IMPORTANCE: Comorbidity between mental and physical health is a frequent problem, resulting in greater morbidity than the sum of the effects of individual diseases. Despite pervasive physiological and behavioral changes during pregnancy, the pattern of comorbidities among pregnant women is not well-understood.
OBJECTIVE: Systematically examine the associations between mental and physical diagnoses around pregnancy.
DESIGN, SETTING, PARTICIPANTS: Population-based sample, containing all children born between January 1st, 1997 and December 31st, 2008 within a health maintenance organization (HMO) in Israel. Cohort children were linked to their mothers' health information, creating mother-child dyads.
MAIN OUTCOMES AND MEASURES: The primary outcome was any ICD-9 mental health diagnosis within the pregnancy period or the preceding 12 months. The secondary outcomes were specific ICD-9 mental health diagnoses. Exposures were all ICD-9 physical (non-mental) health diagnoses received during the exposure period. We used logistic regression to test the risk of physical health diagnoses in pregnant women associated with mental health diagnoses. The covariates for this study included maternal age, birth year, socioeconomic status and total number of ICD-9 diagnoses during the exposure period.
RESULTS: The analytical sample included 76,783 mother-child dyads, with 30,084 unique mothers. The mean age at birth was 29.8 years, with 4.4% of mothers diagnosed with a mental health disorder during the pregnancy period. Of the 18 major ICD-9 diagnostic categories, 10 were positively associated with mental health disorders, including ICD categories of e.g., symptoms, signs, and ill-defined conditions (OR=1.69; 95% CI=1.50, 1.89), musculoskeletal (OR=1.33; 95% CI=1.22,1.45) and digestive system diseases (OR=1.25; 95% CI=1.15, 1.37). Comorbidity between mental and physical health diagnoses was higher than that observed between various physical health diagnoses. Associations between physical health diagnoses and specific mental health conditions were consistent with the results of the general mental health and physical health comorbidity.
CONCLUSION AND RELEVANCE: We observed that associations between maternal diagnoses and mental health stand out from the general pattern of comorbidity between non-mental health diseases. The high co-occurrence of mental health and physical health diagnoses has implications for diagnoses and management of morbidity among pregnant women, with potential impact on pregnancy and child health outcomes.