Sexually transmitted infections: Prevalence and clinical outcomes among pregnant women in Western Sydney.

OBJECTIVE

We report the prevalence, characteristics and clinical outcomes of women with sexually transmitted infections (STIs) in pregnancy in the Western Sydney Local Health District (WSLHD) serving a large culturally and socio-economically diverse community in New South Wales (NSW), Australia, over the last 10 years.

METHODS

A retrospective cohort study of all pregnant women booked for antenatal care at three hospitals in WSLHD between September 2012 and August 2022 inclusive. Characteristics and birth outcomes associated with STIs diagnosed in pregnancy (chlamydia, gonorrhea, and syphilis) are reported using multivariable logistic regression adjusting for relevant confounders.

RESULTS

During 2012-2022, there were 102 905 births and 451 women (0.44%) with an STI diagnosis during pregnancy. The number of women with a history of chlamydia prior to their current pregnancy has increased over the last 10 years (P < 0.001). STIs in pregnancy were more common in younger women aged <20 years (adjusted odds ratio [aOR] 7.30, 95% confidence interval [CI] 5.04-10.57), 20-24 years (aOR 3.12, 95% CI 2.46-3.96), and >40 years (adj OR 1.67, 95% CI 1.07-2.59), in women with body mass index >30 (aOR 1.73, 95%CI 1.37-2.19), and those who smoked (aOR 2.24, 95% CI 1.71-2.94) and consumed alcohol (aOR 3.14, 95% CI 1.88-5.23) and illicit drugs (aOR 2.10, 95% CI 1.31-3.36). STIs in pregnancy were borderline associated with stillbirth (aOR 2.19 95% CI 0.90-5.36) but did not have a significant impact on preterm birth (aOR 1.21, 95% CI 0.87-1.68), admission to neonatal intensive care unit (NICU) (aOR 1.02, 95% CI 0.77-1.34), or having a small-for-gestational-age (SGA) baby (aOR 0.97, 95% CI 0.74-1.27).

CONCLUSIONS

Sociodemographic factors such as age, weight, smoking, and alcohol and drug use, were associated with the STI incidence in pregnancy. While the latter did not have an impact on preterm birth, NICU admission, and SGA in our cohort, there was a borderline association with stillbirth. Future research should identify barriers and facilitators to testing in a multicultural population and understanding the drivers of higher rates of STIs in certain population groups.