Dear Editor

It was a learning experience to go through the article “Early physiological development of infants with intra uterine growth retardation” by JA Jackson et al.[1]

It is heartening to learn about various ongoing endeavours to understand the physiology of intra uterine growth retarded (IUGR) neonates which is the most burning topic in modern neonatology. However, in context of the above mentioned article, we have few observations:

1. The type of IUGR & severity of IUGR have not been considered in this study. Symmetrical & assymetrical IUGR have different pathophysiologies & therefore tend to have different outcomes. Hence, Ponderal index & assessment of severity of IUGR would have been relevant.

2. The environment of neonate in which these recordings were taken has not been taken into account. Noisy surroundings & brightly lit room can bring about sufficient neuro-hormonal derangements to confound the final assessment. The effect of sound pressure levels on heart rate, respiratory rate & mean arterial pressure have already been documented.[2] Hence, standardization with respect to environment especially sound levels & intensity of light, would have added a new dimension to this study.

3. IUGR neonates have decreased muscle mass, which in turn is a determinant of creatinine clearance. Hence, the standardization of cortisol excretion in urine as a ratio of creatinine in IUGR & normal neonates was required. Also, an estimate of BMI in this respect would have acted as a surrogate marker of muscle mass assessment.

4. The gestational age of neonates has not been assessed. All the vital parameters may show a fluctuation with gestational age. Also, renal functions are gestational age dependent. Therefore, assessment of gestational age would have been more meaningful.

We solicit opinion of workers on the remarks.

References

1. Jackson JA, Wailoo MP, Thompson JR, Petersen SA: Early physiological development of infants with intrauterine growth retardation. Arch. Dis. child. 2004; 89; F46

2. Gupta G, Gupta V, Nair MNG, Soodan KS: Effect of sound pressure levels in neonates. Awaiting publication