Approximately 1.5% of all infants born in the United States in 2012 were conceived using assisted reproductive technology, predominantly in vitro fertilization, according to a report published Aug. 14 by the Centers for Disease Control and Prevention.

The highest birth rates from ART – 3% or more of all births – were found in Connecticut, Massachusetts, New Jersey, and the District of Columbia. Nearly one in five multiple births (19.6%) resulted from use of ART.

“In most reporting areas, multiples from ART comprised a substantial proportion of all twin, triplet, and higher-order infants born, and the rates of low-birth-weight and preterm infants were disproportionately higher among ART infants than in the birth population overall,” reported Saswati Sunderam, Ph.D., and associates at the CDC’s Division of Reproductive Health at the National Center for Chronic Disease Prevention.

A total of 157,635 ART procedures were performed in 456 U.S. fertility clinics in 2012, resulting in 51,261 live-birth deliveries and 65,151 newborns, according to data from all 50 states plus the District of Columbia and Puerto Rico that were reported to the National ART Surveillance System. The 456 clinics represent 94% of all U.S. fertility clinics. ( MMWR Surveill Summ. 2015 Aug 14;64[Suppl 6]:1-29 ).

Approximately 2,483 women per 1 million women aged 15-44 years used ART in 2012, with the rates more than double this in Massachusetts, New Jersey and the District of Columbia. Six states accounted for half (50.1%) of all ART procedures performed: California, New York, Illinois, Texas, Massachusetts, and New Jersey. These states’ births comprised 48% of all deliveries and 48% of all infants born from ART.

Among patients using fresh embryos from their own eggs, an average of 1.9 embryos were transferred to women under age 35 while an average of 2.2 were transferred for women aged 35-40 years, and an average of 2.7 for women over age 40. Approximately 15% of women nationally used elective single-embryo transfers, ranging from 2.1% of procedures in Oklahoma to 60% of those in Delaware.

Triplets or higher-order multiples conceived from ART represented 30% of all triplet and higher-order births in 2012. Nearly a third of ART-conceived infants (30%) were low birth weight, compared with 8% among all infants, and 6% of infants conceived with ART were very low birth weight, compared with 1.4% of all infants.

Just over a third of ART-conceived infants (35%) were born preterm, compared with 12% in the general population.

Overall, infants conceived with ART comprised 4.6% of all preterm infants, 5.2% of all very-preterm infants, 5.7% of all low-birth-weight infants and 5.8% of all very-low-birth-weight infants.