Association of antibiotics therapy during pregnancy with spontaneous miscarriage: a systematic review and meta-analysis

PeRinatal, neOnatal, and Maternal OuTcomEs with azithromycin prophylaxis in pregnancy and labour (PROMOTE-PROPHYLAXIS): systematic review and meta-analysis

Background

Initial randomised controlled trials (RCTs) showed that prophylactic azithromycin in pregnant women improved maternal and neonatal outcomes; however, the recent evidence did not show any benefit to neonatal survival. There is conflicting evidence over the role of azithromycin prophylaxis in antenatal and intrapartum periods. We explored whether azithromycin prophylaxis in pregnant women improves maternal and neonatal outcomes.

Methods

For this systematic review and meta-analysis registered on PROSPERO [CRD42023411093], we searched seven databases (PubMed, Scopus, Embase, Cochrane Library, EBSCOHost, ProQuest, and Web of Science) and clinical trial registries until 04/23/2024, for RCTs evaluating antenatal/intrapartum azithromycin prophylaxis against placebo/routine care in pregnant women. The primary outcome was neonatal mortality. Intrapartum and antenatal administration were assessed separately. We used random-effects meta-analysis. The risk of bias was assessed using the Cochrane RoB 2 tool. The GRADE approach was used to evaluate the certainty of the evidence.

Findings

Screening 2161 records retrieved 20 RCTs (56,381 participants). Intrapartum azithromycin may make little or no difference to neonatal mortality [5 RCTs, 44,436 participants; Risk Ratio (RR): 1.02, 95% CI 0.86-1.20, I 2  = 0%, very low certainty], and maternal mortality [3 RCTs, 44,131 participants, RR: 1.26, 0.65-2.42, I 2  = 0%, low certainty]. Similarly, antenatal azithromycin may have little or no effect on neonatal mortality [3 RCTs; 5304 participants; RR: 0.74, 0.35-1.56, I 2  = 43%, very-low certainty] and maternal mortality [3 RCTs; 8167 participants RR: 1.62, 0.67-3.91, I 2  = 0%, low certainty]. There is no data on long-term adverse outcomes and antimicrobial resistance.

Interpretation

Low to very low certainty evidence suggests that intrapartum or antenatal azithromycin prophylaxis in pregnant women might not reduce maternal or neonatal mortality.

Funding

None.

Maternal-Fetal Exposure to Antibiotics: Levels, Mother-to-Child Transmission, and Potential Health Risks

Due to its widespread applications in various fields, antibiotics are continuously released into the environment and ultimately enter the human body through diverse routes. Meanwhile, the unreasonable use of antibiotics can also lead to a series of adverse outcomes. Pregnant women and developing fetuses are more susceptible to the influence of external chemicals than adults. The evaluation of antibiotic exposure levels through questionnaire surveys or prescriptions in medical records and biomonitoring-based data shows that antibiotics are frequently prescribed and used by pregnant women around the world. Antibiotics may be transmitted from mothers to their offspring through different pathways, which then adversely affect the health of offspring. However, there has been no comprehensive review on antibiotic exposure and mother-to-child transmission in pregnant women so far. Herein, we summarized the exposure levels of antibiotics in pregnant women and fetuses, the exposure routes of antibiotics to pregnant women, and related influencing factors. In addition, we scrutinized the potential mechanisms and factors influencing the transfer of antibiotics from mother to fetus through placental transmission, and explored the adverse effects of maternal antibiotic exposure on fetal growth and development, neonatal gut microbiota, and subsequent childhood health. Given the widespread use of antibiotics and the health threats posed by their exposure, it is necessary to comprehensively track antibiotics in pregnant women and fetuses in the future, and more in-depth biological studies are needed to reveal and verify the mechanisms of mother-to-child transmission, which is crucial for accurately quantifying and evaluating fetal health status.

Can the use of azithromycin during labour reduce the incidence of infection among puerperae and newborns? A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This systematic review and meta-analysis investigated whether the use of azithromycin during labour or caesarean section reduces the incidence of sepsis and infection among mothers and newborns.

DATA SOURCES

We independently searched the PubMed, Web of Science, Cochrane Library and EMBASE databases for relevant studies published before February, 2024.

METHODS

We included RCTs that evaluated the effect of prenatal oral or intravenous azithromycin or placebo on intrapartum or postpartum infection incidence. We included studies evaluating women who had vaginal births as well as caesarean sections. Studies reporting maternal and neonatal infections were included in the current analysis. Review Manager 5.4 was used to analyse 6 randomized clinical trials involving 44,448 mothers and 44,820 newborns. The risk of bias of each included study was assessed using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions.Primary outcomes included the incidence of maternal sepsis and all-cause mortality and neonatal sepsis and all-cause mortality; secondary outcomes included maternal (endometritis, wound and surgical site infections, chorioamnionitis, and urinary tract infections) and neonatal outcomes (infections of the eyes, ears and skin). A random-effects model was used to test for overall effects and heterogeneity.

RESULTS

The pooled odds ratios (ORs) were as follows: 0.65 for maternal sepsis (95% CI, 0.55-0.77; I2, 0%; P < .00001); 0.62 for endometritis (95% CI, 0.52-0.74; I2, 2%; P < .00001); and 0.43 for maternal wound or surgical site infection (95% CI, 0.24-0.78; P < .005); however, there was great heterogeneity among the studies (I2, 75%). The pooled OR for pyelonephritis and urinary tract infections was 0.3 (95% CI, 0.17-0.52; I2, 0%; P < .0001), and that for neonatal skin infections was 0.48 (95% CI, 0.35-0.65; I2, 0%, P < .00001). There was no significant difference in maternal all-cause mortality or incidence of chorioamnionitis between the two groups. No significant differences were observed in the incidence of neonatal sepsis or suspected sepsis, all-cause mortality, or infections of the eyes or ears.

CONCLUSION

In this meta-analysis, azithromycin use during labour reduced the incidence of maternal sepsis, endometritis, incisional infections and urinary tract infections but did not reduce the incidence of neonatal-associated infections, except for neonatal skin infections. These findings indicate that azithromycin may be potentially beneficial for maternal postpartum infections, but its effect on neonatal prognosis remains unclear. Azithromycin should be used antenatally only if the clinical indication is clear and the potential benefits outweigh the harms.

Antibiotic use during pregnancy in Sweden: A nationwide utilization study covering 2007-2019

INTRODUCTION

Antibiotics are often prescribed during pregnancy. Assessing the current state of prenatal antibiotic use is therefore imperative for optimizing prescribing and identifying emerging research priorities. The study aimed to describe recent trends and patterns in antibiotic use during pregnancy among women who gave birth in Sweden, including user characteristics.

MATERIAL AND METHODS

Population-based descriptive study using linked nationwide registers. All pregnancies delivered in Sweden from 2007 to 2019 were included. Prevalence of use was defined as the percentage of pregnancies during which at least one prescription forantibiotics was filled. Temporal trends in the prevalence of antibiotic use by calendar year, trimester and weeks of gestation were assessed from time series graphs.

RESULTS

Prescriptions for systemic antibiotics were filled in 20.7% of 1 434 431 pregnancies overall, decreasing from 24.7% in 2007 to 18.0% in 2019. Phenoxymethylpenicillin (8.5%), pivmecillinam (6.5%), nitrofurantoin (4.7%), amoxicillin (1.6%) and cefadroxil (1.5%) use were the most prevalent. Their use decreased over the 13-year period, except for pivmecillinam, which increased from 4.0% to 7.4%. Prevalence of use was highest in the second trimester (9.5%), with weekly trends peaking at 13 and 34 weeks of gestation. Compared with non-users, antibiotic users more often belonged to the youngest and oldest age strata, carried multipleton pregnancies, had delivered before, had attained a lower education level and smoked in early pregnancy. A higher body mass index, asthma, chronic renal disease and diabetes mellitus were more prevalent among antibiotic users than among non-users.

CONCLUSIONS

Although outpatient antibiotic use during pregnancy in Sweden has been declining, one in five pregnancies was exposed to systemic antibiotics.

Drug Exposure During Pregnancy: A Case-Control Study from a Primary Care Database

Objective

Drug exposure during pregnancy is frequent, even more during first trimester as pregnant women might not be aware of their condition. We used available electronic health records (EHRs) to describe the use of medications during the first trimester in pregnant women and to compare drug exposure between those women who had an abortion (either elective or spontaneous) compared to those who had live births.

Materials and Methods

Case-control study of abortions, either elective or spontaneous (cases), and live birth pregnancies (controls) in Sistema d'Informació per al Desenvolupament de la Investigació en Atenció Primària (Catalan Primary Health electronic health records) from 2012 to 2020. Exposure to drugs during first trimester of pregnancy was considered to estimate the association with abortion by conditional logistic regression and adjusted by health conditions and other drugs exposure.

Results

Sixty thousand three hundred fifty episodes of abortions were matched to 118,085 live birth pregnancy episodes. Cases had higher rates of alcohol intake (9.9% vs. 7.2%, p < 0.001), smoking (4.5% vs. 3.6%, p < 0.001), and previous abortions (9.9% vs. 7.8%, p < 0.001). Anxiety (30.3% and 25.1%, p < 0.001), respiratory diseases (10.6% and 9.2%, p < 0.001), and migraine (8.2% and 7.3%, p < 0.001), for cases and controls, respectively, were the most frequent baseline conditions. Cases had lower rate of drug exposure, 40,148 (66.5%) versus 80,449 (68.1%), p < 0.001. Association with abortion was found for systemic antihistamines (adjusted odds ratio [ORadj] 1.23, 95% confidence interval [CI] 1.19-1.27), antidepressants (ORadj 1.11, 95% CI 1.06-1.17), anxiolytics (ORadj 1.31, 95% CI 1.26-1.73), and nonsteroidal anti-inflammatory drugs (ORadj 1. 63, 95% CI 1.59-1.67).

Conclusions

These high rates of drug exposures during the first trimester of pregnancy highlights the relevance of informed prescription to women with childbearing potential.

Association between antibiotic exposure and adverse outcomes of children and pregnant women: evidence from an umbrella review

BACKGROUND

Antibiotics are widely prescribed among children and pregnant women, but their safety profile is controversial. This study aimed to summarize and appraise current evidence for the potential impact of antibiotic exposure on pregnancy outcomes and children's health.

METHODS

PubMed, Embase, Web of Science and the Cochrane Database of Systematic Reviews were searched from inception to June 2022. Meta-analyses of any study design comparing the impact of antibiotic exposure with nonexposure among children, pregnant women and prepregnant women on adverse health outcomes of children and pregnancy were retrieved. The quality of evidence was assessed by a Measurement Tool to Assess Systematic Reviews 2 (AMSTAR2) and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Data were reanalyzed, and the credibility of the evidence was determined.

RESULTS

Out of 2956 studies identified, 19 articles with 39 associations were included. Totally 19 of the associations (48.72%) were statistically significant with a P value ≤ 0.05, while only six were supported by highly suggestive evidence. Children with postnatal antibiotic exposure had a higher risk of developing asthma odds ratio (OR): 1.95, 95% confidence interval (CI): 1.76-2.17, wheezing (OR: 1.81, 95% CI 1.65-1.97) and allergic rhinoconjunctivitis (OR: 1.66, 95% CI 1.51-1.83), with prediction intervals excluding the nulls. Quality assessed by both AMSTAR2 and GRADE of included meta-analyses were very low in general.

CONCLUSIONS

Antibiotic exposure in early life was associated with children's long-term health, especially in cases of allergic diseases. Prenatal exposure might also influence children's health in some aspects but requires more high-quality evidence. Potential adverse effects of antibiotics on pregnancy outcomes were not observed in our study. Studies with higher quality and better quantification of antibiotic exposure are needed in the future.

Antibiotic Use during Pregnancy in South Korea Using 2011-2020 National Health Insurance Claims Data

BACKGROUND

Since antimicrobial overuse and misuse can have substantial impacts on both public health and fetal well-being, it is essential to gain comprehensive insights into antimicrobial consumption patterns in pregnant women. This study aims to demonstrate antimicrobial utilization in pregnant women.

METHODS

We conducted a population-based cohort study using National Health Insurance claims data from January 2009 to December 2020 in South Korea. The target population was pregnancies in women aged 15-45 years who gave birth between 2011 and 2019. The outcome measure was the percentage of antibiotic prescriptions by trimester, subgroup, diagnostic category, and therapeutic category. Antibiotics were defined as J01 in the WHO ATC/DDD classification. To analyze the factors that influenced antibiotic prescriptions, we conducted multivariate logistic regression analysis.

RESULTS

Antibiotics were prescribed at least once in 1,808,588 (50%) of the 3,614,478 pregnancies. The proportion of deliveries with exposure to antibiotic therapy during pregnancy increased from 48% in 2011 to 54.8% in 2020. The prescription rate of antibiotics was highest in mothers younger than 25 years old, and it was lowest in participants aged 30-34 years. Also, antibiotic use was highest in the first trimester (30%) and lowest in the second trimester (18.2%). The most commonly used class was J01D (other beta-lactam antibacterials), which includes cephalosporins, and it accounted for 57% of the prescribed antibiotics. An increased probability of being prescribed antibiotics was associated with those younger than 25 years old, insurance (Medical Aid), hospitalization experience, an increase in physician visits, and comorbidities. For comorbidities, the OR was higher for respiratory tract infection (RTI), sexually transmitted infection, and urinary tract infection compared to those without disease, whereas it was decreased for diabetes and epilepsy.

CONCLUSION

The prescribing rate of antibiotics to pregnant women in South Korea has remained stably high. Also, an increase in the use of broad-spectrum beta-lactam penicillin was noted. It is necessary to monitor antibiotics in pregnant women generally in accordance with recommendations.

The association between genital mycoplasma infection and spontaneous abortion: A systematic review and meta-analysis

Epidemiological findings on the association between genital mycoplasma infection (GMI) and spontaneous abortion are inconsistent. Therefore, this meta-analysis aims to determine whether mycoplasma infection during pregnancy increases the risk of spontaneous abortion. An electronic database search was conducted using China National Knowledge Infrastructure, Elsevier, PubMed, SinoMed, The Cochrane Library, and Wanfang Database from database establishment to October 2021. Sixteen case-controls and 3 prospective cohorts were included. The meta-analysis showed that GMI was positively associated with spontaneous abortion (odds ratio (OR) 2.35, 95% confidence interval (CI) 1.50, 3.67). Of them, case-control studies showed that the GMI proportion in the spontaneous abortion group was higher than that in the normal group (OR 2.13, 95% CI 1.33, 3.43); the cohort study showed that the spontaneous abortion rate in the GMI group was higher than those in non-infected groups (relative risk 5.17, 95% CI 2.07, 12.95; risk difference 0.18, 95% CI 0.09, 0.27). Each outcome indicator was relatively robust in the sensitivity analysis, and no significant publication bias was found in the funnel plots. Our data support that GMI during pregnancy increases the risk of spontaneous abortion. Thus, the monitoring and timely treatment of GMI before pregnancy of GMI are essential to decrease the risk of spontaneous abortion.

Periconceptional antibiotic use and spontaneous abortion: A prospective cohort study

BACKGROUND

Many reproductive-aged North Americans use antibiotics in the weeks preceding conception or during early pregnancy. Antibiotic use may influence risk of spontaneous abortion (SAB) by disrupting the reproductive tract microbiome or treating harmful infections. However, this association has not been extensively studied.

OBJECTIVE

To determine the extent to which periconceptional antibiotic use is associated with the risk of SAB.

METHODS

We analysed data from an internet-based preconception cohort study of pregnancy planners. Eligible participants self-identified as female, were aged 21-45 years, resided in the USA or Canada, and conceived during 12 months of follow-up (n = 7890). Participants completed an enrolment questionnaire during June 2013-September 2021 and bimonthly follow-up questionnaires for up to 12 months or until a reported pregnancy, whichever came first. Pregnant participants completed questionnaires in early (~8-9 weeks) and late (~32 weeks) gestation. We assessed antibiotic use, including type (penicillins, nitrofurantoin, cephalosporins and macrolides) and indication for use, during the previous 4 weeks on preconception questionnaires. Participants reported pregnancies and SAB on follow-up and pregnancy questionnaires. We used Cox proportional hazards regression models with gestational weeks as the time scale to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between periconceptional antibiotic use and SAB, controlling for potential demographic, medical, and lifestyle confounders.

RESULTS

Nineteen percent (n = 1537) of pregnancies ended in SAB. Participants reported periconceptional antibiotic use in 8% of pregnancies ending in SAB and 7% not ending in SAB. Periconceptional antibiotic use was not appreciably associated with SAB (adjusted HR 1.06, 95% CI 0.88, 1.28). We observed no strong associations between antibiotic type, indication for use, or recency of exposure and SAB risk.

CONCLUSIONS

Periconceptional antibiotic use was not appreciably associated with SAB in this study. This association is likely complicated by antibiotic type and dosage, timing of conception, and the individual's overall health.

Pregnancy outcomes following maternal macrolide use: A systematic review and meta-analysis

To determine whether gestational use of all or specific macrolides (azithromycin, clarithromycin, roxithromycin or erythromycin) lead to an increase in rates of overall major congenital malformations, organ-specific malformations, and other adverse pregnancy outcomes in infants. PubMed/MEDLINE, Cochrane Central Register of Controlled Trials and Reprotox® databases were searched. Dichotomous outcomes or calculated log odds ratios and standard errors from observational studies are combined using the random-effects method in Review Manager 5.3. No significant increased risks for major congenital malformation (OR 1.06 [95% CI 0.99, 1.13]) and congenital heart defect (OR 1.05 [95% CI 0.92, 1.19]) following all macrolides use during the first trimester were detected. Prenatal azithromycin use was associated with a significantly increased risk of major congenital malformations in the analysis of cohort studies (OR 1.21 [95% CI 1.08-1.36]). This significance was also present in the sensitivity analysis. There were no statistically significant associations between the risk of organ specific malformations and all or specific macrolide exposures except for the decreased risk in hypospadias following erythromycin use in the meta-analysis of case-control studies (OR 0.38 [95% CI 0.18, 0.81]. Also, a significant 1.5-fold increased risk for spontaneous abortion following macrolide use was detected. A slight yet significantly increased rate of major congenital malformation with azithromycin exposure during pregnancy may be associated with maternal confounders. Nevertheless, level II ultrasound can be suggested following maternal azithromycin use during the first trimester. Future studies should take into account the inclusion of a disease-matched control group and accurate classification of the malformations.

Safety of Antimicrobials for Postexposure Prophylaxis and Treatment of Anthrax: A Review

BACKGROUND

Bacillus anthracis, the causative agent for anthrax, poses a potential bioterrorism threat and is capable of causing mass morbidity and mortality. Antimicrobials are the mainstay of postexposure prophylaxis (PEP) and treatment of anthrax. We conducted this safety review of 24 select antimicrobials to identify any new or emerging serious or severe adverse events (AEs) to help inform their risk-benefit evaluation for anthrax.

METHODS

Twenty-four antimicrobials were included in this review. Tertiary data sources (e.g. Lactmed, Micromedex, REPROTOX) were reviewed for safety information and summarized to evaluate the known risks of these antimicrobials. PubMed was also searched for published safety information on serious or severe AEs with these antimicrobials; AEs that met inclusion criteria were abstracted and reviewed.

RESULTS

A total of 1316 articles were reviewed. No consistent observations or patterns were observed among the abstracted AEs for a given antimicrobial; therefore, the literature review did not reveal evidence of new or emerging AEs that would add to the risk-benefit profiles already known from tertiary data sources.

CONCLUSIONS

The reviewed antimicrobials have known and/or potential serious or severe risks that may influence selection when recommending an antimicrobial for PEP or treatment of anthrax. Given the high fatality rate of anthrax, the risk-benefit evaluation favors use of these antimicrobials for anthrax. The potential risks of antimicrobials should not preclude these reviewed antimicrobials from clinical consideration for anthrax but rather guide appropriate antimicrobial selection and prioritization across different patient populations with risk mitigation measures as warranted.

Use of Azithromycin in Pregnancy: More Doubts than Certainties

Macrolides such as azithromycin are commonly prescribed antibiotics during pregnancy. The good oral bioavailability and transplacental transfer of azithromycin make this drug suitable for the treatment of sexually transmitted diseases, toxoplasmosis, and malaria. Moreover, azithromycin is useful both in the management of preterm pre-labor rupture of membranes and in the adjunctive prophylaxis for cesarean delivery. The aim of this comprehensive narrative review is to critically analyze and summarize the available literature on the main aspects of azithromycin use in pregnant women, with a special focus on adverse offspring outcomes associated with prenatal exposure to the drug. References for this review were identified through searches of MEDLINE, PubMed, and EMBASE. Fetal and neonatal outcomes following prenatal azithromycin exposure have been investigated in several studies, yielding conflicting results. Increased risks of spontaneous miscarriage, major congenital malformations, cardiovascular malformations, digestive system malformations, preterm birth, and low birth weight have been reported in some studies but not in others. Currently, there is no conclusive evidence to support that azithromycin use by pregnant women causes adverse outcomes in their offspring. Therefore, this agent should only be used during pregnancy when clinically indicated, if the benefits of treatment are expected to outweigh the potential risks.

The reproductive tract microbiota in pregnancy

The reproductive tract microbiota plays a crucial role in maintenance of normal pregnancy and influences reproductive outcomes. Microbe–host interactions in pregnancy remain poorly understood and their role in shaping immune modulation is still being uncovered. In this review, we describe the composition of vaginal microbial communities in the reproductive tract and their association with reproductive outcomes. We also consider strategies for manipulating microbiota composition by using live biotherapeutics, selective eradication of pathogenic bacteria with antibiotics and vaginal microbiota transplantation. Finally, future developments in this field and the need for mechanistic studies to explore the functional significance of reproductive tract microbial communities are highlighted.