New Research from Yale University Uncovers Crucial Factor in 90% of Enigmatic Miscarriages

Researchers at Yale University have demonstrated that placenta testing can accurately pathologically determine more than 90% of previously unexplained miscarriages, a finding that researchers say could help inform future pregnancy care. say:

The results of this study were recently published in the journal Reproductive science.

Miscarriage statistics

Of the approximately 5 million pregnancies each year in the United States, 1 million end in miscarriage (miscarriage occurs before 20 weeks of pregnancy) and more than 20,000 end in stillbirth after 20 weeks of pregnancy. Up to 50% of these losses are classified as “unspecified.”

Emotional strain and research purpose

Patients who suffer from these pregnancy outcomes are often told that their loss is unexplained and that they can just try again, contributing to patients’ feelings of responsibility for the loss, said lead author and obstetrics department specialist. said researcher Dr. Harvey Kliman. Department of Gynecology and Reproductive Sciences, Yale School of Medicine.

“Pregnancy loss is a tragedy, and to be told there is no explanation causes great pain to the families of those who have lost,” said Kliman, who is also director of the Reproduction and Placenta Research Unit. “Our goal was to extend the current classification system to reduce the number of cases that remain unidentified.”

Methodology and findings

For this study, Professor Kliman collaborated with Beatrix Thompson, currently a medical student at Harvard University, and Parker Holzer, a former graduate student in the Yale School of Statistics and Data Science, to explore the pathology of loss. We developed an expanded classification system for pregnancy loss based on clinical tests. placenta.

The team started with a series of 1,527 single-child pregnancies that ended up being losses and were sent to Kliman’s Consulting Services at Yale University for evaluation. After excluding cases for which there was insufficient material for testing, 1,256 placentas from 922 patients were tested. Of these, 70% were miscarriages and 30% were stillbirths.

Domenic Rice is 33 weeks pregnant with her fifth child, holding a photo frame of herself with her stillborn son, TJ.Credit: Photo by Nancy Borowicz

By adding distinct categories of “placenta with abnormal growth” (atypical placenta) and “small placenta” (less than 10 placentas);^th For example, the authors were able to establish a pathological diagnosis for 91.6% of pregnancies, including 88.5% of miscarriages and 98.7% of abortions, based on existing categories such as cord accident, avulsion, thrombosis, and infection. I did. stillbirth.

The most common pathological feature observed in unexplained miscarriages was placental dysmorphism (86.2%), a marker associated with genetic abnormalities. The most common pathological feature observed in unexplained stillbirths was a small placenta (33.9%).

Impact and future recommendations

“This study suggests that more than 7,000 small placentas may be detected per year associated with stillbirth.” in the womb “Before the loss, we had flagged these pregnancies as high risk,” Kliman said. “Similarly, identifying placental dysmorphisms could be one way to potentially identify genetic abnormalities in the approximately 1 million miscarriages that occur in our country each year.”

Additionally, “having a specific explanation for the loss of a pregnancy can help families understand that the loss is not their fault, begin the healing process, and, if possible, prevent similar losses in the future, especially It can prevent stillbirths from occurring.”

When asked what the most effective way to prevent stillbirth is, Kliman replied, “Measure the placenta!”

References: “Placental Pathology in Unexplained Pregnancy Loss” by Beatrix B. Thompson, Parker H. Holzer, and Harvey J. Kliman, September 19, 2023. reproductive science.
DOI: 10.1007/s43032-023-01344-3