March 22, 2005

Birth complications & Schizophrenia?

Women with Schizophrenia Have Increased Risk of Obstetric Complications

This study looks at the frequency of complications in pregnancy, labor and delivery that are sustained by people with schizophrenia and mood disorders. They also sought to survey the general newborn characteristics of infants born to mothers with severe mental illness and looked over a large population cohort (group) and collected data over the large sample. The subjects were 3000 babies born to mothers with mood disorders or schizophrenia in Western Australia and they were compared with a similar number of babies born to mothers without mental illness in the same area of the world. The authors used a standardized scale for measuring birth complications in both groups. This research is important because it has long been thought (though not actually proven) that birth complications are a risk for schizophrenia. However, since we know that there is a genetic component to schizophrenia risk, if there is a significantly higher number of a prenatal trauma in mothers with schizophrenia, we wouldn’t know what the role of the birth trauma vs. the genetic component was more causative in the increased risk for schizophrenia in children born to schizophrenic mothers. This study helps to clarify the risk of prenatal trauma so that we can begin to sort out the various risk factors more clearly. In essence, which comes first prenatal risk leading to mental illness or mental illness predisposing for prenatal risk, or both?

This study was done as a large “case-control” study. That means that the authors took all of the “cases” which were women who gave birth and had either schizophrenia or mood disorder and then took a random sample of approximately the same number in which they controlled for various factors such as age, socioeconomic status, etc. They were able to compare the two similar groups that theoretically only differed in their rates of mental illness. They were able to rely on carefully kept records on birth trauma in Australia and look back at the data. This study was done prospectively, in that the authors kept the data with the intent of looking at this question, from the beginning which help add to the quality of the research.

The results show that pregnancy related complications were increased statistically compared to the other groups for schizophrenia, bipolar disorder and major depressive disorder mothers. The increased risk was small, but nonetheless was increased over mothers without a diagnosis of mental illness. However, there were many risk factors for birth complications that were increased in the group with mental illness. For example, women were more likely to have children at extreme ends of the reproductive age spectrum (less than 19 or older than 35.) Also, there were lower socioeconomic status, more single and/or unemployed mothers, smokers, and more of the partners of the women with schizophrenia had disability (including psychiatric) than the other studied groups. Using a mathematical model, the authors showed that smoking was not likely to be the sole factor that contributed to the different outcome between the groups as it was calculated to contribute a certain amount towards the risk of low birth weight babies that was not fully accounted for by the data received compared to the model.

The risk of a problem with delivery was not increased in any of the groups meaning that the actual act of delivering a baby is not impacted by mental illness and there was no increased chance of having an anatomical complication that would hinder delivery or make cesarean section more necessary on an emergent basis. There was no increase in stillbirths or death shortly after birth. There were however some increased heart defects and other developmental defects seen in the group with schizophrenia. However, these were small increases over the regular rate of such outcomes. There was no increase in cerebral palsy in any group. Looking at another mathematical modeling of the data, the authors reported that those with a psychiatric diagnosis and hospitalization prior to the pregnancy were more likely to have a complication than were those who had their diagnosis come after they gave birth. In fact, those with a diagnosis after delivery were no more likely to have a complication than the general population. Additionally, in the small number of women with a psychiatric hospitalization during pregnancy, there was no increased risk of a complication, but that was an uncommon occurrence.

Overall, this study provides some evidence that having a psychiatric disorder is correlated with difficult pregnancies. However, it does not fully explain if there is a causal relation between the two conditions. It is interesting the difference in the data between women with psychiatric diagnoses prior to and following delivery. This difference makes a more compelling case that something is inherently happening in the group after the diagnosis of mental illness, but it does not answer the question related to the other factors related to mental illness that may predispose one to prenatal complications. That answer is still not fully described yet.

Am J Psychiatry. 2005 Jan;162(1):79-91.
Pregnancy, delivery, and neonatal complications in a population cohort of women with schizophrenia and major affective disorders. Jablensky AV, Morgan V, Zubrick SR, Bower C, Yellachich LA.

Click here to access the article on PubMed


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