Assisted reproductive technologies

• Healthy young couples having sex regularly have a 25% chance of conceiving within a month.
• A couple is considered infertile if they haven’t conceived within a year.
• The role of the human male in reproduction was not understood in past civilizations and is still veiled in mystery for many tribes.
• It is important to discover the cause of infertility as this will probably determine the type of treatment needed.
• Age factor


  A woman’s fertility declines sharply after the age of 35.
• Infertility causes in women

  Hormone imbalance<|>Blocked Fallopian tubes<|>Problems with uterus (endometriosis, polyps, fibroids)
• Infertility causes in men

  Low sperm count<|>Poorly formed sperm<|>Production of anti-sperm antibodies<|>Blocked sperm duct
• Infertility treatments


  • In vitro fertilisation (IVF)
  • Ovulation Induction
  • Fertility drugs
  • Artificial Insemination

  
• 1% of births in Australia result from some type of infertility treatment.
• In vitro fertilisation (IVF)

  Literally means ‘fertilisation in glass’.
• Ovulation Induction


  1. Sex hormone injections encourage egg growth and ovulation

  2. Often used in conjunction with IVF treatment
• Fertility drugs


  Stimulate egg growth and ovulation<|>Produce multiple eggs for IVF<|>Improve the condition of the endometrium
• Semen can be injected directly into the woman’s uterus in cases of low sperm count or partner’s cervical mucus containing antibodies.
• In vitro


  Literally, “in glass” i.e. a procedure carried out outside the body.
• In vivo


  Inside a living body.
• IVF procedure


  1. Ovarian stimulation

  2. Egg retrieval

  3. Insemination

  4. Fertilization

  5. Embryo transfer

  
• IVF - Ovarian stimulation

  1. Fertility drugs stimulate ovaries

  2. Follicles monitored using ultrasound
• IVF - Egg retrieval

  1. Harvested using transvaginal ultrasound aspiration

  2. Fine needle guided through vagina into ovary

  
• Insemination, fertilization and embryo culture

  1. Harvested eggs added to sperm in IVF culture medium

  2. Sperm injected directly into egg (ICSI)

  
• Between 1-6 days after fertilisation the embryo is transferred to the woman’s uterus.

  
• Embryo transfer


  Embryo introduced into uterus through thin tube inserted through vagina and cervix
• IVF Procedures


  • Gamete intraFallopian transfer (GIFT)
  • Zygote intraFallopian transfer (ZIFT)
  • Intracytoplasmic sperm injection (ICSI)
  • Epididymal and testicular sperm extraction

  
• Gamete intraFallopian transfer (GIFT)


  Egg and sperm introduced directly into the tube for fertilisation in the body.
• Zygote intraFallopian transfer (ZIFT)

  Fertilisation takes place in the laboratory and the zygote is placed in the Fallopian tube.
• Intracytoplasmic sperm injection (ICSI)

  A single healthy sperm is injected directly into the egg.
• Epididymal and testicular sperm extraction


  Sperm extracted directly from testes or sperm duct if the man’s sperm duct is blocked.

  
• Commonly used infertility treatments

  • Freezing of Gametes and Embryos
  • Genetic Testing
• Sperm, eggs and embryos can all be frozen and stored for several years (5 in Australia).
• Freezing gametes and embryos may be useful if IVF treatments don’t work the first time.
• Genetic tests serve many purposes and are widely used to screen newborns for a variety of disorders.
• In oncology, doctors use gene testing to diagnose cancer, classify cancer into subtypes, or predict a patient’s responsiveness to new treatments.
• Gene Tests – Three Common Methods

  • Amniocentesis
  • Chorionic Villus Sampling
  • Blood tests of mother’s blood
• Amniocentesis


  10 – 20 mL of amniotic fluid taken during the 16th to 20th week of pregnancy
• Amniocentesis can detect down syndrome, cystic fibrosis, neural tube defects, PKU, Tay-Sachs and more.
• Chorionic Villus Sampling


  Cells from the chorion are tested between 9 – 19 weeks of pregnancy
• Chorionic Villus Sampling has a 1 in 100 chance of a miscarriage and cannot detect spina bifida.
• Blood tests of mother’s blood

  1. Occurs 6 weeks after conception

  2. Isolates foetal cells in the mother’s blood
• Biochemical Analysis


  Detects the number of protein markers and is used to detect PKU.
• DNA Probes


  A segment of DNA is attached to the gene in question and is used to identify a ‘gap’ in the DNA.