In 1973, De Kretser and colleagues described the first IVF pregnancy that was achieved in 1972. The oocyte was obtained by way of laparotomy. Since this was a traumatic approach, it was due to the laparoscopy expertise of Patrick Steptoe, that resulted in his successful partnership with Robert Edwards, and as a consequence in the birth of Louise Brown in 1978. This change in oocyte collection was rapidly applied around the world, and was used in the collection of eggs for the Monash team, that converted IVF from a research tool to clinical treatment. It was also used by Jones’ team when in 1982 they achieved the first pregnancies in the USA.
Since the early 1980s, laparoscopic oocyte collection has become a worldwide procedure, until the pioneering work in 1984 of Susan Lenz in Copenhagen, and Wilfred Feichtinger, in Vienna, which changed oocyte collection to a transvaginal, ultrasound-guided technique. Since then, oocyte collection guided by vaginal ultrasound has become the method of choice.
Berger and colleagues devised a special aspiration unit, with a 20-gauge, 10-inch needle connected to a 10 mm vacutainer by a polyethylene tube, which was then connected to a vacuum bottle with an adjustable pressure gauge. Today, sophisticated suction pumps with adjustable aspiration pressure are extensively available commercially.
Aspiration of one follicle after the other, and follicular fluid from the next follicle often flushes the oocyte into a collection tube.
It is possible to use a double lumen needle to flush the follicles with medium in order to retrieve the oocyte. This method is reserved for cases where very few oocytes are expected.
It is important to know that during aspiration, the temperature of follicular fluid drops by 7.7 ± 1.30C. Dissolved oxygen levels rose by 5 ± 2 vol%. The pH increased by 0.04 ± 0.01. These changes could be detrimental to oocyte health, and efforts should thus be made to minimise these.
Since the time of egg collection through the vagina, relaxant analgesia has no longer been required. Currently there are vast variations in the type of analgesias used for oocyte collection. In some areas oocyte collection is undertaken without any analgesia (such as in China), whereas elsewhere para-cervical block, local anesthesia, intravenous sedation, or even general anesthesia is administered. Basically, this depends on cultural expectations, the facility used for oocyte collection, and the medical financial rebate system.
Egg aspiration procedure in progress - an egg is being aspirated from a follicle
The needle is the bright white structure (right side).
Although rare, several possible complications of transvaginal oocyte collection have been reported.
The most common operative complications are
• Trauma to pelvic structures
• Pelvic infection
• Anesthetic complications
The incidence of acute abdomen following egg collection is reported to be between 0.1% and 1.5%.