Factors associated with immediate abortion complications

To identify factors associated with increased risk of immediate complications from induced abortion.

Retrospective analysis of a provincial database.

All Ontario general hospitals in which abortions are performed and all free-standing abortion clinics in Ontario.

Women in Ontario aged 15 to 44 years who underwent an induced abortion in the province (without concurrent sterilization) between Jan. 1, 1992, and Dec. 31, 1993.

Recording of complications at the time of the procedure, gestational age, type of procedure, place of abortion (hospital or clinic), and patient's age, parity and history of previous abortion (spontaneous or induced).

During the study period 83 469 abortions were performed that met our inclusion criteria. Immediate complications were reported in 571 cases (0.7%). Multivariate logistic regression analysis revealed that, after other variables were controlled for, the patient's age, parity and history of previous abortions (spontaneous or induced) were not significant risk factors for immediate complications; however, gestational age, method of abortion and place of abortion were significant risk factors (p < 0.001). The odds ratio (OR) for having a complication from abortion was 1.3 (95% confidence interval [CI] 1.02 to 1.63) between 9 and 12 weeks, compared with having one after abortion at 9 weeks or earlier, and increased to 3.3 (95% CI 2.23 to 5.00) after abortion between 17 and 20 weeks. Compared with surgical dilatation and curettage (D&C), instillation of saline and instillation of prostaglandins were more likely to be associated with immediate complications (OR 24.0, 95% CI 13.22 to 43.70, and OR 11.7, 95% CI 6.43 to 21.18, respectively), whereas both suction D&C and insertion of a laminaria tent were less likely to be associated with immediate complications (OR 0.4, 95% CI 0.26 to 0.67, and OR 0.3, 95% CI 0.19 to 0.52, respectively). Compared with women who had an abortion in a free-standing clinic, the risk for immediate complications was greater among those who had an abortion in a hospital, especially a teaching hospital (OR 1.9, 95% CI 1.38 to 2.58), a nonteaching hospital with 200 to 399 acute care beds (OR 3.1, 95% CI 2.27 to 4.21) and a nonteaching hospital with fewer than 200 acute care beds (OR 5.9, 95% CI 4.04 to 8.64).

The risk of immediate complications from induced abortion is very low. Unlike in previous studies, the woman's age, parity and history of previous spontaneous or induced abortions were not found to be risk factors. However, advancing gestational age and procedures involving instillation of saline or prostaglandins were predictive factors of immediate complications.