First-Time Mothers at Risk for Postpartum Mental Disorders

AARHUS, Denmark, Dec. 6 -- A first-time major mental illness can strike mothers with dramatic suddenness within three weeks of delivering a first child, researchers here reported.

In particular, they cited an elevated first-time risk of schizophrenia, depression, and bipolar disorder in the 10 to 19 days after the birth of a first child. First-time fathers were not at any particular elevated risk for a first-time mental disorder.

The prevalence of severe mental disorders through the first three months after the birth of a live singleton child was 1.03 per 1,000 births for mothers compared with 0.37 per 1,000 births for fathers, according to a report in the Dec. 6 issue of the Journal of the American Medical Association.

The findings of an early increased risk came from a register-based cohort of 2,357, 942 Danish-born persons, followed from 1973 to 2005, in which 630,373 women and 547,431 men became parents for the first time.

Of these, 1,171 mothers and 658 fathers were admitted to a psychiatric hospital with a mental disorder during the first 12 months after parenthood, found Trine Munk-Olsen, M.Sc., of the University of Aarhus, and colleagues.

Severe disorders included schizophrenia, schizophrenia-like disorders, unipolar depressive disorders, bipolar affective disorders, adjustment disorders, puerperal disorders, and assorted other diagnoses.

Compared with women who had given birth 11 to 12 months earlier, primiparous women had an increased risk of incident hospital admission with any mental disorder through the first three months after childbirth, regardless of age (relative risk 1.68; 95% confidence interval 1.23-2.30). At 10 to 19 days postpartum, the risk was seven times greater (RR, 7.31; CI, 5.44-9.81).

As with the hospital results for the women, the risk was higher for psychiatric outpatient contacts through the first three months after childbirth (RR, 1.50, 95% CI, 1.15-1.95), with, again, the highest risk occurring 10 to 19 days postpartum (RR, 2.67; CI, 1.99-3.59).

The authors noted that the diagnosis and timing of perinatal episodes of major depression or other psychiatric disorders has not been consistently identified. The concept of postpartum mental disorders is usually confined to disorders with onset during the first six weeks after childbirth, a reflection of the burden of child rearing rather than child-bearing.

Unlike first-time motherhood, first-time fatherhood was not associated with any increased risk of hospital admission or outpatient contact. These data, the researchers said, argue against any temporal association between fatherhood and mental disorders, since no increase in the incidence of mental disorders was found during the 12 months after the birth of a first child in a group of men never previously admitted to a psychiatric hospital.

"We believe that this result challenges the concept of severe paternal postpartum mental disorder," the researchers wrote. Although the results do not support fatherhood as a specific risk factor for severe mental disorder, "men who become fathers are, of course, not protected against developing mental disorders," they said.

The paternal findings, they emphasized, may indicate that the causes of postpartum mental disorders are more strongly linked to an altered physiological process, such as the mood destabilizing effects of reproductive hormones, than to the psychosocial aspects of motherhood.

Nevertheless, these results could also reflect that because mothers generally are more involved in the child-rearing process, especially with the early demands of breastfeeding and sleep deprivation, the women are more affected by dramatic changes in lifestyle. Finally, the investigators wrote, it is possible, that fathers are less likely to seek care compared with women.

This study, the researchers wrote, included first-time parents and first-time risks of serious mental disorders. Consequently, they said, theses risks may be an underestimate, since there were no data for depression not requiring hospitalization or outpatient treatment, and information on confounders, such as race/ethnicity or socioeconomic status, were not available.

Furthermore, they added, because the study was limited to women and men having a first child, these results cannot be converted into a risk of postpartum mental disorders for multiparous women and their partners.

In conclusion, the Danish investigators wrote, "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."

In an accompanying editorial, Katherine Wisner, M.D., and Dorothy K.Y. Sit, M.D., of the University of Pittsburgh, and Christina Chambers, Ph.D., of the University of California at San Diego wrote that these data and the findings of other studies emphasize the importance of recognizing childbearing as a potent health factor in the life course of women.

Childbearing, they said, influences the course of any disease state and acts as a biopsychosocial factor that may precipitate new episodes of illness. The data also provide evidence to support universal screening for postpartum major mood episodes.

The studies point to the first three months postpartum as the period of elevated risk for both hospitalization and outpatient Contacts, particularly in first-time mothers. Therefore, they wrote, screening should be implemented as early as two weeks after delivery and no later than 12 weeks postpartum to identify episodes of major mood disorder and other mental illnesses.

Effective treatments for these episodes exist, they said. Rapid implementation of treatment is prudent because mood episodes can be lengthy and the psychosocial fallout increases with duration. Maternal depression exacts a heavy toll on women's functioning and on the health and well-being of their children, they concluded.

Dr. Wisner reported that her research funding included grants from Pfizer to study the pharmacokinetics of Geodone (ziprasidone) during pregnancy and that she is on the speaker's bureau for GlaxoSmithKline. Dr. Chambers reported receiving research funding that included Abbott Laboratories, Sanofi Aventis, Sanofi Pasteur, Amgen, Bristol-Myers Squibb, Sandoz Pharmaceuticals, Teva Pharmaceuticals USA, Apotex Inc, Barr Laboratories, and Kali Laboratories for research not involving psychotherapeutic agents. She is also a consultant for Cephalon Inc.