Background: Inconsistencies in information on safety of medicine use during pregnancy and lactation can result in sub-optimal treatment for pregnant and lactating women, risks to the fetus or child and unnecessary weaning off breastfeeding. The objective of this study was to analyze information discrepancies regarding medicine use during pregnancy and lactation between on-line sources for patients and health care professionals (HCPs) in four European languages.Research design and methods: The medicines analyzed were ibuprofen, ondansetron, olanzapine, fingolimod, methylphenidate and adalimumab. Recommendations were classified into different data source categories, for patients and for HCPs, and compared between the data source categories for each medicine and language.Results: For patients, 11/24 (46%) and 4/24 (17%) comparisons of the pregnancy and lactation recommendations, respectively, were consistent between all sources. The corresponding figures for HCP-sources were 13/24 (54%) and 5/24 (21%). Regulatory sources had generally more restrictive recommendations. Teratology Information Services (TIS) centers' recommendations for medicine use during pregnancy and lactation were consistent in 25/27 (93%) and 15/22 (68%) of cases respectively.Conclusion: Discrepancies between online information sources regarding medicine use during pregnancy and lactation are common, especially for lactation. TIS centers recommendations were more aligned. Additional work is needed to harmonize information within and between countries to avoid conflicting messages.
Keywords: Information discrepancies; lactation; medicines; pregnancy.