Sexually Transmitted Infections in Pregnancy: A Narrative Review of the Global Research Gaps, Challenges, and Opportunities

Antenatal Screening for Sexually Transmitted Infections to Improve Maternal and Newborn Outcomes: An Update From 11 Low- and Middle-Income Countries

Screening and treating prevalent, often overlooked sexually transmitted infections during pregnancy is highly feasible in resource-limited settings. A decade of research shows improved maternal outcomes and potential for better birth outcomes. Much-needed studies on cost-effectiveness, implementation, and causal mechanisms will refine policies and optimize interventions.

Sandwich enzyme-linked aptamer-based assay for the detection of Trichomonas vaginalis

Trichomoniasis is the most prevalent curable, non-viral sexually transmitted infection (STI), with an estimated 156 million new infections in 2020. It can potentially result in adverse birth outcomes as well as infertility in men, whilst it also increases the risk of acquiring HIV and contracting other vaginal infections. It is mostly prevalent among women in low-income countries and especially in Africa and the Americas. This STI is caused by Trichomonas vaginalis (TV) and a robust, cost-effective, sensitive, specific and rapid diagnostic test is urgently required. We report the screening of 6 full-length and 4 truncated aptamers previously selected in our group for use in a microplate-based sandwich assay. The combination of dual aptamers comprising a short 14-mer truncated capture aptamer (termed A1_14mer) and a full-length non-truncated reporter aptamer (A6) was elucidated to be the optimum pair for a sensitive sandwich enzyme-linked aptamer assay (ELAA) for the detection of TV achieving a detection limit of 3.02 × 104 TV cells/mL. The results obtained with the A1_14mer-A6 ELAA correlate excellently with wet-mount microscopy for the detection of TV in clinical specimens, cervicovaginal lavages and vaginal swabs, highlighting the potential clinical application of this assay for cost-effective population screening and subsequent prevention of the onset of complications associated with undiagnosed and untreated TV.

Effect of antenatal Chlamydia trachomatis and Neisseria gonorrhoeae screening on postdelivery prevalence and vertical transmission in Gaborone, Botswana: findings from an exploratory study

OBJECTIVES

Chlamydia trachomatis and Neisseria gonorrhoeae are common sexually transmitted infections (STIs). Untreated infection in pregnancy can result in adverse neonatal outcomes, including vertical transmission. Screening for these infections is not routine in low- and middle-income countries (LMICs).

METHODS

The Maduo Study was a non-randomised cluster crossover trial in Botswana to provide preliminary data on the effect of antenatal C. trachomatis and N. gonorrhoeae screening and treatment on postdelivery prevalence and vertical transmission to infants. Pregnant women asymptomatic for STIs were enrolled at four clinics (seven clusters). The intervention arm received C. trachomatis and N. gonorrhoeae screening at first antenatal care, third trimester and postdelivery. The standard-of-care arm received postdelivery screening only. Infants of women with a positive test postdelivery in both arms were screened. A cluster-level analysis was performed to compare the risk of postdelivery infection between intervention and standard-of-care arms.

RESULTS

The study enrolled 500 women; 206 (82.1%) and 187 (75.1%) were retained in the intervention and standard-of-care arms, respectively and screened ≤12 weeks postdelivery. C. trachomatis prevalence in the intervention arm reduced from 22.7% at first antenatal care to 1.0% postdelivery. N. gonorrhoeae prevalence reduced from 1.2% at first antenatal care to 0% postdelivery. The risk of C. trachomatis and/or N. gonorrhoeae was lower in the intervention arm postdelivery (0.6%) compared with the standard-of-care arm (15.7%); adjusted risk difference: -14.7% (95% CI -23.0%, -6.4%). Among 26 infants born to women with either infection postdelivery, 10 (38.5%) tested positive (C. trachomatis: 9; N. gonorrhoeae: 1).

CONCLUSIONS

Postdelivery prevalence of C. trachomatis was significantly lower among pregnant women in Botswana who received diagnostic antenatal screening. Among women with C. trachomatis and/or N. gonorrhoeae postdelivery, more than one-third transmitted the infection to their infants. This exploratory study suggests antenatal STI screening has the potential to reduce infection in newborns in similar LMIC settings.

TRIAL REGISTRATION NUMBER

NCT04955717.

Obstetrical Complications in Venezuelan Refugee and Migrant Women: Analysis of Ecuadorian National Hospital Discharge Data, 2018-2021

An estimated 7.7 million Venezuelans have fled a severe humanitarian crisis in their country, most (70%) to other middle-income host countries in the same Andean region. Migration-related exposures during periconception and other critical gestational periods can adversely impact maternal-perinatal outcomes. Emerging evidence suggests that Venezuelan refugee and migrant women (VRMW) who migrate to Andean host countries are at-risk for delivering preterm and low birthweight infants and for Cesarean-sections. However, relatively few studies have examined obstetrical complications that could contribute to these or other short- and longer-term health outcomes of VRMW and/or their offspring. Our exploratory study analyzed four recent years of national hospital discharge data (2018-2021) from Ecuador to compare the primary discharge diagnoses of VRMW (n = 29,005) and Ecuadorian nationals (n = 1,136,796) for ICD-10 O code obstetrical complications related to or aggravated by pregnancy, childbirth, or the puerperium. Our findings indicated that VRMW were hospitalized for 0.5 days longer than Ecuadorian reference group women and they had higher adjusted odds (aOR) for a primary discharge diagnosis for obstetrical complications including preeclampsia (aOR:1.62, 95% CI:1.55,1.69), preterm labor (aOR:1.20, 95% CI:1.11,1.31), premature rupture of membranes (aOR: 1.72, 95% CI:1.63,1.83), oligohydraminos (aOR:1.24, 95% CI:1.12,1.36), obstructed labor (aOR: 1.39, 95% CI:1.31,1.47), perineal lacerations/other obstetric trauma (aOR:1.76, 95% CI:1.63, 1.91), STIs (aOR:2.59, 95% CI:1.29,2.92), anemia (aOR:1.33, 95% CI:1.24,1.42), and ectopic pregnancy (aOR:1.16 95% CI:1.04,1.28). They had similar aOR for diagnosed gestational diabetes and spontaneous abortion (SAB) compared to the reference group but a reduced aOR for genitourinary infections (aOR:0.79, 95% CI:0.74,0.84) and early pregnancy hemorrhage not ending in SAB (aOR:0.43, 95% CI:0.36,0.51). Our findings underscore the vulnerability of VRMW for a number of potentially serious obstetrical complications with the potential to adversely impact the short- and longer-term health of mothers and their offspring. Future studies should collect more detailed information on the migration status, experiences, and exposures of MRMW that influence their risk for obstetrical complications. These are needed to expand our findings to better understand why they have excess risk for these and to inform social and public health policies, programs and targeted interventions aimed at reducing the risk of this vulnerable refugee and migrant group.

Structural characterization of the (deoxy)hypusination in Trichomonas vaginalis questions the bifunctionality of deoxyhypusine synthase

Trichomonas vaginalis, the causative agent of trichomoniasis, is a prevalent anaerobic protozoan parasite responsible for the most common nonviral sexually transmitted infection globally. While metronidazole and its derivatives are approved drugs for this infection, rising resistance necessitates the exploration of new antiparasitic therapies. Protein posttranslational modifications (PTMs) play crucial roles in cellular processes, and among them, hypusination, involving eukaryotic translation factor 5A (eIF5A), has profound implications. Despite extensive studies in various organisms, the role of hypusination in T. vaginalis and its potential impact on parasite biology and pathogenicity remain poorly understood. This study aims to unravel the structural basis of the hypusination pathway in T. vaginalis using X-ray crystallography and cryo-electron microscopy. The results reveal high structural homology between T. vaginalis and human orthologs, providing insights into the molecular architecture of eIF5A and deoxyhypusine synthase (DHS) and their interaction. Contrary to previous suggestions of bifunctionality, our analyses indicate that the putative hydroxylation site in tvDHS is nonfunctional, and biochemical assays demonstrate exclusive deoxyhypusination capability. These findings challenge the notion of tvDHS functioning as both deoxyhypusine synthase and hydroxylase. The study enhances understanding of the hypusination pathway in T. vaginalis, shedding light on its functional relevance and potential as a drug target, and contributing to the development of novel therapeutic strategies against trichomoniasis.

Evaluating Chlamydia trachomatis and Neisseria gonorrhoeae screening and treatment among asymptomatic pregnant women to prevent preterm birth and low birthweight in Gaborone, Botswana: A secondary analysis from a non-randomised, cluster-controlled trial

OBJECTIVE

To evaluate the impact of screening and treating asymptomatic pregnant women for Chlamydia (C.) trachomatis and Neisseria (N.) gonorrhoeae infections on the frequency of preterm birth or low birthweight infants in Botswana.

DESIGN

Non-randomised, cluster-controlled trial.

SETTING

Four antenatal care clinics in Gaborone, Botswana.

POPULATION

Pregnant women aged ≥15 years, attending a first antenatal care visit, ≤27 weeks of gestation and without urogenital symptoms were eligible.

METHODS

Participants in the intervention clinics received screening (GeneXpert®, Cepheid) during pregnancy and at the postnatal visit. Participants in the standard-of-care clinics received screening at the postnatal visit only. We used multivariable logistic regression and post-estimation predictive margins analysis. Post-hoc analysis was conducted among sub-samples stratified by parity.

MAIN OUTCOME MEASURES

Preterm birth (<37 weeks of gestation) and low birthweight (<2500 g).

RESULTS

After controlling for parity, hypertension, antenatal care visits and clinic site, the predicted prevalence of preterm birth or low birthweight was lower in the intervention arm (11%) compared with the standard-of-care arm (16%) (adjusted odds ratio [aOR] 0.59; 95% confidence interval [CI] 0.28-1.24). In post-hoc analysis, the intervention was more effective than the standard-of-care (aOR 0.20; 95% CI 0.07-0.64) among nulliparous participants.

CONCLUSION

A C. trachomatis and N. gonorrhoeae infection screening and treatment intervention among asymptomatic pregnant women may have reduced preterm birth or low birthweight outcomes, but results were not statistically significant. Post-hoc analysis found that the intervention reduced adverse outcomes among nulliparous participants.

Prevalence of sexually transmitted infections, and its associated factors among students in Ethiopia: a systematic review and meta-analysis study

BACKGROUND

Sexually transmitted infections (STIs) are illnesses mainly spread through unprotected sexual activity. There is a scarcity of aggregate evidence in Ethiopia. The aim of this review was to assess the pooled prevalence of STI, and its associated factors among students in Ethiopia to fill the aforementioned gap.

METHODS

We extensively searched the bibliographic databases of PubMed, Scopus, and Google Scholar to obtain eligible studies. Further screening for a reference list of articles was also done. The Microsoft Excel Spreadsheet was used to extract data, and Stata 17 was used for analysis. The PRISMA-guidline and Newcastle-Ottawa quality assessment scale were used for quality appraisal. To check heterogeneity, the Higgs I2 and Cochran's Q tests were employed. Sensitivity and subgroup analysis were implemented. To detect publication bias, Egger's test and funnel plots were used.

RESULTS

The pooled prevalence of STI among students in Ethiopia was 13.6% with a 95% CI (10.2, 17). Findings from sub group analysis based on student category shows that the pooled prevalence of STI were 14.5% among University students, 14.2% among college students and 10.6% among high school students. Having multiple sexual partners (AOR 3.31; 95% CI: 2.40-4.57), not using condoms during sexual intercourse (AOR 2.56; 95% CI: 1.72-3.81), and having poor knowledge about sexually transmitted infections were 3.08 times (AOR 3.08; 95% CI: 1.84-5.15) significantly associated with STI.

CONCLUSION

The pooled prevalence of STIs among students in Ethiopia was high, and factors like having multiple sexual partners, not using condoms during sexual intercourse, and having poor knowledge about sexually transmitted infections were significantly associated with STIs. Hence, reduce STIs among students, strengthening sexual and reproductive health services, raising awareness about transmission and prevention, and promoting consistent condom use through health information dissemination is crucial. Further qualitative studies are suggested to explore the barriers and facilitators of STI prevention.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project

BACKGROUND

Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil.

METHODS

A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included.

RESULTS

A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86).

CONCLUSION

This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.

Trimethoprim-Sulfamethoxazole Plus Azithromycin to Prevent Malaria and Sexually Transmitted Infections in Pregnant Women With HIV (PREMISE): A Randomized, Double-Masked, Placebo-Controlled, Phase IIB Clinical Trial

Background

This trial tested the effectiveness of a novel regimen to prevent malaria and sexually transmitted infections (STIs) among pregnant women with HIV in Cameroon. Our hypothesis was that the addition of azithromycin (AZ) to standard daily trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis would reduce malaria and STI infection rates at delivery.

Methods

Pregnant women with HIV at gestational age <28 weeks were randomized to adjunctive monthly oral AZ 1 g daily or placebo for 3 days and both groups received daily standard oral TMP-SMX through delivery. Primary outcomes were (1) positive peripheral malaria infection by microscopy or polymerase chain reaction and (2) composite bacterial genital STI (Chlamydia trachomatis, Neisseria gonorrhoeae, or syphilis) at delivery. Relative risk and 95% confidence intervals were estimated using 2 × 2 tables with significance as P < .05.

Results

Pregnant women with HIV (n = 308) were enrolled between March 2018 and August 2020: 155 women were randomized to TMP-SMX-AZ and 153 women to TMP-SMX-placebo. Groups were similar at baseline and loss to follow up was 3.2%. There was no difference in the proportion with malaria (16.3% in TMP-SMX-AZ vs 13.2% in TMP-SMX; relative risk, 1.24 [95% confidence interval, .71-2.16]) or STI at delivery (4.2% in TMP-SMX-AZ vs 5.8% in TMP-SMX; relative risk, 0.72 [95% confidence interval, .26-2.03]). Adverse birth outcomes were not significantly different, albeit lower in the TMP-SMX-AZ arm (preterm delivery 6.7% vs 10.7% [P = .3]; low birthweight 3.4% vs 5.4% [P = .6]).

Conclusions

The addition of monthly azithromycin to daily TMP-SMX prophylaxis in pregnant women living with HIV in Cameroon did not reduce the risk of malaria or bacterial STI at delivery.

Point-of-care testing and treatment of sexually transmitted and genital infections to improve birth outcomes in high-burden, low-resource settings (WANTAIM): a pragmatic cluster randomised crossover trial in Papua New Guinea

BACKGROUND

Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and bacterial vaginosis have been associated with adverse maternal and perinatal outcomes, but there is conflicting evidence on the benefits of antenatal screening and treatment for these conditions. We aimed to determine the effect of antenatal point-of-care testing and immediate treatment of C trachomatis, N gonorrhoeae, T vaginalis, and bacterial vaginosis on preterm birth, low birthweight, and other adverse maternal and perinatal outcomes compared with current standard of care, which included symptom-based treatment without laboratory confirmation.

METHODS

In this pragmatic cluster randomised crossover trial, we enrolled women (aged ≥16 years) attending an antenatal clinic at 26 weeks' gestation or earlier (confirmed by obstetric ultrasound), living within approximately 1 h drive of a study clinic, and able to provide reliable contact details at ten primary health facilities and their catchment communities (clusters) in Papua New Guinea. Clusters were randomly allocated 1:1 to receive either the intervention or control (standard care) in the first phase of the trial. Following an interval (washout period) of 2-3 months at the end of the first phase, each cluster crossed over to the other group. Randomisation was stratified by province. Individual participants were informed about trial group allocation only after completing informed consent procedures. The primary outcome was a composite of preterm birth (livebirth before 37 weeks' gestation), low birthweight (<2500 g), or both, analysed according to the intention-to-treat population. This study is registered with ISRCTN Registry, ISRCTN37134032, and is completed.

FINDINGS

Between July 26, 2017, and Aug 30, 2021, 4526 women were enrolled (2210 [63·3%] of 3492 women in the intervention group and 2316 [62·8%] of 3687 in the control group). Primary outcome data were available for 4297 (94·9%) newborn babies of 4526 women. The proportion of preterm birth, low birthweight, or both, in the intervention group, expressed as the mean of crude proportions across clusters, was 18·8% (SD 4·7%) compared with 17·8% in the control group (risk ratio [RR] 1·06, 95% CI 0·78-1·42; p=0·67). There were 1052 serious adverse events reported (566 in the intervention group and 486 in the control group) among 929 trial participants, and no differences by trial group.

INTERPRETATION

Point-of-care testing and treatment of C trachomatis, N gonorrhoeae, T vaginalis, and bacterial vaginosis did not reduce preterm birth or low birthweight compared with standard care. Within the subgroup of women with N gonorrhoeae, there was a substantial reduction in the primary outcome.

FUNDING

UK Department of Health and Social Care; UK Foreign, Commonwealth and Development Office; UK Medical Research Council; the Wellcome Trust; the Australian National Health and Medical Research Council; and Swiss National Science Foundation.

The association between non-viral sexually transmitted infections and pregnancy outcome in Latin America and the Caribbean: A systematic review

Introduction

Non-viral sexually transmitted infections are known to be associated with adverse pregnancy outcomes. For these pathogens, standard antenatal screening is not broadly performed in Latin America and the Caribbean. The aim of this study was to comprehensively review the association of non-viral sexually transmitted infections and neonatal outcomes among pregnant women in the region.

Methods

Four databases (PubMed, Embase, SciELO and LILACS) were examined to identify eligible studies published up to September 2022. English or Spanish cross-sectional, case-control and cohort studies assessing the association of non-viral sexually transmitted infections and adverse pregnancy outcomes were evaluated. Articles were firstly screened by means of title and abstract. Potential articles were fully read and assessed for inclusion according to the eligibility criteria. Snowballing search was performed by screening of bibliographies of the chosen potentially relevant papers. Risk of bias within studies was assessed using the Joanna Briggs Institute reviewer's manual.

Results

A selection of 10 out of 9772 search records from five Latin America and the Caribbean countries were included. Six studies associated Treponema pallidum infection with preterm birth (1/6), history of previous spontaneous abortion (2/6), fetal and infant death (1/6), low birth weight (1/6) and funisitis of the umbilical cord (1/6). Three studies associated Chlamydia trachomatis infection with preterm birth (2/3), ectopic pregnancy (1/3) and respiratory symptoms on the newborn (1/3). One study associated Mycoplasma genitalium infection with preterm birth.

Conclusion

This review provides evidence on the association of non-viral sexually transmitted infections with adverse pregnancy outcomes. Further investigation is needed to establish more associations between non-viral sexually transmitted infections and pregnancy outcome, especially for Mycoplasma genitalium, Trichomonas vaginalis and Neisseria gonorrhoeae. Overall, this review calls for more research for public health interventions to promote screening of non-viral sexually transmitted infections during pregnancy, among high-risk population groups of pregnant women living in the region.

Prevalence and Predictors of Chlamydia trachomatis and Neisseria gonorrhoeae Among HIV-Negative Pregnant Women in Kenya

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections in pregnancy contribute to adverse perinatal outcomes. We identified predictors of CT and/or NG infection among pregnant Kenyan women.

METHODS

Women without HIV were enrolled at 2 antenatal clinics in Western Kenya. Both CT and NG were assessed using endocervical samples for nucleic acid amplification tests. Poisson regression models were used to evaluate potential CT/NG risk factors. Classification and regression trees were generated to evaluate the joint effects of predictors.

RESULTS

Overall, 1276 women had both CT and NG assessments. Women enrolled at a median of 26 weeks' gestation (interquartile range, 22-31 weeks), median age was 22 years (interquartile range, 19-27 years), and 78% were married. In total, 98 (7.7%) tested positive for CT/NG: 70 (5.5%) for CT and 32 (2.5%) for NG, 4 of whom (0.3%) had coinfections. Two-thirds (66%) of CT/NG cases were asymptomatic and would have been missed with only syndromic management. Risk factors of CT/NG included age <22 years, crowded living conditions, being unmarried, being in partnerships for <1 year, abnormal vaginal discharge, sexually transmitted infection history, and Trichomonas vaginalis diagnosis ( P < 0.1). Classification and regression tree analyses identified unmarried women <22 years in relationships for <1 year as 6.1 times more likely to have CT/NG compared with women without these characteristics (26% vs. 6%, adjusted prevalence ratio = 6.1, 95% confidence interval = 3.55-10.39, P < 0.001).

CONCLUSIONS

Chlamydia trachomatis / Neisseria gonorrhoeae was frequently asymptomatic and common among young unmarried women in newer partnerships in this cohort. Integrating CT/NG testing into routine antenatal care may be beneficial, especially for young women in Kenya.

Experimental Urethral Infection with Neisseria gonorrhoeae

Gonorrhea rates and antibiotic resistance are both increasing. Neisseria gonorrhoeae (Ng) is an exclusively human pathogen and is exquisitely adapted to its natural host. Ng can subvert immune responses and undergoes frequent antigenic variation, resulting in limited immunity and protection from reinfection. Previous gonococcal vaccine efforts have been largely unsuccessful, and the last vaccine to be tested in humans was more than 35 years ago. Advancing technologies and the threat of untreatable gonorrhea have fueled renewed pursuit of a vaccine as a long-term sustainable solution for gonorrhea control. Despite the development of a female mouse model of genital gonococcal infection two decades ago, correlates of immunity or protection remain largely unknown, making the gonococcus a challenging vaccine target. The controlled human urethral infection model of gonorrhea (Ng CHIM) has been used to study gonococcal pathogenesis and the basis of anti-gonococcal immunity. Over 200 participants have been inoculated without serious adverse events. The Ng CHIM replicates the early natural course of urethral infection. We are now at an inflexion point to pivot the use of the model for vaccine testing to address the urgency of improved gonorrhea control. Herein we discuss the need for gonorrhea vaccines, and the advantages and limitations of the Ng CHIM in accelerating the development of gonorrhea vaccines.

Neisseria gonorrhoeae Antimicrobial Resistance: The Future of Antibiotic Therapy

The growing threat of antibiotic-resistant Neisseria gonorrhoeae, which causes gonorrhea, presents a current public health challenge. Over the years, the pathogen has developed resistance to different antibiotics, leaving few effective treatment options. High-level resistance to key drugs, including ceftriaxone, has become a concerning reality. This article primarily focuses on the treatment of gonorrhea and the current clinical trials aimed at providing new antibiotic treatment options. We explore ongoing efforts to assess new antibiotics, including zoliflodacin, and gepotidacin. These drugs offer new effective treatment options, but their rapid availability remains uncertain. We delve into two ongoing clinical trials: one evaluating the efficacy and safety of gepotidacin compared to the standard ceftriaxone-azithromycin combination and the other assessing the non-inferiority of zoliflodacin versus the combination therapy of ceftriaxone-azithromycin. These trials represent crucial steps in the search for alternative treatments for uncomplicated gonorrhea. Notably, gonorrhea has been included in the "WHO Priority Pathogens List for Research and Development of New Antibiotics". In conclusion, the urgent need for innovative treatment strategies is underscored by the rising threat of antibiotic resistance in N. gonorrhoeae; collaboration among researchers, industries, and healthcare authorities is therefore essential.

High incidence of asymptomatic genital tract infections in pregnancy in adolescent girls and young women: need for repeat aetiological screening

INTRODUCTION

Sexually transmitted infection (STI) prevalence and incidence estimates for pregnant adolescents are under-reported. We estimated prevalence and incidence of STIs in pregnant adolescents (15-19 years) in comparison with pregnant women 20-24 and >25 years.

METHODS

Pregnant women registering at primary care clinics in Umlazi, a periurban subdistrict in KwaZulu-Natal, South Africa, were enrolled in an HIV incidence cohort study during February 2017-March 2018. Women were examined for abnormal vaginal discharge, received empirical treatment, tested for HIV-1 and had vaginal swabs taken at their first and a subsequent visit in the third trimester. Vaginal swabs were stored for STI testing at completion of study and tested for Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium using PCR.

RESULTS

A total of 752 HIV-negative pregnant women were enrolled at a median gestational age of 17 weeks: 180 (23.9%), 291 (38.7%) and 281 (37.4%) in the 15-19, 20-24 and >25 years age groups. Pregnant adolescents had an STI prevalence of 26.7% at baseline, not significantly lower than the 20-24 (34.7%, OR 1.4; 95% CI 1.0 to 2.1, p=0.09) and >25 years (33.8%, OR 1.4; 95% CI 0.9 to 2.1, p=0.12) age groups. T. vaginalis (11.1%), C. trachomatis (7.8%) and N. gonorrhoeae (4.4%) were most prevalent in adolescents, a trend similar to the other age groups. Overall, 43.4% were symptomatic and treated at baseline. Overall, 40.7% (118 of 290) of women who tested negative for an STI at baseline tested positive at the repeat visit (incidence 19.5/100 person years). STI incidence in pregnant adolescents was 23.9/100 person years and comparable with older age groups (20.5/100 person years and 16.2/100 person years). At the repeat visit, 19.0% of all women with an STI were symptomatic and treated. Performance of syndromic management was poor at baseline (negative predictive value (NPV) 68.6%, positive predictive value (PPV) 34.0%) and at repeat visit (NPV 58.4%, PPV 34.3%).

CONCLUSIONS

Prevalence of asymptomatic curable STIs in pregnant adolescents is high and comparable with women >20 years old. Adolescents remain at substantial risk of asymptomatic incident STIs during pregnancy.

Neonatal ocular prophylaxis in the United States: is it still necessary?

INTRODUCTION

Much has changed since Credé reported that silver nitrate decreases the incidence of ophthalmia neonatorum. Prenatal screening and treatment of pregnant women for Neisseria gonorrhoeae became standard in the 1950s and for Chlamydia trachomatis in 1993. Neonatal gonococcal and chlamydial conjunctivitis are consequently uncommon today. Currently, only 0.5% erythromycin ophthalmic ointment is available in the United States (U.S.) for neonatal ocular prophylaxis, which is ineffective against C. trachomatis.

AREAS COVERED

This article addresses the altered epidemiology of ophthalmia neonatorum in the U.S. since prophylactic practices began, the lack of data supporting ophthalmic erythromycin for prevention of neonatal gonococcal and chlamydial conjunctivitis, and the impact of prenatal screening and treatment of pregnant women for N. gonorrhoeae and C. trachomatis on conjunctivitis incidence. The authors discuss why erythromycin ophthalmic ointment is likely ineffective against gonococcal ophthalmia, including the development of macrolide resistance. Physiologic limitations and pharmacokinetic properties are considered with respect to ophthalmic erythromycin for the prevention of gonococcal and chlamydial conjunctivitis.

EXPERT OPINION

Administration of erythromycin ophthalmic ointment for the prevention of neonatal conjunctivitis is not literature-supported. Prenatal screening and treatment of pregnant women is the most effective way to prevent ophthalmia neonatorum. National mandates for prophylaxis should be withdrawn.

Global prevalence of Neisseria gonorrhoeae infection in pregnant women: a systematic review and meta-analysis

BACKGROUND

Neisseria gonorrhoeae infection (gonorrhoea) is associated with several pregnancy complications, including preterm labour, spontaneous abortion, stillbirth, miscarriage, growth retardation, and intrauterine death.

OBJECTIVES

We performed a systematic review and meta-analysis to estimate the global and regional prevalence of gonorrhoea in pregnant women as a scientific basis for further studies.

DATA SOURCES

We systematically searched PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO databases from inception to 10 July 2022.

STUDY ELIGIBILITY CRITERIA

We included cross-sectional, cohort, and case-control studies that reported the prevalence of gonorrhoea in pregnant women. In addition, we included baseline data for randomized controlled trials.

PARTICIPANTS

Pregnant women who were tested for gonorrhoea.

METHODS

Pooled prevalence estimates at 95% CIs were calculated using a random-effects meta-analysis model. We stratified countries according to WHO-defined regions and socio-economic factors. Moreover, sub-group-, meta-regression, and sensitivity analyses were conducted to investigate the effects of pre-determined factors on prevalence estimates and heterogeneity.

RESULTS

We identified 235 studies (249 datasets) on 19 104 175 pregnant women from 71 countries. The worldwide pooled prevalence of gonorrhoea in pregnant women was estimated at 1.85% (95% CI 1.73-1.97%), with the highest rate in the African region (3.53%) (2.84-4.29%) and the lowest rate in the European region (0.52%) (0.27-0.84%). Overall, the prevalence estimates were high among low-income countries (3.03%), pregnant women with HIV (2.81%), and pregnant women <20 years old (8.06%). A significant decreasing trend in prevalence was observed over time (β = -0.0008, 95% CI -0.0012 to -0.0004, p 0.001).

DISCUSSION

Our findings indicate that a substantial number of pregnant women have been infected with gonorrhoea globally, which calls for immediate public health measures to reduce the potential risk of infection. The study highlights the inadequacy or lack of data for many countries, emphasizing the need to expand systematic data collection efforts at national and regional levels.

Adverse pregnancy and birth outcomes associated with Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum: a systematic review and meta-analysis

OBJECTIVES

Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum (genital mycoplasmas) commonly colonise the urogenital tract in pregnant women. This systematic review aims to investigate their role in adverse pregnancy and birth outcomes, alone or in combination with bacterial vaginosis (BV).

METHODS

We searched Embase, Medline and CINAHL databases from January 1971 to February 2021. Eligible studies tested for any of the three genital mycoplasmas during pregnancy and reported on the primary outcome, preterm birth (PTB) and/or secondary outcomes low birth weight (LBW), premature rupture of membranes (PROM), spontaneous abortion (SA) and/or perinatal or neonatal death (PND).Two reviewers independently screened titles and abstracts, read potentially eligible full texts and extracted data. Two reviewers independently assessed risks of bias using published checklists. Random effects meta-analysis was used to estimate summary ORs (with 95% CIs and prediction intervals). Multivariable and stratified analyses were synthesised descriptively.

RESULTS

Of 57/1194 included studies, 39 were from high-income countries. In meta-analysis of unadjusted ORs, M. hominis was associated with PTB (OR 1.87, 95% CI 1.49 to 2.34), PROM, LBW and PND but not SA. U. urealyticum was associated with PTB (OR 1.84, 95% CI 1.34 to 2.55), PROM, LBW, SA and PND. U. parvum was associated with PTB (1.60, 95% CI 1.12 to 2.30), PROM and SA. Nine of 57 studies reported any multivariable analysis. In two studies, analyses stratified by BV status showed that M. hominis and U. parvum were more strongly associated with PTB in the presence than in the absence of BV. The most frequent source of bias was a failure to control for confounding.

CONCLUSIONS

The currently available literature does not allow conclusions about the role of mycoplasmas in adverse pregnancy and birth outcomes, alone or with coexisting BV. Future studies that consider genital mycoplasmas in the context of the vaginal microbiome are needed.

PROSPERO REGISTRATION NUMBER

CRD42016050962.

Sexually transmitted infection screening to prevent adverse birth and newborn outcomes: study protocol for a randomized-controlled hybrid-effectiveness trial

Background

Sexually transmitted infections (STIs) during pregnancy are associated with adverse birth outcomes, including preterm birth, low birth weight, perinatal death, and congenital infections such as increased mother-to-child HIV transmission. Prevalence of STIs among pregnant women in South Africa remains high, with most women being asymptomatic for their infection(s). Unfortunately, most STIs remain undetected and untreated due to standard practice syndromic management in accordance with World Health Organization (WHO) guidelines. Although lab-based and point-of-care molecular tests are available, optimal screening strategies during pregnancy, their health impact, and cost-effectiveness are unknown.

Methods

We will implement a 3-arm (1:1:1) type-1 hybrid effectiveness-implementation randomized-controlled trial (RCT). We will enroll 2500 pregnant women attending their first antenatal care (ANC) visit for their current pregnancy at participating health facilities in Buffalo City Metro District, Eastern Cape Province, South Africa. Participants allocated to arms 1 and 2 (intervention) will receive GeneXpert® point-of-care diagnostic testing for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis, with same-day treatment for detected infection(s). Arm 1 will additionally receive a test-of-cure 3 weeks post-treatment, while Arm 2 will receive a repeat test at 30–34 weeks’ gestation. Those allocated to Arm 3 will receive syndromic management (standard-of-care). The RE-AIM framework will be used to guide collection of implementation indicators to inform potential future scale up. Primary outcome measures include (1) frequency of adverse birth outcomes among study arms, defined by a composite measure of low birth weight and pre-term delivery, and (2) change in STI prevalence between baseline and birth outcome among intervention arms and compared to standard-of-care. Estimates and comparative costs of the different screening strategies relative to standard-of-care and the costs of managing adverse birth outcomes will be calculated. Cost-effectiveness will be assessed per STI and disability-adjusted life year averted.

Discussion

This trial is the first RCT designed to identify optimal, cost-effective screening strategies that decrease the burden of STIs during pregnancy and reduce adverse birth outcomes. Demonstrating the impact of diagnostic screening and treatment, compared to syndromic management, on birth outcomes will provide critical evidence to inform changes to WHO guidelines for syndromic management of STIs during pregnancy.

Trial registration

ClinicalTrials.gov NCT04446611. Registered on 25 June 2020.

Adverse pregnancy and perinatal outcomes associated with Mycoplasma genitalium: systematic review and meta-analysis

Objective

To examine associations between Mycoplasma genitalium infection during pregnancy and adverse outcomes.

Methods

We did a systematic review of observational studies. We searched Medline, EMBASE, the Cochrane Library and CINAHL up to 11 August 2021. Studies were included if they compared preterm birth, spontaneous abortion, premature rupture of membranes, low birth weight or perinatal death between women with and without M. genitalium. Two reviewers independently assessed articles for inclusion and extracted data. We used random-effects meta-analysis to estimate summary ORs and adjusted ORs, with 95% CIs, where appropriate. Risk of bias was assessed using established checklists.

Results

We identified 116 records and included 10 studies. Women with M. genitalium were more likely to experience preterm birth in univariable analyses (summary unadjusted OR 1.91, 95% CI 1.29 to 2.81, I²=0%, 7 studies). The combined adjusted OR was 2.34 (95% CI 1.17 to 4.71, I²=0%, 2 studies). For spontaneous abortion, the summary unadjusted OR was 1.00 (95% CI 0.53 to 1.89, I²=0%, 6 studies). The adjusted OR in one case–control study was 0.9 (95% CI 0.2 to 3.8). Unadjusted ORs for premature rupture of membranes were 7.62 (95% CI 0.40 to 145.86, 1 study) and for low birth weight 1.07 (95% CI 0.02 to 10.39, 1 study). For perinatal death, the unadjusted OR was 1.07 (95% CI 0.49 to 2.36) in one case–control and 38.42 (95% CI 1.45 to 1021.43) in one cohort study. These two ORs were not combined, owing to heterogeneity. The greatest risk of bias was the failure in most studies to control for confounding.

Conclusion

M. genitalium might be associated with an increased risk of preterm birth. Further prospective studies, with adequate control for confounding, are needed to understand the role of M. genitalium in adverse pregnancy outcomes. There is insufficient evidence to indicate routine testing and treatment of asymptomatic M. genitalium in pregnancy.

PROSPERO registration number

CRD42016050962.

Impact of aetiological screening of sexually transmitted infections during pregnancy on pregnancy outcomes in South Africa

BACKGROUND

Sexually transmitted infections (STIs) during pregnancy may increase the risk of adverse pregnancy outcomes. STI syndromic management is standard of care in South Africa but has its limitations. We evaluated the impact of diagnosing and treating curable STIs during pregnancy on adverse pregnancy and birth outcomes.

METHODS

We combined data from two prospective studies of pregnant women attending public sector antenatal care (ANC) clinics in Tshwane District and Cape Town, South Africa. Pregnant women were enrolled, tested and treated for STIs. We evaluated the association between any STI at the first ANC visit and a composite adverse pregnancy outcome (miscarriage, stillbirth, preterm birth, early neonatal death, or low birthweight) using modified Poisson regression models, stratifying by HIV infection and adjusting for maternal characteristics.

RESULTS

Among 619 women, 61% (n = 380) were from Tshwane District and 39% (n = 239) from Cape Town; 79% (n = 486) were women living with HIV. The prevalence of any STI was 37% (n = 228); C. trachomatis, 26% (n = 158), T. vaginalis, 18% (n = 120) and N. gonorrhoeae, 6% (n = 40). There were 93% (n = 574) singleton live births, 5% (n = 29) miscarriages and 2% (n = 16) stillbirths. Among the live births, there were 1% (n = 3) neonatal deaths, 7% (n = 35) low birthweight in full-term babies and 10% (n = 62) preterm delivery. There were 24% (n = 146) for the composite adverse pregnancy outcome. Overall, any STI diagnosis and treatment at first ANC visit was not associated with adverse outcomes in women living with HIV (adjusted relative risk (aRR); 1.43, 95% CI: 0.95-2.16) or women without HIV (aRR; 2.11, 95% CI: 0.89-5.01). However, C. trachomatis (aRR; 1.57, 95% CI: 1.04-2.39) and N. gonorrhoeae (aRR; 1.69, 95% CI: 1.09-3.08), were each independently associated with the composite adverse outcome in women living with HIV.

CONCLUSION

Treated STIs at the first ANC visit were not associated with adverse pregnancy outcome overall. In women living with HIV, C. trachomatis or N. gonorrhoeae at first ANC were each independently associated with adverse pregnancy outcome. Our results highlights complex interactions between the timing of STI detection and treatment, HIV infection and pregnancy outcomes, which warrants further investigation.

Sexually transmitted infections in pregnant women from sub-Saharan Africa

Background

Sexually transmitted infections (STIs) are a major health problem in most countries of the world, particularly in developing countries where the resources and technology to diagnose and treat them are limited. Currently, there is limited data on STIs and risk factors for these infections in pregnant women living with human immunodeficiency virus (HIV), especially in sub-Saharan Africa (SSA). This review provides data on the prevalence and risk factors for STIs in pregnant women living with HIV from SSA. This review also describes the association between STIs and HIV on pregnancy and birth outcomes as well as highlights the importance of laboratory-based diagnosis of STIs.

Method

An electronic search of online databases was used to find and collect relevant research articles connected to the prevalence, adverse pregnancy and birth outcomes, health complications and risk factors associated with STIs and HIV in pregnant women from SSA. The search was limited to articles published in English. Relevant studies were identified by searching literature from January 2001 to date. The search yielded 4709 results.

Results

In SSA, STIs are highly prevalent in pregnant women and are widely known to be linked with an increased risk of poor maternal and neonatal outcomes. These infections are often asymptomatic and highly prevalent in pregnant women. The screening of STIs in pregnant women living with HIV can reduce the risk of mother-to-child transmission (MTCT) and screening and treatment for STIs can also prevent adverse perinatal outcomes. It is important to recognise regional and national STI epidemics in order to promote STI prevention and control interventions considering the test and treat approach as opposed to syndromic management.

Conclusion

This review highlights the need to use diagnostic screening methods instead of syndromic STI management in SSA. Moreover, more research into effective prevention and treatment measures for STIs in pregnant women is urgently required.

Where to go to in chlamydia control? From infection control towards infectious disease control

OBJECTIVES

The clinical and public health relevance of widespread case finding by testing for asymptomatic chlamydia infections is under debate. We wanted to explore future directions for chlamydia control and generate insights that might guide for evidence-based strategies. In particular, we wanted to know the extent to which we should pursue testing for asymptomatic infections at both genital and extragenital sites.

METHODS

We synthesised findings from published literature and from discussions among national and international chlamydia experts during an invitational workshop. We described changing perceptions in chlamydia control to inform the development of recommendations for future avenues for chlamydia control in the Netherlands.

RESULTS

Despite implementing a range of interventions to control chlamydia, there is no practice-based evidence that population prevalence can be reduced by screening programmes or widespread opportunistic testing. There is limited evidence about the beneficial effect of testing on pelvic inflammatory disease prevention. The risk of tubal factor infertility resulting from chlamydia infection is low and evidence on the preventable fraction remains uncertain. Overdiagnosis and overtreatment with antibiotics for self-limiting and non-viable infections have contributed to antimicrobial resistance in other pathogens and may affect oral, anal and genital microbiota. These changing insights could affect the outcome of previous cost-effectiveness analysis.

CONCLUSION

The balance between benefits and harms of widespread testing to detect asymptomatic chlamydia infections is changing. The opinion of our expert group deviates from the existing paradigm of 'test and treat' and suggests that future strategies should reduce, rather than expand, the role of widespread testing for asymptomatic chlamydia infections.

Prevalence of Chlamydia trachomatis Among Pregnant Women, Gynecology Clinic Attendees, and Subfertile Women in Guangdong, China: A Cross-sectional Survey

Background

Chlamydia trachomatis (CT) is a major cause of infertility and adverse birth outcomes, but its epidemiology among childbearing-age women remains unclear in China. This study investigated the prevalence of CT and associated factors among Chinese women aged 16–44 years who were either (1) pregnant, (2) attending gynecology clinics, or (3) subfertile.

Methods

We conducted a cross-sectional survey and recruited participants from obstetrics, gynecology, and infertility clinics in Guangdong between March and December 2019. We collected information on individuals’ sociodemographic characteristics, previous medical conditions, and sexual behaviors. First-pass urine and cervical swabs were tested using nucleic acid amplification testing. We calculated the prevalence in each population and subgroup by age, education, and age at first sex. Multivariable binomial regression models were used to identify factors associated with CT.

Results

We recruited 881 pregnant women, 595 gynecology clinic attendees, and 254 subfertile women. The prevalence of CT was 6.7% (95% CI, 5.2%–8.5%), 8.2% (95% CI, 6.2%–10.7%), and 5.9% (95% CI, 3.5%–9.3%) for the above 3 populations, respectively. The subgroup-specific prevalence was highest among those who first had sex before age 25 years and older pregnant women (>35 years). The proportion of asymptomatic CT was 84.8%, 40.0%, and 60.0% among pregnant women, gynecology clinic attendees, and subfertile women, respectively. Age at first sex (<25 years), multipara, and ever having more than 1 partner increased the risk of CT.

Conclusions

Childbearing-age women in China have a high prevalence of CT. As most women with CT were asymptomatic, more optimal prevention strategies are urgently needed in China.

Nonviral sexually transmitted infections in pregnancy: current controversies and new challenges

PURPOSE OF REVIEW

This review provides an update of nonviral, curable sexually transmitted infections (STIs) in pregnancy and summarizes our understanding of the current issues and controversies surrounding risk factors, screening, and treatment of STIs in pregnancy primarily in high-income countries (using the United States and the United Kingdom as examples). The infections covered in this review are syphilis, gonorrhea, chlamydia, trichomoniasis, and Mycoplasma genitalium infections.

RECENT FINDINGS

Overall, limited modern data is available to update researchers and clinicians on the epidemiology and care of STIs in pregnancy. Though common risk factors can be identified among these STIs, like socioeconomic status and inadequate antenatal care, specific screening and treatment challenges vary by geography and pathogen. Wherever available, surveillance data and research evidence are often limited to nonpregnant patients, leading to imperfect pregnancy-specific risk estimates and obstetric lags in the development and adoption of new guidelines. We have identified three areas of opportunity that may enhance the effectiveness of current approaches and inform new ones: improved data collection and evidence-based screening practices; prompt and comprehensive therapy, including partner services, and evaluations of new treatment modalities; and equitable antenatal and sexual healthcare for all pregnant persons and their partners.

SUMMARY

These findings highlight the need to revisit standards of screening and management of STIs in pregnancy in high-income countries.

Assessment of syndromic management of curable sexually transmitted and reproductive tract infections among pregnant women: an observational cross-sectional study

Background

This study estimated the prevalence of curable sexually transmitted and reproductive tract infections (STIs/RTIs) among pregnant women attending antenatal care (ANC) in rural Zambia, evaluated the effectiveness of syndromic management of STIs/RTIs versus reference-standard laboratory diagnoses, and identified determinants of curable STIs/RTIs during pregnancy.

Methods

A total of 1086 pregnant women were enrolled at ANC booking, socio-demographic information and biological samples were collected, and the provision of syndromic management based care was documented. The Piot-Fransen model was used to evaluate the effectiveness of syndromic management versus etiological testing, and univariate and multivariate logistic regression analyses were used to identify determinants of STIs/RTIs.

Results

Participants had a mean age of 25.6 years and a mean gestational age of 22.0 weeks. Of 1084 women, 700 had at least one STI/RTI (64.6%; 95% confidence interval [CI], 61.7, 67.4). Only 10.2% of infected women received any treatment for a curable STI/RTI (excluding syphilis). Treatment was given to 0 of 56 women with chlamydia (prevalence 5.2%; 95% CI, 4.0, 6.6), 14.7% of participants with gonorrhoea (prevalence 3.1%; 95% CI, 2.2, 4.4), 7.8% of trichomoniasis positives (prevalence 24.8%; 95% CI, 22.3, 27.5) and 7.5% of women with bacterial vaginosis (prevalence 48.7%; 95% CI, 45.2, 51.2). An estimated 7.1% (95% CI, 5.6, 8.7) of participants had syphilis and received treatment. Women < 20 years old were more likely (adjusted odds ratio [aOR] = 5.01; 95% CI: 1.23, 19.44) to have gonorrhoea compared to women ≥30. The odds of trichomoniasis infection were highest among primigravidae (aOR = 2.40; 95% CI: 1.69, 3.40), decreasing with each subsequent pregnancy. Women 20 to 29 years old were more likely to be diagnosed with bacterial vaginosis compared to women ≥30 (aOR = 1.58; 95% CI: 1.19, 2.10). Women aged 20 to 29 and ≥ 30 years had higher odds of infection with syphilis, aOR = 3.96; 95% CI: 1.40, 11.20 and aOR = 3.29; 95% CI: 1.11, 9.74 respectively, compared to women under 20.

Conclusions

Curable STIs/RTIs were common and the majority of cases were undetected and untreated. Alternative approaches are urgently needed in the ANC setting in rural Zambia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03573-3.

Adverse pregnancy and neonatal outcomes associated with Neisseria gonorrhoeae: systematic review and meta-analysis

Objective

To examine associations between Neisseria gonorrhoeae (NG) infection during pregnancy and the risk of preterm birth, spontaneous abortion, premature rupture of membranes, perinatal mortality, low birth weight and ophthalmia neonatorum.

Data sources

We searched Medline, EMBASE, the Cochrane Library and Cumulative Index to Nursing and Allied Health Literature for studies published between 1948 and 14 January 2020.

Methods

Studies were included if they reported testing for NG during pregnancy and compared pregnancy, perinatal and/or neonatal outcomes between women with and without NG. Two reviewers independently assessed papers for inclusion and extracted data. Risk of bias was assessed using established checklists for each study design. Summary ORs with 95% CIs were generated using random effects models for both crude and, where available, adjusted associations.

Results

We identified 2593 records and included 30 in meta-analyses. Women with NG were more likely to experience preterm birth (OR 1.55, 95% CI 1.21 to 1.99, n=18 studies); premature rupture of membranes (OR 1.41, 95% CI 1.02 to 1.92, n=9); perinatal mortality (OR 2.16, 95% CI 1.35 to 3.46, n=9); low birth weight (OR 1.66, 95% CI 1.12 to 2.48, n=8) and ophthalmia neonatorum (OR 4.21, 95% CI 1.36 to 13.04, n=6). Summary adjusted ORs were, for preterm birth 1.90 (95% CI 1.14 to 3.19, n=5) and for low birth weight 1.48 (95% CI 0.79 to 2.77, n=4). In studies with a multivariable analysis, age was the variable most commonly adjusted for. NG was more strongly associated with preterm birth in low-income and middle-income countries (OR 2.21, 95% CI 1.40 to 3.48, n=7) than in high-income countries (OR 1.38, 95% CI 1.04 to 1.83, n=11).

Conclusions

NG is associated with a number of adverse pregnancy and newborn outcomes. Further research should be done to determine the role of NG in different perinatal mortality outcomes because interventions that reduce mortality will have the greatest impact on reducing the burden of disease in low-income and middle-income countries.

PROSPERO registration number

CRD42016050962.