Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
CHU Lille, Department of Neonatal Medicine, Jeanne de Flandre Hospital, Lille, France.
Int J Epidemiol. 2020 Oct 1;49(5):1647-1660. doi: 10.1093/ije/dyaa088.
Little is known about the associations between maternal body mass index (BMI) and asphyxia-related morbidity in preterm infants (<37 weeks). We aimed to investigate associations between maternal BMI in early pregnancy and severe asphyxia-related neonatal complications in preterm infants (<37 weeks) and to examine whether possible associations were mediated by overweight- or obesity-related complications.
In this Swedish population-based cohort of 62 499 singleton non-malformed preterm infants born from 1997 to 2011, risks of low Apgar scores (0-3) at 5 and 10 minutes, neonatal seizures and intraventricular haemorrhage (IVH) were estimated through two analytical approaches. In the conventional approach, the denominator for risk was all live births at a given gestational age. In the fetuses-at-risk (FAR) approach, the denominator for risk was ongoing pregnancies at a given gestational age.
Using the conventional approach, adjusted risk ratios per 10-unit BMI increase were 1.32 [95% confidence interval (CI) 1.13-1.54] and 1.37 (95% CI 1.12-1.67) for low Apgar scores at 5 and 10 minutes, respectively; 1.28 (95% CI 1.00-1.65) for neonatal seizures; and 1.18 (95% CI 1.01-1.37) for IVH. Using the FAR approach, corresponding risks were higher. These associations varied by gestational age (<32 and 32-36 weeks). Associations between maternal BMI and asphyxia-related outcomes were partly mediated through lower gestational age.
Increasing maternal BMI in early pregnancy is associated with increased risks of severe asphyxia-related complications in preterm infants. Our findings add to the evidence to support interventions to reduce obesity in woman of reproductive age.
关于母亲体重指数（BMI）与早产儿（<37 周）窒息相关发病率之间的关系，我们知之甚少。我们旨在研究孕早期母亲 BMI 与早产儿（<37 周）严重窒息相关新生儿并发症之间的关系，并研究这些关联是否可通过超重或肥胖相关并发症来解释。
在这项针对 1997 年至 2011 年间出生的 62499 名非畸形单胎早产儿的瑞典基于人群的队列研究中，通过两种分析方法来评估低 Apgar 评分（0-3 分）在 5 分钟和 10 分钟时、新生儿癫痫发作和脑室内出血（IVH）的风险。在传统方法中，风险的分母是特定胎龄的所有活产儿。在胎儿风险（FAR）方法中，风险的分母是特定胎龄的持续妊娠。
使用传统方法，每增加 10 个 BMI 单位，5 分钟和 10 分钟时 Apgar 评分较低的调整风险比分别为 1.32（95%置信区间 [CI]，1.13-1.54）和 1.37（95% CI，1.12-1.67）；新生儿癫痫发作的风险比为 1.28（95% CI，1.00-1.65）；IVH 的风险比为 1.18（95% CI，1.01-1.37）。使用 FAR 方法，相应的风险更高。这些关联因胎龄而异（<32 周和 32-36 周）。母亲 BMI 与窒息相关结局之间的关联部分通过较低的胎龄来解释。
孕早期母亲 BMI 的增加与早产儿严重窒息相关并发症的风险增加有关。我们的研究结果为支持减少育龄妇女肥胖的干预措施提供了更多证据。
