* Number of ART cycles and transfers in 2002: 912 (Nearly all ART cycles use IVF. If a patient uses donor eggs or frozen embryos, the CDC labels the procedure a transfer rather than a cycle.)
* Percentage of ART cycles from non-donor fresh embryos resulting in live births in 2002: 60% (under age 35), 51% (ages 35-37), 44% (ages 38-40), 23% (ages 41-42)
* Boasts 2002 IVF success rates that are twice the national average for women ages 38 to 42 who are using their own eggs
* Is researching ways to improve the chance of pregnancy for patients with endometriosis or polycystic ovarian syndrome
* Attracts 40% of its patients from outside the Colorado area
For most women trying IVF, physicians return two to seven fertilized eggs, called embryos, hoping one will implant. But about 30% of women who become pregnant are carrying twins, and 7% are expecting triplets or more. "Twin pregnancies are at a three- to five-fold greater risk for pregnancy complications and perinatal mortality [death between 28 weeks gestation and a week after delivery] compared to carrying one fetus. With triplets, there's at least a seven-fold greater risk," says Eric Surrey, M.D., medical director of the Colorado Center for Reproductive Medicine (CCRM) and president of the Society for Assisted Reproductive Technology, a top group in the field.
Dr. Surrey's team recruited patients, 48 in two years, between ages 26 and 48 to study the feasibility of returning just one embryo. "This is common in some Western European countries, but the success rate is about 30% to 35%," says Dr. Surrey. "We wanted to see if we could improve on those rates."
Earlier work at CCRM paved the way for embryos, which used to be returned three days after fertilization, to develop into blastocysts, a process that takes about two more days. Waiting longer gives doctors a better idea of the embryos' quality and helps them decide which one has the best chance of survival.
Half the women in the study received one embryo, and the remainder got two. All were given the option of freezing leftover embryos for use at another time. In the group receiving a single embryo, 61% had a clinical pregnancy (a heartbeat shown on ultrasound) and there were no twins. By comparison, the ongoing pregnancy rate in the group receiving a pair of embryos was 76%, but nearly half the pregnancies resulted in twins. "The slightly lower chance for pregnancy in the single-embryo group outweighs the significant risks associated with multiples," says Dr. Surrey. "Larger trials will more carefully define just who the ideal candidates for this approach will be."
Current Rank: 1.00
Votes: 1
+Search The Web
More: