Pregnancy & Childbirth Hormones

What is the role of hCG?

Secreted by trophoblast (placenta). Maintains corpus luteum in early pregnancy, ensures progesterone/estrogen secretion. Basis of pregnancy tests.

What is the role of human placental lactogen (hPL)?

Secreted by placenta. Alters maternal metabolism → ensures glucose supply for fetus, promotes lipolysis.

What is the role of progesterone during pregnancy?

Maintains uterine lining, suppresses contractions, keeps cervix closed, promotes breast alveolar development.

What is the role of estrogen during pregnancy?

Promotes uterine enlargement, increases uterine blood flow, prepares breasts (duct growth), upregulates oxytocin receptors in uterus near term.

What is the role of relaxin during pregnancy?

Secreted by placenta and corpus luteum. Softens cervix, relaxes pelvic ligaments, facilitates parturition.

What is the role of oxytocin in labor and lactation?

Secreted by posterior pituitary. In labor: stimulates uterine contractions (positive feedback loop). In lactation: stimulates milk ejection (let-down reflex).

What is the role of prolactin in lactation?

Secreted by anterior pituitary. Stimulates milk production in mammary glands.