February 19, 2005

Pregnancy risks


Jablensky AV, Morgan V, Zubrick SR, Bower C, Yellachich LA.
Am J Psychiatry. 2005 Jan;162(1):79-91.

Introduction: Some studies have suggested that women with schizophrenia may be at a higher risk for more pregnancy problems. But, it is unclear whether these bad outcomes are specifically related to schizophrenia or some other nonspecific reasons due to being pregnant and having a severe mental illness. This study wanted to look at the frequency, nature and severity of obstetric (pregnancy related) complications in women with schizophrenia and then compare them to women with mood disorders (e.g. depression, bipolar disorder) and women without a diagnosed psychiatric disorder. They also wanted to look at the timeline between pregnancies and the start of the mother’s psychiatric illness as well as other pregnancy outcomes in relation to risk factors in the mother.

Method: This was an Australian population study. They looked at all women with diagnoses of schizophrenia or mood disorder who gave birth in Western Australia during 1980–1992. They looked at records in a psychiatric case register and then randomly selected a comparison sample of 3,129 births to women without a psychiatric diagnosis.

Results: They found that mothers with schizophrenia and mood disorders both had increased risks of pregnancy, birth, and neonatal (newborn) complications. These complications included placental abnormalities, bleeding and fetal distress. Women with schizophrenia were significantly more likely to have placental abruption, to give birth to infants in the lowest weight/growth group and to have children with birth heart defects. Complications in the newborn were more likely to occur in winter months and low birth weight was the highest in the spring. Complications (other than low birth weight and birth defects) were higher in pregnancies that occurred after a psychiatric illness was diagnoses than in pregnancies that occurred before a diagnosis.

Discussion: Overall, this study found that relative to a nonpsychiatric comparison group, women with schizophrenia, bipolar disorder, and depression had more birth complications. Specifically, there were two pregnancy complications that stood out in the women with schizophrenia and the women with bipolar disorder (but not in women with depression). These were placenta abnormalities and bleeding. They also found that there were more birth or congenital malformations (especially heart related) diagnosed either at birth or in the first years of life for women with schizophrenia. There were no significant differences among the groups for neural tube defects, other CNS malformations, or cerebral palsy. Also, they found that while being a single, divorced, or separated mother was common in all three groups, women with schizophrenia were more likely than any other group to experience socioeconomic disadvantage, lack social support and be either younger than 20 years or older than 34 years. Also, low birth weight was the main obstetric complication that occurred only in mothers with schizophrenia in pregnancies both before and after the onset of psychotic illness and showed a seasonal variation. Low birth weight is associated with many risk factors, including maternal nutritional status, smoking, alcohol abuse, maternal physique, birth order and hypertension in pregnancy. These results emphasize the need for preventive prenatal programs that can help expecting mothers and provide education and care especially in vulnerable groups.

This study was limited because they did not have data on the dad’s psychiatric status - which could have also been a significant factor for both genetic and environmental risks. They also didn’t look at medication or illicit drug use during pregnancy. Finally, the comparison sample could have included a number of women with milder disorders who never had a psychiatric inpatient or outpatient admission but shared some of the risk factors with the other groups. Yet, this study offered advantages over other studies, since it was based on an entire population birth group, including all births to women with schizophrenia and mood disorders. They also used a comparison group of randomly selected nonpsychiatric women from the same overall group who was from a specific geographic population unaffected by outmigration. Another advantage of this study is that they prospectively (ahead of time) collected data on pregnancy complications and risk factors in the mother. Overall, this study suggests that risk factors in the mother and biological and behavioral complications due to severe mental illness are the major culprits in increasing reproductive problems. But genetic risk and gene-environment interactions may have also accounted for some outcomes and more research is needed.

Acknowledgements: This study was supported by a Theodore and Vada Stanley Foundation Research Award (319520/31951).

Click here to find this article on PubMed


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