Amenorrhea Notwithstanding, Women with Anorexia Nervosa Are at Risk for Unplanned Pregnancy

As many as 9 in 10 women with anorexia nervosa have amenorrhea. To assess rates of unplanned pregnancy among women with recent histories of anorexia, researchers analyzed data from 62,060 enrollees in a prospective pregnancy cohort study in Norway. Questionnaires were completed during pregnancy (median, 18.6 weeks’ gestation) and included questions about eating disorders and behaviors, whether pregnancies were planned, occurrence of amenorrhea during the year before pregnancy, and histories of induced abortions.

A total of 62 women (0.1%) had anorexia nervosa within 6 months before pregnancy. Women with anorexia were younger at pregnancy than those without eating disorders (mean age, 26.2 vs. 29.9). Half of women with anorexia reported that their pregnancies were unplanned, compared with only 19% of nonanorectic women. After adjustment for age and infertility treatment, risk for unplanned pregnancy was substantially higher in women with anorexia than in women without anorexia (relative risk, 2.1; 95% confidence interval, 1.6–2.7). However, amenorrhea was not significantly associated with unplanned pregnancy in either group. More women with anorexia than those without eating disorders reported having undergone at least one induced abortion (24% vs. 15%; P=0.03).

Comment: These authors hypothesize that amenorrhea associated with anorexia nervosa might give anorectic women a false sense that they are unlikely to become pregnant. Although self-reported amenorrhea during the year before pregnancy did not raise risk for unplanned pregnancy in this cohort, other factors that were not examined fully here (e.g., use of contraception) might influence unplanned pregnancy rates in anorectic women. Women with anorexia might avoid use of oral contraceptives out of concern that the pill will cause weight gain. In any case, these findings indicate that women with anorexia are at higher risk for unplanned pregnancy (as well as for elective abortion) than women without eating disorders. Clinicians should counsel women with anorexia that they are at risk for unplanned pregnancy and should encourage consistent contraceptive use.