In Vitro Fertilisation (IVF)

Key requirements, pros and cons

  • More demanding than OI / IUI
  • Suitable for almost all forms of infertility
  • Better success rates than OI / IUI
  • More diagnostically informative than OI / IUI
  • May need sperm injection to assist fertilisation

Reproductive techniques were revolutionised by the birth of Louise Brown in 1978. This was the world’s first IVF birth and Louise was delivered by a mother who did not have fallopian tubes. This is the routine treatment now offered to patients whose tubes are not suitable for tubal surgery or if tubal surgery has failed.

Oocyte pick-up and In Vitro Fertilisation (IVF)

Following stimulation of the ovaries with FSH injections, the eggs are collected from the patient via a vaginal ultrasound guided needle either under general anaesthesia or local anaesthetic. On average 11-12 eggs are collected after ovarian stimulation with FSH. The eggs are fertilised by the husband’s sperm and 1 to 3 of the resultant embryos are transferred to the mother’s uterus between 2 and 5 days following the egg collection. On average 65% percent of the eggs will be fertilised. The fertilised eggs are the grown (cultured) in the laboratory to either the day 2 / 3 stage known as cleavage stage embryos or to day 5/6 when the embryos have become blastocysts.  

Cleavage stage embryo transfer (Day 2 or 3)

In general day 3 transfer is used as it allows more time for the faster developing embryos to become apparent, which assists in selecting embryos with a better potential. However, if there are only 1 or 2 embryos or the selection of embryos is clear earlier then embryos will be transferred on day 2. Surplus embryos can be frozen at this stage with a high degree of success (approximately 75% of embryos are suitable for transfer after thawing).

Blastocyst stage embryo transfer (Day 5 or 6)

Culturing the embryos for a further 2 or 3 days provides evidence of further developmental potential. This is useful in patients who have more than 3 embryos. Blastocysts can now be frozen with thaw survival rates as good if not better than cleavage stage embryos. 

Other assisted reproduction methods

Various modifications to the conventional IVF method described above have been developed over the years and these are listed below. Some of these techniques have been shown to offer little advantage over conventional IVF or IVF supplemented with intra-cytoplasmic sperm injection and are now not commonly used. Whereas others are employed in specific circumstances only.

Gamete Intra Fallopian Transfer (GIFT)

GIFT is an appropriate therapy for some couples where there has been a past history of endometriosis and for unexplained infertility. Following stimulation of the ovaries with FSH injections, the eggs are collected via a vaginal ultrasound directed needle under general anaesthetic and while the patient is still asleep, 2 or 3 eggs are transferred to the mother’s tubes via a laparoscopy with semen from the husband for fertilisation then to occur in the tubes.

Pronuclear Stage Transfer (PROST)

PROST is a step further than GIFT in that fertilised eggs are place in the woman’s tubes one day after egg collection. This is particularly appropriate where there is a male factor and if there is some concern that fertilisation may not occur. The down side is that the woman requires 2 anaesthetics within 24 hours and is a technique now rarely used as it does not seem to improve the pregnancy rates compared to uterine embryo transfer in our experience.

Tubal Embryo Stage Transfer (TEST)

With the TEST procedure the embryos are placed into the fallopian tubes on the 2nd day after egg collection. The woman needs an anaesthetic for this transfer. Again this is rarely used, as we cannot demonstrate an improved pregnancy rate to justify the administration of two anaesthetics.

GIFT, PROST and TEST procedures are not commonly used these days.