Chlamydia trachomatis - new evidence for association with adverse birth outcomes, Florida 2008-2010

Background: Prior population based study that controlled for 21 independent variables, found the odds of low birth weight for women with inadequate weight and history of chlamydial infection during the pregnancy was nearly twice that of women without chlamydial infection(AOR 1.98, p< 0.02). A stronger association was observed with pre-term low birth weight (AOR 2.34, p<0.01). Subsequently statewide laws and regulations were passed to require chlamydia screening during pregnancy, and electronic laboratory reporting into newly launched surveillance systems. Objectives: To examine associations between sexually transmitted infections during pregnancy and birth outcomes among a population-based sample of women who gave birth in Florida. Main outcome variables were low- /term-/ and pre-term low birth weight. Methods: Matched case control analysis among women tested and found positive for chlamydia, treated and gave birth during the period 01/01/2008 to 12/31/2010. Dependent and independent indicator variables were developed to support the calculation of crude and adjusted odds ratios. Results: Among women 18-35 years old, with singleton births, 2.1% were reported with chlamydia during pregnancy and 7.0 % experienced low-birth-weight outcome. Preliminary significant association between chlamydia and low birth weight disappeared when adjusted for demographics, while controlling for smoking, prenatal care, timely treatment, gestational age at treatment and inadequate weight gain. Conclusions: Proactive public health policies for chlamydia screening during pregnancy and intensified treatment timeliness contributed to improved pregnancy outcomes. This has implication for targeted regulatory changes to enhance practice guidelines and expansion of electronic laboratory reporting to improve STI case management in pregnancy.