Effect Of Birth Weight On Life-Course Blood Pressure Levels Among Children Born Premature: The Cardiovascular Risk In Young Finns Study

Objectives:Both fetal growth restriction and prematurity have been associated with elevated blood pressure (BP). However, their combined effects on adult BP are unclear.Methods:Our analyses were based on 1756 participants in the population-based Cardiovascular Risk in Young Finns Study who had information on birth weight and gestational age, together with longitudinal data on cardiovascular risk markers from age 3-18 years in 1980 to age 34-49 years in 2011. Three groups were defined by birth data: those born at term (term); those born preterm (<37 weeks) with an appropriate birth weight (>-1 SD z score according to national sex and gestational week-stratified data) for gestational age (preterm appropriate birth weight for gestational age); and those born preterm with low birth weight (<=-1 SD z score) for gestational age [preterm small birth weight for gestational age (SGA)].Results:There were no differences between the three groups in BP at baseline, but at the 31-year follow-up (mean age 41 years), mean SBP in the preterm SGA group was 7.2 mmHg (95% confidence interval = 2.3-12.1 mmHg, P = 0.004) higher than the preterm appropriate birth weight for gestational age group and 7.3 mmHg (95% confidence interval = 5.2-9.4 mmHg, P < 0.0001) higher than the term group, adjusted for age and sex. In addition, preterm SGA individuals had a higher prevalence of adult hypertension compared with those born at term (36.9 vs. 25.4%; age, sex, and risk factors adjusted P = 0.006).Conclusion:These longitudinal data suggest that elevated BP levels associated with prematurity are more likely to be present in those with fetal growth restriction.