During pregnancy, organism development and its differentiation are stimulated and modulated by fetal and placental hormones. However the exact role played by all the different growth factors has not been explained yet. This study summarizes knowledge about secretion, regulation and role of GH, IGF-1 and SRIF during perinatal age. It also reports the results of researches into GH, IGF-1 and SRIF in amniotic fluid, in mothers and in newborns at delivery and at four days of age. Amniotic fluid GH levels proved significantly higher during middle pregnancy that at delivery (p < 0.001); a significant difference was also found between mean GH concentrations observed in amniotic fluid collected at delivery in preterm and full-term pregnancies. In amniotic fluid, significant reductions of SRIF and IGF-1 concentrations correspond to a sudden decrease of GH concentration during the last months of pregnancy. Fetal serum GH levels resulted higher than venous cordonal GH concentration at birth (p < 0.001). High levels of IGF-1 were found in the amniotic fluid and in the maternal plasma. These values were higher than those observed in cord blood during pregnancy or at delivery. Preterm and full-term newborns showed similar serum GH levels at birth and at the age of 4 days. Mean GH values in newborns, both at birth and at the age of 4 days, proved to be significantly higher than the values of their mothers (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)