- Exposure to amoxicillin and amoxicillin combined with clavulanic acid (ACA) during the first trimester of pregnancy was not associated with an increased risk for major congenital malformations in general or major malformations associated with organ systems.
Why this matters
- Recent studies have suggested that changes in the microbiome induced by antibiotics influence pregnancy outcome.
- Population-based retrospective study involving 101,615 pregnancies.
- Risk for major malformations following first-trimester exposure to amoxicillin and ACA assessed.
- Funding: None.
- Overall, 6919 (6.8%) pregnancies were exposed to amoxicillin, 1045 (1.0%) to amoxicillin only and 6041 (5.9%) to ACA.
- No significant association was observed between first-trimester exposure to amoxicillin or clavulanic acid and major malformations in general or related to organ system:
- Total amoxicillin (crude relative risk [RR], 1.05; 95% CI, 0.95-1.16; adjusted RR [aRR], 1.09, 95% CI, 0.98-1.20).
- Amoxicillin alone (crude RR, 1.00; 95% CI, 0.78-1.28; aRR, 1.03; 95% CI, 0.80-1.32).
- ACA (crude RR, 1.06; 95% CI, 0.95-1.17; aRR, 1.09; 95% CI, 0.98-1.21).
- No significant associations were observed between:
- exposure to amoxicillin and clavulanic acid and sub-classes of major malformations.
- exposure in terms of defined daily dose of amoxicillin and clavulanic acid and major malformations.
- Retrospective design.