Department of Obstetrics and Gynaecology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands.
Department of Public Health, Healthcare Innovation, and Medical Humanities, Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands.
PLoS One. 2021 Sep 23;16(9):e0257722. doi: 10.1371/journal.pone.0257722. eCollection 2021.
Maternal body mass index (BMI) below or above the reference interval (18.5-24.9 kg/m2) is associated with adverse pregnancy outcomes. Whether BMI exerts an effect within the reference interval is unclear. Therefore, we assessed the association between adverse pregnancy outcomes and BMI, in particular within the reference interval, in a general unselected pregnant population.
Data was extracted from a prospective population-based multicentre cohort (Risk Estimation for PrEgnancy Complications to provide Tailored care (RESPECT) study) conducted between December 2012 to January 2014. BMI was studied in categories (I: <18.5, II: 18.5-19.9, III: 20.0-22.9, IV: 23.0-24.9, V: 25.0-27.4, VI: 27.5-29.9, VII: >30.0 kg/m2) and as a continuous variable within the reference interval. Adverse pregnancy outcomes were defined as composite endpoints for maternal, neonatal or any pregnancy complication, and for adverse pregnancy outcomes individually. Linear trends were assessed using linear-by-linear association analysis and (adjusted) relative risks by regression analysis.
The median BMI of the 3671 included women was 23.2 kg/m2 (IQR 21.1-26.2). Adverse pregnancy outcomes were reported in 1256 (34.2%). Linear associations were observed between BMI categories and all three composite endpoints, and individually for pregnancy-induced hypertension (PIH), preeclampsia, gestational diabetes mellitus (GDM), large-for-gestational-age (LGA) neonates; but not for small-for-gestational-age neonates and preterm birth. Within the reference interval, BMI was associated with the composite maternal endpoint, PIH, GDM and LGA, with adjusted relative risks of 1.15 (95%CI 1.06-1.26), 1.12 (95%CI 1.00-1.26), 1.31 (95%CI 1.11-1.55) and 1.09 (95%CI 1.01-1.17).
Graded increase in maternal BMI appears to be an indicator of risk for adverse pregnancy outcomes even among women with a BMI within the reference interval. The extent to which BMI directly contributes to the increased risk in this group should be evaluated in order to determine strategies most valuable for promoting safety and long-term health for mothers and their offspring.
母体体重指数（BMI）低于或高于参考区间（18.5-24.9kg/m2）与不良妊娠结局有关。BMI 是否在参考区间内发挥作用尚不清楚。因此，我们在一般未选择的孕妇人群中评估了不良妊娠结局与 BMI 之间的关系，特别是在参考区间内。
数据来自于 2012 年 12 月至 2014 年 1 月期间进行的一项前瞻性基于人群的多中心队列（风险评估妊娠并发症提供个性化护理（RESPECT）研究）。BMI 按类别（I：<18.5、II：18.5-19.9、III：20.0-22.9、IV：23.0-24.9、V：25.0-27.4、VI：27.5-29.9、VII：>30.0kg/m2）和参考区间内的连续变量进行研究。不良妊娠结局定义为母体、新生儿或任何妊娠并发症的复合终点，以及不良妊娠结局的个体终点。线性趋势通过线性线性关联分析和回归分析（调整）相对风险进行评估。
3671 名纳入女性的平均 BMI 为 23.2kg/m2（IQR 21.1-26.2）。1256 名（34.2%）报告了不良妊娠结局。BMI 类别与所有三个复合终点以及妊娠高血压（PIH）、子痫前期、妊娠糖尿病（GDM）、巨大儿（LGA）新生儿个体终点之间均观察到线性关联；但与小于胎龄儿和早产无关。在参考区间内，BMI 与母体复合终点、PIH、GDM 和 LGA 相关，调整后的相对风险分别为 1.15（95%CI 1.06-1.26）、1.12（95%CI 1.00-1.26）、1.31（95%CI 1.11-1.55）和 1.09（95%CI 1.01-1.17）。
即使在 BMI 在参考区间内的女性中，母体 BMI 的逐渐增加似乎也是不良妊娠结局的风险指标。应评估 BMI 在该组中增加风险的程度，以确定最有利于促进母亲及其后代安全和长期健康的策略。
