(090) Use of Medication for Gastroesophageal Reflux During Pregnancy and Adverse Birth Outcomes

Publication Number: 1085

Background: Symptoms of gastroesophageal reflux disease occur in approximately half of all pregnancies. Consequently, many pregnant people use over-the-counter medication, including antacids and proton pump inhibitors (PPIs), to treat these symptoms, but data on the safety of use during pregnancy are scarce.

Objectives: To determine whether calcium-based antacid and PPI use during pregnancy is associated with selected adverse birth outcomes.

Methods: In this prospective cohort study, we included 9,153 pregnancies enrolled in the PRIDE Study (2012-2019) and The Dutch Pregnancy Drug Register (2014-2019). Validated web-based questionnaires and obstetric records were used to collect data on exposures (use of calcium-based antacids and PPIs, including details on timing of use and dosage), outcomes (preterm birth, low birth weight, small-for-gestational-age [SGA], and low Ponderal Index), and confounders. We fitted crude and weighted modified Poisson regression models and Cox proportional hazard models for use of calcium-based antacids and PPIs before gestational day 161 and time-varying exposures after gestational day 160, respectively, using inverse probability of treatment weighting.

Results: Calcium-based antacid use before gestational day 161 was not associated with any of the outcome measures, but use after gestational day 160 was associated with a decreased risk of low birth weight (hazard ratio [HR] 0.5, 95% confidence interval [CI] 0.3-0.9) and SGA (HR 0.6, 95% CI 0.4-0.8). We observed increased risks for use of high-dose PPIs before gestational day 161 and preterm birth (risk ratio [RR] 2.3, 95% CI 1.2-4.4) and low birth weight (RR 2.9, 95% CI 1.4-6.0), whereas any PPI use after gestational day 160 was associated with low birth weight (HR 2.0, 95% CI 1.2-3.6), SGA (HR 1.5, 95% CI 1.0-2.3), and low Ponderal Index (HR 2.3, 95% CI 1.3-4.2).

Conclusions: Use of calcium-based antacids seemed safe during pregnancy with regard to birth outcomes, with associations that may be explained by reverse causation. PPI use in early and late pregnancy, however, was associated with multiple adverse birth outcomes including preterm birth, low birth weight, SGA and low Ponderal Index, warranting restraint use of this over-the-counter medication during pregnancy.