contraception 5.3.4

• contraception is designed to prevent pregnancy

  • it prevents an egg or sperm meeting or
  • prevents a fertilised egg implanting in the nucleus
• oral contraception is called the pill
• the pill used to contain high doses of oestrogen, but it caused a lot of side effects so is no longer used
• oral contraception now contains lower doses of oestrogen or only progesterone
• the pill can also be used for cases of heavy bleeding during a period
• the oestrogen only pill inhibits FSH all the time so the eggs dont mature, the uterus lining remains and may stop periods
• the progesterone only pill inhibits FSH and LH and stimulates the womb lining to remain, it stops the release of the egg and prevents ovulation
• the pill prevents heavy bleeding because the lining always remains as no egg is released, so it does not leave, it never gets the signal to break down
• families are now smaller in the developed world - this has helped reduce poverty as less food is needed
• taking the pill can cause health problems so it needs overseeing by a doctor, which can cost money they may not have
• the pill has helped reduce birth rate in crowded countries like china
• the pill is not available in poorer countries due to lack of money - they still have high birth rates and poverty, which means the pill is not where its needed
• the pill could lead to less abortions of unwanted babies, which has better morality and gives people a choice
• some religious groups think that preventing contraception is denying life and ban the use of the pill, this removes personal preference and can cause conflict in families
• hormonal contraception prevents the egg implanting, whereas non-hormonal contraception prevents them from ever meeting, barrier methods or surgery
• hormonal methods include:

  • implants
  • injections
  • patch
  • oral contraception
• non-hormonal methods include:

  • condom
  • vasectomy
  • spermicide
  • turbal ligation
  • diaphragm
  • femidom
• hormonal based contraception:

  • hormones inhibit FSH production
  • thickens mucus in vagina and uterus (harder for sperm to swim in)
  • thins uterus lining
  • administered through pill, patch, implant
• hormone based contraception risks:

  • doesnt protect against STIs
  • possible side effects - breast tenderness, headaches, nausea, mood swings
• chemical methods:

  • spermicide - cover vaginal substances, use with diaphragm or condom
• chemical methods risks:

  • possible urinary tract infections
  • possible vaginal irritation, allergic reactions
  • doesnt protect against STIs
• barrier methods:

  • condom/ femidom / diaphragm / sponge
  • prevents sperm entering the uterus
  • prevents STI transmission
• barrier methods risk:

  • sponge / diaphragm doesnt protect against STIs
  • condoms can split
• intrauterine devices:

  • placed inside uterus - prevents fertilised egg from implanting
  • some contain progesterone
  • some contain copper wire - toxic to sperm
• intrauterine devices risks:

  • has to be fitted by medical practitioner - possible infection source
  • higher chance of yeast infection
  • doesnt protect against STIs
• abstinence is not having sex
• rhythm method:

  • track menstrual cycle and avoid unprotected sex during the fertile period
• rhythm method risks:

  • doesnt protect against STIs
  • one of the least effective forms of contraception (75% effective)
• surgical methods:

  • vasectomy - cut sperm ducts
  • tubal ligation - tie oviducts so eggs dont reach the oviducts
• surgical methods risks:

  • both involve operations
  • dont protect against STIs
  • relatively permanent, not easy to reverse
• the progesterone only pill is taken by mouth, the contraceptive implant is injected below skin, the patch is stuck on the skin
• infertility can be caused by:

  • genetics
  • hormone imbalance
  • smoking / drugs
  • lack of sperm
  • endometriosis
• low FSH causes infertility because there would be no stimulation of maturity of eggs in their ovaries
• artificial LH is used to ovulate, artificial FSH is used to mature ovary eggs and oestrogen production is triggered
• in the past, hormone treatment caused issues such as doses not being right, so more eggs would implant and there would be too many foetuses
• now, hormone treatment is more carefully controlled so there are less foetuses ( 1 or 2)
• IVF means in-vitro fertilisation
• IVF is used when:

  • the fallopian tubes are blocked or damaged
  • a donor egg has to be used
  • there is no obvious cause for long term infertility
  • the male does not produce many sperm or they do not mature properly
• FSH and LH are found in fertility drugs for IVF
• IVF:

  1. fertility drugs make a lot of eggs mature at the same time
  2. these eggs are collected and placed in a solution in a petri-dish
  3. semen and eggs are mixed in the petri-dish
  4. the eggs are checked to make sure they are developing successfully
  5. 1 or 2 are placed in the uterus of the mother and will hopefully grow