Prenatal and maternal characteristics and later risk for coronary heart disease among women

Abstract

Objective

The pace and pathways of early growth have major influences on later health. Coronary heart disease (CHD) is a major killer and kills more women than men, but usually manifests about 10 years later in women. Therefore there are fewer studies of early growth and CHD amongst women than men.

Methods

The Helsinki Birth Cohort Study includes 9817 women born during 1924–1944. We used national registers to identify hospital admissions and deaths from CHD during 1971–2010. We used a Cox model to obtain hazard ratios (HRs) for CHD.

Results

Altogether 967 women (9.9%) developed CHD. Socioeconomic factors were strongly and inversely associated with CHD. Neither maternal age nor body mass index (BMI) was associated with CHD in the daughters. There were inverse associations of birth weight (p = 0.07) and length (p = 0.02) with CHD in adult life. We divided the mothers according to parity. Daughters of primiparous women had lower birth weight and shorter birth length than the offspring of multiparous women (both p-values < 0.001). Birth weight (p = 0.008), birth length (p = 0.05) and birth BMI (p = 0.02) were all inversely associated with CHD. Among first-born women, a 1 kg increase in birth weight was associated with a 25% lower risk for CHD (HR 0.75, 95% confidence interval (CI) 0.60–0.93). The findings changed little after adjustment for socioeconomic factors. Among later-born women none of the birth characteristics was associated with CHD.

Conclusions

Small birth size is associated with CHD among women. First-born women with high birth weight appear to be at lower risk for CHD compared with later born women.