Matched Multiple Birth Data Set (MMB)

Topic/focus: Demographics
Year(s): 1989 - 1995, 1995 - 1997, 1995 - 2000
Source: National Center for Health Statistics
Study and sample characteristics: Raw data from vital records
Universe: United States births, infant deaths, and fetal deaths that occurred as part of a twin, triplet, or quadruplet delivery
Variables: Approximately 260
Access: Available via the EDRC
Cost: Check with EDRC Coordinator
Key web links: CDC: National Vital Statistics System
Primary Institutional Contact: EDRC Coordinator (

Summary: The Matched Multiple Birth Data Set contains data on sets of multiple deliveries--specifically, twin, triplet, and quadruplet deliveries--that occurred in the U.S. Sets may be composed of any combination of live births and fetal deaths. Data are derived from the National Center for Health Statistics' Natality, Fetal Death, and Linked Birth/Infant Death databases. Thus, the Matched Multiple Birth Data Set contains information from birth, fetal death, and infant death certificates. Fetal and infant data elements include sex, birth weight, Apgar score, gestational age, set birth order, and gestational age. Age and race variables are available for mothers and fathers; additional maternal demographic and health variables are also available. The database also contains medical encounter data, including place of delivery, type of attendant at delivery, and hospital and patient status at time of death.