Introduction: The purpose of this study was to redress weaknesses in past studies of a psychogenic etiology for hyperemesis gravidarum (HG) by (1) estimating from a known population what proportion of HG cases also have psychiatric diagnoses, (2) determining if psychiatric disorder preceded HG, and (3) re-considering whether non-pregnancy somatic conditions also precede HG.
Methods: We analyzed insurance data for all 11,016 members who gave birth to singletons in 2000-2004, 208 of whom had HG.
Results: Prevalence of HG was 1.8% overall, 3.8% with one psychiatric diagnosis, 5.8% with >1 psychiatric diagnosis. One in 10 HG cases had pre-pregnancy depression, anxiety, or substance abuse diagnoses. One in five HG cases had either a psychiatric or a somatic condition (e.g., chronic pelvic pain, dysmenorrhea) diagnosis prior to pregnancy. Pre-pregnancy psychiatric diagnosis doubled the adjusted odds of HG. Combined psychiatric and somatic diagnoses quadrupled the adjusted odds of HG.
Discussion: Vomiting is a non-specific sign that may have multiple etiologies. For 10-20% of HG sufferers, vomiting may be a physical comorbidity of a psychiatric condition occurring in the context of pregnancy. Psychobiological research with HG cases with past or current psychiatric diagnoses is needed to consider plausible mechanisms.