human placental lactogen

A baby of one to three months should eat about four to six ounces per feeding. Some babies with a larger appetite may want more per feeding.

In humans, the outer layer of the blastocyst, called the trophoblast, secretes human chorionic gonadotrophin (hCG),human placental lactogen (HPL), and other hormones.

Estrogen

It's under hormonal control (which is mostly under brain control).

An entire collection of hormones:

Progesterone

oestrogen

follicle stimulating hormone

luteinizing hormone

prolactin

oxytocin

Human placental lactogen

at least.