Controversial rhythm method study revealed

The "rhythm method" relies on abstinence during the most fertile period of a woman's menstrual cycle. For women who have regular 28-day cycles, that occurs around days 10 to 17 of the cycle.

It's believed the method works by preventing conception from occurring. But Professor Luc Bovens of the London School of Economics says it may owe much of its success to the fact that embryos conceived on the fringes of the fertile period are less viable than those conceived toward the middle.

Bovens says it can be calculated that two to three embryos will have died every time the rhythm method results in a pregnancy.

Bovens cites anti-abortion rights activists who equate global oral contraceptive use to chemical abortion that is responsible for tens of thousands of deaths of embryos, or unborn children, every year.

But, says Bovens, if all oral contraceptive users converted to the rhythm method, they would be effectively causing the deaths of millions of embryos.

The study appears in the Journal of Medical Ethics.

Copyright 2006 by United Press International