reproduction: frozen sperm works as well as fresh in IVF

Researchers have long been concerned that using frozen sperm instead of fresh to create test-tube babies might reduce the chances of a successful pregnancy for an infertile couple. But a Mayo Clinic study presented last week at the annual meeting of the American Urological Association reveals that frozen sperm is just as effective for in vitro fertilization, or IVF, where sperm is allowed to fertilize an egg in a lab dish, and the resulting embryo is implanted within a woman’s uterus. After reviewing 10 years of data collected at the Mayo Clinic and comparing birth rates from IVF attempts, researchers found that the likelihood of a successful pregnancy was the same, whether the sperm used was fresh or frozen. Though the clinic’s doctors still prefer to use fresh sperm, since freezing and thawing reduces sperm number and motility, couples can now rest easily, knowing they’re not jeopardizing their chances of pregnancy if fresh is not available. “The in vitro process is long and can be difficult — emotionally, physically and financially. These results make the process just a little bit easier,” the study’s senior author, Alan Thornhill, director of the clinic’s IVF lab, stated in a press release.

This news brief appeared in the Discoveries column of the Boston Globe’s Health/Science section on 5/18/2004.