What does current evidence show about acetaminophen use in pregnancy?

A large Lancet meta-analysis found no clinically meaningful association between prenatal acetaminophen exposure and autism, ADHD, or intellectual disability after restricting analyses to adjusted and sibling-comparison studies, with odds ratios essentially null; acetaminophen remains first-line for pain and fever in pregnancy. A Nordic BMJ case-control study of more than 17,000 gastric cancer cases found no increased risk of non-cardia adenocarcinoma with long-term proton pump inhibitor use after comprehensive confounder adjustment. Finally, a U.S. cohort study of older adults linked shingles vaccination to lower inflammation and slower biological aging across multiple systems, though causality cannot be confirmed due to observational design.