PP136. Blood pressure patterns in pregnant women who developed pre-eclampsia or hypertension

Abstract

Early recognition of pregnant women at risk of pre-eclampsia (PE) in developing countries is essential to ensure timely transfer to the appropriate level of care. Our aim was to determine the predictive value of blood pressure (BP) measurements taken in 4 week windows to identify women who will develop PE or new onset hypertension (NOHPT). A prospective observational study.Women with one or more risk factors for PE presenting at a tertiary hospital for antenatal care before 14 weeks' gestation were approached to participate. After obtaining informed consent, a single researcher completed a comprehensive structured questionnaire regarding previous medical, pregnancy and contraceptive history, also including information of the patient's mother, siblings and the father. Clinical findings and the results of routine antenatal tests were documented. Subsequent care was according to existing management policies. The primary outcome was the development of PE (ISSHP definition). We enrolled 318 women, 9 of whom had uncomplicated deliveries elsewhere. There were 35 cases (12.6%) of PE and 39 cases of NOHPT amongst women who delivered after 20 weeks' gestation. Systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) and pulse pressure (PP) did not differ between groups at presentation. SBP was significantly higher in women in the PE group from 12-15 weeks' gestation (129.1±13.6 vs. 115.9±16.1mmHg) onwards, while the DBP became significantly higher from 24-27 weeks' gestation (84.0±13.3 vs. 69.3mmHg) onwards. MAP was also higher from 12-15 weeks' gestation (94.8±8.5mmHg) onwards. PP was not of value. In women with NOHPT, SBP became significantly higher at 16-19 weeks' gestation (124.1±12.1 vs. 118.4±14.6), MAP became significantly higher at 24-27 weeks' gestation (89.8±14.6 vs. 85.7±11.3mmHg) and DBP at 32-35 weeks' gestation (78.8±72 vs. 72.1±10.9mmHg). ROC curve analysis revealed poor ability of all four parameters to distinguish between women who will develop PE or NOHPT. SBP, DBP and MAP increases earlier in women who will develop PE compared with those who develop NOHPT. In both groups SBP and MAP changed earlier than DBP. PP did not differ between the various groups. There is no specific cut-off value of any parameter which will predict disease without an accompanying high false positive rate. SBP and DBP are only of clinical importance if specific threshold values as identified in existing classification systems are exceeded.