Maternal Weight After Childbirth Versus Aging-Related Weight Changes

Published in: Women's Health Issues, [Epub January 2017]

Posted on on March 14, 2017

by Olga Yakusheva, Kandice A. Kapinos, Marianne Weiss

Read More

Access further information on this document at Women's Health Issues

This article was published outside of RAND. The full text of the article can be found at the link above.


Pregnancy weight gain is believed to contribute to female overweight and obesity. However, most studies do not account for the changes in body weight expected to occur as women age. We examined the long-term weight trajectory of childbearing women relative to weight progression that could be expected in the absence of pregnancy.


From the hospital records of 32,187 women with two births in Wisconsin during 2006 to 2013, we extracted the maternal weight at pregravid, delivery, and subsequent pregravid. We predicted the corresponding aging-progressed weights using a weight-for-age equation adjusted for sociodemographic variables. Nonparametric mixed effects models estimated the average maternal weight trajectory and the corresponding aging-related progression through 5 years after birth.


The estimated aging-related progression predicted a gradual annual weight increase of 1.94 pounds (95% confidence interval 1.90–1.98), from 152.79 pounds at pregravid to 163.76 pounds by 5 years after birth. Actual maternal weight followed a sinusoidal pattern: increasing during gestation, decreasing during the first postbirth year, converging with the aging-related progression during the second postbirth year, and then increasing at 2.89 pounds (95% confidence interval 2.23–3.55) annually and diverging upward from the aging-related progression to 168.03 pounds by 5 years after birth.


Pregnancy weight gain did not contribute to the aging-related trend, but lifestyle changes of parenthood may later exacerbate the long-term trend.

This report is part of the RAND Corporation External publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

Our mission to help improve policy and decisionmaking through research and analysis is enabled through our core values of quality and objectivity and our unwavering commitment to the highest level of integrity and ethical behavior. To help ensure our research and analysis are rigorous, objective, and nonpartisan, we subject our research publications to a robust and exacting quality-assurance process; avoid both the appearance and reality of financial and other conflicts of interest through staff training, project screening, and a policy of mandatory disclosure; and pursue transparency in our research engagements through our commitment to the open publication of our research findings and recommendations, disclosure of the source of funding of published research, and policies to ensure intellectual independence. For more information, visit

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.