Miscarriage is one of the most common pregnancy complications worldwide. Estimates indicate that about 15% of known pregnancies end in miscarriage, while the actual rate is likely much higher due to the loss of many pregnancies before they are detected.
اضافة اعلان
In a new study published in the journal Nature, researchers found strong evidence suggesting that abnormalities in the number of chromosomes in embryos—one of the most common causes of miscarriage—may be linked to genetic factors that develop in women many years before they are born.
The researchers explain that about half of miscarriages occurring in the first and second trimesters are due to the embryo having an extra or missing chromosome, a condition scientifically known as aneuploidy.
To better understand the roots of this phenomenon, a research team from Johns Hopkins University analyzed genetic data from nearly 140,000 embryos examined through in vitro fertilization (IVF) programs, including data from 22,850 parental couples.
Lead researcher Rajiv McCoy, a professor of computational biology at the university, said the study provides “the clearest evidence to date of the molecular pathways that lead to differences in the risk of chromosomal errors among humans.”
The findings showed that the strongest genetic associations were found in genes that control how chromosomes pair and separate during meiosis in eggs.
Among the most notable of these is a gene responsible for producing a protein that helps hold chromosomes together. Certain mutations in this gene were linked to an increased likelihood of chromosomal errors in embryos, and consequently a higher risk of miscarriage.
The study also identified associations with other genes known for their vital role in chromosome recombination—mechanisms previously studied in animal models such as mice and worms.
Notably, meiosis in females begins during the development of the female fetus itself, then pauses for many years before resuming later at ovulation. Researchers suggest that any genetic defect occurring during this early stage may remain dormant for decades before its effects appear during pregnancy.
Future Prospects
Although researchers emphasize that predicting an individual’s risk of miscarriage remains difficult due to the interaction of other factors such as maternal age and environmental influences, understanding these genetic foundations opens the door to developing future treatments and improving fertility care.
The researchers conclude that these findings represent an important step toward a more precise understanding of the earliest stages of human development and may ultimately help reduce the risk of pregnancy loss.
Al Arabiya
