Some couples have difficulty conceiving children and this can be caused by a number of factors. The man might have a lower than average number of sperm in his semen, or the sperm may not be very mobile. Some women don’t produce enough FSH to allow their eggs to mature.

Fertility treatments

Fertility drugs contain FSH, which stimulates eggs to mature in the ovaries. This treatment increases the woman’s chance of becoming pregnant, although the treatment may not always work. Because the treatment boosts the production of mature eggs, it increases the chance of twins or triplets. Multiple pregnancies carry a higher risk of complications, and may lead to premature or underweight babies.

In vitro fertilisation (IVF) treatment

If a couple are having difficulty conceiving a child because there are issues with the quality of the man's sperm, or a woman has blocked oviducts, then in vitro fertilisation or IVF can be used.

• 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 (in vitro literally means 'in glass').
• 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.

The development of microscopy techniques has allowed IVF treatments to be developed further.

In some cases, the sperm have difficulty moving so cannot fertilise the egg. Scientists can now directly inject the egg with a sperm cell. They use a powerful light microscope to carry out this technique.