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Session: Diet, Body Size, and Diabetes in Pregnancy: Impact on Offspring Metabolic Health (Oral 12)

(OR12-03-23) Weight Trajectories Across Women’s Reproductive Years and Risk of Adverse Pregnancy Outcomes

Sunday, July 23, 2023

4:24 PM – 4:36 PM ET

Location: Constitution A

Presenting Author(s)

SW

Siwen Wang, MD (she/her/hers)

Research Fellow
Harvard T.H. Chan School of Public Health
Boston, Massachusetts, United States

Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

Co-Author(s)

Mariel Arvizu, MD, Sc.D.

Postdoctoral Research Fellow
Harvard T.H. Chan School of Public Health
Boston, Massachusetts, United States
MM

Makiko Mitsunami, MD

Postdoctoral Research Fellow
Harvard T.H. Chan School of Public Health
Boston, Massachusetts, United States
AG

Audrey J. Gaskins, ScD

Assistant Professor
Emory University Rollins School of Public Health
Atlanta, Georgia, United States
LM

Lidia Mínguez-Alarcón, MPH, PhD

Senior Research Scientist
Harvard T.H. Chan School of Public Health
Boston, Massachusetts, United States
BR

Bernard Rosner

Harvard T.H. Chan School of Public Health
JR

Janet Rich-Edwards, ScD

Associate Professor
Harvard T.H. Chan School of Public Health
Boston, Massachusetts, United States
Jorge E. Chavarro, MD, PhD

Associate Professor of Medicine, Harvard Medical School
Harvard T.H. Chan School of Public Health
Boston, Massachusetts, United States

Disclosure(s):

Siwen Wang, MD: No relevant financial relationship(s) with ineligible companies to disclose.

Objectives: To evaluate the association of pre-pregnancy and inter-pregnancy weight trajectories with the risk of adverse pregnancy outcomes (APOs).

Methods: We followed 16421 women (25386 pregnancies) without chronic diseases in the Nurses’ Health Study II. Anthropometrics (weight at age 18, current weight, and height) were assessed at enrollment, and weight was updated biennially. Lifetime pregnancy history was self-reported in 2009. The primary outcome was a composite of any APO: gestational hypertension, preeclampsia, gestational diabetes (GDM), preterm birth, and stillbirth. Secondary outcomes were individual APOs. The relative risk (RR) and 95% confidence interval (95%CI) of APOs by weight change since age 18 and between pregnancies were estimated using log-binomial regression with generalized estimating equations, adjusting for demographic, lifestyle, and reproductive factors.

Results: The mean (SD) weight change was +6.4 (4.3) kg from age 18 years to each pregnancy and +2.3 (4.8) kg between pregnancies. Nearly 1 in 5 pregnancies were complicated by one or more APOs (n=4596, 18.2%). Compared to women whose weight remained stable (+0–2 kg) since age 18 to pregnancy, women who gained >2 kg weight had greater risk of APO (RR [95%CI]: 2.1–9.9 kg: 1.12 [1.02–1.23]; 10.0-14.9 kg: 1.43 [1.29–1.60]; ≥15 kg: 1.87 [1.69–2.08], p trend < 0.001), additionally adjusting for BMI at age 18. The associations were significant for all APOs examined except preterm birth and stillbirth. Weight loss between age 18 years and pregnancy was associated with 34% lower risk of GDM (95%CI=0.50–0.87), but not other APOs. Similarly, compared to women whose weight remained stable (+0–2 kg) between pregnancies, women who gained ≥5 kg between pregnancies had a higher risk of GHTN (RR=1.24, 95%CI=0.85–1.82, p trend=0.06) and preeclampsia (RR=1.36, 95%CI=0.81–2.27, p trend=0.03), additionally adjusting for pre-pregnancy BMI. Interpregnancy weight loss was not associated with risk for any APO.

Conclusions: Weight trajectories prior to and between pregnancies are strongly associated with the risk of APOs. Weight loss between pregnancies, while rare, did not appear to reduce the risk of APOs. Primary prevention of weight gain before pregnancy may yield benefits in combating obesity-related APOs.

Funding Sources: National Institutes of Health