What hormones are involved in pregnancy? What role do they play?

What will be an ideal response?

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Answer: 

The major hormones that play important role in pregnancy are :

1. Progesterone
2. hCG
3. Oxytocin
4. Relaxin
5. Estrogen
6. Prolactin

Roles :

1) Progesterone : Progesterone is released from corpus luteum and the placenta. It acts on endometrium of uterus and matain its thickness. It prepares the endometrium to receive fertilized egg. It also inhibits uterine contractions to maintain the pregnancy.

2) Human chorionic gonadotropin (hCG) : In the beginning of pregnancy, hCG released from placenta maintains corpus luteum. Corpus luteum is very important structure for availability of progesterone.
hCG helps in detection of pregnancy.

3) Oxytocin : Oxytocin is secreted from posterior pituitary gland. Uterine contractions during labor stimulate the release of oxytocin. Oxytocin inducce more vigorous uterine contractions to expel the fetus out of the womb.

4) Relaxin : Relaxin hormone is released by placenta. It functions to soften and dilate the cervix during stages of labor. It is also involved in rupture of fetal membranes and weaking of pelvic ligaments to stretch the pelvis during delivery.

5) Estrogen : Estrogen cause vasodilation to increase the blood flow to uterus. It promotes growth of mammary glands and stimulate release of prolactin from anterior pituitary gland.

6) Prolactin : Prolactin stimulates milk production in the mammary glands.