Mirvie’s Quest for a Blood Test to Predict Preeclampsia
Today, with the rising maternal mortality rate in the U.S. and in many developing countries, we have people looking for answers in the least likely places. Mirvie, a relatively new start-up, is looking for a blood test to predict preeclampsia. To my understanding, the organization is about five years old and has raised 90 million dollars. Google has donated money and recently the Bill and Melinda Gates Foundation donated 4.6 million dollars to Mirvie.
According to Mirvie’s website, they are pioneers in predicting “unexpected pregnancy complications.” In all fairness to objectivity and accuracy, “complications” should be singular, not plural, since Mirvie’s claim to fame is really looking for a blood test which has some ability to predict or forecast preeclampsia.
But this test in no way identifies who’s going to die from suicide, homicide, or drug overdose. It will not predict who is going to be left to bleed to death after a vaginal birth or a cesarean section. Nor will it predict a pulmonary embolus, a serious infection, myocarditis, or any of the other causes of maternal mortality. So, to set the record straight, Mirvie is not looking for “many”complications to prevent maternal mortality with this blood test, but one complication.
We must also remember that we are the only developed country with a rising maternal mortality rate. In this country, the mortality rate is about 40 per 100,000 for native Americans and native Alaskans, and 80 per 100,000 for people of color. Countries such as Norway, Sweden, Denmark, Japan, and Germany have the same prenatal problems we do, but they have maternal mortality rates between two and three per 100,000 births. So, it would seem that there’s something else going on. And yes, you betcha there is. This maternal mortality disaster in the U.S. is infinitely more complex than the lack of a blood test. It’s way past the time to understand that.
The American College of Obstetricians and Gynecologists (ACOG) publish excellent educational materials which are well written, concise, and easy to understand. They recently (April 2023) have taken into consideration research in lowering the blood pressure guidelines for treatment of chronic hypertension in pregnancy. In my more than four decades and 6000 births, my patients have had no maternal mortality, no strokes or seizures, and no permanent illness. I’ve had hundreds of patients with preeclampsia, but none of them died. I didn’t need a blood test to predict preeclampsia. I knew how important it was to recognize and manage high blood pressure in pregnancy.
My rule for managing blood pressure has always been to treat high blood pressure. Invariably, with the first high blood pressure it will be possible to sample blood pressures readings until you get one that’s lower. But in my experience, it’s not the lower one that counts. It’s the one high blood pressure reading that counts. That’s when we need to start managing blood pressure elevations in pregnancy.
All countries use what we call the “preeclampsia model.” In other words, the main accomplishment during prenatal care is to look for, find, and manage preeclampsia to avoid complications. So, we already have one very useful and predictive factor in the preeclampsia model which works well. Over 40 years ago, I learned the hard way about blood pressure testing. I would see a patient in my clinic with an elevated blood pressure at say, 35 weeks of gestation. I would send the patient to labor and delivery at the hospital only to be told that the patient’s blood pressure was normal or much lower than we had found in the clinic. I soon discovered that the nurses re-tested the blood pressure in the left lateral decubitus position several times until they got a low pressure and recorded the low pressure. While the testing and retesting until the blood pressure lowers is workable in some situations, it is not effective with prenatal hypertension.
What is this $90 million blood test supposed to do? How does it work and why is it considered to be reliable? The article about Mirvie states: “Unexpected ‘complications’ effect one in five pregnancies, with large economic costs and lifelong health consequences for parents and babies.” And a few sentences later: “Yet today women and doctors lack a reliable way to detect complications before symptoms appear.” The claim is made that: “The platform combines revolutionary analysis of tens of thousands of RNA messages from the baby, the placenta and the mom with machine learning. It enables proactive, preventive and personalized pregnancy care for the well-being of moms and babies.”
This last sentence implies that we presently don’t have “proactive, preventative and personalize pregnancy care for the well-being of moms and babies.” ACOG and many obstetricians would disagree.
We should ask how this test is supposed to work and how should a new “preventative” time window in the second trimester add anything to prenatal care management. We will still need to gauge our treatment on our success in managing and treating blood pressure, physical activity, and the other presently used well-known labs.
A previous article about Mirvie, also predicted that 75 percent of women who will develop preeclampsia will be identified by this test. Further, it is stated that only 20 percent of pregnancy complications can be predicted today using generalized risk assessment based on pregnancy history, race, ethnicity, body, mass index, and medical history. Risk assessment? Nothing here about the obstetrician watching for blood pressure increases and a patient’s changing lab values.
For those of you who are not obstetricians, the definitive treatment of preeclampsia and eclampsia is delivery. So, delivery even at 26 weeks can be indicated based on the severity of symptoms and problems. Again, the “predictive blood test” will not make a difference in the final plan as delivery is based on the blood pressure and the other labs which most likely will be abnormal. So cautiously stated, this appears to be a test looking for an illness.
Many people who don’t understand the complexities of prenatal care have invested money to the tune of $90 million dollars. There seems to be a lack of understanding that even though this test might predict preeclampsia, it will not change treatment. The implication is that this test will ostensibly improve treatment outcome. Physicians can already identify preeclampsia by carefully watching blood pressure and labs. Nor will this test predict other causes of pregnancy related complications, whether they be death, illness from infection, bleeding, surgical misadventure, pulmonary emboli, suicide, homicide, drug overdose, myocarditis, pulmonary emboli, and the other potential causes for mortality.
Reducing maternal mortality today rests squarely in the purview of the obstetrician, with or without the Mirvie blood test. Sometimes, when something seems to be too good to be true, it is. We should all be reminded of the 946 million-dollar lesson learned from Elizabeth Holmes and the Theranos industries. Some of the world’s wisest investors, including Rupert Murdoch and the Bill and Melinda Gates Foundation, should have recognized familiar lessons from the past.