Preeclampsia

Preeclampsia is a pregnancy condition marked by new high blood pressure after 20 weeks, together with protein in the urine or signs that other organs are affected, such as the kidneys, liver, brain or blood. It can also develop in the weeks after birth. It is caused by problems with the placenta. Risk is higher in a first pregnancy, with twins, in people with chronic high blood pressure, diabetes, kidney disease or a previous preeclampsia, and with older age or obesity. It can affect the baby's growth and, if severe, lead to seizures (eclampsia) and other serious complications.

Lab tests linked to preeclampsia:

• Protein, total, random urine: measures protein in a single urine sample.
• Protein/creatinine ratio: compares urine protein with creatinine to estimate how much protein is lost in a day.
• Doctors also check blood pressure, a CBC with platelets, kidney function, liver enzymes and, in some cases, LDH and uric acid. Some centers use the sFlt-1/PlGF ratio to help predict preeclampsia. Ultrasound checks the baby's growth.

How results are read:

• A urine protein/creatinine ratio of 0.3 mg/mg or higher counts as significant protein loss.
• Preeclampsia can be diagnosed without protein in the urine if blood pressure is high and there are signs of organ involvement, such as low platelets or raised liver enzymes or creatinine.
• Low platelets, high liver enzymes and signs of red cell breakdown can mean HELLP syndrome, a severe form.

When to see a doctor:

• Go to your scheduled prenatal visits, where blood pressure and urine are checked.
• Contact your maternity care provider the same day for new swelling of the face or hands, a headache that won't go away, or a home reading with a top (systolic) number of 140 or higher or a bottom (diastolic) number of 90 or higher. For a systolic reading of 160 or higher, or a diastolic reading of 110 or higher, contact them immediately for emergency assessment, even without symptoms.
• Call your emergency number for severe headache, vision changes, pain under the ribs on the right, breathlessness, or seizures, during pregnancy or after birth.

Clinical takeaway: preeclampsia is diagnosed from high blood pressure in pregnancy with urine protein or blood test signs of organ involvement, and the urine protein/creatinine ratio is a key test.