommended for treatment of this condition are reviewed.

Effect of antibiotic exposure on Nugent score among pregnant women with and without bacterial vaginosis

OBJECTIVE

To evaluate whether vaginal flora is altered by antibiotic exposure and associated with a risk of preterm birth, particularly among women with initially normal vaginal flora.

METHODS

This was a secondary analysis of a randomized trial of metronidazole and erythromycin for the prevention of preterm birth among women with a positive fetal fibronectin test. Vaginal swabs for Nugent Gram stain score were collected for classification of bacterial vaginosis before and after antibiotic exposure and read at a central laboratory. Change in Nugent score was assessed for women with (score 7 or higher) or without (score lower than 7) bacterial vaginosis. Linear regression analysis evaluated whether change in Nugent score was associated with preterm birth.

RESULTS

Two hundred women without and 69 women with bacterial vaginosis had Gram stain performed before and after antibiotic therapy. Median Nugent score for all women declined from 4.0 to 2.0 after antibiotic therapy (P<.001). Nugent score declined both for those without (from 2.0 to 1.5, P=.11) and, more dramatically, those with bacterial vaginosis (from 8.0 to 3.0, P<.01). The components of the Nugent score that were affected by antibiotic exposure were similar among women with and without bacterial vaginosis. Antibiotic exposure and the change in Nugent score were unrelated to preterm birth among bacterial vaginosis-negative women.

CONCLUSION

Antibiotic exposure is not associated with preterm birth and does not worsen Nugent score among women with normal vaginal flora and positive fetal fibronectin.

LEVEL OF EVIDENCE

II.

Periodontal disease and bacterial vaginosis as genetic and environmental markers for the risk of spontaneous preterm labor and preterm birth

OBJECTIVE

The aim of this study was to review the evidence associating periodontal disease, and bacterial vaginosis with preterm birth, and the link with gene polymorphism, as well as the preventions and interventions which might reduce the risk of spontaneous preterm labor and preterm births in women with periodontal disease and/or bacterial vaginosis.

BACKGROUND

Preterm birth accounts for 70% of perinatal mortality, nearly 50% of long term neurological morbidity, and a significant impact on health care costs. There is evidence that spontaneous preterm labor and preterm birth are associated with intrauterine infection due to abnormal genital and/or oral colonization. Periodontal disease and bacterial vaginosis share microbiological similarities, and both conditions are associated with spontaneous preterm labor and preterm birth. In addition, periodontal disease and bacterial vaginosis have been linked through gene polymorphism.

METHODS

A review of the literature using widely accepted scientific search engines in English language.

RESULTS

Studies evaluating antibiotic administration to eradicate periodontal disease and/or bacterial vaginosis responsible organisms, and minimize the risk of preterm births have yielded conflicting results. With respect to bacterial vaginosis, the timing and the choice of antibiotic administration might partly explain the conflicting results. The use of scaling and/or root planning for women with periodontal disease appears to reduce the risk of preterm birth, but routine administration of antibiotics has not demonstrated any impact on preterm birth.

CONCLUSION

Prospective studies evaluating the association of gene polymorphism with preterm birth, and the contribution of periodontal disease and bacterial vaginosis are needed.

Practices for predicting and preventing preterm birth in Ireland: a national survey

BACKGROUND

Preterm birth can result in adverse outcomes for the neonate and/or his/her family. The accurate prediction and prevention of preterm birth is paramount. This study describes and critically analyses practices for predicting and preventing preterm birth in Ireland.

METHODS

A questionnaire seeking information on practices for predicting and preventing preterm birth was mailed to all consultant obstetricians practising in Ireland in February 2006.

RESULTS

For predicting preterm birth, 97% of respondents did not use foetal fibronectin testing, 71% carried out routine second and third trimester cervical assessments and 75% routinely screened for genital tract infection. For preventing preterm birth, 62% prescribed bed rest, 24% prescribed antibiotics, 14% routinely inserted a cervical cerclage in women with a history of mid-trimester miscarriage and 61% routinely used tocolytics.

CONCLUSION

The findings of this survey, for the most part, reflect the empirical evidence base, international practices and best practice recommendations.