Diagnosis of hypertensive disorders in pregnancy.

Hypertensive disorders of pregnancy, including chronic hypertension (CHTN), superimposed preeclampsia, gestational hypertension, and preeclampsia, affect 10% to 20% of pregnancies and are a significant cause of maternal and perinatal morbidity and mortality. The incidence of these disorders is increasing because of factors, such as advanced maternal age, obesity, assisted reproductive technology, and increased rates of preexisting comorbidities. Differentiating pregnancy-associated hypertension from preexisting CHTN is challenging, as the overlap between the 2 may be broadening because of the changing demographics of the pregnant population. This review critically evaluated the evidence regarding the current periods recommended to make a diagnosis of a hypertensive disorder of pregnancy. This review does not provide evidence to support the arbitrary 4-hour period or any particular period for the diagnosis of hypertensive disorders in pregnancy. In addition, there is no clear definition of what is considered persistent or sustained blood pressure elevations in blood pressure. Every effort should be made to ensure accurate diagnosis of new-onset elevated blood pressures during pregnancy before labeling the patient with the diagnosis and, thus, recommending serial maternal and fetal testing and delivery at or before 37 weeks of gestation.