Specific microRNAs in this cluster which might cause abnormal spiral artery invasion include miR-520h, miR-520b, and 520c-3p. This impairs extravillus trophoblast cells invasion to the maternal spiral arteries, causing high resistance and low blood flow and low nutrient supply to the fetus. There is tentative evidence that vitamin supplementation can decrease the risk.Immune factors may also play a role. Diagnosis
Testing for pre-eclampsia is recommended throughout pregnancy via measuring a womans blood pressure. Diagnostic criteria
Pre-eclampsia is diagnosed when a pregnant woman develops:
Blood pressure ≥140 mmHg systolic or ≥90 mmHg diastolic on two separate readings taken at least four to six hours apart after 20 weeks gestation in an individual with previously normal blood pressure. In a woman with essential hypertension beginning before 20 weeks gestational age, the diagnostic criteria are an increase in systolic blood pressure (SBP) of ≥30 mmHg or an increase in diastolic blood pressure (DBP) of ≥15 mmHg. Proteinuria ≥ 0.3 grams (300 mg) or more of protein in a 24-hour urine sample or a SPOT urinary protein to creatinine ratio ≥0.3 or a urine dipstick reading of 1+ or greater (dipstick reading should only be used if other quantitative methods are not available).Suspicion for pre-eclampsia should be maintained in any pregnancy complicated by elevated blood pressure, even in the absence of proteinuria. Ten percent of individuals with other signs and symptoms of pre-eclampsia and 20% of individuals diagnosed with eclampsia show no evidence of proteinuria.
Pre-eclampsia is a disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine. When it arises, the condition begins after 20 weeks of pregnancy. In severe cases of the disease there may be red blood cell breakdown, a low blood platelet count, impaired liver function, kidney dysfunction, swelling, shortness of breath due to fluid in the lungs, or visual disturbances. Pre-eclampsia increases the risk of undesirable outcomes for both the mother and the fetus. If left untreated, it may result in seizures at which point it is known as eclampsia.Risk factors for pre-eclampsia include obesity, prior hypertension, older age, and diabetes mellitus. It is also more frequent in a womans first pregnancy and if she is carrying twins. The underlying mechanism involves abnormal formation of blood vessels in the placenta amongst other factors. Most cases are diagnosed before delivery. Commonly, pre-eclampsia continues into the period after delivery, then known as postpartum pre-eclampsia. Rarely, pre-eclampsia may begin in the period after delivery. While historically both high blood pressure and protein in the urine were required to make the diagnosis, some definitions also include those with hypertension and any associated organ dysfunction. Blood pressure is defined as high when it is greater than 140 mmHg systolic or 90 mmHg diastolic at two separate times, more than four hours apart in a woman after twenty weeks of pregnancy.