Led by Dr. Katherine A. Comtois, lead investigator from the Harborview Injury Prevention and Research Center and the University of Washington School of Medicine, a research team analysed the hospitalisation and birth records of Washington State from 1992 to 2001.
About 335 women were hospitalised for suicide attempts, while another 1420 women who had given birth but had not been hospitalised for a suicide attempt served as a control group.
After adjusting for foetal or infant death and other variables, the team found that women with a history of psychiatric disorders were 27 times more likely to attempt suicide than women without this medical history.
Moreover, women with a history of substance abuse were six times as likely to attempt suicide, while psychiatric hospitalisation and substance abuse together increased the risk by 11 times.
"In the current study, we focused on pre-existing psychiatric risk factors for postpartum suicide attempts resulting in hospitalisation. Most importantly, a prior psychiatric or substance use diagnosis among postpartum women significantly increased the risk of a serious postpartum suicide attempt," said Comtois.
"One implication of this study is that screening for past history of psychiatric and substance use diagnoses as part of routine prenatal care may be a means of identifying women at high risk of postpartum suicide attempt, although a recent review of prenatal screening for depression cited insufficient evidence to recommend screening as a way to improve outcomes," she added.
The study has been published the American Journal of Obstetrics and Gynecology.