Menstrual Cycle & Reproductive Hormones & Contraception & Fertility

Where is FSH produced and what does it do?

FSH is produced by the pituitary gland and causes an egg to mature in an ovary.

Where is LH produced and what does it do?

LH is produced by the pituitary gland and stimulates ovulation — release of the egg.

Where is oestrogen produced and what does it do?

Oestrogen is produced by the ovaries and causes the uterus lining to develop/thicken.

Where is progesterone produced and what does it do?

Progesterone is produced by the corpus luteum in the ovary and maintains the lining of the uterus.

How does FSH interact with oestrogen?

FSH stimulates oestrogen production. Oestrogen inhibits FSH production.

How does oestrogen affect LH?

High oestrogen levels stimulate LH production, leading to ovulation.

How does progesterone affect FSH and LH?

Progesterone inhibits FSH and LH production.

How do hormonal contraceptives prevent pregnancy?

Hormones inhibit FSH production, so eggs do not mature; some also affect cervical mucus and the uterus lining.

How do barrier methods work?

They prevent sperm from reaching the egg.

What is sterilisation?

A surgical method in which the sperm ducts or oviducts are cut or blocked, preventing sperm and egg from meeting.

How can fertility drugs help someone become pregnant?

FSH stimulates eggs to mature and LH stimulates ovulation.

Describe IVF.

FSH and LH are given to stimulate maturation and release of several eggs → eggs are collected → fertilised with sperm in a laboratory → embryos develop → one or more embryos are inserted into the uterus.

Give disadvantages of IVF.

It is emotionally and physically stressful, has a low success rate, and can cause multiple births, increasing risks to mother and babies.