Preeclampsia is a serious condition that affects about 5 percent of pregnant women and typically starts after 20 weeks of pregnancy. Elevated blood pressure is the primary symptom, but there may be others such as protein in the urine, or liver or kidney abnormalities.
The condition most commonly shows up after you’ve reached 37 weeks, but it can develop any time in the second half of pregnancy, including during labor or even after delivery (usually in the first 48 hours).
It’s possible to have symptoms of preeclampsia before 20 weeks, but only in rare cases, such as with a molar pregnancy.
Preeclampsia can range from mild to severe, and it can progress slowly or rapidly. Your doctor will screen you for the condition at every prenatal visit by taking your blood pressure and checking your urine sample for protein.
The more severe the condition and the earlier it appears, the greater the risks for you and your baby. Most women who get preeclampsia develop a mild version near their due date, and they and their babies do fine with proper care.
But when preeclampsia is severe, it can affect many organs and cause serious or even life-threatening problems. That’s why you’ll need to deliver early if your condition is severe or getting worse.
Preeclampsia causes the blood vessels to constrict, resulting in high blood pressure and a reduced blood flow that can affect organs in your body, such as your liver, kidneys, and brain.
When less blood flows to your uterus, it can mean problems for your baby, such as poor growth, too little amniotic fluid, and placental abruption (when the placenta separates from the uterine wall before delivery). In addition, your baby may suffer the effects of prematurity if you need to deliver early to protect your health.
Changes in your blood vessels caused by preeclampsia may cause your capillaries to “leak” fluid into your tissues, which results in swelling (known asedema). And when the tiny blood vessels in your kidneys leak, protein from your bloodstream spills into your urine. (It’s normal to have a small amount of protein in your urine, but more than a little bit can signal a problem.)
Some women with preeclampsia develop a condition called HELLP syndrome. HELLP stands for Hemolysis, the breakdown of red blood cells; Elevated Liver enzymes; and Low Platelets, the blood cells that are necessary for clotting.
HELLP syndrome puts you and your baby at an even higher risk for the same kinds of problems that can result from severe preeclampsia alone. Once you develop preeclampsia, you’ll have your blood tested periodically for signs of HELLP syndrome.
Infrequently, preeclampsia can lead to seizures, a condition called eclampsia. Eclampsia can have very serious consequences for both the mother and the baby.
The seizures may be preceded by symptoms such as severe or persistent headache, vision changes (blurred vision, seeing spots, or sensitivity to light), mental confusion, or intense upper abdominal pain. Sometimes, though, the seizures occur without warning. For this reason, all women with severe preeclampsia are given magnesium sulfate, an anti-seizure medication.