Preterm delivery is more likely in women with depressive symptoms

BMJ 2008; 337 doi: (Published 28 October 2008) Cite this as: BMJ 2008;337:a2312
  1. Janice Hopkins Tanne
  1. 1New York

    Women who have depressive symptoms early in pregnancy are more likely to deliver their babies prematurely than those without such symptoms, a new study has found.

    The large US, non-profit healthcare group Kaiser Permanente, which was behind the study, had already begun using a simple questionnaire to screen for depressive symptoms in pregnant women in a pilot project in northern California and is expecting to using it more widely, said the study’s lead author, De-Kun Li, senior research scientist at the Kaiser Foundation Research Institute, Oakland, California.

    The study reported that 41% of women in early pregnancy had significant depressive symptoms and 22% had severe symptoms. In comparison with women without depressive symptoms, women with severe symptoms had almost twice the risk of preterm delivery, while those with significant symptoms had a 60% higher risk (Human Reproduction, doi:10.1093/humrep/den342).

    Delivery before 37 weeks of gestation is the leading cause of infant morbidity and mortality in the United States. The authors estimated that the cost of such deliveries in 2005 was $26.2bn (£17bn; €21bn). They say the causes of preterm delivery remain “largely unknown.”

    Depression and mood disorders have been emerging as possible causes for preterm delivery. Some researchers have suggested that such disorders might affect placental hormones and placental function. Whether depressive symptoms might lead to hormonal problems affecting the placenta was beyond the scope of his study, Dr Li said.

    The population based cohort study followed 791 pregnant members of the Kaiser Permanente health plan in the San Francisco Bay area in 1996 to 1998 until they gave birth to a live infant. (Women who had miscarriages were not included.)

    At about 10 weeks into the women’s pregnancies the researchers, using the short Center for Epidemiological Study depression scale, asked the women about depressive symptoms. A score of more than 16 indicates significant depressive symptoms and a score of more than 22 indicates severe depressive symptoms. Dr Li said that women with a score above 22 were “quite often” later given a diagnosis of clinical depression.

    Dr Li emphasised that women with depressive symptoms were not technically depressed, because such a diagnosis can be made only by a clinician. He also noted that no good data existed on the prevalence of depression in women in the same age group in the general population.

    He said that depressive symptoms can be diagnosed, treated, and reduced. Such symptoms are “significantly underdiagnosed, dismissed, or ignored as just being part of being pregnant.” He said that treatment does not necessarily involve antidepressants but might involve psychotherapy or increased support from partners, family members, or friends.

    Most women in the study were married, and most of the pregnancies were planned. Women who had significant depressive symptoms in early pregnancy tended to be less than 25 years old, unmarried, African American, less well educated, and with lower family income. They were also slightly more likely to have had previous pregnancies and a history of subfertility (taking more than six months of unprotected intercourse to become pregnant) and preterm delivery.

    “They were also more likely to have smoked, used illicit drugs, or vomited, and less likely to have planned the index pregnancy and used vitamin supplements during pregnancy,” the authors wrote.


    Cite this as: BMJ 2008;337:a2312

    View Abstract

    Sign in

    Log in through your institution

    Free trial

    Register for a free trial to to receive unlimited access to all content on for 14 days.
    Sign up for a free trial