Dear Editor,
The positive effects of routine weighing of neonates were examined in
relation to breastfeeding (McKie, Young, Macdonald, 20 October 2005,
doi: 10.1136/adc.2005.074484). This study found that regular weighing of
infants up to 6 weeks did not threaten rates of breastfeeding, despite
some suggestions to the contrary. The authors suggest that the effect may
be from the reassurance and encouragement provided by the visiting nurses.
Indeed, it is unlikely that the mechanics of weighing the infant would
have any effect at all.
I would like to introduce a note of caution. Some years ago, with
colleagues in Brisbane, Australia, I undertook a study of the amount of
error which can occur when weighing babies. We found that normal
physiological processes can alter the weight of an infant by ±80 g a day.
The calculation of weight gain requires two measurements, and each is
liable to error, so that the error of the difference is greater than the
error for each measurement. The change in weights (between the two
measurements) may be up to 100 g (SD 50g) more or less than the amount
calculated from the two weighings.[1] We
concluded that under 9 months of age, only weighings a fortnight apart
would detect any real weight gain, under that any change was probably not
real.[2] Attaching any significance to the routine weighing of babies
outside the psychological support the child health nurse offers to the
mother could be deleterious.
References
1. Alsop-Shields L, Alexander HG, Dugdale AE. The accuracy of weighing
infants. Med J Aust 1994;161:489-90.
2 Alsop-Shields L, Alexander H. A study if errors that can occur when
weighing infants. J Adv Nurs 1997;25:587-94.
Dear Editor,
The positive effects of routine weighing of neonates were examined in relation to breastfeeding (McKie, Young, Macdonald, 20 October 2005, doi: 10.1136/adc.2005.074484). This study found that regular weighing of infants up to 6 weeks did not threaten rates of breastfeeding, despite some suggestions to the contrary. The authors suggest that the effect may be from the reassurance and encouragement provided by the visiting nurses. Indeed, it is unlikely that the mechanics of weighing the infant would have any effect at all.
I would like to introduce a note of caution. Some years ago, with colleagues in Brisbane, Australia, I undertook a study of the amount of error which can occur when weighing babies. We found that normal physiological processes can alter the weight of an infant by ±80 g a day. The calculation of weight gain requires two measurements, and each is liable to error, so that the error of the difference is greater than the error for each measurement. The change in weights (between the two measurements) may be up to 100 g (SD 50g) more or less than the amount calculated from the two weighings.[1] We concluded that under 9 months of age, only weighings a fortnight apart would detect any real weight gain, under that any change was probably not real.[2] Attaching any significance to the routine weighing of babies outside the psychological support the child health nurse offers to the mother could be deleterious.
References
1. Alsop-Shields L, Alexander HG, Dugdale AE. The accuracy of weighing infants. Med J Aust 1994;161:489-90.
2 Alsop-Shields L, Alexander H. A study if errors that can occur when weighing infants. J Adv Nurs 1997;25:587-94.