Effect of normal and pre-eclamptic pregnancies on plasma cholinesterase in Nigerian women

Background: Pre-eclampsia can be devastating and life-threatening for both mother and baby, particularly in developing countries. It is a major cause of maternal and foetal mortality and morbidity. Early diagnosis and management are very important to the reduction of mortality and morbidity. A sensitive diagnostic and prognostic marker will therefore be of great value. There is paucity of data on the effect of pre-eclamptic pregnancy on plasma cholinesterase activity especially in Nigerians. Objective: Our aim was to determine the changes in plasma cholinesterase concentration in normal and pre-eclamptic pregnancies in Nigerians. Setting: Antenatal Clinic and Prenatal Diagnostic and Therapy Centre in a Tertiary University Teaching Hospital in Lagos. Patients and Methods: Plasma cholinesterase concentration was determined using a colorimetric method in 30 healthy non-pregnant, 30 healthy pregnant, 30 and 27 pregnant women with mild and severe pre-eclampsia, respectively, between 28 and 41 weeks of gestation. Cholinesterase activity was re-assessed 6 weeks postpartum. Results: The mean plasma cholinesterase levels in healthy non-pregnant women, women with normal pregnancy, pregnant women with mild pre-eclampsia and those with severe pre-eclampsia were 3594±1042, 2135±422, 1781±330 and 1630±326 (m/L), respectively. Six weeks postpartum, the mean cholinesterase levels in the normal pregnant, mild eclamptic and severe eclamptic groups were 3212±346, 3157±750 and 2864±700 (/L), respectively. Conclusions: Our study suggests that normal pregnancy, mild and severe pre-eclampsia cause a significant (p< 0.01) reduction in plasma cholinesterase activity compared to non-pregnant state, with the greatest decrease in severe pre-eclamptic pregnancy. This decline does not return to normal non-pregnant state in subjects with severe pre-clampsia within six weeks postpartum. The place of plasma cholinesterase concentration as a diagnostic and prognostic marker in pre-eclamptic and eclamptic pregnancies should be further explored.