Prenatal, maternal factors tied to later suicidal behavior

OB/GYN News, Nov 15, 2004 by Sharon Worcester

Certain prenatal and maternal factors may be associated with attempted or completed suicide in offspring, according to Ellenor Mittendorfer-Rutz and her colleagues at the Karolinska Institute, Stockholm.

In a large cohort study involving more than 713,000 young adults born in Sweden between 1973 and 1980 and followed through 1999, a total of 563 committed suicide, and 6,676 attempted suicide. A significantly increased risk for attempted suicide was found in those with gestational age-adjusted short birth length, defined as length between 39 and 47 cm (hazard ratio 1.29), as well as in those born fourth or later in birth order (hazard ratio 1.79).

They found this increased risk in those born to mothers with a low educational level, defined as fewer than 9 years of education (hazard ratio 1.36), and in those born to a teenage mother (hazard ratio 2.09).

Significant predictors of completed suicide included gestational age-adjusted low birth weight, which was defined as a birth weight below 2,500 g (hazard ratio 2.23) and being born to a teenage mother (hazard ratio 2.30), the investigators in the study reported (Lancet 2004;364:1135-40).

They acknowledged that the study is limited by the fact that some patient registers exclude those who were not admitted after a suicide attempt, and by the upper patient age of 26 in this study, which suggests the findings may not apply to older individuals. But they also noted that their findings are in accord with those from earlier studies suggesting a link between low birth weight and various mental disorders, as well as between maternal education level and attempted suicide; teenage motherhood and attempted and completed suicide; and multiparity of at least four and major suicide risk factors.

The findings open a new line of inquiry regarding the relationship between intrauterine and perinatal conditions and other contributors, which might lead to clarification of the determinants of the heritability of suicidal behavior, Maria Oquendo, M.D., and Enrique Baca-Garcia, M.D., said in an accompanying editorial (Lancet 2004;364:1102-3).

The effects of the risk factors identified are mild, and less than the risks conferred by family history of suicidal behavior, but the findings do aid in the construction of a model for understanding--and thus possibly preventing--suicidal behavior.

BY SHARON WORCESTER

Tallahassee Bureau