THU305 Pregravid Weight Gain Is Associated With An Increased Risk Of Gestational Diabetes Especially In Primigravid Women: A Nationwide Population Based Study In South Korea

Disclosure: S. Kim: None. S. Choi: None. S. Choi: None. J. Yim: None. K. Han: None. Background: Gestational diabetes (GDM) is associated with a variety of perinatal complications and future development of metabolic diseases and type 2 diabetes mellitus (DM) in both mothers and their offspring. It is also well-known that maternal obesity and excessive gestational weight gain are risk factors for the development of GDM. Objective: This study aimed to investigate the association between pregravid weight gain and the risk of development of GDM in the following pregnancy. Study design: This was a retrospective nationwide population-based cohort study using Korean National Health Insurance Service database. There were 1,098,353 women who delivered their babies between 2015 and 2017. We identified 270,374 women who underwent national health screening examination (NHSE) within 1 year before 280 days of their delivery (index checkup). Among them, 159,798 women who also took the NHSE 2 years before the index checkup (baseline checkup) were enrolled for the study. Women with previous overt DM (n=11,852) or missing data (n=10,316) were excluded. Women who had developed GDM were identified by the presence of more than three times of claim of GDM (ICD-10 code O24.4 and O24.9) during their pregnancy period with or without prescriptions of insulin or oral diabetic medication. Body weight at the index checkup was compared to that of baseline checkup and the whole study population was divided into three weight change groups: i) more than 5% of loss (<-5%), ii) within 5% of change (−5% ∼ +5%), and iii) 5% or more gain (≥ +5%). The association between pregravid weight change and the risk of developing GDM was evaluated. Results: Of the 137,680 women included in the analyses, 10,213 (7.4%) women were diagnosed with GDM during their pregnancy. The incidence of GDM were 6.7% (n=1129), 7.0% (n=5876), and 8.7% (n=3208) for the three weight change groups respectively. In multivariate analysis, the stable weight group (−5% ∼ +5% of weight change) was set as a reference and the population who gained weight (≥ +5%) had a 20% (OR 1.20, 95% CI 1.15-1.26) increased risk of developing GDM, while the population who lost weight (<-5%) was associated with a decreased risk of GDM (OR 0.89, 95% CI 0.84-0.96). The relationship was evaluated in subgroup analyses stratified by age, obesity parameters (BMI and WC), metabolic syndrome, and obstetric parameters (first pregnancy and multifetal gestation). In all subgroups, pregravid weight gain was associated with an increased risk of GDM. Among all parameters, being primigravid was significantly associated with an increased risk of GDM in relation to their pregravid weight gain (OR 1.27, 95% CI: 1.20-1.34), while that for 2nd or more order of pregnancy was not statistically significant (OR 1.03, 95% CI: 0.94-1.13) (p for interaction=0.0005). Conclusions: Pregravid weight gain (≥ +5%) was associated with an increased risk of GDM especially in primigravid women. Presentation: Thursday, June 15, 2023