Time of onset of pre-eclampsia as a determinant of risk of cardiovascular disease and renal impairment at six weeks post partum: a cohort study in Lagos, Nigeria

Abstract

OBJECTIVES: Pre-eclampsia causes significant maternal and perinatal morbidity and mortality. It also causes changes in the cardiovascular, endothelial and metabolic systems, from which women may not fully recover after delivery. This study examined the association between the time of onset of pre-eclampsia and the risk for cardiovascular disease (using glucose tolerance, lipid profile and blood pressure) and renal function at 6 weeks post partum. STUDY DESIGN: A prospective cohort study. SETTING: Lagos University Teaching Hospital, Idi-Araba, Mother and Child Centre, Gbaja, Surulere and Lagos Island Maternity Hospital, Lagos, Nigeria. PARTICIPANTS: 44 women with pre-eclampsia were studied and data on their sociodemographic characteristics, gestational age at diagnosis and blood pressure were collected on admission. They were followed up through delivery till 6 weeks post partum, when blood pressure check, 75 g oral glucose tolerance test, fasting lipid profile and serum creatinine were done. OUTCOME MEASURES: The exposure was pre-eclampsia. The outcomes were cardiovascular disease risk markers, viz persistent hypertension, glucose intolerance and dyslipidaemia, and renal function at 6 weeks post partum in women who had pre-eclampsia. STATISTICAL ANALYSIS: Data were analysed using Stata V.16.1. Mann Whitney-U test was used to compare medians and Fisher's exact test was used to compare the categorical variables. RESULTS: Of the women studied, 13 (29.5%) had early onset pre-eclampsia and 31 (70.5%) had late onset pre-eclampsia. Mean gestational age at diagnosis was 30.8±1.57 weeks in women with early-onset pre-eclampsia and 35.6±1.26 weeks in women with late-onset pre-eclampsia (p<0.001). There was no significant difference in terms of disease severity in women who had early-onset compared with late-onset disease. Of the cardiovascular risk markers assessed at 6 weeks post partum, only serum triglyceride was found to be statistically higher in women with early onset compared with late onset pre-eclampsia, median values of 135 mg/dL (130-182 mg/dL) vs 128 mg/dL (121-139 mg/dL), p = 0.008. Only eight (18.2%) of the pre-eclamptic women became normotensive at the end of puerperium. CONCLUSION: The prevalence of persistent hypertension at 6 weeks post partum is high in women with pre-eclampsia. Serum triglyceride concentration was significantly higher in early onset compared with late onset pre-eclampsia; subsequent studies powered to determine the full cardiovascular risk and how long to follow postnatal women up will be beneficial.