Pregnancy outcome following in utero exposure to hydroxychloroquine: A prospective comparative observational study

Objective: To evaluate pregnancy safety of hydroxychloroquine (HCQ) for rheumatologic diseases. Design: Prospective comparative observational study done at the Israeli teratology information service between 1998 and 2006. Results: 114 HCQ-exposed pregnancies (98.2% in the first trimester, T1) were followed-up and compared with 455 pregnancies of women counseled for non-teratogenic exposure. The difference in the rate of congenital anomalies was not statistically significant [7/97 (7.2%) vs. 15/440 (3.4%), p=0.094]. The analysis was repeated among those exposed in T1 excluding genetic or cytogenetic anomalies or congenital infections [5/95 (5.3%) vs. 14/440 (3.2%), p=0.355]. There were no cases of neonatal lupus erythematosus. The gestational age at delivery was earlier, rate of preterm delivery higher, and birth weight lower, in the HCQ group. Conclusion: The present study suggests that HCQ treatment in pregnancy is not a major human teratogen. The earlier gestational age and lower birth weight might be associated with maternal disease.