Hormones in human reproduction

Where is FSH (follicle stimulating hormone) produced and what does it do?

• It is produced in the pituitary gland

• It causes an egg to mature in an ovary

• Stimulates the ovaries to release oestrogen

Where is oestrogen produced and what does it do?

• It is produced in the ovaries

• It inhibits the production of FSH

• Thickens the uterus lining

• Stimulates the pituitary gland to release LH

Where is LH (luteinising hormone) produced and what does it do?

• It is produced in the pituitary gland

• Triggers ovulation

Where is progesterone produced and what does it do?

• It is produced in the ovaries

• It inhibits the production of FSH and LH

• Maintains the lining of the uterus during the middle of the menstrual cycle and during pregnancy

How long does the menstrual cycle last?

Approximately 28 days

Describe the relationship between the different hormones during the 28 days.

• Days 1 to 12 – oestrogen gradually increases and peaks approximately on the 12th day. Progesterone, LH and FSH stay approximately at the same levels and begin to increase slightly from around day 12.

• FSH and LH patterns are very similar and peak during ovulation at approximately 14 days during this cycle. They drop sharply on day 15 and stay constant until day 28.

• Oestrogen drops during days 13 and 14, and progesterone continues to gradually increase until about day 21, when it slowly beings to decrease again. Oestrogen mirrors this shape and also has a second lower peak at about day 21.

Give two types of oral hormonal contraceptives

• The oestrogen & progesterone pill - combined pill

• The progesterone pill

How effective are oral contraceptives and how are they effective

They are more than 99% effective if taken correctly and can reduce the risk of some cancers

Give some side effects to oral contraceptives

Changes in weight, mood and blood pressure

Give four types of non-oral hormonal contraceptives

• Progesterone injection

• Oestrogen and progesterone patch

• Progesterone implant

• Intrauterine device that releases progesterone

Give some non-hormonal methods of contraception

• Physical barrier methods: Condoms, diaphragms

• Intrauterine devices (IUD)

• Spermicidal agents

• Abstinence

• Surgical methods of sterilisation eg a vasectomy

Give some benefits of non-hormonal contraceptives

• Condoms are quick and easy to use

• IUDs can remain in position for 10 years

• Vasectomies can be reversed

Give some risks of non-hormonal contraceptives

• Condoms can tear

• Diaphragms need to be put in just before sex and have to left in several hours after

• IUDs need to be fitted by a health professional and could cause an ectopic pregnancy

• Some people can have an allergic reaction to spermicides

• Some surgical methods are permanent

What hormones do Fertility Drugs contain

FSH and LH which stimulates eggs to mature in the ovary and the release of eggs from an ovary

What happens in IVF (In vitro fertilisation) treatment?

• IVF involves giving a mother FSH and LH to stimulate the maturation of several eggs.

• The eggs are collected from the mother and fertilised by sperm from the father in a dish in the laboratory.

• The fertilised eggs develop into embryos.

• At the stage when they are tiny balls of cells one or two embryos are inserted into the mother's uterus (womb)

Advantages of IVF treatments

• It allows people to have babies of their own, who otherwise can't due to a variety of reasons.

• It has a safe track record and has been used since 1978. The embryos can be screened for genetic diseases, which is important for families that already have an affected child. Only unaffected embryos are used.

• Unused eggs can be used for research or donated to other couples.

Disadvantages of IVF treatments

• If couples cannot be treated via the NHS then they can pay £5000 for private treatment

• There are side effects form the drugs used, such as hot flushes and severe headaches.

• There is a possibility of multiple births, which is dangerous for mother and babies.

• Ovarian hyper-stimulation syndrome (OHS), when too many eggs develop in the ovaries.

• It is very emotionally and physically stressful.

• The success rates are not high.

Ethical Concerns of IVF Treatments

• The embryos that are not used are destroyed

• Concerns about couples wanting designer babies with desirable qualities