menstruation, fertility and contreceptives

• hormones that control menstrual cycle

  FSH, LH, oestrogen, progesterone
• 1st stage of the menstrual cycle

  menstruation starts. uterus lining breaks down for about 4 days
• 2nd stage of the menstrual cycle

  uterus lining builds up again, from day 4 - 14, into a thick spongy layer full of blood vessels, ready to receive fertilised egg.
• 3rd stage of the menstrual cycle

  an egg develops and is released from the ovaries at day 14 - ovulation
• 4th stage of the menstrual cycle

  the wall is maintained for about 14 days until day 28. if no fertilised egg has been received, spongy lining starts to break down and the cycle starts again
• FSH

  produced at the pituitary gland. causes egg to mature in follicle in the ovary - stimulates release of oestrogen
• oestrogen


  produced in the ovary. causes lining of uterus to grow - stimulates the release of LH. stops FSH production
• LH


  produced in the pituitary gland . stimulates follicle to burst and release an egg - ovulation (day 14)
• progesterone

  produced in ovary. maintains uterus lining. inhibits release of LH and FSH
• types of contreceptives

  physical - physical barrier between sperm and egg

  chemical - uses hormones
• natural family planning/rhythm method

  avoid intercourse on most fertile days

  (+) no side effects

  (-) not reliable
• withdrawal method


  (+) no side effects

  (-) not reliable
• sterilisation

  men - tie sperm ducts. women - fallopian tubes are tied and cut

  (+) long term

  (-) may change your mind
• abstinence


  (+) 100% guarantee

  (-) miss that part of a physical relationship
• IUD


  prevents egg from attaching to uterine lining

  (+) LARC

  (-) can be painful, no STI protection
• LARC

  long acting reversible contraceptive
• oral combined pill

  contains progesterone and oestrogen (inhibits release of FSH to stop ovulation)

  (+) highly effective

  (-) easy to forget, no STI protection
• contraceptive injection

  injections contain oestrogen and progesterone - lasts about 12 weeks

  (+) LARC

  (-) doesn't protect against STI'S
• contraceptive implant


  small rod that sits in skin - contains hormones

  (+) LARC

  (-) no STI protection
• condom


  (+) very effective & protects from STI'S

  (-) could split
• Femi-dom

  put into vagina

  (+) blocks STI's, no hormones, no unpleasant side effects

  (-) could split
• diaphragm


  (+) coated in spermicide, protects against STIs

  (-) needs to be fitted to woman - if female gains/loses weight it could be less effective
• emergency contraceptive pill

  used after unprotected sex tp prevent pregnancy

  (+) prevents egg from embedding into theto wall

  (-) side effects
• what causes low fertility

  • low sperm count
  • bad sperm mobility
  • age
  • damaged ovaries
  • obesity
  • eating disorders
• in vitro fertilisation (IVF)


  collect woman's eggs and fertilise them in a lab with the mans sperm
• advantages of IVF

  • can give infertile couples a child
  • unused eggs can be used for stem cells
• disadvantages of IVF


  • multiple births can happen as they inject multiple eggs into a woman
  • can be emotionally stressful for the couple
  • expensive
• why are some people against IVF

  some unused embryos eventually get destroyed so some believe it is unethical.
• Stages of IVF


  Hey give the woman injections of FSH & LH

  Eggs collected and mixed with sperm in a dish

  Embryo is formed

  The put into woman's uterus