We sought to examine the relationship between maternal exposure to adult
respiratory infections and
schizophrenia spectrum disorder (
SSD) in the Prenatal Determinants of
Schizophrenia (PDS) Study, a large birth cohort investigation. Previous work suggests that second trimester exposure to respiratory
infection may be a risk factor for
SSD. We therefore examined whether this class of
infection was associated with adult
SSD. For this purpose, we capitalized on several design advantages of the PDS Study, including a comprehensive, prospective data base on physician-diagnosed
infections and a continuous followup in which diagnoses of
SSD were made, in the majority, by face-to-face interview. Second trimester exposure to
respiratory infections was associated with a significantly increased risk of
SSD, adjusting for maternal smoking, education, and race (rate ratio [RR] = 2.13 [1.05-4.35], chi2 = 4.36, df= 1,p = 0.04); no associations were shown for first trimester and third trimester exposure to these
respiratory infections. These findings support-and extend-previous studies suggesting that second trimester
respiratory infections are risk factors for
SSD. This study therefore has implications toward uncovering the etiology of
schizophrenia and developing preventive strategies.