Fig. 1: Change in hormonal activity during the transition from fetal to postnatal life.

Hormonal activity levels in the newborn undergo changes, caused by the dissociation of the maternal-placental-fetal unit with birth and the maturation of the newborn. PGH placental growth hormone, IGF insulin-like growth factor, GH growth hormone, hPL human placental lactogen, Thyroid thyroid hormones.