Researchers have discovered that a protein enzyme may be responsible for some cases of infertility and recurrent miscarriage. The SGK1 enzyme needs to be carefully balanced to promote pregnancy and maintain pregnancy, according to research. Initial findings were a part of human research, but further research was completed on animal studies.
About 100 women treated at Imperial College London volunteered tissue samples from the uterine lining. Women were treated for infertility or recurrent miscarriages. Infertility was defined as inability to conceive after two years. All common causes of infertility were ruled out before participating in the study. Recurrent miscarriage was defined as three or more lost pregnancies.
When the uterine lining of the patients were tested, researchers found SGK1 may have played an important role in fertility and miscarriage. During fertile days, SGK1 levels drop dramatically. This allows the embryo to implant successfully in the uterus. Women unable to conceive tested for high levels of SGK1 in the uterine lining. After conception, SGK1 levels are supposed to rise. In some cases, enzyme levels do not rise, which could lead to miscarriage.
Researchers took the knowledge from human studies and extended the study with lab mice. When SGK1 remained low during pregnancy, mice produced smaller than average litters. Bleeding in the uterus was also noted in some cases. This led researchers to believe that SGK1 levels could be directly responsible for recurrent miscarriages.
The exact reason why low SGK1 levels cause miscarriage are unknown, but researchers believe it has something to do with oxidative stress. SGK1 helps control oxidative stress on the fetus. Without the enzyme, free radicals build up to the point of serious developmental problems and the fetus naturally aborts.
Possible Future Treatment Implications
In the future, doctors may be able to test the uterine lining for SGK1. If levels are too high to promote fertility, the uterus could be washed with an SGK1 blocking solution. The effect would only be temporary, but it could be enough to promote embryo implantation. Furthermore, contraceptives causing increased SGK1 could be used to prevent pregnancy.
Source: Madhuri S Salker, Mark Christian, Jennifer H Steel, Jaya Nautiyal, Stuart Lavery, Geoffrey Trew, Zoe Webster, Marwa Al-Sabbagh, Goverdhan Puchchakayala, Michael Föller, Christian Landles, Andrew M Sharkey, Siobhan Quenby, John D Aplin, Lesley Regan, Florian Lang, Jan J Brosens. Nature Medicine. 17 October, 2011.