title: Does the season of conception influence the frequency of post partum mental illness?
abstract: The study is based on two series of patients with post partum mental illness, one consisting of 71 women in Gothenburg 1952-56 and another of 68 women in Stockholm 1976-77. The total number of births in the two cities during the periods in question were used as reference. A strategy of chi-squared test and the Edwards' criteria of seasonality was applied for statistical analyses of the results. A yearly double periodic trend in month of conception could be observed.
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology* / Q000523:psychology; D011247:Pregnancy; D011644:Puerperal Disorders / Q000453:epidemiology* / Q000523:psychology; D012621:Seasons; D013548:Sweden