Obstetric complications in patients with depression--a population-based case-control study

To examine whether sufferers of affective disorders are more likely to be subject to obstetric complications than normal healthy people.

Data based on prospectively recorded birth case-notes for patients with a diagnosis of depression (or related disorders) with early onset were compared to those of normal healthy controls, individually matched by gender, time and parity of birth, maternal age and marital status.

Forty-one case-controls pairs born between 1964 and 1978 were compared. No differences between cases and controls in gestational age or birthweight were significant, though depressive patients on average weighed 200 g less than controls at birth. Patients were more likely than controls to be small for their gestational age (22 vs. 1: chi(2)=4.34, P=0.03). They were significantly more likely than controls to have suffered at least one obstetric complication: 35 (85%) vs. 25 (60%), chi(2)=5.03, P=0.02; or more than one (two on average, as opposed to one on average among controls). No obstetric complication was seen significantly more among cases than controls, apart from bleeding during gestation, which was observed for four cases and no controls. The prevalence of complications with a clear brain damaging potential did not differ significantly between cases and controls: 11 (26%) vs. 8 (19%).

A developmental deficit, as indicated by lower birthweight and gestational age, may contribute to the risk of depressive breakdowns and affective disorders in later life. Severe, brain damaging obstetric complications are unlikely to be a significant risk factor for affective disorders, though some early onset cases may be accounted for by prenatal brain lesions.

Sample size limits statistical power for isolation of a rare, single risk factor.