Miscarriage and Loss

British researchers have discovered a link between an enzyme and infertility and miscarriage. Enzymes are proteins that increase the rates of chemical reactions. This enzyme, called SGK1, acts as a type of "fertility switch," with high levels linked to infertility and low levels linked to miscarriage.

The study, published in Nature Medicine, examined tissue samples from the uterine lining, which were donated by 106 women who were being treated at Imperial College Healthcare NHS Trust either for unexplained infertility or for recurrent pregnancy loss. The women with unexplained infertility had been trying to get pregnant for two years or more, with the common reasons for infertility being ruled out. Researchers found that the uterine lining in these women had high levels of the enzyme SGK1.

The researchers found more information from experiments with mice. Levels of SGK1 in the womb lining decline during the fertile window in mice. When the researchers implanted extra copies of the SGK1 gene into the womb lining, the mice were unable to get pregnant. This suggests that a fall in SGK1 levels is essential for making the uterus receptive to embryos.