Maternal eating disorders, underweight, obesity linked to offspring psychiatric disorders

Key takeaways:

• Maternal eating disorders, prepregnancy underweight and overweight/obesity were associated with offspring neurodevelopmental and psychiatric disorders.
• Adverse birth outcomes further increased some risks.

Offspring from mothers with an eating disorder history or prepregnancy BMI outside of normal weight range appeared to be at higher risk for neurodevelopmental and psychiatric disorders, according to a study published in JAMA Open Network.

Previous studies have established that disordered eating in mothers may result in nutritional deficiencies that impact offspring mental health, Ida A. K. Nilsson, PhD, associate professor in the department of molecular medicine and surgery at Karolinska Institute in Stockholm, and colleagues wrote.

Noting that additional research is needed on the role of BMI and eating disorder not otherwise specified (EDNOS), the researchers were inspired to perform a population-based cohort study to investigate the association of maternal eating disorders and prepregnancy BMI with nine neurodevelopmental and psychiatric diagnoses in offspring.

Nilsson and colleagues used data from Finnish national registers to assess all live births from 2004 to 2014, identifying 392,098 mothers (mean age, 30.15 ± 5.38 years) and 649,956 offspring (51.14% male).

The researchers created two models to adjust for potential risk factors. Model 1 adjusted for offspring birth year and sex; number of fetuses; parity; and maternal age, country of birth, smoking and socioeconomic status. Model 2 included those factors as well as information on maternal systemic or bowel inflammatory disorder and diabetes.

Overall, 6,273 (1.6%) of the mothers had a history of an eating disorder, 23,114 (5.89%) had prepregnancy underweight and 208,335 (53.13%) mothers had overweight or obesity.

Of the offspring, 106,777 (16.43%) were diagnosed with a neurodevelopmental or psychiatric disorder from birth to age 17 years. These included:

• specific developmental disorders (6.4%);
• anxiety disorder (5.18%);
• ADHD or conduct disorders (4.96%)
• mood disorder (3.02%);
• autism spectrum disorder (1.49%);
• social functioning and tic disorders (1.31%);
• intellectual disabilities (0.87%);
• sleep disorders (0.58%); and
• feeding disturbances in infancy and childhood (0.57%).

The researchers found that maternal eating disorders, prepregnancy underweight and overweight or obesity were associated with most of the studied disorders in offspring in both models.

Specifically, maternal EDNOS showed the largest effect sizes in model 2 for offspring sleep disorders (HR = 3.34; 95% CI, 2.39-4.67) and social functioning and tic disorders (HR = 2.79; 95% CI, 2.21-3.52). Anorexia and bulimia showed similar associations with these offspring outcomes.

The researchers noted that adverse birth outcomes further increased the risks associated with maternal eating disorders. Specifically, the HR was “markedly higher” for feeding disturbances of childhood and infancy (maternal eating disorders, HR = 4.53; 95% CI, 2.97-6.89; anorexia, HR = 4.3; 95% CI, 2.38-7.78; bulimia, HR = 4.46; 96% CI, 2.32-8.58; EDNOS, HR = 4.25; 95% CI, 2.03-8.94). Mothers with adverse birth outcomes and anorexia also had offspring with increased risk for ADHD and conduct disorders (HR = 2.27; 95% CI, 1.74-2.96).

Regarding maternal prepregnancy underweight, the researchers observed associations with smaller effect sizes after adjustment for anxiety (HR = 1.1; 95% CI, 1.04-1.16), intellectual disabilities (HR = 1.33; 95% CI, 1.16-1.51), specific developmental disorders (HR = 1.18; 95% CI, 1.12-124) and social functioning and tic disorders (HR = 1.18; 95% CI, 1.06-1.31).

For maternal pregnancy overweight and obesity in adjusted model 2, the researchers observed associations with most of the offspring diagnoses, with greater effect sizes with increasing BMI. The largest effect sizes occurred for offspring intellectual disabilities (overweight, HR = 1.25; 95% CI, 1.17-1.33; obesity, HR = 1.61; 95% CI, 1.48-1.77; severe obesity, HR = 2.04; 95% CI, 1.83-2.28).

The researchers noted several limitations to this study, including the relatively short follow-up considered that some psychiatric diagnoses have a late onset.

“The findings of this cohort study suggest that offspring born to mothers with eating disorders before or during pregnancy, or who had prepregnancy underweight, overweight or obesity, may be at higher risk of neurodevelopmental and psychiatric disorders, indicating a need to consider these exposures clinically to help prevent offspring mental illness,” Nilsson and colleagues wrote.

Further studies should investigate the underlying biological mechanisms behind these associations, they added.