Gender differences in newborn subcutaneous fat distribution.

Area of Science:

• Neonatal physiology
• Body composition analysis
• Pediatric endocrinology

Background:

• Subcutaneous fat distribution is crucial for neonatal thermoregulation and metabolic health.
• Understanding gender and gestational age variations in fat patterns is essential for assessing infant health.
• Previous studies have indicated potential differences, but comprehensive analysis across a wide gestational range is needed.

Purpose of the Study:

• To assess the pattern and distribution of subcutaneous fat in term and preterm newborns.
• To describe variations in skinfold thicknesses (ST) based on gender and gestational age.
• To evaluate the central to total skinfold ratio (CTS) as an indicator of fat distribution independent of gestational age.

Main Methods:

• Measurement of weight, length, and four skinfold thicknesses (triceps, biceps, subscapular, suprailiac) in 4634 neonates (32-41 gestational weeks).
• Calculation of the central to total skinfold ratio (CTS = (suprailiac + subscapular)/sum of 4 ST).
• Statistical analysis to compare measurements between genders and across gestational ages.

Main Results:

• Males were heavier and longer than females.
• Females exhibited a higher sum of 4 ST and CTS from 35 weeks gestational age onwards.
• The sum of 4 ST per kg body weight was significantly higher in females from 32-33 weeks.
• Skinfold thicknesses increased significantly with gestational age, but CTS remained constant in both genders.

Conclusions:

• Term and preterm females possess a more centralized pattern and a greater amount of subcutaneous fat compared to males.
• The central to total skinfold ratio (CTS) serves as a reliable index of centripetal fat stores, independent of gestational age.