点击显示 收起
Nov. 16, 1999 (New York) ? Therapy involving a combination of superovulation -- the use of powerful fertility drugs -- and intrauterine insemination (implanting donor semen in the uterus) is at least three times more likely to result in pregnancy compared with intracervical insemination (implanting donor semen in the cervix) alone, New York researchers have found.
For couples whose infertility hasn?t responded to conventional treatment or has no identified cause, the combination approach may be an effective alternative to in vitro fertilization (placing fertilized eggs directly into the uterus), according to David S. Guzick, MD, University of Rochester, Rochester, N.Y., and fellow researchers.
The study, published in a recent issue of The New England Journal of Medicine, involved 932 couples where the women had no identifiable cause of infertility and the men had a sperm count considered adequate. Couples treated with the combination technique were 3.2 times as likely to become pregnant as those where only intracervical insemination was used. The combination technique also was 1.7 times more likely to result in pregnancy compared with intrauterine insemination alone.
Of 186 pregnancies that occurred during the study, 72% resulted in live births, with 24 of the pregnancies being multiple births.
Infertility appears to be a growing problem in the United States. According to the American Society for Reproductive Medicine, an estimated 6.1 million people in the U.S. -- roughly 10% of reproductive-age adults -- are infertile. Among women, the percentage who think they have a fertility problem has increased from approximately 5.7% to 7.7% in the last 10 years.
In an editorial accompanying the study, Dutch researchers question whether infertility rates really are rising or whether patients are making premature assumptions about their fertility status. Egbert R. Te Velde, MD, and Bernard J. Cohlen, MD, of University Hospital in Utrecht, the Netherlands, suggest that couples with perceived infertility may not be counseled properly on their chances of conceiving spontaneously. They also stated that a similar percentage of couples who became pregnant through a combination of intrauterine insemination and superovulation in the New York study probably would have conceived normally by waiting an additional year and having regular intercourse during that time.
But a study co-author says that the average length of infertility among the couples in the study merited trying more aggressive therapy. "One hundred percent had a history of infertility lasting more than one year, or they were not eligible for the study," Sandra Ann Carson, MD, Baylor College of Medicine, Houston, tells WebMD. "The average duration of infertility was 43 months. I don't know how much longer they would have wanted these couples to wait."
Te Velde and Cohlen also point out that the risks of superovulation, particularly the increased rate of multiple pregnancies, should not be overlooked. They suggest that much "milder" treatments should be used to reduce the high proportion of twins and triplets seen in this study.
Carson countered the criticism by noting that the use of fertility drugs always increases the likelihood of multiple births, and that using the combination therapy didn?t further increase the multiple-birth rate. "We had 24 multiple pregnancies, and although that's more than in the natural population, it's certainly not more than what is generally considered the rate of multiples with these drugs," Carson says. "What's important about this study is that we really were able to have a very good success rate with these drugs but keep it safe, and keep the rate of multiples relatively low."
作者： L.A.McKeown 2006-6-27