Examining the effect of eating disorders in pregnancy on neurodevelopmental risk in infants

Eating disorders are a difficult behavioral condition to treat and relapse is not rare. Some experiences can make relapse more likely, such as pregnancy when weight gain or loss become a part of the discussion at every doctor’s visit. Understanding the impact of a history of an eating disorder or even an active one on risk of suboptimal outcomes in the offspring is important and a new report looked into whether eating disorders during pregnancy lead to an increased risk of developing neuropsychiatric diseases.¹

The investigators used the Swedish Medical Birth Registry for a population-based prospective cohort study. They identified singleton births that had been registered between January 1990 and December 2012. Children who were delivered to mothers with a diagnosis of an eating disorder were matched with children who had mothers with no eating disorder diagnoses. Every child was followed up from his or her first birthday for autism spectrum disorder and from his or her third birthday for attention-deficit/hyperactivity disorder.

A total of 52,878 children were included in the study. The investigators found that maternal eating disorder exposure (n = 8813) was linked to an increased risk of attention-deficit/hyperactivity disorder ADHD (hazard ratio [HR] for anorexia nervosa, 1.42 [95% CI, 1.23-1.63]; HR for bulimia nervosa, 1.91 [95% CI, 1.43-2.54]; and HR for unspecified eating disorder, 2.00 [95% CI, 1.72-2.32]) as well as autism spectrum disorder (HR for anorexia nervosa, 2.04 [95% CI, 1.58-2.63]; HR for bulimia nervosa, 2.70 [95% CI, 1.68-4.32]; and HR for unspecified eating disorder, 1.95 [95% CI, 1.49-2.54]). Following adjustment for parental confounders, they found that the risk of attention-deficit/hyperactivity disorder was still significantly increased, but the risk of autism spectrum disorder in children born to mothers with bulimia nervosa was found to be no longer significant. They also found that ongoing cases of anorexia nervosa was tied to higher risks for attention-deficit/hyperactivity disorder (HR, 2.52 [95% CI, 1.86-3.42]) and autism spectrum disorder (HR, 3.98 [95% CI, 2.49-6.27]) when compared to a history of disease (HRs, 1.26 [95% CI, 1.06-1.48] and 1.81 [95% CI, 1.38-2.38], respectively).

The investigators concluded that the children of mothers with eating disorders and in particular those that experienced an eating disorder during pregnancy are at an increased risk of either attention-deficit/hyperactivity disorder and autism spectrum disorder.

Commentary from Editorial Advisory Board member Harlan Gephart, MD

I would like to additional thoughts and observations regarding this study, from a clinician’s point of view:

1. Duration of the Study: 1990 through 2017. This covers the period of the Diagnostic & Statistical Manual of Mental Disorders, 3rd edition (DSM-III-R_, when attention-deficit/hyperactivity disorder (ADHD) was first described by a list of 14 traits listed by parents, to DSM-IV, when ADHD symptoms had to be noted before age 6 years, to DSM-5, when ADHD symptoms had to be noted before age 12 years, thus ushering a whole new group of “Inattentive ADHD” children, eg, the girls and some boys, who were not hyperactive early on. And in 2006 we even opened up the door to pre-school diagnosis. So in other words, we kept “moving the goal posts” as to who qualified for the diagnosis of ADHD.
2. Definition of ADHD. Roughly 70% of children/adolescents diagnosed with ADHD have a neurodevelopmental diagnosis, highly inheritable as shown by studies of identical twins raised apart, family predilection etc., and now we even know some of the several genes involved. The other 30% of children/adolescents are a mixed bag of etiologies, of conditions that mimic or can be incorrectly called ADHD because they have the signs or traits, but not the genetics. I refer to them as “ADHD look-alikes.” And they can arise from a very diverse set of circumstances: eg, intrauterine (Premies, Small for Gestational age); medical disasters, eg, near drowning; mental/behavioral, eg, posttraumatic stress disorder; developmental, eg, learning disabilities; and even syndromes, eg, fetal alcohol syndrome, etc. They can even sometimes respond to ADHD medications, though not as well as “genetic” ADHD.
3. Diagnosis of ADHD. The third area of the article I want to comment upon is the diagnoses in the study came off the health statistics for Sweden based on “receiving ADHD medication” eg, a stimulant or atomoxetine. Obviously that’s less than optimal if one is trying to decide impact of in-pregnancy eating disorders and ADHD.

So what can we say in closing. Obviously having anorexia or bulimia during pregnancy is and should be a great cause for concern, and we should be expressing that concern to our obstetric colleagues. It is not a healthy environment to grow a baby. However, for reasons stated above, there are too many confounders to definitely say it “causes ADHD”.

Reference

1. Mantel A, Örtqvist A, Hirschberg A, Stephansson. Analysis of neurodevelopmental disorders in offspring of mothers with eating disorders in Sweden. JAMA Netw Open. 2022;5(1):e2143947. doi:10.1001/jamanetworkopen.2021.43947