controlling fertility

• how can oestrogen be used to reduce ferility?

  if it is taken everyday so its at high level constantly it stops the production of FSH and after a while, egg development and production stop
• how does progesterone reduce fertility?

  process thick mucus which prevents sperm getting through
• what does the contraceptive implant do?

  releases continuous progesterone which stops the ovaries releasing eggs
• what does the contraceptive catch contain?

  oestrogen and progesterone
• what does the contraceptive injection contain?

  progesterone
• what does the intrauterine device(IUD) do (t-shaped)?

  is inserted into the uterus which kills sperm and prevents implantation of a fertilised egg
• what does a plastic IUD release?

  progesterone and copper
• what does the other type of IUD do?

  prevents sperm surviving
• what are the barriers to stop the egg and sperm meeting?

  condoms (protects against sexually transmitted diseases)

  a diaphragm (shallow plastic cup that fits over the cervix has to be used with spermicide)

  spermicide(a substance that disables or kills the sperm)
• what are the other ways to avoid pregnancy?

  sterilisation

  natural methods

  abstinence
• what hormones can be used in a fertility drug?

  FSH, LH
• how does IVF work?

  -collecting eggs and fertilise them in a lab, then transferring them into the women's uterus or injecting sperm directly into an egg
• why are people against IVF?

  unethical and could lead to selection of preferred characteristics