Increased mammary growth was observed in test female non lactating mice, as compared to controls when placental lactogen
In late pregnancy, human placental lactogen
also promotes lipolysis and fat mobilization.
The placenta produces a hormone called the human placental lactogen
(HPL), which raises the mother's blood glucose level and makes her body less sensitive to insulin.
This is a consequence of ewes that carry twins during their gestation have a higher number of differentiated and active pre-lambing mammary gland cells (Cappio-Borlino et al., 1997), higher plasmatic levels of placental lactogen
(Schoknecht et al., 1991; Gootwine, 2004) and a higher stimulus of mammary gland during suckling by lambs (Gabina et al., 1993).
Human placental lactogen
(hPL) is produced in the placenta and acts as an immunosuppressant inducing tolerance and gestational fetal growth factor (2).
Consider the case of placental lactogen
The changes in glucose and fat metabolism that he observed during pregnancy are now known to be due to human placental lactogen
and placental growth hormone and not due to hCG.
It also acts on placental trophoblast cells by inducing differentiation into mature syncytiotrophoblast and stimulates its secretion of placental lactogen
and chorionic gonadotropin (Baldwin 1992; Garcia-Lloret et al.
 Human genes: PLAC4, placenta-specific 4; CSH1, chorionic somatomammotropin hormone 1 (placental lactogen
); CGB, chorionic gonadotropin, beta polypeptide; CRH, corticotropin releasing hormone.
Experts suspect it is related to changing hormone levels, particularly human placental lactogen
, produced by the placenta.
But as pregnancy progresses, human placental lactogen
, progesterone, and prolactin cause insulin resistance, so the dose must be increased.
Additional factors in GDM that may contribute to hyperglycemia include human placental lactogen
, progesterone, and other gestational hormones.[6,32] Few have considered, however, the introduction of drugs that promote glucose intolerance as an alternative cause of gestational diabetes.