Blood Test for Severe Preeclampsia Will Save Lives

There is amazing news for the world of obstetrics and for all pregnant women. The Food and Drug Administration recently approved a blood test that will predict, with 96% accuracy, if a pregnant woman will develop severe preeclampsia within 2 weeks. Severe preeclampsia is a critical obstetrical condition that can have serious outcomes for a mother and baby. It can lead to eclampsia, an obstetrical emergency, which often results in death of the mother and/or baby.

Based on research published in the Journal of the American Heart Association, the incidence of new-onset hypertensive disorders of pregnancy (gestational hypertension and preeclampsia/eclampsia) have nearly doubled in the United States from 2007 to 2019. And they continue to climb.

According to the Preeclampsia Foundation, 5%-8% of all pregnancies in the United States will result in preeclampsia. Black women are at a 60% higher risk than white women, and according to various sources, other risk groups include those who became pregnant via in vitro fertilization, mothers of multiples (twins and triplets), women with gestational diabetes, women over age 35, women with chronic hypertension, obesity, polycystic ovary syndrome, sickle cell disease, rheumatoid arthritis, lupus, migraines, antiphospholipid syndrome, previous pregnancy with preeclampsia, family history, and scleroderma.

Screening and treatment

Preeclampsia is a multiorgan disease of pregnancy, and can be mild, but may quickly progress to severe, which can be life-threatening for mother and baby. It was previously referred to as toxemia or the high blood pressure disease of pregnancy. It primarily involves the cardiovascular, neurologic and renal systems, and the liver. Patients typically present with elevated blood pressures, but other symptoms may include headache, swelling of hands and feet, blurry/double vision or seeing spots, nausea/vomiting, and epigastric pain. It is diagnosed with elevated blood pressures, blood work, and protein in the urine.

Early screening for preeclampsia is done in the first trimester. Presently, a combination of prenatal blood work, blood pressure monitoring, and recognition of high-risk groups is used to determine a treatment plan going forward. The American Congress of Obstetricians and Gynecologists recommends women that fall into this group for potentially developing preeclampsia take daily aspirin as a preventative measure.

In its milder form, a pregnant woman can be observed as an outpatient – monitored with antepartum testing, lab work, and patient education to report significant symptoms as listed above. Teaching patients about fetal kick counts to monitor their baby’s movements is equally important. Women with mild preeclampsia usually can safely deliver at term, being induced between 37-39 weeks’ gestation.

On the other hand, if mild preeclampsia progresses to severe preeclampsia, delivery may be preterm for the safety of mother and baby. Severe preeclampsia can lead to maternal organ damage, seizures, and even death of mother and/or baby.

About 20% of women with severe preeclampsia will develop HELLP (Hemolysis, Elevated Liver enzymes, and Low Platelets) syndrome, a life-threatening disease that often warrants immediate delivery. According to the National Library of Medicine, the mortality rate of women with HELLP syndrome is up to 24% and the perinatal death rate is up as high as 37%. These serious conditions can cause ineffective maternal clotting, liver rupture, placental abruption, and postpartum hemorrhage. It is most prevalent in the third trimester but can occur within 48 hours of delivery.

The only cure for preeclampsia in any form is delivery.

Patients with severe preeclampsia are hospitalized until delivery – sometimes a few days to a couple of weeks. Mother and baby are closely watched for further progression, including signs of organ damage in the mother and changes to the well-being of the baby. If the mother’s health is severely compromised, then the baby will be compromised as well. A preterm delivery may be necessary.

Impact of the new test

The National Institute of Health states that preterm babies born from preeclamptic mothers can suffer many health problems including cerebral palsy, deafness, blindness, epilepsy, and a host of other respiratory, cardiovascular, and endocrine issues. But the biggest issue is preterm birth, defined as birth before 37 weeks gestation. Being born preterm can require a long stay in the intensive care nursery.

This is where the first-of-its-kind prognostic blood test comes into play. The test’s ability to predict severe preeclampsia within 2 weeks can help save lives. The test can offer health care providers the ability to administer steroids for fetal lung maturity before delivery and be more prepared to care for what could be a very compromised newborn.

The blood test, which is recommended between 23-35 weeks gestation, involves analyzing a ratio between two proteins from the placenta, sFlt1 and PIGF. The higher the ratio, the higher the risk that severe preeclampsia will develop. Results can be available within 30 minutes, which is critical when contemplating treatment.

An example of the use of this ratio is illustrated with chronic hypertension in pregnancy, which is defined as elevated blood pressure before 20 weeks or even before conception. Since chronic hypertension can be a primary precursor to preeclampsia, patients with this condition are at higher risk. The FDA-approved blood test would be helpful in determining the plan of care; that is, delivery versus hospitalization versus monitor as an outpatient.

With a positive test result, a pregnant woman can be immediately hospitalized where she can get the care she and baby need as they await delivery. Since health care providers already know the high-risk groups, surveillance can begin early, utilizing this blood test to predict the progression to severe preeclampsia. Conversely, if the test is negative, a treatment plan can be made as an outpatient and the pregnancy continues.

Not all hospitals are equipped to care for premature babies. If delivery is not imminent, providers can use this blood test to identify those that should be transferred to a tertiary center for observation and monitoring. Mother and baby would then not be separated after birth.

We really don’t know who will develop severe preeclampsia and who won’t. This new blood test will be a critical tool as pregnant patients go through their second and third trimesters. It will be especially pivotal for these women, but important for all pregnant women in reducing maternal and fetal mortality and morbidity.

Ms. Barnett is a registered nurse in the department of obstetrics, Mills-Peninsula Medical Center, Burlingame, Calif. She has disclosed no relevant financial relationships.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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