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

Abstract

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.

Keywords: Chlamydia trachomatis; Neisseria gonorrhoeae; low birthweight; pregnancy; preterm birth; sexually transmitted infections; syndromic management.

Figure 1:

Flow of participants in the Maduo study, February 2021-December 2022, Gaborone, Botswana Notes: SoC=Standard-of-Care, PTB=preterm birth, LBW=low birth weight

Figure 2.

Predicted prevalence of preterm birth/low birth weight, preterm birth, and low birth weight by intervention arm assignment. Notes: PTB=preterm birth; LBW=low birth weight; SoC=Standard-of-Care assignment; Intv=Intervention assignment. Predicted prevalence using post-estimation predictive margins analysis resulting from multivariable logistic regression controlling for parity, antenatal care visits, hypertension, and clinic.