Hypertensive disorders of pregnancy: definition, management, and out-of-office blood pressure measurement

Abstract

Hypertensive disorders of pregnancy increase the risk of adverse maternal and fetal outcomes. In 2018, the Japanese classification of hypertensive disorders of pregnancy was standardized with those of other countries, and a hypertensive disorder of pregnancy was considered to be present if hypertension existed during pregnancy and up to 12 weeks after delivery. Strategies for the prevention of hypertensive disorders of pregnancy have become much clearer, but further research is needed on appropriate subjects and methods of administration, and these have not been clarified in Japan. Although guidelines for the use of antihypertensive drugs are also being studied and standardized with those of other countries, the use of calcium antagonists before 20 weeks of gestation is still contraindicated in Japan because of the safety concerns that were raised regarding possible fetal anomalies associated with their use at the time of their market launch. Chronic hypertension is now included in the definition of hypertensive disorders of pregnancy, and blood pressure measurement is a fundamental component of the diagnosis of hypertensive disorders of pregnancy. Out-of-office blood pressure measurements, including ambulatory and home blood pressure measurements, are important for pregnant and nonpregnant women. Although conditions such as white-coat hypertension and masked hypertension have been reported, determining their occurrence in pregnancy is complicated by the gestational week. This narrative review focused on recent reports on hypertensive disorders of pregnancy, including those related to blood pressure measurement and classification.

Keywords: Antihypertensive Agents; Blood Pressure; Hypertension; Masked Hypertension; Pregnancy-Induced; White-Coat Hypertension.

Fig. 1

Schematic diagram of the two-stage theory of preeclampsia. In normal pregnancy, appropriate EVT invasion into the maternal endometrium (red arrow) leads to sufficient maternal blood flow from the spiral artery (A). PlGF, which is secreted from the placenta, activates VEGF and maintains a healthy endothelium (B). On the other hand, in preeclamptic pregnancy, incomplete invasion of the EVT (blue arrow) leads to insufficient maternal blood flow from the spiral artery and subsequent placental hypoxia (C). sFlt1 is then secreted from the placenta, which suppresses VEGF, resulting in systemic endothelial dysfunction and the appearance of various clinical symptoms (D). HELLP syn. hemolysis, elevated liver enzymes, low platelet count syndrome, FGR fetal growth restriction, NK cells natural killer cells, EVT extravillous trophoblast, PlGF placental growth factor, sFlt1 soluble fms-like tyrosine kinase-1, VEGF vascular endothelial growth factor