Department of Public Health and Primary Care, University of Cambridge, 2 Worts' Causeway, Cambridge, CB1 8RN, Cambridge, UK.
Department of Obstetrics and Gynaecology, University of Cambridge, Box 223, The Rosie Hospital and NIHR Cambridge Biomedical Research Centre, Cambridge, UK.
Int J Obes (Lond). 2020 Nov;44(11):2246-2255. doi: 10.1038/s41366-020-0627-2. Epub 2020 Jun 15.
BACKGROUND/OBJECTIVES: Successful pregnancy requires the de novo creation of low-resistance utero-placental and feto-placental circulations and incomplete remodeling of this vasculature can lead to maternal or fetal compromise. Maternal BMI and fetal sex are known to influence vascular compliance and placental development, but it is unknown if these are independent or synergistic effects. Here we aim to investigate the impact of maternal obesity, fetal sex, and any interaction thereof on maternal cardiovascular adaptation to pregnancy, by assessing the physiological drop of uterine artery doppler pulsatility (UtA-PI) and umbilical artery doppler pulsatility index (UA-PI) over gestation.
SUBJECTS/METHODS: Nulliparous women with a singleton pregnancy participating in a prospective cohort study (n = 4212) underwent serial UtA-PI and UA-PI measurements at 20-, 28- and 36-weeks gestation. Linear mixed regression models were employed to investigate the influence of maternal BMI, fetal sex and interactions thereof on the magnitude of change in UtA-PI and UA-PI.
Throughout gestation, UtA-PI was higher for male fetuses and UA-PI was higher for female fetuses. The physiological drop of UtA-PI was significantly smaller in overweight (change -24.3% [95%CI -22.3, -26.2]) and obese women (change -21.3% [-18.3, -24.3]), compared to normal-weight women (change -25.7% [-24.3, -27.0]) but did not differ by fetal sex. The physiological drop in UA-PI was greater for female than male fetuses (-32.5% [-31.5, -33.5] vs. -30.7% [-29.8, -31.7]) but did not differ by maternal BMI. No interactions between maternal BMI and fetal sex were found.
Maternal cardiovascular adaptation to pregnancy is independently associated with maternal BMI and fetal sex. Our results imply sexual dimorphism in both maternal cardiovascular adaptation and feto-placental resistance.
背景/目的：成功妊娠需要新形成低阻力的子宫胎盘和胎儿胎盘循环，而这种血管结构的不完全重塑可导致母体或胎儿受损。已知母体 BMI 和胎儿性别会影响血管顺应性和胎盘发育，但尚不清楚这些是独立的还是协同的影响。在这里，我们旨在通过评估子宫动脉多普勒搏动指数（UtA-PI）和脐动脉多普勒搏动指数（UA-PI）在妊娠期间的生理性下降，来研究母体肥胖、胎儿性别以及它们之间的任何相互作用对母体心血管适应妊娠的影响。
受试者/方法：参与前瞻性队列研究的初产妇（n=4212）在 20 周、28 周和 36 周妊娠时进行了连续的 UtA-PI 和 UA-PI 测量。线性混合回归模型用于研究母体 BMI、胎儿性别及其相互作用对 UtA-PI 和 UA-PI 变化幅度的影响。
在整个妊娠期间，男性胎儿的 UtA-PI 较高，女性胎儿的 UA-PI 较高。超重（变化-24.3% [95%CI-22.3，-26.2]）和肥胖（变化-21.3% [-18.3，-24.3]）女性与正常体重女性（变化-25.7% [-24.3，-27.0]）相比，UtA-PI 的生理性下降幅度明显较小，但与胎儿性别无关。女性胎儿的 UA-PI 生理性下降幅度大于男性胎儿（-32.5% [-31.5，-33.5] vs. -30.7% [-29.8，-31.7]），但与母体 BMI 无关。未发现母体 BMI 和胎儿性别之间存在相互作用。
母体对妊娠的心血管适应与母体 BMI 和胎儿性别独立相关。我们的结果表明，母体心血管适应和胎儿胎盘阻力均存在性别二态性。
