Growth pattern of skinfold thicknesses in term symmetric & asymmetric small for gestational age infants

A etiologically symmetric and asymmetric small for gestational age (SGA) infants are two distinct entities. In view of absence of longitudinal information on growth pattern of skinfold thicknesses (SFTs) among Indian infants, this study was conducted to assess the auxological dynamics of SFTs (sub-cutaneous fat) of symmetric and asymmetric SGA infants.

Triceps, sub-scapular, biceps, mid-axillary and anterior thigh SFTs among full-term, 100 symmetric SGA, 100 asymmetric SGA and 100 appropriate for gestational age (AGA) infants were measured at one, three, six, nine and 12 months. Ponderal Index (PI) was used to categorize infants into symmetric SGA (PI ≥2.2 g/cm³) and asymmetric SGA (PI <2.2 g/cm³). Intra-group (symmetric vs. asymmetric), inter-group (SGA vs. AGA) and gender differences were quantified.

SFTs among symmetric, asymmetric SGA infants increased to attain peak by six months. Maximum fat deposition in SGA infants was noticed for triceps, minimum for mid-axillary SFT. Mean triceps and sub-scapular skinfolds were measured higher in symmetric SGA than in asymmetric infants. SGA infants had significantly (P≤0.05) thinner SFTs than AGA. Growth velocity for SFTs, among symmetric and asymmetric SGA, was measured maximum between one and three months, threreafter it declined and relatively, steepness of fall was maximum for mid-axillary SFT followed by sub-scapular SFT.

Thinner SFTs obtained for symmetric and asymmetric SGA as compared to AGA infants reveal their compromised adiposity and nutritional status. Comparatively, higher SFTs in symmetric than in asymmetric SGA infants appear to suggest that the former have a tendency to accumulate more fat, than the latter during infancy.