Epidurals are widely used and widely trusted for pain relief during labor. So when a 2020 study reported that they might be linked to autism, it raised a troubling question: could a routine medical decision have long-term consequences? We follow that claim from headline to evidence—and watch what happens when other scientists take a closer look. We dig into the original study, a wave of replication studies from around the world, and a meta-analysis that tries to make sense of it all. Along the way, we unpack hazard ratios, Cox regression, inverse probability weighting, and sibling analyses—and why even sophisticated statistical adjustment can’t eliminate confounding. Plus: why bigger datasets don’t solve everything, what happens when results shrink after adjustment, and how a controversial study turned into a case study in science working as it should. Bonus: our first guest journalist interview!
Statistical topics
- Confounding
- Cox regression
- Hazard ratios
- Inverse probability weighting (IPTW)
- Multivariable adjustment
- Observational studies
- Residual confounding
- Retrospective cohort studies
- Sibling analysis
- Statistical adjustment
- Statistical significance vs practical significance
- Survival analysis
Methodological morals
- “Every time you adjust the model and the effect gets smaller, that's the universe whispering, maybe don't build a causal story out of this.”
- “Consistency across studies is gold.”
- “There's more to the story than the statistics.”
References
- Dattaro, Laura. A questionable study linked autism to epidurals. Then what? Spectrum. April 18, 2023.
- Dattaro, Laura. How to find baby sharks. Nautilus. September 9. 2024.
- Laura Dattaro’s home page.
- Phil Kearney’s blog post about the SMART framework.
- Qiu C, Lin JC, Shi JM, et al. Association Between Epidural Analgesia During Labor and Risk of Autism Spectrum Disorders in Offspring. JAMA Pediatr. 2020;174:1168-1175.
- Joint Statement. Labor Epidurals Do Not Cause Autism; Safe for Mothers and Infants, say Anesthesiology, Obstetrics, and Pediatric Medical Societies. American Society of Anesthesiologists. October 12, 2020.
- Wall-Wieler E, Bateman BT, Hanlon-Dearman A, Roos LL, Butwick AJ. Association of Epidural Labor Analgesia With Offspring Risk of Autism Spectrum Disorders. JAMA Pediatr. 2021;175:698-705.
- Christakis DA. More on epidurals and autism. JAMA Pediatrics. 2021; 175: 705.
- Mikkelsen AP, Greiber IK, Scheller NM, Lidegaard Ø. Association of Labor Epidural Analgesia With Autism Spectrum Disorder in Children. JAMA. 2021;326:1170–1177.
- Hanley GE, Bickford C, Ip A, et al. Association of Epidural Analgesia During Labor and Delivery With Autism Spectrum Disorder in Offspring. JAMA. 2021;326:1178-1185.
- Hegvik TA, Klungsøyr K, Kuja-Halkola R, et al. Labor epidural analgesia and subsequent risk of offspring autism spectrum disorder and attention-deficit/hyperactivity disorder: a cross-national cohort study of 4.5 million individuals and their siblings. Am J Obstet Gynecol. 2023;228:233.e1-233.e12. Epub 2022 Aug 13. Hu X, Wang B, Chen J, Han D, Wu J.
- Association Between Epidural Labor Analgesia and Autism Spectrum Disorder in Offspring: A Systematic Review and Meta-Analysis. J Pain Res;17:227-240.
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Writing in the Sciences
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn &ReginaNuzzo.com
- (00:00) - Intro
- (01:40) - Why autism is hard to study
- (05:18) - The original 2020 study
- (11:38) - Results & hazard ratios
- (15:24) - Confounding & adjustment
- (27:29) - Criticism & plausibility
- (35:08) - Replications begin
- (45:57) - Converging evidence & meta-analysis
- (52:07) - What does it mean?
- (54:57) - Guest & wrap-up
