Characteristics Of Labor-Onset Hypertension: A Single Center'S Experience Over The Course Of 15 Years

Aim: The aim of this study was to examine the occurrence rate and clinical characteristics of labor-onset hypertension (LOH).Methods: This was a retrospective study. Subjects were patients diagnosed with LOH at Hachioji Medical Center of Tokyo Medical University between January 1998 and December 2012. LOH was defined as systolic blood pressure (sBP) >= 140 mm Hg after labor onset despite no symptoms of prior pregnancy induced hypertension. We classified LOH subjects into three groups as follows: mild (140 mmHg <= maximum sBP < 160 mmHg), severe (160 mmHg <= maximum sBP < 180 mmHg) and emergent (180 mmHg >= maximum sBP). The control group comprised 405 normotensive pregnant women. We assessed the occurrence rate of LOH, eclampsia and cerebrovascular disease. We then evaluated the clinical characteristics of each LOH group, and compared them to the control group.Results: A total of 1312 women (20.7%) were diagnosed with LOH (mild, 834 (13.2%); severe, 406 (6.4%); emergent, 72 (1.1%)). Three women had eclampsia (0.047%) and two had stroke (0.032%). The maximum sBP and diastolic blood pressure (dBP) during labor, proteinuria before labor and Apgar score were significantly different between groups.Conclusion: Although it had little effect on fetal and placental condition, LOH may occur in one-fifth of normotensive pregnancies.