In the absence of proteinuria, preeclampsia is also diagnosed if pregnant women meet diagnostic criteria for new-onset hypertension and have new onset of any of the following signs of end-organ damage: Thrombocytopenia (platelets < 100, 000 / mcL) Renal insufficiency (serum creatinine > 1.1 mg / dL or doubling of serum creatinine in women without renal disease) Impaired liver function (aminotransferases > 2 times normal) Pulmonary edema New-onset headache (unresponsive to medication and not accounted for by alternative diagnoses) Visual symptoms The following points help differentiate among other hypertensive disorders in pregnant women: Chronic hypertension is identified if hypertension precedes pregnancy, is present at < 20 weeks gestation, or persists for > 6 weeks (usually > 12 weeks) postpartum (even if hypertension is first documented at > 20 weeks gestation).