2.5 IN SINGLETONS BORN AT TERM, LOWER GESTATIONAL AGE IS ASSOCIATED WITH INCREASED AORTIC PULSE WAVE VELOCITY IN YOUNG ADULTHOOD: THE NORTHERN IRELAND YOUNG HEARTS PROJECT (NIYHP)

Abstract

Decreases in the mean gestational age of babies born at term have been reported over the past decade in several developed countries, linked to increases in the rates of planned births by labour induction and/or pre-labour caesarean sections. In contrast to the effects of pre-term birth, the extent to which lower gestation age within the ‘at-term’ range (i.e. ≥37–≤42 weeks) affects individuals’ cardiovascular heath is largely unknown, however. We have therefore examined the association between gestational age (obtained from the Northern Ireland Child Health Services’ records) and aortic pulse wave velocity (aPWV) in 351 young adults from the NIYHP (50.4% women, mean age of 22.4 ± 1.6 years, all singletons and born at term, 98% with birth weight>2.5 kg). In analyses adjusted for age, sex, birth weight (in SDs relative to UK’s 1990 reference), birth order, breast-feeding, maternal and paternal age at child’s birth, and social economic status, we found that each week increase in gestational age was significantly associated with lower levels of aPWV [standardized ß = −0.11 (95% CI:−0.21;−0.01, p = 0.039)]. Additional adjustments for individuals’ adult BMI and mean arterial pressure did not appreciably affect this association. None of the other birth covariates were independently associated with aPWV. These findings suggest that lower gestational age, even within the at-term range, may be a key determinant of early vascular ageing as each additional week conferred benefits. This aspect may have been neglected by the over-simplistic characterization of individuals as ‘born at-term’ and may have clinical implications for policies around planned deliveries, given the current trends.