Problem/Condition: Assisted reproductive technology (ART) includes fertility treatments in which both eggs and sperm are handled in the laboratory (ie, in vitro fertilization and related procedures). Patients who undergo ART procedures are more likely to deliver multiple-birth infants than women who conceive naturally. Multiple births are associated with increased risk for mothers and infants (eg, pregnancy complications, premature delivery, low-birthweight infants, and long-term disability among infants). This report presents the most recent national data and state-specific results.

Reporting Period Covered: 2005.

Description of System: In 1996, CDC initiated data collection regarding ART procedures performed in the United States, as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (FCSRCA)(Public Law 102-493 [October 24, 1992]). Beginning with 2004, CDC has contracted with a statistical survey research organization, Westat, Inc., to obtain data from ART medical centers in the United States. Westat, Inc., maintains CDC's web-based data collection system called the National ART Surveillance System (NASS).

Results: In 2005, a total of 134,260 ART procedures were reported to CDC. These procedures resulted in 38,910 live-birth deliveries and 52,041 infants. Nationwide, 73% of ART procedures used freshly fertilized embryos from the patient's eggs, 15% used thawed embryos from the patient's eggs, 8% used freshly fertilized embryos from donor eggs, and 4% used thawed embryos from donor eggs. Overall, 42% of ART transfer procedures resulted in a pregnancy, and 35% resulted in a live-birth delivery (delivery of one or more live-born infants). The highest live-birth rates were observed among ART procedures that used freshly fertilized embryos from donor eggs (52%). The highest numbers of ART procedures were performed among residents of California (18,655), New York (12,032), Illinois (9,449), New Jersey (9,325), and Massachusetts (8,571). These five states also reported the highest number of live-birth deliveries. Of 52,041 infants born through ART, 49% were born in multiple-birth deliveries. The multiple-birth risk was highest for women who underwent ART transfer procedures that used freshly fertilized embryos from either donor eggs (41%) or their own eggs (32%). Approximately 1% of US infants born in 2005 were conceived through ART. Those infants accounted for 17% of multiple births nationwide. Approximately 9% of ART singletons, 57% of ART twins, and 95% of ART triplets or higher-order multiples were low birthweight. Similarly, 15% of ART singletons, 66% of ART twins, and 97% of ART triplets or higher-order multiples were born preterm.

Interpretation: Whether an ART procedure resulted in a pregnancy and live-birth delivery varied according to different patient and treatment factors. ART poses a major risk for multiple births that are associated with adverse maternal and infant outcomes (eg, preterm delivery, low birthweight, and infant mortality). This risk varied according to the patient's age, the type of ART procedure performed, the number of embryos available for transfer to the uterus, the number actually transferred, and the day of transfer (day 3 or day 5).