Gestational weight change in a diverse pregnancy cohort and mortality over 50 years: a prospective observational cohort study

Background High weight gain in pregnancy is associated with greater postpartum weight retention, yet long-term implications remain unknown. We aimed to assess whether gestational weight change was associated with mortality more than 50 years later.Methods The Collaborative Perinatal Project (CPP) was a prospective US pregnancy cohort (1959-65). The CPP Mortality Linkage Study linked CPP participants to the National Death Index and Social Security Death Master File for vital status to 2016. Adjusted hazard ratios (HRs) with 95% CIs estimated associations between gestational weight gain and loss according to the 2009 National Academy of Medicine recommendations and mortality by pre-pregnancy BMI. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular and diabetes underlying causes of mortality.Findings Among 46 042 participants, 20 839 (45<middle dot>3%) self-identified as Black and 21 287 (46<middle dot>2%) as White. Median follow-up time was 52 years (IQR 45-54) and 17 901 (38<middle dot>9%) participants died. For those who were underweight before pregnancy (BMI <18<middle dot>5 kg/m(2); 3809 [9<middle dot>4%] of 40 689 before imputation for missing data]), weight change above recommendations was associated with increased cardiovascular mortality (HR 1<middle dot>84 [95% CI 1<middle dot>08-3<middle dot>12]) but not all-cause mortality (1<middle dot>14 [0<middle dot>86-1<middle dot>51]) or diabetes-related mortality (0<middle dot>90 [0<middle dot>13-6<middle dot>35]). For those with a normal pre-pregnancy weight (BMI 18<middle dot>5-24<middle dot>9 kg/m(2); 27 921 [68<middle dot>6%]), weight change above recommendations was associated with increased all-cause (HR 1<middle dot>09 [1<middle dot>01-1<middle dot>18]) and cardiovascular (1<middle dot>20 [1<middle dot>04-1<middle dot>37]) mortality, but not diabetes-related mortality (0<middle dot>95 [0<middle dot>61-1<middle dot>47]). For those who were overweight pre-pregnancy (BMI 25<middle dot>0-29<middle dot>9 kg/m(2); 6251 [15<middle dot>4%]), weight change above recommendations was associated with elevated all-cause (1<middle dot>12 [1<middle dot>01-1<middle dot>24]) and diabetes-related (1<middle dot>77 [1<middle dot>23-2<middle dot>54]) mortality, but not cardiovascular (1<middle dot>12 [0<middle dot>94-1<middle dot>33]) mortality. For those with pre-pregnancy obesity (>= 30<middle dot>0 kg/m(2); 2708 [6<middle dot>7%]), all associations between gestational weight change and mortality had wide CIs and no meaningful relationships could be drawn. Weight change below recommended levels was associated only with a reduced diabetes-related mortality (0<middle dot>62 [0<middle dot>48-0<middle dot>79]) in people with normal pre-pregnancy weight.Interpretation This study's novel findings support the importance of achieving healthy gestational weight gain within recommendations, adding that the implications might extend beyond the pregnancy window to long-term health, including cardiovascular and diabetes-related mortality.Copyright (c) 2023 Elsevier Ltd. All rights reserved.