First-time mothers at increased risk for postpartum mental disorders

December 5, 2006

New mothers are at an increased risk for mental disorders such as schizophrenia, depression and bipolar disorder in the 3 months following the birth of their first child, according to a study in the December 6 issue of JAMA. The study also found that first-time fathers do not have an increased risk for mental disorders.

Postpartum depression is a serious mental health problem for women and their families, with an estimated prevalence of about 10 percent to 15 percent among mothers. Postpartum disorders can also include more severe mental disorders, with a prevalence of about 1 per 1,000 births, according to background information in the article. There is some indication that a small percentage of men experience postpartum depression, but the possible relationship between becoming a father and first onset of mental disorders has not been established.

Trine Munk-Olsen, M.Sc., of the University of Aarhus, Denmark and colleagues conducted a study to estimate the risk of postpartum mental disorders requiring hospital admission or outpatient contact for first-time mothers and fathers up to 12 months after becoming a parent. The researchers analyzed data from Danish health and civil service registers, which for this study included a total of 2,357,942 Danish-born persons who were followed up from their 15th birthday or January 1973, whichever came later, until date of onset of the disorder in question, date of death, date of emigration from Denmark, or July 2005, whichever came first.

From 1973 to 2005, a total of 630,373 women and 547,431 men became parents for the first time. A total of 1,171 women and 658 men were admitted with a mental disorder to a psychiatric hospital during the first 12 months after parenthood, and the corresponding prevalence of severe mental disorders through the first 3 months after childbirth was 1.03 per 1,000 births for mothers and 0.37 per 1,000 births for fathers. For first-time mothers, the first weeks and months after the delivery were associated with an increased risk of first admission with any mental disorder, and the period from 10 to 19 days following the birth was associated with the highest risk (7.3 times increased risk) compared with women who had given birth 11 to 12 months previously. The increased risk of admission among mothers remained statistically significant through the first 3 months after childbirth regardless of age of the mother. Risk for mothers was also increased for psychiatric outpatient contacts through the first 3 months after childbirth, also with the highest risk occurring 10 to 19 days following the birth.

Unlike motherhood, fatherhood was not associated with any increased risk of hospital admission or outpatient contact. "This may indicate that the causes of postpartum mental disorders are more strongly linked to an altered physiological process related to pregnancy and childbirth than psychosocial aspects of motherhood."

"Accurate estimates of the rates of and risk factors for postpartum depression are highly important for the scientific and clinical understanding of mental and behavioral disorders during the postpartum period as well as for planning mental health services for childbearing women and their families," the authors write.

Source: JAMA and Archives Journals