Study Population
The study population included pregnant women in the Maduo study, which was a cluster-controlled, cross-over trial conducted in four antenatal care clinics in Gaborone, Botswana. The primary aim of the main study was to evaluate the impact of asymptomatic screening on post-delivery prevalence and the vertical transmission of C. trachomatis orN. gonorrhoeae infections. Madua study details have been previously described.(11) In brief, starting in February 2021, consenting pregnant women in both arms were enrolled if they met the following eligibility criteria: aged 15 years or older, attending their first antenatal care visit, 27 weeks gestation or less, not treated for an STI in the past 30 days, and without signs or symptoms of an STI (most commonly vaginal discharge) and therefore not in need of syndromic management (i.e. standard-of-care).
Initially two clinics participated in the study, one intervention and one standard-of-care clinic (February 2021 to mid-September 2021). As previously described,(11) clinics were similar in terms of patient volume and services offered; however, one clinic had space readily available for the screening intervention and was designated the initial intervention clinic. However, COVID-related recruitment challenges resulted in expansion to an additional two clinics, assigned to the intervention arm, in mid-September 2021. In January 2022, the standard-of-care clinic crossed-over and received the intervention and two intervention clinics crossed-over and received the standard of care.
Our primary analysis sample included participants with non-missing values for each of our key outcomes (low birth weight, preterm birth), and non-missing values for covariates. We excluded participants who experienced a miscarriage or stillbirth. We also restricted the sample to participants with singleton pregnancies as non-singleton births are more likely to have lower birthweight and shorter gestation.