by James S » Jun 9, 2006 @ 8:15pm
No, it's 99.9%. Birth Control pills are more effective than a vasectomy on a statistical basis. (i.e. more people have gotten pregnant because their vasectomy was done wrong than people have gotten pregnant when on birth control).
The pill's effectiveness is entirely proportional to how precise she is in taking the pill. If it's a daily pill, did she miss a day or take the pill a couple hours later than she was supposed to. That affects the pill's effectiveness. If it's monthly, did she fudge it by a couple days? If she did it all correctly and took the pill when she was supposed to take it, then the pill is pretty much a guarantee. Just as with the vasectomy, the only time people have become pregnant while on the pill is when the pill was not taken as regularly as it should have been taken.
The pill works by effectively counter-acting progesterone caused to be released by the gonadotropins LH and FSH which are produced by the corpus luteum and the follicle. These hormones are what cause the uterus's endoderm to grow in size in order to accomodate an implanted, fertilized egg. The pill prevents this process so that a fertilized egg cannot implant and become nourished, meaning the fertilized egg dies. If she missed a day taking the monthly pill, enough progesterone could have been released to cause just enough growth to allow an egg to become implanted. That egg then causes the release of more homones to signal that it has successfully docked and it needs more nourishment and a greater vascular network.
Last edited by
James S on Jun 9, 2006 @ 8:27pm, edited 1 time in total.
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Birth control pills; how effective are they?
