Analyzing more than 50 years of pregnancy and mortality data, researchers found that excessive gestational weight gain (GWG) was associated with increased risk for earlier death.
For women with a normal pre-pregnancy weight, excessive GWG was associated with a 9% (95% CI 1.01-1.18) increase in all-cause mortality, according to Stefanie Hinkle, PhD, of the University of Pennsylvania Perelman School of Medicine in Philadelphia, and co-authors.
Women who were overweight prior to pregnancy and who had excessive GWG had a 12% (95% CI 1.01-1.24) increase in all-cause death, Hinkle and colleagues reported in The Lancet.
Those who were underweight pre-pregnancy but had excessive GWG had an 84% increased risk of cardiovascular-related mortality (95% CI 1.08-3.12) but not all-cause or diabetes-related mortality, they found. Normal-weight women with excessive GWG also saw increased risk of cardiovascular death (HR 1.20, 95% CI 1.04-1.37), but not diabetes-related mortality.
And overweight women also had an increased risk of diabetes-related mortality (HR 1.77, 95% CI 1.23-2.54) but not cardiovascular mortality, researchers found.
“The data gleaned from this study strongly indicate that excessive weight gain during pregnancy may contribute to the development of chronic diseases in the long term, thereby increasing the risk of premature mortality,” Hinkle told MedPage Today, noting that nearly half of pregnant people gain more weight than guidelines recommend.
“It underscores the pressing need to provide support and guidance to pregnant individuals to help them achieve healthy weight gain during pregnancy, thus mitigating the risk of future chronic diseases and early mortality,” she added.
The researchers assessed data from the Collaborative Perinatal Project (CPP), which enrolled 48,197 pregnant people at their first prenatal visit at 12 clinical centers from 1959 to 1966. Their vital status was ascertained as of 2016 for the CPP Mortality Linkage Study.
Ultimately, a total of 46,042 women were included, and the median follow-up was 52 years, by which time about 39% of participants had died. There were near-equal numbers of Black and white participants (45.3% and 46.2%, respectively).
Hinkle and colleagues used 2009 guidance for weight gain during pregnancy established by the U.S. National Academy of Medicine (NAM), determined by body mass index (BMI): underweight (28 to 40 lb); normal weight (25 to 35 lb); overweight (15 to 25 lb); and obese (11 to 20 lb).
The researchers found no meaningful associations between GWG and mortality among women who were obese prior to pregnancy, which they theorized is because obese women already have higher risk for chronic conditions. In addition, weight change below recommended levels was only associated with a reduced risk of diabetes-related death (HR 0.62, 95% CI 0.48-0.79) in people who had normal weight before pregnancy.
The study was limited by a lack of follow-up after delivery, “limiting the ability to understand the process for developing chronic diseases and asses how an individual’s risk might be altered with postpartum interventions,” the authors wrote.
Still, they said that “although existing literature has shown that weight gain within NAM recommendations is crucial for optimizing pregnancy outcomes such as birthweight, this study shows that for individuals without pre-pregnancy obesity, gestational weight gain might have a lasting effect on health beyond pregnancy, increasing mortality risk from cardiometabolic diseases.”
In an accompanying editorial, Tomomi Kotani, MD, PhD, and Sho Tano, MD, both of the Nagoya University Graduate School of Medicine in Nagoya, Japan, cautioned that the findings should be interpreted with caution “to avoid alarming pregnant people, because this study is an observational prospective study, not a clinical trial.”
“Excessive GWG could result in weight retention after delivery and visceral fat accumulation, but further studies are needed,” they wrote.
“Healthcare professionals should be aware that those who had excess GWG are a population at high risk of cardiovascular mortality and should also consider some prevention strategies for cardiovascular disease,” they wrote, “although further research is needed to assess their validity.”
Hinkle suggested future research “should focus on identifying novel strategies to help pregnant people achieve a healthy weight gain in pregnancy.”
The study was funded by the NIH.
Neither the authors nor the editorialists reported any conflicts of interest.
Source Reference: Hinkle S, et al “Gestational weight change in a diverse pregnancy cohort and mortality over 50 years: a prospective observational cohort study” Lancet 2023; DOI: 10.1016/S0140-6736(23)01517-9.
Source Reference: Kotani T, Tano S “Long-term effects of gestational weight gain on mortality” Lancet 2023; DOI: 10.1016/ S0140-6736(23)01837-8.