A large collaborative cohort study by researchers at Ben-Gurion University, Negev, says, H2 Blocker drugs like Famotidine, Cimetidine and Ranitidine, approved for acid reflux (heartburn) in the U. S., pose no significant risks for the unborn foetus.

The findings of the examining infants born to mothers exposed to H2 blockers, particularly Famotidine, during pregnancy, published in the Journal of Clinical Pharmacology, reassurest H2 blocker drugs given for relieving acid reflux during pregnancy, are safe enough for the foetus.

Symptoms of acid reflux are usually more frequent and severer in the last few months of gestation, with an estimated 30% to 80% of pregnant women affected.

The Israeli researchers investigated the safety of H2 blockers used during the first trimester of pregnancy by linking a database of medications dispensed over a 10-year period to all women registered with Clalit Health Services in the Southern District of Israel, with databases that contained maternal and infant hospital records, including therapeutic abortion records of Soroka University Medical Centred during the same period.

The study found of the 84,823 infants born to mothers during the study period, 1,148 or 1.4% of the women were exposed to H2 blockers during the first trimester of pregnancy, with major congenital malformations rates identified in the group exposed to H2 blockers during the first trimester being 5.7% i. e. 65 of 1,148 infants, compared to 5.3% i. e. 4,400 of 83,675 infants in the unexposed group.