Abstract: Objective To investigate the significance of the ambulatory 24-hour blood pressure monitoring during middle pregnancy in the outcomes of pregnancy and in predicting hypertensive disorder complicating pregnancy. Methods Data of 200 pregnant women chosen at random from March 2007 to August 2007 in Beijing Obstetrics and Gyneology Hospital were analyzed. All these women had single-fetus pregnancy and were at 20~24 weeks of gestation without any complication. Ambulatory 24-hour blood pressure monitoring(ABPM) was conducted for all the subjects and the outcomes of the pregnancy were observed and recorded. Results Seventy of the cases had white-coat hypertension, 89 cases were normotensive at the end of pregnancy, 23 cases developed hypertensive disorder complicating pregnancy, and 18 cases had primary hypertension. The comparisons were carried out among the four groups in 24 hours systolic blood pressure(24 h SBP), 24 hours diastolic blood pressure(24 h DBP), day systolic blood pressure(dSBP) and night diastolic blood pressure(nDBP). The normotensive group and the hypertensive disorder complicating pregnancy group had no significant difference in the four indexes, but the latter had higher nDBP. The primary hypertension group and the other two groups had significant difference in the four indexs(P<0.05). The onormotensive group and the other groups had significant difference in the circadian blood pressure(P<0.05). Conclusion Single 24-hour blood pressure monitoring during the middle pregnancy had no definite significance in predicting hypertensive disorder that may complicate pregnancy, but repeated blood pressure monitoring in high risk group may be beneficial to outcomes through early diagnosis and treatment. The 24-hour blood pressure monitoring could diagnose white-coat hypertension early.

Key words: middle pregnancy, ambulatory blood pressure monitoring, hypertensive disorder complicating pregnancy