The effect of Intra Uterine Growth Restriction (IUGR) on heart rate and blood pressure in children

Infants with Intra Uterine Growth Restriction (IUGR) are reported to be more prone to develop obesity and cardiovascular problems as adults. Research in this field is complicated due to use of different statistical models and inadequate cardiovascular measurements. I intended to find out whether the difference in body size between IUGR and normal infants persisted through the childhood and whether there were any differences in cardiovascular parameters and maturation of circadian biorhythms between these groups. 75 nine year olds were recruited and forty-one of them were IUGR. All the children had their twenty-four hour heart rate variability, blood pressure and urinary Cortisol excretion measured. IUGR children showed a greater increase in their weight between birth and nine years but the z scores for current weight, height and Body Mass Index (BMI) and incidence of obesity were higher in the control group. Both groups showed similar diurnal variation of all cardiovascular parameters and no evidence of the cardiovascular system being dominated by the Sympathetic nervous system in the IUGR children, which could have been detrimental to their cardiovascular health. The Systolic Blood Pressure (SBP) was significantly higher in the control group. Later weight was the better predictor of SBP. BMI was a significant predictor of SBP. Urinary cortisol/Creatinine ratio was not different between the two groups. I conclude that IUGR children grow faster but remain shorter and lighter than their normal counterparts. IUGR children on average are physiologically indistinguishable from normal children and do not show any abnormality in the cardiovascular parameters, which could link them to future disease. Normal children have higher SBP than the IUGR children which is related to larger body mass. The current body size appears to have more impact on the level of blood pressure at the age of nine years compared to IUGR.