Regulation of fetal growth by the somatotrophic axis.

Suboptimal fetal growth is associated with higher fetal mortality and with higher neonatal morbidity and mortality. It increases the likelihood of premature birth that in turn further compounds perinatal health risks. Moreover, an abnormal fetal environment, as reflected in an altered birth size phenotype, increases the propensity for disease in childhood and adulthood. Fetal growth represents the culmination of interaction between the fetal genome and the in utero environment determined by maternal-placental function. The role of endocrine and metabolic factors in mediating this interaction will be reviewed. There is also evidence that fetal growth, as measured in late gestation, is dependent not only on the maternal environment but on events that occurred during the periconceptual period. Thus, fetal growth not only reflects the immediate fetal environment but events surrounding conception and embryonic life.