BACKGROUND AND PURPOSE:

• Damkier et al. (AJOG, 2019) assessed the association between 10 antibiotics and congenital malformations

METHODS:

• Cohort study (2000 to 2015)
  • Validated Danish health-care and civic registries
• Participants
  • Singleton liveborn children in Denmark over a 15 year period
• Data sets and analysis
  • Data collected from the first trimester included
    • Pregnancy information | Prescription drug purchases for the 10 most commonly prescribed antibiotics | Congenital malformations
  • Crude odds ratio (OR) were calculated and adjusted (aOR) using logistic regression models were applied to control for confounders
  • Covariates: Maternal age at delivery | Year of delivery | Parity | Pre-pregnancy BMI | Smoking | Educational status | Employment status | Personal income
• 10 common antibiotics
  • Doxycycline | Amoxicillin | Pivmecillinam | Dicloxacillin | Sulfamethizole | Erythromycin | Roxithromycin | Azithromycin | Ciprofloxacin | Nitrofurantoin
• Primary analysis
  • Exposed cohort vs exposure to penicillins considered safe in pregnancy: Ampicillin | Pivampicillin | Benzylpenicillin | Phenoxymethylpenicillin
• Secondary analysis
  • Exposed cohort vs unexposed cohort (no antibiotics)

RESULTS:

• No increased risk of congenital malformations found for any of the 10 antibiotics when compared to ‘safe’ penicillin exposure
• Compared to no exposure, there was an increased risk of major malformations and cardiac malformations for the following
  • Pivmecillinam: Major OR 1.13 (95% CI, 1.06 to 1.19) | Cardiac OR 1.15 (95% CI, 1.04 to 1.28)
  • Sulfamethizole: Major OR 1.15 (95% CI, 1.07 to 1.24 | Cardiac OR 1.22 (95% CI, 1.07 to 1.39)
  • Azithromycin: Major OR 1.19 (95% CI, 1.03 to 1.38 | Cardiac OR 1.29 (95% CI, 0.99 to 1.67)

CONCLUSION:

• No increased risk of congenital malformations was found for first trimester exposure to 10 common antibiotics vs 4 commonly prescribed ‘safe’ penicillins
• Small increased risk found when compared to no antibiotic exposure (secondary outcome)

Learn More – Primary Sources:

In utero exposure to antibiotics and risk of congenital malformations: A population-based study

Related ObG Topics:

ACOG Guidance on Use of Sulfonamides and Nitrofurantoin for UTIs in the First Trimester

Does Antibiotic Use Increase Risk of Spontaneous Abortion?

FDA Drug Safety Communication: Antiretroviral Dolutegravir in Pregnancy and Association with NTD in Offspring

Antiepileptic Drugs: What is the Impact on Risk for Birth Defects