There have been conflicting findings for severe mental illnesses and the risk for gestational diabetes mellitus (GDM). Outside of pregnancy, both severe mental illnesses and specific antipsychotic medications have been associated with an elevated risk for metabolic disorders, including type 2 diabetes mellitus.

This study examined the risk of developing GDM in relation to mental disorder, psychotropic treatment and comorbid risk factors.

Materials and Methods
A retrospective study of 539 pregnant women with mental disorders was carried out. Measures included GDM diagnosis, mental health diagnosis, psychotropic medication, body mass index, age, smoking, alcohol and illicit substance use.

This study found that women with psychotic disorders had a significantly elevated risk for GDM (20.9%) compared with women with non‐psychotic severe mental illnesses during pregnancy (P = 0.023), and nearly threefold the expected population rate (8.3%). Furthermore, women using specific antipsychotic agents – risperidone (P = 0.016), clozapine (P < 0.001) and higher‐dose quetiapine (P = 0.029) – also had a higher risk of developing GDM. After adjusting for maternal age and body mass index, women taking these specific agents continued to have a fourfold risk of having GDM compared with women not taking these agents. Smoking, alcohol consumption and illicit drug use were not associated with elevated GDM rate in women with mental disorders. Conclusions These findings support the need for early screening and closer surveillance of metabolic risk in pregnancy for women with psychotic disorders and those taking specific atypical antipsychotic agents.