Adipose tissue development ?in Utero?

Abstract

Some metabolic and hormonal variables, thought to affect adipose tissue development "in utero" were studied in a group of 50 presumably healthy mothers and in their full-term infants. No sex-related differences were observed at birth in skinfold thickness, body fat mass, fat cell volume or fat cell number. Body fat mass in newborns was significantly correlated to fat cell size (r = 0.75; p < 0.001), but not to fat cell number. Weight gain during pregnancy but not prepregnancy weight was correlated to fat cell volume in the newborn (r = 0.67; p< 0.001) and to body fat mass (r = 0.66; p < 0.001). Maternal placental lactogen levels correlated to decreased glucose tolerance in the mothers (r = 0.62; p < 0.001), as well as to body fat mass (r = 0.61; p < 0.001) and fat cell size (r = 0.58; p < 0.001) in newborns. Neonatal plasma insulin levels in addition correlated with body fat mass (r = 0.39; p < 0.05) and fat cell weight (r = 0.69; p < 0.001) of the neonate. Placental NEFA transfer could be demonstrated, but there was no correlation between maternal plasma NEFA levels and neonatal body fat mass or fat cell weight. Similarly, maternal insulin and growth hormone levels were not correlated with neonatal body fat mass or with fat cell size or number. Thus the nutritional and hormonal factors considered do not appear to be involved in fat cell multiplication. During intrauterine life, in full-term infants of presumably healthy mothers, fat mass expansion seems to occur almost exclusively by means of fat cell hypertrophy.