Postpartum Weight Retention and Mortality Over 50 Years of Follow-up

Chakraborti, Yajnaseni; Mumford, Sunni; Yeung, Edwina; Grantz, Katherine; Mendola, Pauline; James L. Mills; Caniglia, Ellen; Colleen M. Brensinger; Cuilin Zhang; Schisterman, Enrique; Hinkle, Stefanie

doi:10.5281/zenodo.17488445

Postpartum Weight Retention and Mortality Over 50 Years of Follow-up

Chakraborti, Yajnaseni; Mumford, Sunni; Yeung, Edwina; Grantz, Katherine; Mendola, Pauline; James L. Mills; Caniglia, Ellen; Colleen M. Brensinger; Cuilin Zhang; Schisterman, Enrique; Hinkle, Stefanie

Publisher: Zenodo
DOI: 10.5281/zenodo.17488445
Repository: zenodo.org
Language: en

Abstract

ABSTRACT Background: Unhealthy weight gain is associated with a higher risk of mortality. Childbearing may further contribute to this risk through postpartum weight retention (PPWR), a potential yet unexplored mechanism. This study examined the link between interpregnancy weight change (IPWC)—a proxy for PPWR, and mortality over 50 years post-pregnancy in a diverse cohort. Methods: In participants with ≥2 pregnancies (n=8165) from the prospective Collaborative Perinatal Project (U.S., 1959-1966), the exposure was IPWC, the difference between self-reported pre-pregnancy weight at the 1st and 2nd CPP pregnancies. IPWC was examined as quintiles with the median quintile as the reference. Vital status through 2016 was obtained through linkages with the National Death Index and Social Security Death Master File. Missing data were imputed 10 times. All-cause mortality was modeled using discrete Cox proportional hazard models, weighted for potential selection bias. Secondary analyses examined pre-pregnancy body mass index (BMI)-specific IPWC quintiles. Models were adjusted for 1st CPP pregnancy demographics, reproductive history, and medical conditions. Results: The median follow-up was 54 years [inter-quartile range (IQR): 47-56]; 41.7% (n=3405) of the participants died. The median IPWC was 0.91 kg [IQR:-0.45, 3.63]; 56.3% (n=4593) of the participants had a net weight gain. Compared to those with IPWC between 0 and 1.8 kg (quintile 3), the adjusted all-cause mortality hazard ratios (HRs) and 95% confidence intervals (CIs) were: 1.01 (0.89-1.15) IPWC ≤-1.4 kg; 0.87 (0.76-0.99) for IPWC between -1.4 and 0 kg; 1.06 (0.93-1.21) for IPWC between 1.9 and 4.5 kg; and 1.13 (0.99-1.29) for IPWC ≥4.5 kg. Further, among those with pre-pregnancy BMI of 18.5-24.9 kg/m2, IPWC ≥ 4.5 kg was linked to higher HR of 1.20 (1.02-1.42). Conclusion: Modest postpartum weight retention may raise mortality risk, and further studies are needed to identify strategies to support healthy postpartum weight goals.

Full text

Postpartum Weight Retention and Mortality Over 50 Years of Follow-up Yajnaseni Chakraborti, Sunni L. Mumford, Edwina H. Yeung, Katherine L. Grantz, Pauline Mendola, James L. Mills, Ellen C. Caniglia, Colleen M. Brensinger, Cuilin Zhang, Enrique F. Schisterman, Stefanie N. Hinkle What do we know so far? Obesity rates are 2x as high in women who have given birth compared to those who haven't, likely due to postpartum weight retention. Only 1 in 4 women return to their pre-pregnancy weight one year postpartum. Background Why do we care about postpartum weight retention? Postpartum weight retention is linked to adverse cardiometabolic health, with risks such as poor metabolic profiles, pre-diabetes, diabetes, and cardiovascular disorders What did we find? Methods Data: CPP Mortality Linkage Study – prospective cohort of pregnant women in 1959-1965 linked to death records for vital status through 2016. Study Sample: Participants with ≥ 2 CPP pregnancies (n = 8165) Exposure: 1) Interpregnancy Weight Change (IPWC) 2) Postpartum Weight Change (PPWC) Adjusted for Inter-conception interval (ICI) and confounders including, pregnancy 1 age, smoking, race, gravidity, marital, income, education, prior to pregnancy diabetes, c a n ce r, cardiovascular, respiratory, renal, and neurological diseases, pre-pregnancy BMI, and study site. ICI: time difference between the LMP of the 1st and 2nd CPP pregnancies Impact Reduced postpartum weight retention corresponded with lower risks of mortality across 50 years of follow-up. Our results underscore the urgent need for effective strategies to prevent postpartum weight retention or new weight gain. 38th Annual Meeting June 10, 2025 Funding Statement: This research was supported in part by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (contract # HHSN275200800002I/27500013). Want to connect or learn more? Email ID: [email protected] or Find me on CPP Linkage Collaborative Perinatal Project What do we not know? Effect of postpartum weight retention on time to mortality Outcome: All-cause mortality Start of follow up: Date of the last menstrual period (LMP) of the participant’s 2nd CPP pregnancy). End of follow-up: Date of death or Dec 31, 2016, whichever occurred first. Models: Inverse probability weighted Cox proportional hazard models, accounting for right censoring and selection of only those with ≥ 2 CPP pregnancies Risk of all cause mortality associated with quintiles of interpregnancy weight change (IPWC) Risk of all cause mortality associated with quintiles of Postpartum Weight Change (PPWC) Adjusted for Inter-pregnancy interval (IPI) and confounders including the above variables as well as hypertensive disorders of pregnancy, and pregnancy 1 total weight gain. IPI: time difference between 1st pregnancy delivery date and LMP of the 2nd pregnancy Hypothesis Postpartum weight retention or new weight gain → increased risks of mortality over 50 years of follow-up Separating out the weight gain group from Q5 Pre-pregnancy weight: Self-reported Delivery weight: Measured at admission for delivery Postpartum Weight Change Interpregnancy Weight Change