Assisted Reproductive Technology Surveillance - United States, 2015.

PROBLEM/CONDITION: Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Although the majority of infants conceived through ART are singletons, women who undergo ART procedures are more likely than women who conceive naturally to deliver multiple-birth infants. Multiple births pose substantial risks for both mothers and infants, including obstetric complications, preterm delivery ( 37 years). Among women aged <35 years, the national elective single-embryo transfer (eSET) rate was 34.7% (range: 11.3% in Puerto Rico to 88.1% in Delaware). In 2015, ART contributed to 1.7% of all infants born in the United States (range: 0.3% in Puerto Rico to 4.5% in Massachusetts). ART also contributed to 17.0% of all multiple-birth infants, 16.8% of all twin infants, and 22.2% of all triplets and higher-order infants. The percentage of multiple-birth infants was higher among infants conceived with ART (35.3%) than among all infants born in the total birth population (3.4%). Approximately 34.0% of ART-conceived infants were twins and 1.0% were triplets and higher-order infants. Nationally, infants conceived with ART contributed to 5.1% of all low birthweight infants. Among ART-conceived infants, 25.5% had low birthweight, compared with 8.1% among all infants. ART-conceived infants contributed to 5.3% of all preterm (gestational age <37 weeks) infants. The percentage of preterm births was higher among infants conceived with ART (31.2%) than among all infants born in the total birth population (9.7%). Among singletons, the percentage of ART-conceived infants who had low birthweight was 8.7% compared with 6.4% among all infants born. The percentage of ART-conceived infants who were born preterm was 13.4% among singletons compared with 7.9% among all infants. INTERPRETATION: Multiple births from ART contributed to a substantial proportion of all twins, triplets, and higher-order infants born in the United States. For women aged <35 years, who are typically considered good candidates for eSET, the national average of 1.6 embryos was transferred per ART procedure. Of the four states (Illinois, Massachusetts, New Jersey, and Rhode Island) with comprehensive mandated health insurance coverage for ART procedures (i.e., coverage for at least four cycles of IVF), three (Illinois, Massachusetts, and New Jersey) had rates of ART use exceeding 1.5 times the national rate. This type of mandated insurance coverage has been associated with greater use of ART and likely accounts for some of the difference in per capita ART use observed among states. PUBLIC HEALTH ACTION: Twins account for the majority of ART-conceived multiple births. Reducing the number of embryos transferred and increasing use of eSET when clinically appropriate could help reduce multiple births and related adverse health consequences for both mothers and infants. State-based surveillance of ART might be useful for monitoring and evaluating maternal and infant health outcomes of ART in states with high ART use.