Decision-making for termination of pregnancies with fetal anomalies: analysis of 53,000 pregnancies

OBJECTIVE: To evaluate the degree to which prenatal knowledge of fetal anomalies and sociodemographic characteristics determined outcome of 53,000 pregnancies. METHODS: Pregnancies were consecutively evaluated at a university hospital between 1984 and 1997. The severity of anomalies was graded by using an ordinal scale, in which 0 was no anomalies, 1 was no impact on quality of life, 2 was little impact but possibly requiring medical therapy, 3 was serious impact on quality of life even with optimal medical therapy, and 4 was incompatible with life. RESULTS: The abortion rates for grades 1 and 3 anomalies increased from 0.9% to 72.5%, and 0.9% to 37.1% for central nervous system and non‐ central nervous system anomalies, respectively (P < .001). Multiple logistic regression showed that mothers without a high school education were more likely than those who completed high school to abort a normal pregnancy (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.07, 2.45). In the 452 pregnancies in which there was one grade 3 anomaly, logistic regression also showed that the abortion rate decreased by 6% per year as maternal age decreased (OR 0.94, 95% CI 0.91, 0.97). CONCLUSIONS: The severity of anomalies directly correlates with abortion rates, but at similar degrees of severity, central nervous system anomalies are more likely to lead to abortion. Maternal level of education inversely correlates with likelihood of termination of a normal pregnancy, whereas maternal age directly correlates with pregnancy termination when serious anomalies are present. Serious congenital anomalies may disproportionately affect children from families with the youngest mothers because these mothers are likely to continue these pregnancies. (Obstet Gynecol 2002;99:216 ‐22. © 2002 by the American College of Obstetricians and Gynecologists.) Technical advances and legislative changes have altered many aspects of reproductive behavior in the last quarter of the 20th century. In the United States and Canada, elective termination of pregnancy has been available for more than 25 years, and routine sonography has enabled physicians to identify numerous fetal anomalies relatively early in pregnancy. Although the results of sonography may be expected to affect the decision to terminate an individual pregnancy, there have been few systematic investigations of the multiple variables that influence the probability of therapeutic abortion when a fetal anomaly is identified in the mid-trimester of pregnancy. Pryde et al reported that the severity of sonographic anomalies identified in the central nervous system and other organs correlated with the decision to terminate a pregnancy. 1 In a study restricted to neural tube defects, Grevengood et al found that the spinal level of the defect influenced the decision to have a therapeutic abortion. 2 Neither of these studies estimated the contribution of sociodemographic factors in determining pregnancy outcome. More recently, Velie and Shaw showed that the likelihood of elective termination of pregnancy for neural tube defects was directly correlated with white race, educational level, and household income, although they could only identify pregnancy outcomes, not whether decisions to terminate had been based on results of sonography. 3 In the course of a more limited study of pregnancy outcomes, we became interested in the relationship between prenatal discovery of a fetal anomaly and the decision to electively abort a pregnancy. We used a large existing prenatal diagnosis database to retrospectively investigate factors that influence outcome decisions when ultrasound evidence indicates a congenital anomaly. We decided to test three hypotheses. First, there is a correlation between the severity of individual fetal anomalies as estimated by genetic specialists and the frequency of therapeutic abortion in our database. Second, the likelihood of therapeutic abortion differs depending on the presence of central nervous system anomalies or anomalies of other organ systems. Finally, sociodemographic factors that influence the probability of therapeutic abortion can be isolated once an anomaly has been diagnosed by sonography.