Problem/condition: In 1996, CDC initiated data collection regarding assisted reproductive technology (ART) procedures performed in the United States, as mandated by the Fertility Clinic Success Rate and Certification Act (FCSRCA) (Public Law 102-493, October 24, 1992). ART includes fertility treatments in which both eggs and sperm are handled in the laboratory (i.e., in vitro fertilization and related procedures). Patients who undergo ART treatments are more likely to deliver multiple-birth infants than women who conceive naturally. Multiple births are associated with increased risk for mothers and infants (e.g., pregnancy complications, premature delivery, low-birthweight infants, and long-term disability among infants).
Reporting period covered: 2003.
Description of system: CDC contracted with the Society for Assisted Reproductive Technology (SART) to obtain data from ART medical centers located in the United States. Since 1997, CDC has compiled data related to ART procedures.
Results: In 2003, a total of 122,872 ART procedures were reported to CDC. These procedures resulted in 35,785 live-birth deliveries and 48,756 infants. Nationwide, 74% of ART procedures used freshly fertilized embryos from the patient's eggs; 14% 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 using freshly fertilized embryos from donor eggs (51%). The highest numbers of ART procedures were performed among residents of California (15,911), New York (15,534), Massachusetts (8,813), Illinois (8,676), and New Jersey (8,299). These five states also reported the highest number of infants conceived through ART. Of 48,756 infants born through ART, 51% were born in multiple-birth deliveries. The multiple-birth risk was highest for women who underwent ART transfer procedures using freshly fertilized embryos from either donor eggs (40%) or their own eggs (34%). Number of embryos transferred, embryo availability (an indicator of embryo quality), and patient's age were also strong predictors of multiple-birth risk. Approximately 1% of U.S. infants born in 2003 were conceived through ART. Those infants accounted for 18% of multiple births nationwide. The percentage of ART infants who were low birthweight ranged from 9% among singletons to 94% among triplets or higher order multiples. The percentage of ART infants born preterm ranged from 15% among singletons to 97% among triplets or higher order multiples.
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. This risk varied according to the patient's age, the type of ART procedure performed, the number of embryos transferred, and embryo availability (an indicator of embryo quality).
Public health actions: ART-related multiple births represent a sizable proportion of all multiple births nationwide and in selected states. Efforts should be made to limit the number of embryos transferred for patients undergoing ART. In addition, adverse infant health outcomes (e.g., low birthweight and preterm delivery) should be considered when assessing the efficacy and safety of ART.