Blood pressure as a risk factor for eclampsia and pulmonary oedema in pre-eclampsia

Objective: We evaluated whether blood pressure and change in blood pressure measurements during pregnancy were associated with eclampsia or pulmonary oedema among women with pre-eclampsia. Study design: Observational study of women with eclampsia, pre-eclampsia complicated by pulmonary oedema and pre-eclampsia without end-organ complications (pre-eclampsia controls) at a large referral center in Cape Town, South Africa. Main outcome measures: Blood pressure measurements at presentation for antenatal care were compared to measurements after a diagnosis of pre-eclampsia. Mean blood pressures and changes in blood pressures were also calculated and compared between groups at different time points. A sub analysis including women who presented for antenatal care before 20 weeks of gestation was performed. Results: When diagnosed with pre-eclampsia, women with pulmonary oedema had increased systolic blood pressures and women with eclampsia had increased diastolic blood pressures compared to pre-eclampsia controls. There were no differences in blood pressure measurements in early pregnancy between women who later developed eclampsia or pulmonary oedema compared to pre-eclampsia controls. Conclusion: Blood pressure measurements in early pregnancy do not seem useful as a risk factor for the development of eclampsia or pulmonary oedema among women diagnosed with pre-eclampsia. Increased systolic or diastolic pressure at diagnosis of pre-eclampsia may be useful as a risk factor for the development of pulmonary oedema or eclampsia. Further research is needed to confirm these findings.