Resting heart rate does not predict growth in preterm infants

Background

Previous reports indicate that preterm infants with higher baseline heart rate (HR) have greater weight gain than preterm infants with lower baseline HR. To verify this correlation and the potential utility of resting HR as a bench mark for risk of extrauterine growth restriction (EUGR), we studied preterm infants born between 32 and 36 weeks gestation. Earlier gestation infants (27 to 31 weeks) were included.

Methods

In retrospective chart review we collected heart rate (HR) and growth data on 156 infants between 27.0 and 34.0 weeks gestation from birth to hospital discharge.

Results

There was a significant increase in weight gain from day 10 of life in infants with higher resting HR compared to infants with lower resting HR. However, upon controlling for birth weight and gestational age, there was no significant relationship between HR and weight gain for any gestational age group of premature infants.

Conclusions

Contrary to previous reports, there was no significant relationship between HR and growth at any gestational age after controlling for birth weight and gestational age. It is important to continue to search for a clinical marker of risk for poor growth in preterm infants and to give an opportunity for nutritional interventions which may support better growth and developmental outcomes.