Hunter Krystal, Ehrlich Michael, Mitchell-Williams Jocelyn
Department of Medicine, Cooper Medical School of Rowan University, Camden, New Jersey, United States of America.
Cooper Hospital Research Institute, Cooper Hospital, Camden, New Jersey, United States of America.
PLoS One. 2025 May 8;20(5):e0321876. doi: 10.1371/journal.pone.0321876. eCollection 2025.
The March of Dimes Global action report indicated that preterm birth (PTB) rates are increasing in most countries. It is the most important cause of neonatal deaths and the second leading cause of death in children under age 5. Literature reporting the relationship between maternal pre-pregnancy body mass index (BMI) and PTB has previously yielded inconsistent conclusions. Our objective is to fill in the knowledge gap by evaluating the interaction of socio-economic status (SES) and BMI and its relationship to the rate of PTB. This is a case control study using the Natality Data of the National Vital Statistics System from the years 2020-2022. BMI was a significant factor in PTB for lower socioeconomic status (LSES) women. For every increase in BMI, there was a decrease in the probability of PTB (OR = 0.923, 95% CI 0.915-0.931, P < 0.001). Those who were LSES also had a curved relationship with PTB indicating that the as BMI increases, the odds of PTB decreases up until a BMI value, then the PTB rate increases. This relationship was not found in higher economic status women. Our study had two significant findings. We first found an obesity paradox in PTB for those mothers who are LSES. We also found that the relationship between BMI and PTB was not linear but curvilinear, bridging the gap in the conclusions of other studies. This study fills in the knowledge gap of BMI and PTB by adding the consideration of social class and by creating a polynomial BMI term.
美国疾病控制与预防中心全球行动报告指出，大多数国家的早产率都在上升。早产是新生儿死亡的最重要原因，也是5岁以下儿童死亡的第二大主要原因。此前，关于孕妇孕前体重指数（BMI）与早产之间关系的文献得出了不一致的结论。我们的目标是通过评估社会经济地位（SES）与BMI的相互作用及其与早产率的关系来填补知识空白。这是一项病例对照研究，使用了2020年至2022年国家生命统计系统的出生数据。对于社会经济地位较低（LSES）的女性，BMI是早产的一个重要因素。BMI每增加一点，早产的概率就会降低（OR = 0.923，95% CI 0.915 - 0.931，P < 0.001）。LSES女性与早产之间也存在曲线关系，表明随着BMI的增加，早产几率会下降，直到达到某个BMI值，然后早产率会上升。在经济地位较高的女性中未发现这种关系。我们的研究有两个重要发现。我们首先发现了LSES母亲在早产方面存在肥胖悖论。我们还发现BMI与早产之间的关系不是线性的，而是曲线的，弥合了其他研究结论中的差距。这项研究通过考虑社会阶层并创建多项式BMI项，填补了BMI与早产方面的知识空白。
