Abstract：
Women\'s blood pressure (BP) changes throughout pregnancy. The effect of BP trajectories on preterm delivery is not clear. The authors aim to evaluate the association between maternal BP trajectories during pregnancy and preterm delivery. The authors studied pregnant women included in the Born in Guangzhou Cohort Study in China between February 2012 and June 2016. Maternal BP was measured at antenatal visits between 13 and 40 gestational weeks, and gestational age of delivery data was collected. The authors used linear mixed models to capture the BP trajectories of women with term, and spontaneous and iatrogenic preterm delivery. BP trajectories of women with various gestational lengths (34, 35, 36, 37, 38, 39, 40 weeks) were compared. Of the 17 426 women included in the analysis, 618 (3.55%) had spontaneous preterm delivery; 158 (.91%) had iatrogenic preterm delivery; and 16 650 (95.55%) women delivered at term. The BP trajectories were all J-shaped curves for different delivery types. Women with iatrogenic preterm delivery had the highest mean BP from 13 weeks till delivery, followed by those with spontaneous preterm delivery and term delivery (p < .001). Trajectory analysis stratified by maternal parity showed similar results for nulliparous and multiparous women. Excluding women with pre-eclampsia and gestational hypertension (GH) significantly attenuated the aforementioned association. Also, women with shorter gestational length tend to have higher BP trajectories during pregnancy. In conclusion, Women with spontaneous preterm delivery have a higher BP from 13 weeks till delivery than women with term delivery, while women with iatrogenic preterm delivery have the highest BP.
摘要：
妇女的血压（BP）在整个怀孕期间的变化。BP轨迹对早产的影响尚不清楚。作者旨在评估妊娠期间母体血压轨迹与早产之间的关联。作者研究了2012年2月至2016年6月在中国广州出生队列研究中的孕妇。在13至40孕周的产前访视时测量产妇的血压，并收集了分娩的胎龄数据。作者使用线性混合模型来捕获女性的BP轨迹，以及自发性和医源性早产。比较了具有不同妊娠长度（34、35、36、37、38、39、40周）的妇女的BP轨迹。在分析中包括的17.426名妇女中，618（3.55％）有自发性早产；158（.91％）有医源性早产；16.650（95.55％）妇女在足月分娩。不同输送类型的BP轨迹均为J形曲线。医源性早产的女性从13周到分娩的平均血压最高，其次是自发早产和足月分娩的患者(p<.001)。按产妇产次分层的轨迹分析显示，未产和多产妇女的结果相似。排除患有先兆子痫和妊娠高血压（GH）的妇女可显着减弱上述关联。此外，妊娠长度较短的女性在怀孕期间的血压轨迹往往较高.总之,自发性早产的女性从13周到分娩的BP高于足月分娩的女性，而医源性早产的女性血压最高。
