Major Adverse Perinatal Outcomes Reported in Women with Eating Disorders

Eating disorders affect most women during the peak childbearing years, placing them at increased risk for having low-birth-weight infants and miscarriages, according to the results of a recent study.

Drs. Nadia Micali, Emily Simonoff and Janet Treasure, from King’s College, London, used data from the Avon Longitudinal Study of Parents and Children, a prospective study, which followed all pregnant women living in Avon, UK, during 1991 to 1992, to evaluate the effects of eating disorders on pregnancy and childbirth (Br J Psychiatry 2007; 190:255). Among the 12,254 women who participated in the Avon Longitudinal Study, the team identified 171 with anorexia nervosa (AN), 199 with bulimia nervosa (BN), 82 with AN and BN, 1,116 with other psychiatric disorders, such as severe depression, drug addiction, and substance abuse, and 10, 636 who were classified as the “general population,” and acted as a comparison group.

Lower maternal prenatal BMIs, smoking increased risks

Women in the three eating disorder groups did not differ from the general population sample in parity or employment status, but they were more likely to have smoked during the first trimester of pregnancy; women with other psychiatric disorders were significantly more likely to have smoked during the second trimester and to have drunk alcohol during the first trimester. All four clinical groups were less likely to be living with a partner than were the women in the general population group, and the mean age at delivery was 28 years for all groups.

When Dr. Micali and colleagues compared body mass index (BMI) among all the women and the proportion who reported vomiting and laxative use for weight loss, women in the three eating disorders groups were significantly more likely to have used laxatives and self-induced vomiting to lose weight, and these women also had significantly lower BMIs than did women in the other groups.

As in earlier studies, mean birth weights for infants born to women with a history of AN were significantly lower than for babies of women in the control group; this was also the trend among the babies of women with other psychiatric disorders. The significantly lower birth weights among women with AN were mainly due to the mothers’ lower pre-pregnancy BMIs. These mothers also had higher rates of preterm delivery than did women in all the other groups.

Mothers with BN are at higher risk of miscarriages

Only the women with a history of BN and other psychiatric disorders were significantly more likely to have a history of previous miscarriages (P= 0.01). Women with a history of BN with or without a history of AN also had an increased rate of lifetime miscarriages P<0.05).

The authors noted that two previous studies of clinical samples have shown higher rates of prematurity in babies of women with eating disorders (J Clin Psychiatry 1999; 60:130; Am J Obset Gynecol 1987; 190:206). Recall and sampling differences, as well as the self-report nature of their study, might explain the differences in their results. According to the authors, it is very important for clinicians to advise women with eating disorders to delay becoming pregnant until the disorder is in complete remission. The possible effects of smoking and eating disorders during pregnancy should also be stressed.