Researchers in a large network funded by the National Institute of Child Health and Human Development (NICHD) have determined the most effective of a series of common infertility treatments. The study appears in the January 21 issue of The New England Journal of Medicine.
Briefly, the authors found that, for certain kinds of infertility, artificially inducing a woman to ovulate and artificially inseminating her by depositing her partner's sperm directly into the uterus resulted in more pregnancies than did several similar techniques.
"The demand for effective infertility treatments is high and this frequently leads to use of therapies that haven't been tested by clinical trials," said NICHD Director Duane Alexander. "This rigorous evaluation--perhaps the most comprehensive of its kind--will provide invaluable information for those who need it most."
The research team was composed of scientists in NICHD's National Cooperative Reproductive Medicine Network, and the study's first author was David S. Guzick, MD, PhD,of the University of Rochester, in Rochester, New York.
In all, the investigators tested 932 couples with infertility in which the woman appeared to ovulate normally, including what is known as unexplained infertility as well as less severe forms of male factor infertility. Couples who have this condition are unable to conceive a child, despite the fact that the woman appears normal and her male partner produces at least some sperm, explained Dr. Donna Vogel, Associate Chief for Clinical Research of NICHD's Reproductive Sciences Branch and a coauthor of the study.
The couples who took part in the study were assigned to one of four groups. In the control group, the women did not receive any drugs to induce ovulation, and were inseminated in the cervix (intracervical insemination). Insemination took place when the women's urinary levels of luteinizing hormone (LH) peaked. A surge in (LH) indicates that ovulation is taking place.
In the second group, the women did not receive any drugs to induce ovulation but were inseminated in the uterus with their partner's sperm (intrauterine insemination) when their urinary levels of luteinizing hormone peaked.
The third group of women received injections of follicle stimulating hormone (FSH) to induce them to ovulate, and then received intracervical insemination. The fourth group received FSH injections and intrauterine insemination.
The 231 women in the group receiving FSH injections and intrauterine insemination had the highest rate of pregnancy, at 33 percent. In comparison, the 234 couples receiving induced ovulation and intracervical insemination had a pregnancy rate of 19 percent, the 234 women receiving intrauterine insemination timed to coincide with a surge in LH had a pregnancy rate of 18 percent, and the 233 women receiving intracervical insemination timed to a surge in LH had a pregnancy rate of 10 percent.
"Clearly, treatment with induced ovulation and intrauterine insemination is more effective in this population than any of the other methods we tested," Dr. Vogel said. "This information is particularly important in view of the high costs of the procedures involved-- induced ovulation, for example averages about $1,300 per cycle."
Dr. Vogel noted, however, that these procedures are considerably less expensive than many other infertility treatments.
Dr. Vogel added that pregnancy rates in each of the four groups were not affected by the women's age or the man's age. However, pregnancy rates declined with longer durations of infertility: the pregnancy rate was 28 percent, for couples who had previously experienced 12 to 23 months of infertility; 20 percent with 24 to 35 months of infertility; and 17 percent, with 36 months of infertility.
Dr. Vogel cautioned that any couple considering the infertility treatments mentioned above should be advised of the risks involved. From one to two percent of women receiving superovulation--the treatment used to induce ovulation--may require hospitalization for ovarian hyperstimulation. This condition may result in extreme swelling of the ovaries, accumulation of fluid in the abdomen and lungs, as well low blood pressure and a high pulse rate. Superovulation may also lead to the release of large numbers of eggs, which could lead to a multiple pregnancy. In this study, the researchers took precautions against a large number of conceptions. For example, they did not inseminate the women when the ovaries appeared to contain a large number of eggs. In all, 6 of the women undergoing superovulation were hospitalized due to ovarian hyperstimulation, 3 of whom were pregnant. Other researchers are looking at whether or not superovulation may increase the risk of ovarian cancer.
Of the pregnancies that resulted in the study, there were three quadruplet pregnancies, one in the superovulation and intracervical insemination group, and two in the superovulation and intrauterine insemination group. Similarly, there was one triplet pregnancy in the superovulation/ intracervical insemination group, and three triplet pregnancies in the superovulation/intrauterine insemination group. Of the 18 sets of twins, 17 were in the superovulation groups.
"We conclude that for infertile couples in which the woman has no identifiable infertility factor and the man has motile sperm, the combination of superovulation and intrauterine insemination is an effective means of achieving pregnancy," the study's authors wrote.
The authors concluded that physicians devising treatment for their infertile patients should consider the costs of the various procedures, the women's age, the results of semen analysis and weigh them against the incidence of ovarian hyperstimulation and the likelihood of multiple pregnancy.
"We recommend that couples be informed of all their options, be given realistic information about the chances of success as well as the costs and complications, and be involved in the final decisions," they wrote.