Fetal Medicine Unit, St George's University of London, London, UK.
St George's University Hospitals NHS Foundation Trust, Molecular and Clinical Sciences Research Institute, London, UK.
Ultrasound Obstet Gynecol. 2017 Dec;50(6):761-765. doi: 10.1002/uog.17428. Epub 2017 Nov 8.
Maternal obesity is associated with significant pregnancy complications and is a risk factor for the development of hypertensive disorders of pregnancy as well as other adverse outcomes. There are few data regarding the hemodynamic aberrations observed in maternal obesity. The aim of this study was to investigate maternal hemodynamics in morbidly obese women.
This was a prospective, case-control study of morbidly obese women (body mass index (BMI) ≥ 40 kg/m ) and controls (BMI 20-29.9 kg/m ). The control population was matched for maternal age and gestational age. BMI was calculated based on maternal height and weight at the time of recruitment to the study, which occurred on the same day as the hemodynamic assessment. Pregnant women in the second or third trimester of pregnancy were included. Women who were found to be hypertensive at any time were excluded from the study. A USCOM-1A® device was used to assess hemodynamic parameters (heart rate, stroke volume (SV), cardiac output and systemic vascular resistance (SVR)). The parameters were corrected for body surface area (BSA) to provide the SV index (SVI), cardiac index (CI) and SVR index (SVRI). Mann-Whitney U-test was used to compare the medians of the hemodynamic variables between the two groups.
In total, 23 morbidly obese women and 327 controls were included in the analysis. There was no difference in maternal (P = 0.506) or gestational (P = 0.693) age at recruitment between the groups. Mean arterial pressure was higher both at pregnancy booking (90 vs 80 mmHg, P < 0.001) and study recruitment (91 vs 85 mmHg, P < 0.001) in the obese group compared with the controls. Heart rate was higher in the obese group (P = 0.003), but there was no difference in SV (P = 0.271), cardiac output (P = 0.238) or SVR (P = 0.635). Following correction of these parameters for BSA, compared with the control group, SVI (34 vs 45 mL/m , P < 0.001) and CI (2.96 vs 3.64 L/min/m , P < 0.001) were significantly reduced in the obese group, whereas SVRI was significantly higher (2354 vs 1840 dynes × s/cm , P < 0.001).
The findings of our study suggest that cardiac function is significantly altered in morbidly obese pregnant women. In order to make appropriate comparisons between individuals, it is imperative that hemodynamic parameters are indexed for BSA, as is standard practice in pediatric cardiology. The novel finding of reduced CI in morbidly obese pregnant women may explain the predisposition to pre-eclampsia and other adverse outcomes in this population and warrants further investigation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
母体肥胖与重大妊娠并发症有关，也是妊娠高血压疾病以及其他不良结局的危险因素。关于母体肥胖中观察到的血液动力学异常的数据很少。本研究的目的是研究病态肥胖妇女的母体血液动力学。
这是一项前瞻性的病态肥胖妇女（体重指数（BMI）≥40kg/m2）和对照组（BMI 20-29.9kg/m2）的病例对照研究。对照组按产妇年龄和妊娠龄匹配。BMI 根据招募到研究中的产妇身高和体重计算，招募日与血液动力学评估同日进行。纳入妊娠中期或晚期的孕妇。任何时候发现高血压的妇女均被排除在研究之外。使用 USCOM-1A®设备评估血液动力学参数（心率、每搏量（SV）、心输出量和全身血管阻力（SVR））。为了提供 SV 指数（SVI）、心指数（CI）和 SVR 指数（SVRI），参数按体表面积（BSA）校正。采用 Mann-Whitney U 检验比较两组间血液动力学变量的中位数。
共有 23 名病态肥胖妇女和 327 名对照组纳入分析。两组产妇（P=0.506）或妊娠（P=0.693）年龄在招募时无差异。与对照组相比，肥胖组在妊娠预约时（90 对 80mmHg，P<0.001）和研究招募时（91 对 85mmHg，P<0.001）的平均动脉压更高。肥胖组的心率更高（P=0.003），但 SV（P=0.271）、心输出量（P=0.238）或 SVR（P=0.635）无差异。这些参数经 BSA 校正后，与对照组相比，肥胖组的 SVI（34 对 45mL/m，P<0.001）和 CI（2.96 对 3.64L/min/m，P<0.001）明显降低，而 SVRI 明显升高（2354 对 1840 达因×s/cm，P<0.001）。
本研究结果表明，病态肥胖孕妇的心脏功能明显改变。为了在个体之间进行适当的比较，必须按 BSA 索引血液动力学参数，这是儿科心脏病学的标准做法。病态肥胖孕妇 CI 降低的新发现可能解释了该人群中子痫前期和其他不良结局的易感性，值得进一步研究。版权所有©2017 ISUOG。由 John Wiley & Sons Ltd 出版。
