Of the nearly 4 million births each year in the United States, approximately 50,000 are affected by life-threatening complications, with up to 900 resulting in maternal death during childbirth. A major, often life-threatening complication is placenta accreta spectrum (PAS), which poses a threat to both mother and baby. The incidence of placenta accreta is estimated at 1 case in 2,500 pregnancies and represents 80% of cases of placental complications.
Placenta accreta is characterized by a placenta that is too firmly attached to the uterine muscle (myometrium). The placenta increta on the other hand is completely inserted into the uterine muscle, with the placenta percreta even spilling beyond the uterine muscle until it touches other organs, such as the bladder.
There are 2 major complications: abnormal delivery of the placenta after birth and heavy bleeding. Identifying cases of placental abnormalities before delivery helps to reduce and prepare for such complications.
Diagnose the placental complication from the 2nd trimester of pregnancy
Currently, these placental complications are identified by ultrasound (ultrasound), MRI and a predictive clinical picture, however these different methods miss between 33% and 50% of cases which are thus undetected before delivery.
The study aimed to develop a targeted test to predict these placental complications during pregnancy and therefore before childbirth, in order to better anticipate the conditions of childbirth. The study of circulating microparticle (CMP) protein panels in pregnant women enabled the Boston team to identify a set of 5 circulating proteins predictive of the risk of placental complications. CMPs are tiny extracellular vesicles that cells use to communicate with each other and are already widely studied in other disciplines as they provide insight into cellular crosstalk. The team set out to study these CMPs at the mother-fetus interface, in order to identify a clinically significant biomarker.
“The placenta accreta is a major contributor to maternal morbidity and mortality worldwide”recalls one of the lead authors, Dr. Hope Yu, a maternal-fetal medicine physician in the Brigham’s Department of Obstetrics and Gynecology. “To date, up to half of cases are not detected before delivery. Our results will make it possible to reduce this detection rate with the help of a new blood test”.
The case-control study conducted with 35 patients with placental complications and 70 control patients reveals:
- in plasma samples taken from 26-week pregnant participants, 5 CMP proteins that distinguish complicated patients from controls;
- at 35 weeks of pregnancy, 4 CMP proteins, which distinguish patients with placental complications from controls;
- in the second trimester of pregnancy, iron homeostasis and erythropoietin signaling appear to be overrepresented in participants with placental complications, which reflects abnormal immune function.
In conclusion, 5 circulating proteins in plasma during the second trimester of pregnancy constitute a fine predictive signature of these placental complications, well before delivery. If other clinical trials are necessary to validate the application of this signature in the form of a blood test, these data mark a step towards better preparation for childbirth for the women concerned, or even their orientation in a service or childbirth center. specialized.
“It’s one more step towards proactive and personalized prenatal care”conclude the authors.