Viroon Likhitlertlum,MD., Tanarat Choon-ngam, MD.* Wilai Puavilai, MD.*  Surasak Jantarasaengaram,MD.**

Sutham Suterapatranon, MD.*Napa Siriwiwattanakul, MD.* Korn Thongtong MD.* Pariwat Pengkeaw, MD.*

*Division of Cardiology, Department of Medicine, Rajavithi Hospital,
**Division of Obstetrics and Gynecology, Rajavithi Hospital

Abstract

Background:
White coat hypertension can be found in pregnancy. 24 hour ambulatory blood pressure monitoring can detect white coat hypertension which has favorable outcome compared to true hypertension or pregnancy induce hypertension.

Objective:
To assess the prevalence of white coat hypertension in pregnancy and outcome of white coat hypertension with 24 hour ambulatory blood pressure monitoring.

Method:
Hypertensive pregnant women at any age ( systolic BP140-170 mmHg. or diastolic BP 90-110mmHg. ) of any gestational age and any gravida from Rajavithi Hospital. Exclusion of patients with of pregnancy, previous treatment of hypertension, and known case of hypertension before pregnancy.  Underwent 24 hour ambulatory blood pressure monitoring (24-hrABPM) to differentiate between white coat hypertension (WCH) and true hypertension. Pregnant  women with WCH and true hypertension were followed up through the end of pregnancy.

Result:
The prevalence of white coat hypertension was 85.7%(12/14). Twelve pregnant women  were follow up until labor (11case with WCH group and 1case with true HT group). Two case develops severe pre-eclampsia 16.7%(2/12) and two case develops true hypertension16.7%(2/12). In pre-eclampsia case, one case with true HT develops pre-eclampsia 2 weeks after 24hr.ABPM with showed diastolic HT, normal dipper and no morning BP surge at the time ABPM. One another case of pre-eclampsia had WCH at the first time and develops true HT at the second time of ABPM, she had night-time HT and develops pre-eclampsia later.

Conclusion:
The prevalence of white coat hypertension in pregnancy was 85.7% in this population.  During the study,  we found two case who developed pre-eclampsia. One case with high diastolic blood pressure level and normal dipper pattern, another case with WCH and turn to night-time HT before develops pre-eclampsia later. We conclude that 24-hrABPM is useful for detection of WCH and true HT. Normal dipper pattern in pregnancy does not exclude the development of pre-eclampsia. Close follow up of BP should be done because pre-eclampsia may be occurred anytime in late pregnancy even in patients with earlier normal at 24-hrABPM.