MMWR Morb Mortal Wkly Rep. 1997 Feb 14;46(6):121-5.
During 1980-1994, the number of twin births in the United States increased by 42%, from 68,339 to 97,064, and the twin birth rate (i.e., the number of twin births to total live births) increased 30%, from 18.9 to 24.6 per 1000 live births. These increases are important because the risks for preterm birth, low birthweight (LBW), long-term disability, and early death are greater for twins than for singletons (1; CDC, unpublished data, 1991). to estimate state-specific rates of twin births, CDC analyzed data from the U.S. certificates of birth for 1992-1994. This report presents the findings of this analysis of these data, which indicate that state-specific rates of twin births varied substantially, and the variations reflect factors other than state-specific differences in maternal age distributions.
1980年至1994年期间，美国双胞胎出生数量增加了42%，从68339例增至97064例，双胞胎出生率（即双胞胎出生数与总活产数之比）增加了30%，从每1000例活产中的18.9例增至24.6例。这些增长很重要，因为双胞胎早产、低出生体重、长期残疾和早夭的风险高于单胎（1；疾病控制和预防中心，未发表数据，1991年）。为了估算各州的双胞胎出生率，疾病控制和预防中心分析了1992年至1994年美国出生证明的数据。本报告展示了对这些数据的分析结果，结果表明各州的双胞胎出生率差异很大，且这些差异反映的因素并非各州产妇年龄分布的差异。
