麻豆传媒

SAN FRANCISCO -- A survey of more than 2,000 couples seen at U.S. fertility clinics showed that three-fourths of the men had not undergone a fertility workup, even though male infertility contributes to half of all infertility cases.

In the subgroup of 1,537 couples without a workup of the male partner, 17% had a history of assisted reproduction procedures, including intrauterine insemination (IUI) and in vitro fertilization (IVF).

Lifestyle factors play a major role in male infertility, and addressing those factors could restore a man's fertility, allowing many couples to avoid costly procedures that might be doomed to failure from the beginning, andrology specialists said here at the meeting. Use of testosterone supplements and topical finasteride (Propecia) are among major contributors to the problem.

"Many infertile couples in North America are being treated with IUI or IVF prior to a male factor infertility investigation," said Keith Jarvi, MD, of the University of Toronto. "Testosterone is being used very widely ... but the downside of testosterone is that it can make almost all men infertile. Among couples coming to U.S. fertility clinics, 5% of the men were on testosterone. They knew they were infertile but the men were still on testosterone. That tells me there is a lot of misinformation out there."

"I don't think that the guys don't care," he added. "I think a lot of them just don't know... . There were even men going through IUI and IVF who were on testosterone. That highlights that we have fairly easy misses, but if you don't [work up the men] you'll miss it."

Jarvi summarized findings from a survey of 4,335 couples (mean age 37 for men, 34 for women) seen at 23 fertility centers in Canada (N=2,264) and the U.S. N=2,071), who are members of the Andrology Research Consortium. Jarvi focused on what he called "the growing problem of male infertility." Once thought to be considerably less common than female infertility, male infertility accounts directly for about 30% of all infertility cases and either directly or indirectly to half of all cases.

Two key approaches to assisted reproduction, IUI and IVF, are essentially treating the sperm without treating the men, Jarvi continued. The practice has major economic implications, as infertile couples worldwide undergo about 1 million cycles of IUI or IVF each year (about one-fourth in North America), at a cost exceeding $12,000 per cycle.

"The demand for IVF has skyrocketed in the past 20 years, but the per-cycle pregnancy rate has not -- why?" Jarvi asked.

The survey provided some insights to the question. The data showed a 4.9% prevalence of testosterone use among men seen at the U.S. centers but only 0.8% of those in Toronto. The 4.9% represented an average; testosterone use ranged as high as 10% at some clinics. Similarly, 4.2% of the U.S. men reported using Propecia, which is associated with reduced sperm count, compared with 0.1% of the men from Toronto.

Why the disparity? Jarvi said he didn't know for sure but pointed out that direct-to-consumer advertising of prescription drugs is allowed in the U.S. but not in Canada.

The survey identified other potential lifestyle contributors to male infertility:

• Smoking: 470 of 4,335
• Marijuana use: 411
• Alcohol consumption: 280
• Cocaine use: 85

Additionally, 387 men had undergone vasectomy.

"This highlights that maybe patients don't understand the risks," said Jarvi. "I don't think physicians even understand the risks, but patients certainly don't."

Most fertility clinics do not have a urologist or male health specialist, said Ajay Nangia, MD, of the University of Kansas in Kansas City.

"A couple walks into a gynecologist's office, and primary care physician has done a semen analysis showing a low sperm count. The gynecologist says 'Oh, you need IVF.' Brief history of the man; no exam; no clinical understanding of the medication issues. Then they have an IVF. When all it could have taken for a person on testosterone was stopping it. Gynecologists are getting better at recognizing it and not forcing everyone to IVF, but it must take the equal evaluation of the male and an understanding by a urologist or male health provider that there is a problem with the medication."

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