Pregnancy Loss and Genetic Factors: New Study Reveals Insights
Pregnancy loss is a common occurrence worldwide, with about 15 percent of known pregnancies ending in miscarriage. However, the actual number may be higher due to early pregnancy losses. One of the most common causes of pregnancy loss is aneuploidy, which is an abnormality in the number of chromosomes in a cell.
A recent study has shed light on genetic factors related to aneuploidy, offering valuable information on why miscarriages occur. Chromosomal abnormalities, such as having too many or too few chromosomes, are a significant factor in approximately half of all known miscarriages in the first or second trimester.
Researchers conducted a study analyzing genetic data from nearly 140,000 in vitro fertilization (IVF) embryos to understand the genetic basis of aneuploidy. This study revealed how common genetic variations can increase the risk of pregnancy loss for some parents.
Senior author Rajiv McCoy, a computational biologist at Johns Hopkins University, stated, “This work provides the clearest evidence to date of the molecular pathways through which variable risk of chromosomal errors arises in humans.”
The study found that chromosomal abnormalities typically arise in the egg, with a higher frequency in older mothers. By analyzing a large volume of genetic data from thousands of embryos and their biological parents, researchers were able to identify genetic variations that contribute to an increased risk of aneuploidy.
The analysis focused on genes involved in chromosome pairing, recombination, and cohesion during meiosis in egg cells. One of the key findings was the association of a variant of the gene SMC1B with an increased risk of maternal meiotic aneuploidy.
Other genes related to crossover recombination, such as C14orf39, CCNB1IP1, and RNF212, were also highlighted in the study. McCoy noted, “The genes that emerged from our study in humans are exactly the ones that experimental biologists have detailed over decades as critical for recombination and chromosome cohesion in model organisms like mice and worms.”
Understanding these genetic factors could have implications for drug development and pave the way for future research on maternal and paternal genetic variations associated with pregnancy loss. While predicting individual risk remains challenging due to additional factors like maternal age and environmental exposures, this study provides a foundation for further investigations.
The study, published in Nature, provides valuable insights into the genetic factors influencing pregnancy loss and opens up possibilities for advancements in reproductive genetics and fertility care.
