Current Concept and Research Progress of Pre-Eclampsia (Early-Onset and Late-Onset Pre-Eclampsia)

Pre-eclampsia is a syndrome that belongs to the group of hypertensive disorders of pregnancy. It is a multi-organ disease and can affect the kidney, liver, brain and the blood clotting system [1,2]. Pre-eclampsia is one of the most common causes of maternal and fetal morbidity and mortality [3]. Pre-eclampsia is defined as new-onset hypertension developed after 20 weeks of gestation (systolic or diastolic blood pressure ≥140 and/or ≥90 mmHg, respectively, measured at least two occasions, 4 hour to 1 week apart) and proteinuria(≥300 mg in a 24- hour urine collection, or two random urine specimens obtained 4 hours to 1 week apart containing≥1+ by dip stick or one dipstick demonstrated ≥2+ protein)[22,23]. Mild pre-eclampsia was diagnosed as pre-eclampsia was systolic blood pressure <160 mmHg, diastolic blood pressure <110 mmHg, platelet count≥100,000 per mm3, non-elevated liver enzymes, absence of renal insufficiency, pulmonary edema, cyanosis, new-onset cerebral/visual disturbances, and/or right upper quadrant or epigastric pain[24,25]. Severe pre-eclampsia is diagnosed as pre-eclampsia with systolic blood pressure ≥160 mmHg, or diastolic blood pressure ≥110 mmHg, platelet count <100,000 per mm 3, elevated liver enzymes, renal insufficiency, pulmonary edema or cyanosis, new-onset cerebral/visual disturbances, and/or right upper quadrant or epigastric pain [24,25]. A major advance in the classification of pre-eclampsia is its subdivision into early-onset and late-onset pre-eclampsia[26,27]. Especially, early-onset and late-onset pre-eclampsia have a serious threat to the maternal and neonatal lives, and in the clinical practice, it is of great difficulties and challenging in its treatment. Therefore, it is of great importance to pay enough attention to early-onset and late-onset pre-eclampsia. According to the statistics of recent years in China, the prevalence of pre-eclampsia has become less due to increase in attention paid to the pregnant women with the hypertensive disorder and in the maternity examination during their period of antenatal check-up.