Background: Understanding determinants of antibiotic use during pregnancy is crucial for optimizing their utilization in clinical practice. We aimed to investigate which individual-level factors are associated with antibiotic use among pregnant women.
Methods: Population-based cohort study using linked data from the Swedish national health and population registers spanning from 2006 to 2019. Sociodemographic characteristics, medical and obstetric history, lifestyle and healthcare utilization were investigated as independent variables. Any systemic antibiotic use during pregnancy, the primary outcome, was determined from filled prescriptions, with broad-spectrum antibiotics and multiple courses of antibiotics as secondary outcomes. Multiple logistic regression was used to estimate odds ratios (ORs), including all independent variables in the model.
Results: Among 20 variables associated with any systemic antibiotic use during pregnancy, preconception prescription drug use (OR 1.93 [95% CI 1.87-1.98] for > 4 vs. 0-1 unique therapeutic subgroups), chronic renal disease (1.82 [1.73-1.93]) and low maternal age (1.67 [1.61-1.74] for ages < 20 vs. 30-34 years) had the highest odds. Chronic renal disease, immunodeficiency disorders and preconception drug use (> 4 vs. 0-1 therapeutic subgroups) had the highest odds of broad-spectrum antibiotic use and use of multiple antibiotic courses.
Conclusions: Pre-existing morbidities and low maternal age were most strongly associated with antibiotic use during pregnancy, suggesting a needs-based approach in prescribing. Proactive management of morbidities and infection prevention strategies, particularly targeting young women of reproductive age, could potentially reduce the need for antibiotic treatment in prenatal care.
Keywords: Antibiotics; Pharmacoepidemiology; Pregnancy; Sweden.
© 2025. The Author(s).