Egg retrieval procedures are performed approximately 36 hours after hCG injection. The procedure is done under a mild anesthetic and it takes between 10 and 50 minutes to complete, depending on the number of follicles present on the ovary. Under ultrasound guidance, a thin needle is inserted into each follicle and the follicular fluid is aspirated by applying gentle suction. This fluid is passed on to the laboratory where it is examined under a microscope by an embryologist in order to identify the egg(s). Once identified, the egg(s) is isolated and placed into a specialized petri dish containing droplets of a nutrient fluid or ‘culture medium’.
The dish (GPS) and the culture medium (Global) in use in our laboratory were both developed by scientists associated with the ART Institute of Washington, and are now used by hundreds of other clinics worldwide. Once all the eggs are collected, the GPS dish is placed inside an incubator where it remains until the time of insemination – or when the eggs and sperm are combined. The incubators in the laboratory are state of the art warm chambers that are filled with ultra-clean air, obtained by removing the gas phase above liquid nitrogen. This gas is free from volatile organic compounds and is further cleaned by filtration through a special filter, the CODA filtration system, developed by scientists associated with the ART Institute of Washington. The incubators are meticulously monitored by the embryologists to assure optimal function but they are also connected to a centralized alarm system which is active 24 hours a day and will warn embryologists in the event that any of the incubator functional parameters is outside the pre-determined range.
Most patients do not experience pain related to the aspiration procedure, but they do often report pressure or menstrual-like cramps. Patients should not drive after the egg retrieval; normal activities may be resumed 24 hours later.