Patterns of remission, continuation and incidence of broadly defined eating disorders during early pregnancy in the Norwegian Mother and Child Cohort Study (MoBa).

Background. We explored the course of broadly defined eating disorders during pregnancy in the Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health. Method. A total of 41 157 pregnant women, enrolled at approximately 18 weeks' gestation, had valid data from the Norwegian Medical Birth Registry. We collected questionnaire-based diagnostic information on broadly defined anorexia nervosa (AN), and bulimia nervosa (BN), and eating disorders not otherwise specified (EDNOS). EDNOS subtypes included binge eating disorder (BED) and recurrent self-induced purging in the absence of binge eating (EDNOS-P). We explored rates of remission, continuation and incidence of BN, BED and EDNOS-P during pregnancy. Results. Prepregnancy prevalence estimates were 0.1 % for AN, 0.7 % for BN, 3.5 % for BED and 0.1 % for EDNOS-P. During early pregnancy, estimates were 0.2 % (BN), 4.8 % (BED) and 0.1 % (EDNOS-P). Proportions of individuals remitting during pregnancy were 78 % (EDNOS-P), 40 % (BN purging), 39 % (BED), 34 % (BN any type) and 29 % (BN non-purging type). Additional individuals with BN achieved partial remission. Incident BN and EDNOS-P during pregnancy were rare. For BED, the incidence rate was 1.1 per 1000 person-weeks, equating to 711 new cases of BED during pregnancy. Incident BED was associated with indices of lower socio-economic status. Conclusions. Pregnancy appears to be a catalyst for remission of some eating disorders but also a vulnerability window for the new onset of broadly defined BED, especially in economically disadvantaged individuals. Vigilance by health-care professionals for continuation and emergence of eating disorders in pregnancy is warranted.