Our aim was to evaluate the relationship between serum vitamin D levels before 20 weeks of pregnancy and the risk of gestational diabetes mellitus. This study is a retrospective study. We analyzed the relationship between serum 25 (OH) D level before 20 weeks of pregnancy (first antenatal examination) and the risk of gestational diabetes mellitus. Age, parity and pre-pregnancy body mass index were used as confounding factors. 8468 pregnant women were enrolled in this study between January 2018 and March 2020 at the Obstetrics and Gynecology Hospital of Fudan University. Adjusted smoothing splinespline plots, subgroup analysis and multivariate logistic regression analysis was conducted to estimate the relative risk between 25(OH)D and gestational diabetes mellitus. After fully adjusting the confounding factors, serum vitamin D is a protective factor in gestational diabetes mellitus (OR = 0.90). Compared with vitamin D deficiency, vitamin D insufficiency (OR = 0.78), sufficience (OR = 0.82) are a protective factor for gestational diabetes mellitus. Sufficience vitamin D before 20 weeks of pregnancy is a protective factor for gestational diabetes mellitus. Vitamin D > 20 ng/mL can reduce the risk of GDM, which is not much different from the effect of > 30 ng/mL. The protective effect of vitamin D is more significant in obese pregnant women.

中文翻译：

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怀孕 20 周前补充足够的血清维生素 D 可降低患妊娠糖尿病的风险

我们的目的是评估妊娠 20 周前血清维生素 D 水平与妊娠糖尿病风险之间的关系。本研究为回顾性研究。我们分析了妊娠 20 周（第一次产前检查）前血清 25 (OH) D 水平与妊娠期糖尿病风险之间的关系。年龄、产次和孕前体重指数被用作混杂因素。2018 年 1 月至 2020 年 3 月，在复旦大学妇产科医院共招募了 8468 名孕妇参加了本研究。进行了调整平滑样条曲线图、亚组分析和多变量逻辑回归分析，以估计 25(OH)D 与妊娠期糖尿病之间的相对风险。充分调整混杂因素后，血清维生素 D 是妊娠期糖尿病的保护因子（OR = 0.90）。与维生素D缺乏相比，维生素D不足（OR=0.78）、充足（OR=0.82）是妊娠期糖尿病的保护因素。妊娠 20 周前充足的维生素 D 是妊娠糖尿病的保护因素。维生素 D > 20 ng/mL 可以降低 GDM 的风险，这与 > 30 ng/mL 的效果差别不大。维生素D对肥胖孕妇的保护作用更为显着。维生素 D > 20 ng/mL 可以降低 GDM 的风险，这与 > 30 ng/mL 的效果差别不大。维生素D对肥胖孕妇的保护作用更为显着。维生素 D > 20 ng/mL 可以降低 GDM 的风险，这与 > 30 ng/mL 的效果差别不大。维生素D对肥胖孕妇的保护作用更为显着。