Identifying the Impact of Chlamydia trachomatis Screening and Treatment on Mother-to-Child Transmission, and Respiratory Neonatal Outcomes in Mexico.

Chlamydia trachomatis (C. trachomatis) screening and treatment in pregnancy allows the opportunity to reduce adverse pregnancy and neonatal outcomes worldwide. Although C. trachomatis infection is easily treated and cured with antibiotics, only some countries have routine pregnancy screening and treatment programs. We therefore evaluated whether just one maternal screening for C. trachomatis is enough to prevent adverse pregnancy and negative neonatal outcomes. Among the 4087 first-time gynecological-obstetric consultations granted at the National Institute of Perinatology in 2018, we selected the study population according to a case-cohort design. Antenatal C. trachomatis screening and treatment interventions were performed on 628 pregnant women using COBAS^® TaqMan CT. C. trachomatis DNA was also detected in samples from 157 infants of these mothers. In the maternal cohort, incidence of C. trachomatis infection was 10.5%. The vertical transmission rate was 1.5% for the cohort of mothers who tested positive for C. trachomatis and received treatment, and 29.7% for those with a negative test. By evaluating symptomatic neonatal infection, the hazard rate of perinatal pneumonia was 3.6 times higher in C. trachomatis-positive babies than in C. trachomatis-negative babies. Despite the low rate of mother-to-child transmission in women positive for C. trachomatis, possible maternal infection that is not detected in pregnancy significantly increases the risk of neonatal infection with consequent perinatal pneumonia.