Controlling fertility

• Hormones can be used to reduce fertility
• oestrogen can be used to prevent the release of an egg so can be used as contraception
• if oestrogen is taken every day to keep the level of it permanently high, it inhibits the production of FSH and after a while egg development and production stops and stay stopped
• Progesterone reduces fertility by stimulating the production of thick mucus which prevents sperm getting through and reaching an egg
• combined oral contraceptive pill

  contains oestrogen and progesterone

  over 99% but can cause side effects like headaches and nausea no protection against STDs
• progesterone only pill 


  fewer side effects and just as effective
• contraceptive patch 


  oestrogen and progesterone

  patch stuck to skin lasting a week
• contraceptive implant 


  inserted under skin of the arm

  releases continuing amount of progesterone which stops ovaries releasing eggs

  lasts 3 years
• contraceptive injection 


  contains progesterone

  dose lasts 2-3 months
• IUD


  t shaped device inserted to uterus kill sperm and prevent implantation of a fertilised egg

  plastic IUD- released progesterone

  copper IUD- prevents sperm surviving uterus
• hormones can also be used to increase infertility
• IVF can help people have children
• IVF


  involves collecting eggs from the woman's ovaries and fertilising them in a lab using the mans sperm
• IVF


  1. can involve a technique 'Intra Cytoplasmic Sperm Injection (ICSI)' where the sperm is injected directly into an egg

  2. fertilised eggs are then grown into an embryo in a labratory incubator

  3. once the merbyos are tiny balls of cells, one or two of them are transferred to the womans uterus to imrpove the chance of preganancy
• downsides to IVF


  multiple births can happen if more than one embryo grows into a baby causing a higher risk of a miscarriage or still birth making the process very stressful and often upsetting

  process if physically stressful for the woman and some woman have strong reaction to the hormones leading to abdominal pain, vomiting and dehydration
• improvements in IVF


  advances in microscope techniques

  specialised micro tools to do geneitc testing

  development of time lapse imaging