In Vitro Fertilisation

Previous
Next

ninja icon

Application:

•  The use in IVF of drugs to suspend the normal secretion of hormones, followed by the use of artificial doses of

    hormones to induce superovulation and establish a pregnancy

    
In vitro fertilisation (IVF) refers to fertilisation that occurs outside of the body (in vitro = 'in glass’)

  • It involves using drugs to suspend normal ovulation (down regulation), before using hormone treatments to collect multiple eggs (superovulation) 


Down regulation

  • Drugs are used to halt the regular secretion of FSH and LH – this in turn stops the secretion of estrogen and progesterone
  • By arresting the hormonal cycle, doctors can take control of the timing and quantity of egg production by the ovaries
  • The drug treatment usually takes about two weeks and is typically delivered in the form of a nasal spray


Superovulation

  • Superovulation involves using artificial doses of hormones to develop and collect multiple eggs from the woman
  • The patient is firstly injected with large amounts of FSH to stimulate the development of many follicles
  • The follicles are then treated with human chorionic gonadotrophin (hCG) – a hormone usually produced by a developing embryo
  • hCG stimulates the follicles to mature and the egg is then collected (via aspiration with a needle) prior to the follicles rupturing


Fertilisation

  • The extracted eggs are then incubated in the presence of a sperm sample from the male donor
  • The eggs are then analysed under a microscope for successful fertilisation


Implantation

  • Approximately two weeks prior to implantation, the woman begins to take progesterone treatments to develop the endometrium
  • Healthy embryos are selected and transferred into the female uterus (or the uterus of a surrogate)
  • Multiple embryos are transferred to improve chances of successful implantation (hence multiple births are a possible outcome)
  • Roughly two weeks after the procedure, a pregnancy test is taken to determine if the process has been successful


In Vitro Fertilisation Procedure

IVF


shes fit

Summary of the Key Stages of IVF

  • Stop normal menstrual cycle (with drugs)
  • Hormone treatments to promote super ovulation
  • Extract multiple eggs from the ovaries
  • Sperm collected, then prepared (via capacitation) and injected into egg
  • Fertilisation occurs externally under controlled conditions (in vitro)
  • Implantation of multiple embryos into uterus (either patient or surrogate)
  • Test for pregnancy after ~ two weeks


Mnemonic:  SHE’S FIT