Department of Obstetrics and Gynecology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
BMC Pregnancy Childbirth. 2022 Mar 19;22(1):226. doi: 10.1186/s12884-022-04573-7.
Hypertension has been known to increase the risk of obstetric complications. Recently, the American College of Cardiology endorsed lower thresholds for hypertension as systolic blood pressure of 130-139 mmHg or diastolic blood pressure 80-89 mmHg. However, there is a paucity of information regarding the impact of pre-pregnancy blood pressure on pregnancy outcomes. We aimed to evaluate the effect of pre-pregnancy blood pressure on maternal and neonatal complications.
In this nationwide, population based study, pregnant women without history of hypertension and pre-pregnancy blood pressure < 140/90 mmHg were enrolled. The primary outcome of composite morbidity was defined as any of the followings: preeclampsia, placental abruption, stillbirth, preterm birth, or low birth weight.
A total of 375,305 pregnant women were included. After adjusting for covariates, the risk of composite morbidity was greater in those with stage I hypertension in comparison with the normotensive group (systolic blood pressure, odds ratio = 1.68, 95% CI: 1.59 - 1.78; diastolic blood pressure, odds ratio = 1.56, 95% CI: 1.42 - 1.72). There was a linear association between pre-pregnancy blood pressure and the primary outcome, with risk maximizing at newly defined stage I hypertension and with risk decreasing at lower blood pressure ranges.
'The lower, the better' phenomenon was still valid for both maternal and neonatal outcomes. Our results suggest that the recent changes in diagnostic thresholds for hypertension may also apply to pregnant women. Therefore, women with stage I hypertension prior to pregnancy should be carefully observed for adverse outcomes.
高血压已被证实会增加产科并发症的风险。最近，美国心脏病学会认可了更低的高血压诊断标准，收缩压为 130-139mmHg 或舒张压为 80-89mmHg。然而，关于孕前血压对妊娠结局的影响，相关信息还很有限。我们旨在评估孕前血压对母婴并发症的影响。
在这项全国性的基于人群的研究中，纳入了无高血压病史且孕前血压<140/90mmHg 的孕妇。复合发病率的主要结局定义为以下任何一种情况：子痫前期、胎盘早剥、死胎、早产或低出生体重。
共纳入 375305 名孕妇。在校正了混杂因素后，与血压正常组相比，I 期高血压患者发生复合发病率的风险更高（收缩压，优势比=1.68，95%可信区间：1.59-1.78；舒张压，优势比=1.56，95%可信区间：1.42-1.72）。孕前血压与主要结局之间存在线性关联，风险在新定义的 I 期高血压时最大，并随着血压范围的降低而降低。
“越低越好”的现象对母婴结局仍然有效。我们的结果表明，高血压诊断阈值的最近变化也可能适用于孕妇。因此，孕前患有 I 期高血压的女性应密切观察不良结局。
