Risk for obstetric complications and schizophrenia

Are obstetrical complications really involved in the etiology and course of schizophrenia and mood disorders?

“…In contrast, Preti and co-authors demonstrated that schizophrenic patients had significantly more frequently obstetrical complications than healthy subjects (Preti et al, 2000). Other authors indicated that prematurity was modestly associated with the risk to develop schizophrenia (Byrne et al, 2007).…”

Serious obstetric complications interact with hypoxia-regulated/vascular-expression genes to influence schizophrenia risk

“…Contributing to the modest number of events termed serious OCs is our strict definition (McNeil-Sjostrom Scale score of > 4); the use of the strict definition has two advantages: it defines a subset of individuals who have at minimum potentially greatly harmful obstetric complications and in our sample the OCs reported with severity X5 were nearly all associated with the potential to cause hypoxia in the fetus. However, other researchers have used a less stringent criterion for defining serious OCs (McNeil-Sjostrom Scale score of > 3; for example, Preti et al 5 ). We found that the frequency of OCs > 3 in probands was greater than reported by other studies (Preti et al 5 frequency of cases with OCs > 3 = 34%; present study: frequency of probands with OCs > 3 = 75%), which may reflect participation bias: mothers of probands who experienced OCs may have been more likely to respond to the birth questionnaire.…”

“…However, other researchers have used a less stringent criterion for defining serious OCs (McNeil-Sjostrom Scale score of > 3; for example, Preti et al 5 ). We found that the frequency of OCs > 3 in probands was greater than reported by other studies (Preti et al 5 frequency of cases with OCs > 3 = 34%; present study: frequency of probands with OCs > 3 = 75%), which may reflect participation bias: mothers of probands who experienced OCs may have been more likely to respond to the birth questionnaire. Our use of the strict definition of serious OCs in interaction with hypoxia-regulated genes may suggest a threshold effect for severity of OCs; furthermore, reanalysis of the seven SNPs in Table 1 with the less strict definition of OCs > 3 leads to a larger number of probands classified as experiencing serious obstetric complications and thus increases statistical power but produced significant evidence for interaction with only two of the seven SNPs (AKT1 rs2494735 and rs1130233) (data not shown).…”

“…Many studies have shown that the prevalence of obstetric complications is higher in individuals with schizophrenia than in the general population, [1][2][3][4][5][6] which has led to an often-stated, but never empirically tested, theory that serious obstetric complications interact with genetic risk factors to increase risk. 1,5,[7][8][9][10] A recent review by Schmidt-Kastner and colleagues 11 suggested that susceptibility genes for schizophrenia were more likely than randomly selected genes to be regulated by hypoxia/ischemia and/or expressed in the cerebrovasculature.…”

“…1,5,[7][8][9][10] A recent review by Schmidt-Kastner and colleagues 11 suggested that susceptibility genes for schizophrenia were more likely than randomly selected genes to be regulated by hypoxia/ischemia and/or expressed in the cerebrovasculature. In fact, a substantial fraction of the genes reported to be significantly associated with schizophrenia in at least two published studies fit this description, even though only 1-2% of known genes are involved in hypoxia-induced regulation.…”