Aim: To study delivery outcome including presence of infant congenital malformations after maternal use of loperamide in early pregnancy.
Methods: Using the Swedish Medical Birth Register, women reporting the use of loperamide in early pregnancy were compared with other women for the period July 1, 1995-2004. Odds ratios (OR) or risk ratios (RR) were estimated after adjustment for some variables, which were associated with the use of loperamide (year of delivery, maternal age, parity, smoking, number of previous miscarriages).
Results: Characteristics of women using loperamide in early pregnancy were identified. An analysis of concomitant drug use indicated that only few of the women had inflammatory bowel disease. The risk of any congenital malformation was increased (OR = 1.43, 95% CI 1.04-1.96), based on 43 cases, but no major contributing type could be identified. The risk of hypospadias was significantly increased (RR = 3.2, 95% CI 1.3-6.6), based on seven cases. A statistically significant increase was seen also for placenta previa, large for gestational age and caesarean section.
Conclusion: Maternal use of loperamide in early pregnancy may be associated with a moderate risk increase for a malformation in the infant. The finding should be evaluated from other large studies.