Pregnancy complications and maternal risk of ischaemic heart disease: a retrospective cohort study of 129,290 births

Background Individuals who are small at birth are at increased risk of isch aemic heart disease (IHD) in later life. One hypothesis to explain this ass ociation is fetal adaptation to a suboptimum intrauterine environment. We i nvestigated whether pregnancy complications associated with low birthweight are related to risk of subsequent IHD in the mother. Methods Routine discharge data were used to identify all singleton first bi rths in Scotland between 1981 and 1985. Linkage to the mothers' subsequent admissions and deaths provided 15-19 years of follow-up. The mothers' risks of death from any cause or from IHD and admission for or death from IHD we re related to adverse obstetric outcomes in the first pregnancy. Hazard rat ios were adjusted for socioeconomic deprivation, maternal height and age, a nd essential hypertension. Findings Complete data were available on 129 920 (95.6%) eligible deliverie s. Maternal risk of IHD admission or death was associated with delivering a baby in the lowest birthweight quintile for gestational age (adjusted haza rd ratio 1.9 [95% CI 1.5-2.4]), preterm delivery (1.8 [1.3-2.5]), and pre-e clampsia (2.0 [1.5-2.5]). The associations were additive; women with all th ree characteristics had a risk of IHD admission or death seven times (95% C I 3.3-14.5) greater than the reference category. Interpretation Complications of pregnancy linked to low birthweight are ass ociated with an increased risk of subsequent IHD in the mother. Common gene tic risk factors might explain the link between birthweight and risk of IHD in both the individual and the mother.