Objectives: Affective psychosis has its peak incidence during the childbearing years, but little is known about the effects of the illness on pregnancy. We investigated risks of preterm delivery (PTD), low birthweight (LBW), births of infants small for their gestational age (SGA), stillbirth and infant death in births to mothers with affective psychosis using a nested case–control design within a cohort of 1,558,071 singleton births in Sweden during 1983–1997.
Methods: Using prospectively collected data from population registers, we compared the pregnancy outcomes of 5,618 births to women with affective psychosis with the outcomes of 46,246 births to unaffected mothers.
Results: Mothers with affective psychosis had elevated risk for giving birth to preterm, small or growth-retarded babies. The risk for stillbirth and infant death during the first year of life was not significantly higher. The risks were greatest in mothers receiving hospital treatment for affective disorder during pregnancy: (i) preterm delivery: odds ratio (OR) = 2.67, 95% confidence interval (CI) = 1.71–4.17; (ii) SGA: OR = 2.36; 95% CI = 1.34–4.16; (iii) low birthweight: OR = 2.22; 95% CI = 1.31–3.76; and (iv) stillbirth: OR = 2.19; 95% CI = 0.55–8.76. After adjustment for covariates, particularly smoking, the risks were attenuated but remained significant.
Conclusions: Clinicians should be aware of the increased risk of adverse pregnancy outcomes in women with affective psychosis, some of which may be preventable.