Preterm birth may be a larger risk factor for increased blood pressure thanintrauterine growth restriction

AimVery low birthweight (VLBW) and prematurity have been associated with an increased risk of high blood pressure (BP). We compared BP and salivary cortisol responses to a stressful situation between adolescents with a VLBW and controls. MethodsWe compared three groups aged 12-17years: 30 born VLBW but appropriate for gestational age (AGA) at a mean of 27weeks, 19 born VLBW but small for gestational age (SGA) at a mean of 31weeks and 43 term-born AGA controls. Three consecutive BP measurements were performed before a magnetic resonance imaging (MRI) examination. Salivary cortisol and perceived stress were assessed before and after the MRI. ResultsSystolic and diastolic BP decreased significantly for each repeated measurement in the VLBW-SGA group and controls, but remained unchanged in the VLBW-AGA group. The third systolic BP measurement was 9-12mmHg higher in the VLBW-AGA group than the other groups (p<0.05). There were no differences in salivary cortisol between the groups, before and after the MRI or between the sexes. ConclusionDynamic BP responses differed between adolescents born VLBW-AGA and the other groups, indicating that extremely preterm birth may be a larger risk factor for increased BP than intrauterine growth restriction.