by Alison O'Donoghue

Created on: July 01, 2008

Understanding assisted reproductive technology (ART)

In the beginning

Assisted reproductive technology (ART) first came to our attention in 1978 when the world's first "test tube baby", Louise Brown, was born in the UK. Her mother Lesley Brown underwent a surgical procedure known as laparoscopic egg retrieval, a single egg was fertilized in the laboratory (in vitro fertilization [IVF]), and later transferred back into the womb. Soon after, children were born in the USA, Australia and many other countries, using assisted techniques, which subsequently evolved and improved. Today's ART is very different to that used in the early days it is readily accessible throughout most of the developed world and success rates are high.

Cryopreservation: a major advance

There have been a number of different evolutions of ART. One of the key problems in the early days of IVF was that cryopreservation (freezing and thawing) techniques were poor. Therefore any embryos not immediately implanted were usually given to another infertile couple or used in experimental research. Fortunately, cryopreservation techniques improved markedly during the 1980s and now many embryos are stored and implanted at a later date. This process can also help patients who are receiving cancer treatments which may render them infertile. As an alternative to cryopreserving embryos, sperm or ovarian tissue may be stored for future use, should this be more appropriate.

Understanding the acronyms: GIFT, ZIFT and IVF

During the mid-1980s, efforts to simplify and improve ART success rates led to the development of gamete intrafallopian transfer (GIFT), where eggs were retrieved from the ovaries using a laparoscope and immediately transferred into fallopian tubes along with sperm. The advantage of this approach is that fertilization occurs in the natural environment of the fallopian tube and it is possible to avoid the damage to the womb that can occur during transfer of the embryo through the cervix.

The next refinement in technique was transferring laparoscopically-retrieved eggs fertilized in vitro into the fallopian tube via a second laparoscopy. This procedure was known as zygote intrafallopian transfer (ZIFT) and it allowed the confirmation of fertilization but maintained some of the theoretical benefits of GIFT. However, the use of two laparoscopies, one for egg retrieval and the other for zygote transfer, was a major limitation of this approach.

Improvements in ultrasound scanning techniques during the 1980s

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