Steroids bring the endometrium (lining of the womb) to a receptive state for 4-5 days each cycle, so it will allow embryos to attach. However the exact mechanism by which they do this is still unclear.
“We have identified one of the key signal transduction pathways required to bring the endometrium to a receptive state. A molecule called LIF, is secreted in response to steroids and it signals to the epithelial cells lining the womb to become receptive to the embryo. This was known before. What is new is that we have shown that when LIF binds its receptor, out of all the signalling molecules that it activates only one – called STAT3 – is essential for activating receptivity. If STAT3 signalling is blocked, embryos will not implant- hence the contraceptive effect,” said Dr Andrew Sharkey, Principal Investigator of the study.
This finding provides a new target for contraception development that is not a steroid, side effects of which can include increased risk of blood clots, breast cancer and increased blood pressure, necessitating careful monitoring of users.
Although this is a preliminary research finding based on a non-human model, the findings provide important insight in terms of understanding contraception as well as infertility. There is good evidence that LIF signalling is also important in implantation in humans.
“STAT3 is involved in tumours and diabetes and there is a very active research area in developing antagonists to STAT3 by drug companies. This new finding suggests that an unforeseen effect of these drugs may be on implantation. Conversely these compounds may be effective at preventing implantation in humans if appropriate dose and delivery systems can be devised to target the uterus, such as gels,” said Dr Sharkey.
In addition to the potential contraceptive effects, the researchers are also investigating whether deficiencies in STAT3 signalling are responsible for certain types of infertility. They believe that it may be possible to treat certain types of infertility by activating STAT3 signalling.
This research was funded by the World Health Organisation special program to identify novel targets for contraception development.
SOURCE: AlphaGalileo Press Release
I can see anti-abortion groups calling this an abortion method. As described, it indeed does that, depending on the definition one handles of the start of human life (I say it’s when the DNA of the spermatozoid and the egg fuse, you say it’s when the embryo forms, he says it’s when the heart begins pumping, she says it’s when the brain activity starts, it says it’s when the baby is born).
I don’t want to turn this into a abortion flame war (we got enough of that in Usenet), but it does sound like a novel abortion method indeed (in my book, the first definition above is the one that counts).
Just a thought – isn’t the “coil” (IUD, intrauterine device) a physical method that prevents implantation too? Does that make the coil a method of regular abortion, if it does, then this novel chemical approach would fit in the same ethical position presumably. Like I say just a thought, not flame kindling.