2.3

• Contraception


  Method or device used to prevent pregnancy
• Ectopic pregnancy


  A pregnancy where the embryo implants and starts to develop in an oviduct
• Fertility


  The ability to reproduce
• Follicle stimulating hormone (FSH)


  A hormone which stimulates oestrogen production and the growth of follicles (egg-sacs) in the ovary. It is secreted by the pituitary gland
• Hormone


  A chemical substance, produced by a gland and carried by the blood, which alters the activity of specific target organs
• Infertility


  The inability to reproduce
• Interstitial cell stimulating hormone (ICSH)


  A hormone produced by the pituitary gland that stimulates the production of testosterone in the testes
• Menstruation (or period)


  The loss of blood and tissue from the lining of the uterus through the vagina during the menstrual cycle
• Mucus


  Fluid produced in the body which can act as protective barrier or provide lubrication
• Oestrogen


  A female sex hormone produced in the ovaries, responsible for puberty in girls and the regulation of the menstrual cycle
• Ovulation


  The release of an ovum (egg) from one of the ovaries
• Progesterone


  Sex hormone produced by the ovaries and placenta, responsible for thickening of the uterus lining
• Sterile


  Inability to create offspring (children)
• Zygote


  A fertilised egg cell
• Infertility treatments and contraception are based on the biology of fertility
• Women show cyclical fertility leading to a fertile period. Levels of oestrogen, progesterone, FSH and LH fluctuate. As a result, women are only fertile for only a few days during each menstrual cycle
• Men show continuous fertility. Levels of testosterone, FSH and ICSH are kept relatively constant through negative feedback. As a result, men continually produce sperm in their testes
• Identifying the fertile period

  1. Body temperature increase after ovulation

  2. Cervical mucus changes around ovulation

  3. Timing of the menstrual cycle
• Stimulating ovulation


  1. Drugs that prevent the negative feedback effect of oestrogen on FSH secretion

  2. Drugs that mimic the action of FSH and LH
• Artificial insemination


  1. Collect semen samples over time

  2. Treat semen to remove dead sperm, low sperm and impurities

  3. Pass concentrated sample of healthy sperm through a catheter into the uterus
• Intra-cytoplasmic sperm injection (ICSI)

  Draw the head of the sperm into a needle and inject directly into the egg to achieve fertilisation
• In vitro fertilisation (IVF)

  1. Give the mother FSH and LH to stimulate maturation of several eggs

  2. Surgically remove eggs from ovaries

  3. Mix eggs with sperm in a culture dish

  4. Incubate fertilised zygotes until they form an embryo

  5. Transfer embryo to the uterus for implantation
• The use of IVF in conjunction with pre-implantation genetic diagnosis (PGD) where one or both parents are at risk of passing an a serious inherited disease to their children. PGD can be used to identify single gene disorders and chromosomal abnormalities in developing embryos before they are implanted into the uterus
• Ratio


  A way of comparing two or more quantities
• Physical methods of contraception

  • Condoms
  • Diaphragms
  • Intrauterine devices (IUD)
  • Spermicidal agents
  • Abstinence
  • Surgical methods of male and female sterilisation
• Condoms


  • Easy and quick to use, can be effective when used properly
• Diaphragms


  • Can remain in position for up to 10 years
• Intrauterine device (IUD)


  • Can be used successfully, no cost and non-intrusive, small risk of causing an ectopic pregnancy
• Abstinence


  • Can be used successfully, no cost and non-intrusive, high chance of pregnancy if timings are not accurate
• Surgery


  • Can be very effective, sometimes cannot be reversed and is considered permanent
• Chemical methods of contraception

  • Oral contraceptive pill
  • Progesterone-only (mini) pill
  • Morning-after pill
• Oral contraceptives


  • More than 99% effective if taken correctly, can reduce the risk of certain cancers, potential side effects such as changes in weight, mood and blood pressure due to high levels of oestrogen
• Contraceptive injections


  • More than 99% effective, repeat injections needed every 8-13 weeks before it expires or becomes ineffective
• Oral contraceptive pill


  Contains a combination of synthetic oestrogen and progesterone that mimics negative feedback preventing the release of FSH and LH from the pituitary gland. Eggs cannot mature.
• Progesterone-only (mini) pill


  Causes thickening of the cervical mucus
• Morning-after pill


  Contains a stronger dose of oestrogen and progesterone than the contraceptive pill. It prevents ovulation or implantation.