Tietze C, Bongaarts J
Stud Fam Plann. 1982 Dec;13(12 Pt 1):373-9, 384.
The increasing numbers and proportions of repeat abortions in the United States, including higher order repeat abortions, can be adequately explained by the increasing numbers of women at risk and the heterogeneity of the population in regard to the need for and utilization of abortion services. The same factors, rather than a deterioration of contraceptive practice following abortion, explain the higher levels of repeat abortion rates compared with first abortion rates.
美国重复堕胎（包括多次重复堕胎）的数量和比例不断增加，这可以通过面临风险的女性数量增加以及在堕胎服务需求和利用方面人口的异质性得到充分解释。同样的因素，而非堕胎后避孕措施的恶化，解释了重复堕胎率高于首次堕胎率的原因。
