A new study looked at a protein called BMI1 in the lining of the uterus (endometrium). Researchers compared tissue samples from 78 patients who had elective abortions, 39 who had spontaneous abortions (miscarriages), and 50 infertile patients. They found that BMI1 levels were significantly lower in tissue from miscarriages compared to elective abortions.
In the group of infertile patients, who were followed for two years, those whose tissue tested positive for BMI1 had higher rates of pregnancy and live births than those who tested negative. The study did not report any safety concerns, as it was analyzing tissue samples, not testing a treatment.
The main reason to be careful is that this was an observational study. It can show a link between BMI1 levels and pregnancy outcomes, but it cannot prove that low BMI1 causes miscarriage or that raising it would help. The study groups were also relatively small.
Readers should take from this that scientists are learning more about the biology of pregnancy loss and infertility. The BMI1 protein might one day be a useful marker to help understand a person's reproductive health, but much more research is needed before any test or treatment based on this finding could be developed.