Weller R H, Hobbs F B
Fam Plann Perspect. 1978 May-Jun;10(3):168-72.
Unwanted U.S. marital fertility was down to just nine percent by 1973. The largest proportion of unwanted births was reported by poor black women--23 percent--but this group registered the steepest decline in unwanted childbearing of all the poverty-status and racial groups studied.
到1973年,美国意外生育的比例降至仅9%。意外生育比例最高的是贫困黑人女性,达23%,但在所有研究的贫困状况和种族群体中,这一群体意外生育的下降幅度最大。