IVF and reproductive hormones HT: Homeostasis and response: Biology: GCSE (9:1)

• Pituitary gland


  The master gland that is responsible for releasing FSH and LH

  
• Follicle-stimulating hormone (FSH)


  Stimulates the growth of a follicle and promotes the maturation of an egg in the ovary

  
• FSH interaction with other hormones

  Causes follicle growth which promotes the release of oestrogen from the ovaries
• Oestrogen


  Responsible for the growth, repair and maintenance of the lining of the uterus

  
• Oestrogen interaction with other hormones

  Promotes the release of LH from the pituitary gland and inhibits the release of additional FSH
• Luteinising hormone (LH)


  Responsible for ovulation by stimulating the release of the egg from a follicle in the ovary

  
• LH interaction with other hormones


  Causes the corpus luteum to form which promotes the release of progesterone from the ovaries

  
• Progesterone


  Maintains the lining of the uterus during the latter part of the menstrual cycle and during pregnancy
• Progesterone interaction with other hormones

  Inhibits FSH and LH production as an example of negative feedback
• If fertilisation does not occur


  The corpus luteum dies and levels of progesterone decreases, resulting in menstruation and the start of a new cycle
• Corpus luteum

  A structure in the ovaries that forms from a follicle when an egg is released, releases progesterone

  
• Ovary


  An organ of the female reproductive system where egg development occurs and oestrogen and progesterone are released

  
• Infertility


  Where a couple are not able to conceive which could be due to age, cancer, faulty sperm production or other reproductive system complications
• Fertility drug

  FSH and LH can be supplemented as a treatment for infertility

  
• In vitro fertilisation (IVF)

  A process where eggs are extracted from the ovary and are artificially fertilised outside of the body, before implanting back into the uterus

  
• Early stages of IVF

  FSH and LH are given to stimulate egg development, eggs are then collected from the mother's ovaries

  
• Incubation stage of IVF

  Eggs are kept in a laboratory and are fertilised with sperm from the father, eggs are left to develop into embryos

  
• Later stages of IVF

  When embryos are tiny balls of cells, one or two embryos are inserted into the mother's uterus where foetal development can occur

  
• Surrogate mother

  Someone who volunteers to carry a baby in their womb, usually when the biological mother is not able to do so
• Complications of fertility treatments

  Can be stressful, with low success rates and can also lead to multiple births which is a risk to the mother and babies