More Evidence Maternal Obesity Linked to Psychosis in Offspring

Nancy A. Melville

April 03, 2015

COLORADO SPRINGS, Colorado — The adult children of mothers who had prepregnancy obesity have a significantly increased risk for psychosis, new research shows.

"This is now the fourth large study to show a positive association between maternal prepregnancy obesity and psychosis outcomes," said lead author James Scott, MD, of the University of Queensland, Brisbane, Australia. "It appears that prepregnancy obesity may be casting a long shadow into lives of offspring," he added.

The findings were presented here at the 15th International Congress on Schizophrenia Research (ICOSR).

Adjusted for Important Confounders

Although previous studies have linked maternal obesity with the risk for psychosis in offspring, few large studies have adjusted for a variety of potentially important confounders, including birth complications, he said.

For the study, Dr Scott and his colleagues evaluated data from the large, population-based Mater University Study of Pregnancy, looking at factors that included maternal body mass index (BMI), which was reported at the first confinement visit.

Data on a cohort of 2303 offspring of the mothers with a mean age of 19.9 years (range, 18 to 23 years) were assessed with regard to psychosis-related outcomes. The offspring included 48.5% males.

After adjusting for the variables, including maternal age, education, and income, as well as child sex, age, and birth complications, the results showed a significant association between being overweight or obese prior to pregnancy and offspring reporting any delusion at age 21 years (adjusted odds ratio [aOR], 1.54; 95% confidence interval [CI], 1.09 - 2.17; P = .02).

The association between the highest quartile of the Peters Delusional Inventory (PDI) compared with the lowest quartile PDI was also significant (aOR, 1.40; 95% CI, 1.00 - 1.97), and there was a trend for offspring reporting any hallucination (aOR, 1.42; 95% CI, 0.98 - 2.07).

Dr Scott noted that an important limitation of the study was the relatively low rates of obesity in the mothers, which was only approximately 15%.

"In order to evaluate the data on the adult offspring, we had to look back to birth data on the mothers from the 1980s, and we know that obesity rates have increased since then," he said.

Atypical Neurodevelopment

The findings nevertheless underscore more troubling effects of obesity that can cross generations, he said.

"We know that the consequences of prepregnancy obesity on adult offspring include the risk of a wide range of metabolic disorders, including obesity, hypertension, and insulin resistance and diabetes, and we now see that it also increases the risk of atypical neurodevelopment," Dr Scott said.

In a study published in Schizophrenia Bulletin in 2000, researchers first showed a significant relationship between a woman's prepregnancy BMI and schizophrenia in adult offspring in a birth cohort study.

"That was the first such study of its kind, and it used diagnoses of schizophrenia as the outcome," Alan S. Brown, MD, MPH, who was a coauthor of that study, told Medscape Medical News.

"The current study adds to our seminal finding," said Dr Brown, who is professor of psychiatry and epidemiology at the Columbia University College of Physicians and Surgeons, in New York City, and director of the Unit in Birth Cohort Studies at New York State Psychiatric Institute.

"While they didn't have a sufficient sample size to examine schizophrenia in particular, the findings do provide further evidence, because hallucinations and delusions were increased and the study was well conducted," he said.

Potential Mechanisms

The causes of the link between maternal obesity and psychosis in offspring remain unknown, but some theories have emerged, he added.

"The more proximal causes are unclear, but they include increased risk of pregnancy and birth complications, diabetes, and increases in release of inflammatory immune molecules," Dr Brown said.

"My group has shown that the last of these is associated with an increased risk of schizophrenia in two birth cohorts."

The body of research adds more weight to the host of other reasons to avoid obesity before and during pregnancy, when possible, he added.

"While obesity should always be a priority in management, this suggests that women of reproductive age or those planning a pregnancy should be especially monitored for weight gain and measures to move closer to ideal body weight, through management of caloric intake and exercise, for instance, which should be especially emphasized."

Dr Scott is on the advisory boards for Lundbeck and Roche. Dr Brown reports no relevant financial relationships.

15th International Congress on Schizophrenia Research (ICOSR). Abstract 2106829. Presented March 31, 2015.


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