It's not the norm, but more than one dismayed woman has found herself pregnant after her man has been declared infertile. At this point of course, she may safely assume that her man is in fact not sterile. To understand how this can happen, one needs to know a little bit about male infertility.
Identification
Infertility is diagnosed in a man when sperm count is below 20 million per milliliter of semen, or when poor motility or sperm shape is not conducive to egg fertilization. The possible causes of male infertility are numerous, including surgical sterilization, hormone imbalance, defects in the reproductive tract or abnormalities in sperm production.
Misconceptions
A diagnosis of infertility in a man does not necessarily mean that he cannot impregnate a woman. Rather, it means that conception is very unlikely. The difference between unlikely and impossible has confused countless couples who assumed they could not conceive. For a couple wishing to avoid pregnancy, it's important to understand whether the man has no sperm, just a few sperm or sperm of low quality, and whether the condition is permanent.
Prevention/Solution
Plenty of men deliberately render themselves infertile by undergoing surgical sterilization, or vasectomy. During a vasectomy the vas deferens--the tubes between the testicles and the urethra--are clamped or severed so that sperm cannot exit the body. Vasectomy is 99 percent reliable as a method of contraception. However, that leaves a 1 percent pregnancy rate to be explained.
Considerations
While most post-vasectomy babies turn out to have been conceived shortly before the vasectomy, actual vasectomy failures do happen. Instances of postoperative regrowth of the vas deferens have been reported, as has the formation of auxiliary sperm pathways. On rare occasions, a man will have an extra vas deferens that is overlooked during surgery. More commonly, pregnancy results from residual sperm in the semen of the post-operative vasectomy patient.
Time Frame
Vasectomy patients are routinely informed that they cannot be assured of infertility until the absence of sperm is verified by an examination of a semen specimen. Typically a couple is advised to use other contraception for 10 to 20 weeks, at which point the man's sperm count is checked. Sperm count is usually checked again after a year.
Tags: have been, male infertility, sperm count, surgical sterilization