Assisted reproductive procedures are more successful than ever, according to a new government report.1 Focusing on fertility clinic success rates in 2002, the Centers for Disease Control and Prevention (CDC) estimates that some 45,000 infants were born in the U.S. using assisted reproductive technologies (ART) in 2002. That's an increase of about 5,000 babies over the 2001 total, according to the government annual report. 2002 is the latest year for which such figures are available.
Making an Informed Decision
The CDC stated: "The goal of this report is to help potential ART users make informed decisions about ART by providing some of the information needed to answer the following questions:
• What are my chances of having a child by using ART?
• Where can I go to get this treatment?"
For the purposes of the report, ART included IVF, in which a woman's eggs are surgically extracted, combined with sperm in a laboratory, and transferring the resulting embryos into the woman's uterus to begin pregnancy; GIFT (gamete intrafallopian transfer), involving the use of a laparoscope to guide the transfer of unfertilized eggs and sperm into a woman's fallopian tubes; and ZIFT (zygote intrafallopian transfer), which involves fertilizing a woman's eggs in a laboratory, then guiding the transfer of the fertilized eggs into her fallopian tubes. The CDC focused on success rates from 391 U.S. fertility clinics involved in more than 115,000 ART cycles.
Fresh Versus Frozen Embryos Used
The government reported that nearly three-quarters of all ART cycles performed in 2002 involved the use of fresh nondonor eggs or embryos. About 14% of the cycles involved frozen nondonor embryos. Less than 1% involved the evaluation of a new treatment procedure, most using preimplantation genetic diagnosis (PGD), a technique in which embryos are genetically tested for potential abnormalities prior to implantation.2
Of the ART cycles cited in the report, 11,307 were discontinued for various reasons, including inadequate egg production, patient withdrawal from treatment, a too-high response to ovarian stimulation medication or patient illness.
'Dramatic' ART Success Rates
The CDC found that more than 34% of treatment cycles performed resulted in a successful pregnancy in 2002. Of those, about 28% resulted in a successful live birth (the rest ended in miscarriage, induced abortion or stillbirth). The government also noted that nearly 35% of all the embryo transfers performed resulted in a live birth. One author of the report called those statistics "dramatic", noting that the ART success rate in 1996 was just 28%.
The CDC also reported that about one-fifth of all ART cycles performed resulted in a successful singleton birth. About 12% of the ART cycles performed resulted in multiple births.
The Impact of Maternal Age
The report also noted that age is still a factor in a woman's attempts to become pregnant using assisted reproduction. "Success rates declined steadily from the mid-30's onward as fertility declined with age," the report noted. Nearly 50 percent of the women in their early to mid 20's who underwent ART became pregnant, compared to about 20 to 25 percent of those in their early 40s, the CDC found.
A woman's age also affects her chances of having a miscarriage, the government agency noted, though the report states that miscarriage risk using ART appears to be similar to that faced by women who conceive naturally, even when age is a factor. According to the report, the odds of having a miscarriage begin to increase in a woman's late 30s.
Which Infertility Cause Had Lower Success Odds?
Infertility diagnoses varied, as well, the CDC found. The majority of patients who underwent ART in 2002 had either female and male factors or a male factor alone, about 13 percent had a tubal factor, approximately 12.5 percent had a female factor, and the next highest percentage of patients (11.1 percent) had an unexplained cause.
Of the diagnoses, those with tubal factor, ovulatory dysfunction, endometriosis, a male factor or unexplained infertility had "above-average success rates." Those who faced the lowest odds of success had diminished ovarian reserve.
Increasing Popularity of ART
Finally, the CDC noted that the use of ART in the United States is steadily increasing. The number of cycles performed jumped 78%, and the number of live-birth deliveries as a result of ART skyrocketed 125% in just 6 years.
"Although ART offers important options for the treatment of infertility, the decision to use ART involves many factors in addition to success rates," the CDC report stated. "Going through repeated ART cycles requires substantial commitments of time, effort, money, and emotional energy. Therefore, consumers should carefully examine all related financial, psychological, and medical issues before beginning treatment."
Of all the pregnancies, nearly two-thirds resulted in a live singleton birth, less than a third of the women who became pregnant had twins, and a small percentage had triplets or higher.
1. Centers for Disease Control and Prevention. 2002 Assisted Reproductive Technology Success Rates. National Summary and Fertility Clinic Reports.
2. Genetics and Public Policy Center. Phoebe R. Berman Bioethics Institute. Johns Hopkins University. Available at: http://www.dnapolicy.org/genetics/pgd.jhtml. Accessed January 11, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include coverage of health news for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
