Approaching the diagnosis of growth-restricted neonates: a cohort study

Abstract

Background: The consequences of in utero growth restriction have been attracting scholarly attention for the past two decades. Nevertheless, the diagnosis of growth-restricted neonates is as yet an unresolved issue. Aim of this study is the evaluation of the performance of simple, common indicators of nutritional status, which are used in the identification of growth-restricted neonates.

Methods: In a cohort of 418 consecutively born term and near term neonates, four widely used anthropometric indices of body proportionality and subcutaneous fat accretion were applied, singly and in combination, as diagnostic markers for the detection of growth-restricted babies. The concordance of the indices was assessed in terms of positive and negative percent agreement and of Cohen's kappa.

Results: The agreement between the anthropometric indices was overall poor with a highest positive percent agreement of 62.5% and a lowest of 27.9% and the kappa ranging between 0.19 and 0.58. Moreover, 6% to 32% of babies having abnormal values in just one index were apparently well-grown and the median birth weight centile of babies having abnormal values of either of two indices was found to be as high as the 46th centile for gestational age (95%CI 35.5 to 60.4 and 29.8 to 63.9, respectively). On the contrary, the combination of anthropometric indices appeared to have better distinguishing properties among apparently and not apparently well-grown babies. The median birth weight centile of babies having abnormal values in two (or more) indices was the 11th centile for gestational age (95%CI 6.3 to 16.3).

Conclusions: Clinical assessment and anthropometric indices in combination can define a reference standard with better performance compared to the same indices used in isolation. This approach offers an easy-to-use tool for bedside diagnosis of in utero growth restriction.

Figure 1

Proportion of babies with abnormal values in one or more anthropometric indices. Columns stand for all cases with abnormal values (≤ 10^th centile for gestational age) in the individual indices. Unfilled areas of columns represent cases with abnormal values of only the indicated index. The three shaded areas of each column represent cases with abnormal values of both the indicated index and of any 1, 2 or 3 additional indices, from bottom to top, respectively. MAC, mid-arm circumference; PI, ponderal index; CC, chest circumference; HC, head circumference