The younger a woman is, the more likely she will be successful giving birth to a child using in vitro fertilization (search) (IVF).

Centers for Disease Control (search) researchers found women in their 20s and early 30s had the most success in getting pregnant and having a child using assisted reproductive technologies, such as in vitro fertilization.

Assisted reproductive technology (search) (ART) includes all forms of infertility treatment in which both the egg and sperm are handled in a laboratory. Most assisted reproductive technology procedures involve in vitro fertilization in which the egg and sperm are fertilized in a laboratory and then fertilized eggs are inserted into a woman’s uterus.

“Women in their 20s and early 30s who used ART had the most success with pregnancies, and single live births. However, success rates declined steadily once a woman reached her mid-30s,” says researcher Victoria Wright, a public health analyst at the CDC, in a news release. “This is a reminder that age remains a primary factor with respect to pregnancy success and younger women have greater success than older women, even with technology.”

Age Major Factor in Infertility Treatment Success

In their report, CDC researchers analyzed information on assisted reproductive technology success rates in 2002 from 391 fertility clinics throughout the U.S.

They found 37 percent of women under age 35 who used their own eggs successfully got pregnant and gave birth to a child. But the percentage of births decreased to 31 percent among women aged 35-37, 21 percent among women aged 38-40, 11 percent among women aged 41-42, and 4 percent among women over age 42.

The report also shows that more than 45,000 babies were born in the U.S. with the help of in vitro fertilization and other forms of assisted productive technology, which is an increase from the 40,687 babies in 2001.

There were also more ART procedures performed in 2002: 115,392 compared with 107,587 in 2001.

Overall the report showed that 28.3 percent of in vitro fertilization and other ART procedures resulted in the birth of a baby for women who used their own freshly fertilized eggs. That represents a slight increase in success rates compared with 2001 (27 percent).

More than a third (35 percent) of the deliveries among women who used their own eggs were multiple births (twins or more) compared with 3 percent among the general population during 2002.

“For many people, the goal of having a baby is difficult to attain,” says Wright. “Our report can help those considering ART to make informed decisions by providing them with detailed information about fertility clinics in their own state.”

But Wright says people should be cautious in comparing the success rates at various fertility clinics if they’re considering in vitro fertilization because the clinic’s skill is only one factor affecting a woman’s chances of becoming pregnant. Also important is the cause of a woman’s infertility and her age.

By Jennifer Warner, reviewed by Michael W. Smith, MD

SOURCES: CDC, 2002 Assisted Reproductive Technology Success Rates. News release, CDC.