Egg & Sperm - Lock & Key?

I finally opened a twitter account for Fertility Stories (feel free to follow me - http://twitter.com/fertilitystorie) and someone sent me a message asking me if I'd seen this article.

The article mentions Dr. Martin Brinkworth, Dr. David Miller at the University of Leeds and Dr. David Iles (but doesn't mention where -if anywhere- results of the study are being published). It summarizes their findings:

The study researchers have found out a mechanism called lock-and-key mechanism by which reproduction takes place.
In living organisms, sperm and egg cells unite in a distinct way. The sperm cells have keys (genetic signals or codes) and the eggs have locks (genetic signals or codes) and only the most suitable key signal can fit into the lock of an egg.

OK. Sounds interesting, but how does this help, I asked myself... Later in the article comes their explanation:

The scientists could use the newer understanding to develop some test to screen infertile man. This would cut down the failure rate of IVF by 75 percent as filtering out male candidates who can never produce children would become possible.

To this, all I can say is, "Yeah, right". Who's going to take a sperm sample that looks fairly normal and then run it by a lab that stamps a big "FAIL" on the results and decide, "oh, OK, so I'll just never have a biological child"? And what happens if the woman, even just once, got pregnant naturally and, even if it ended in miscarriage, are they really going to accept that his sperm isn't able to fertilize her ova? I just don't believe that a lab test, without ever actually going through the process of IVF is going to convince the average couple...

Now, if these guys could find a way to fix the 'key' mechanism, I'd be the first to say they were on to something...

I did hate those IUIs

Forbes published a story a few days ago about a study that tested results of couples who went through either three or six IUI cycles before moving on to IVF. I looked for the original article, which they said was published by Fertility and Sterility, but I wasn't able to find it in their list of articles.

According to the Forbes article, the couples were divided into two groups of 256 (3-cycle program) and 247 (6-cycle program). Couples from both groups who had not yet achieved pregnancy went on to up to six cycles of IVF.

The results were surprising - the average time to pregnancy in the 3-cycle group was eight months whereas it was eleven months in the 6-cycle group. In addition, the couples in the 3-cycle group saved on average over $2600. They explained part of this savings by the fact that more women from the 3-cycle group had singleton births (and births of multiples are more expensive). Overall, 67% of the couples in the 3-cycle group and 61% of the couples in the 6-cycle group ended the study with a baby.

I would be interested to hear why the researchers think that the success rate in the 3-cycle group was higher (if it is statistically significant) - does it have to do with being run down? Do the IUI cycles have a long-term negative effect on the uterine lining?