Medical Complications

As with any surgical procedure, abortion carries an inherent risk of medical complications, including death. Complications known to be directly related to the procedure include hemorrhage, uterine perforation, cervical injury, and infection, which is often due to incomplete abortion. Later complications that have been investigated include possible negative effects on subsequent pregnancy outcomes, particularly low birthweight, midtrimester spontaneous abortion, and premature delivery. The vast majority of abortions performed in this country are first-trimester vacuum aspiration procedures. Pregnancy outcomes among women who have had one vacuum aspiration abortion are no different than those among women who have not had an abortion. Results are mixed, however, as regards the influence on subsequent pregnancy outcomes of having had more than one abortion or having second-trimester abortions by vacuum extraction. At present, investigators are studying a possible relationship between abortion and an increased risk of developing premenopausal breast cancer (Daling et al., 1994).

Rates of Complications

To assess the frequency with which the well-documented complications of abortion occur, between 1970 and 1978 the Centers for Disease Control and the Population Council conducted the Joint Program for the Study of Abortion in three waves: 1970–1971, 1971–1974, and 1975–1978. These surveys showed that the risk of developing major complications 1 from legal abortion decreased greatly during the 1970s: from 1.0 percent in the first wave to 0.29 percent in the last (Buehler et al., 1985; Cates and Grimes, 1981; Grimes et al., 1977; Tietze and Lewit, 1972). Although the total complication rate2 increased from 9.0 to 14.8 percent over the three waves, this probably reflected an increased follow-up rate, a change in the distribution of firstand second-trimester abortions among the study populations, and an increase in reports of minor complications. Alternatively, the change may have been due to an actual increase in complications. More recent data show a total complication rate of induced abortion of less than 1 percent (Gold, 1990; Hakim-Elahi et al., 1990).


The major complications rate denotes the percentage of women sustaining 1 or more of 15 complications that include cardiac arrest, convulsion, fever for 3 or more days, hemorrhage necessitating blood transfusion, pneumonia, psychiatric hospitalization for 11 or more days, and death.


The total complication rate refers to the percentage of women who sustained one or more complications of any variety or severity.

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