Prevalence of Chronic Hypertension and White Coat Hypertension in Women Presenting with at Least One Hypertension Level on Two to Three Consecutive Measurements in a Clinical Setting at <20 Weeks of Gestation (JP-WCH1 Study): A Multicenter Prospective Cohort Study

Aim: To investigate the prevalence of chronic hypertension (CH), white coat hypertension (WCH), and masked hypertension (MHT) in women with suspected hypertension at < 20 weeks of gestation. Methods: If we suspected hypertension, defined as at least one hypertension level on two to three consecutive measurements in a clinical setting at < 20 weeks of gestation, we lent the patient a home blood pressure (HBP) device. Ultimately, they were diagnosed with CH, WCH, or masked hypertension (MHT).Results: Four institutes participated in this prospective cohort study. We evaluated 44 patients with suspected hypertension at < 20 weeks of gestation. The prevalences of CH, WCH, and MHT were 11, 30, and 2%, respectively. Incidence of preeclampsia (PE) in women with CH was 20% (1/5); incidences of gestational hypertension (GH) and PE in women with WCH were 0% (0/12) and 17% (2/12), respectively. Incidences of GH and PE in women without hypertension were 17% (4/24) and 8% (2/24), respectively.Conclusions: If pregnant women presented with suspected hypertension at <20 weeks of gestation, HBP monitoring should be recommended for a differential diagnosis of hypertension, and close observation should be planned to detect onset of PE/ GH.