Temporary hypertension and white coat hypertension in the first trimester as risk factors for preeclampsia.

We compared the risk of preeclampsia (PE) among women with normal blood pressure (BP), high-normal BP, high BP, temporary hypertension (THT), white coat hypertension (WCH), and chronic hypertension (CH) in the first trimester. This was a retrospective cohort study involving 2858 pregnant women, who received regular maternal checkups at <12 weeks. BP levels were evaluated using the average of the second and third BP readings. When patients showed HT in the first trimester that later normalized during 14-19 weeks, we called this condition THT. BP levels were classified as normal BP, high-normal BP, high BP, THT, WCH, and CH. PE was defined as a new onset of HT after 20 weeks accompanied by either proteinuria or other organ dysfunctions. Gestational hypertension (GH) was defined as the new onset of HT after 20 weeks. The proportion of WCH in women with newly diagnosed HT was 47%. PE occurred in 1.3, 4.3, 8.1, 8.2, 14.3, and 25.0% of women with normal BP, high-normal BP, high BP, THT, WCH, and CH, respectively. GH occurred in 0.3, 1.8, 9.9, 2.0, and 28.6% of women with normal BP, high-normal BP, high BP, THT, and WCH, respectively. After adjusting for possible confounding variables, high-normal BP, high BP, THT, WCH, and CH were independent risk factors for PE vs. normal BP; in addition, high-normal BP, high BP/THT, and WCH were independent risk factors for GH vs. normal BP. In conclusion, THT and WCH in the first trimester were risk factors for PE, and WCH was a risk factor for GH.