Fetal hypopituitarism: perinatal endocrine and morphological studies in two cases.

We report two infants with congenital absence of the anterior pituitary gland, documented by magnetic resonance imaging (MRI) or autopsy. In cord plasma obtained at birth from both infants, prolactin (PRL), pituitary growth hormone (hGH), placental growth hormone (hPGH) and thyrotropin (TSH) were undetectable; cortisol was low; thyroxine (T4) was 31 nmol/l in one infant and 85 nmol/l in the other infant who had been treated prenatally with intra-amniotic L-T4 administration. In maternal plasma at birth, PRL, hPGH and T4 were normal and hGH was undetectable. These observations suggest that plasma hGH and PRL in the fetus are exclusively of fetal pituitary origin, hPGH is secreted into the maternal circulation and is not transferred to the fetus and fetal growth can be normal in the absence of hGH, hPGH and PRL in fetal plasma.