Antibiotic use during pregnancy and the risk of preterm birth: a population-based Swedish cohort study

Area of Science:

• Reproductive Medicine
• Microbiology
• Public Health

Background:

• A healthy maternal microbiome is hypothesized to be protective against preterm birth.
• Systemic antibiotic use during pregnancy may disrupt the maternal microbiome, potentially impacting pregnancy outcomes.
• Understanding the association between gestational antibiotic exposure and preterm birth is crucial for maternal and infant health.

Purpose of the Study:

• To evaluate the association between antibiotic use during pregnancy and the risk of preterm birth.
• To investigate whether this association differs based on maternal comorbidities and the timing of antibiotic exposure.

Main Methods:

• A population-based cohort study utilized data from all first pregnancies in Sweden between 2006 and 2016.
• Multivariable logistic regression analysis assessed the association between gestational and pre-conception antibiotic use and preterm birth.
• Analyses were adjusted for pre-gestational comorbidities, trimester of exposure, antibiotic class, and treatment duration.

Main Results:

• Antibiotic exposure during pregnancy was linked to an increased risk of preterm birth in both mothers with (OR=1.32) and without (OR=1.09) comorbidities.
• Pre-conception antibiotic use showed no association with preterm birth.
• Increased risk was observed for first and second-trimester use, while third-trimester use showed a decreased risk. Specific antibiotic classes, including macrolides and quinolones, were associated with higher risks.

Conclusions:

• Gestational antibiotic use is associated with an elevated risk of preterm birth.
• The risk is particularly pronounced in mothers with pre-existing chronic diseases.
• Further research is needed, as antibiotic indications were not available and could influence outcomes.