Uterine vascular resistance and other maternal factors associated with the risk of developing hypertension during pregnancy

Gestational hypertension and pre-eclampsia are important causes of perinatal morbidity. The objective of the present study was to determine the increase in relative risk for developing hypertensive disorders of pregnancy based on the evaluation of pregnant women between 20 and 25 weeks of gestation, and to correlate the findings at this period with the outcome of pregnancy. We conducted a prospective cohort study, with a convenience sample of 1417 patients evaluated at this gestational age, of which 1306 were contacted at childbirth. We detected an increased relative risk of 2.69 (95%CI: 1.86 to 3.89) associated with pulsatility index of the uterine arteries, a 2.8 increase (95%CI: 1.58 to 5.03) in relative risk attributed to maternal age above 35 years, a 1.68 increase (95%CI: 1.17 to 2.40) attributed to parity greater than or equal to 3, and a 5.35 increase (95%CI: 4.18 to 6.85) attributed to chronic hypertension and obesity, with a progressive increase in relative risk according to the degree of overweight, i.e., grades 1, 2, 3, and morbid obesity (2.58, 3.06, 5.84, and 7.28, respectively).

妊娠高血压与子痫前期是引发围产期发病的重要病因。本研究旨在通过对孕20至25周孕妇的评估，明确罹患妊娠高血压疾病的相对风险（relative risk，RR）增幅，并将该孕周的检测结果与妊娠结局进行关联分析。本研究采用前瞻性队列研究设计，纳入便利抽样的1417名该孕周孕妇，其中1306名在分娩时完成了随访。研究结果显示：子宫动脉搏动指数（pulsatility index of the uterine arteries）异常可使妊娠高血压疾病的相对风险升高2.69倍，95%置信区间（95%CI）为1.86~3.89；产妇年龄超过35岁时，相对风险升高2.8倍，95%CI为1.58~5.03；产次≥3次时，相对风险升高1.68倍，95%CI为1.17~2.40；合并慢性高血压与肥胖时，相对风险升高5.35倍，95%CI为4.18~6.85。且相对风险随超重程度加重呈进行性升高：Ⅰ级、Ⅱ级、Ⅲ级超重及病态肥胖对应的相对风险分别为2.58、3.06、5.84及7.28。