Hormones

Hormones regulate the functions of many organs and cells. Hormones are chemicals that are secreted (produced) by , that are transported to all parts of the body through the , and affect specific target organs.

Examples of Hormones

• Adrenaline - 'Flight or Fight' response
• Insulin and Glucagon - Control of blood sugar level
• Testosterone - Male sex hormone

During the 28 day menstrual cycle the old lining of the is shed and then a fresh lining built up again in readiness for a possible pregnancy. The shedding of the lining which is accompanied, by a loss of blood, is called and marks the beginning of a new cycle.

On the 14th day of the cycle a mature (Ovum) is released from one of the in a process known as .

If the egg is fertilised by the , the lining of the uterus provides protection and food for the developing embryo. If the egg is not the lining of the uterus and the egg are shed from the body and this is called a .

Click image to see cycle in full

Use the diagram above to complete the following:

FSH which is secreted by the and causes eggs to in the ovaries, and also stimulates the ovaries to produce hormones including .

Oestrogen which is secreted by the and inhibits the further production of as well as stimulating the to produce a hormone called .

Women can take oral (by mouth) contraceptives which contain the hormone which inhibits FSH production so that no eggs mature. This practically reducing the chance of getting pregnant to zero. However if just one daily pill is missed then the women may become unprotected.

We must also consider the reported side effects such as:

• breakthrough bleeding and spotting - especially during the first 3 months of taking,
• breast tenderness and breast enlargement,
• change in shape of the cornea (front covering of the eye) resulting in discomfort when wearing contact lenses,
• depression (low mood),
• fluid retention,
• headache,
• migraine,
• nausea (feeling sick) or vomiting (being sick),
• reduced libido (interest in sex),
• rise in blood pressure,
• rise in blood sugar,
• stomach upset,
• temporary infertility after stopping the COC pill,
• vaginal thrush,
• weight gain.

Find out more from the NHS

Fertility Treatment

Fertility Drug

can be given as a 'fertility drug' to a woman whose own level of hormone is too low to stimulate eggs to mature. Fertility treatments increase a woman's chance of becoming pregnant, although the treatment may not always work.

On the other hand, because the treatment boosts the production of mature eggs, multiple conceptions sometimes occur, with twins or triplets being expected. This increases the risk of complications in pregnancy and childbirth, and may lead to premature or underweight babies.

IVF

'In-vitro Fertilisation' (IVF) is the process of hormonally controlling the ovulatory process, removing eggs from the woman's ovaries and letting sperm fertilise them in a 'test tube'. In fact 'In Vitro' means 'in glass'. The fertilised egg (zygote) is then transferred to the patient's with the intent to establish a successful pregnancy.

If FSH is injected into the patient then several mature eggs can be produced at once. This doesn't normally happen because the produced by the would normally stop the production of FSH. Injecting FSH allows a number of eggs to be havested at once, increasing the chance of success while minimising trauma to the patient.

Some people worry about the ethical implications of IVF. They are concerned that couples may only want fertilised eggs with 'desirable' qualities - so called 'designer babies'. For example, they may want a girl if they have lots of boys in the family, or they may wish to avoid producing a baby with an inherited defect.

Find out more from the NHS