Recurrent pregnancy loss can be explained by specific genetic variations that prevent suppression of the immune system during pregnancy, finds new research from Nazarbayev University School of Medicine.
Professor Kuralay Atageldiyeva, with colleagues from Kazakhstan, Canada, and Tunisia, investigated the association between PD-L1 (programmed death-ligand 1) gene variants and recurrent pregnancy loss in women of Kazakh ethnic background, focusing on five variants.
The genetic component to recurrent miscarriages
PD-L1 helps control the immune system by preventing excessive immune response; for example, against a foetus during pregnancy.
The phenotypic and genotypic characteristics of patients with multiple miscarriages were compared to individuals who had experienced several pregnancies and live births.
The researchers found that lower levels of PD-L1 expression, dependent on the PD-L1 gene variant inherited, were associated with a higher risk of recurrent pregnancy loss; specifically, G/C rs822336 and A/T rs822337 genotypes.
However, this association was only observed in women from West Kazakhstan, not Central Kazakhstan.
West and Central Kazakhstan were compared due to genetic and environmental differences, which could explain the differing impact of the PD-L1 gene variant inherited on pregnancy.
Despite the focus of this research being women of Kazakh ethnicity, these findings are also important for women globally.
“One per cent of the female population worldwide is affected by recurrent miscarriages, but half won’t actually be given a reason, known as idiopathic pregnancy loss.
Our team aimed to identify possible new genetic causes and identified a list of genes linked to idiopathic pregnancy loss,” says Professor Atageldiyeva. “Possibly we’ll end up with screening which leads to suggestions for treatment strategy that improves the outcome of pregnancy.”
These findings highlight the importance of considering genetic differences in understanding the causes of pregnancy loss, and for devising future treatments to ensure healthy pregnancy and labour for women around the world.
“There are a lot studies worldwide with similar aims and techniques. Our research adds to this with data from Central Asia,” explains Professor Atageldiyeva.
“After doing a bioinformatic analysis, we can come up with the most probable cause of recurrent pregnancy loss, and create genetic testing.”
This research was published in the Journal of Reproductive Immunology.