In Vitro Fertilization – Stage 2

Egg Aspiration (Oocyte Retrieval)  at our Colorado Fertility Center for patients seen at our 2 Colorado locations and South Dakota office.

Despite the continuous growth of the follicle for more than 10 days, the egg does not complete the final maturation until a specific signal is given. This signal is given by the release of LH from the pituitary gland in the natural cycle. This release is blocked with the use of GnRH agonist or antagonist. During the IVF process, once it is determined the eggs are mature (by ultrasound assessment of the follicles and measurement of estradiol), this signal is given by the injection of human chorionic gonadotropin (hCG).

The timing of this injection is very important. Spontaneous release of the eggs will begin at about 38-40 hours after this injection. It is necessary to retrieve the egg BEFORE ovulation has taken place. It is realized that the closer to ovulation the retrieval is performed, the greater the success of fertilization with Colorado IVF. Timing is critical. Therefore, in rare instances ovulation may occur naturally before retrieval is possible.

During a transvaginal retrieval, a needle is inserted through the vagina under sonographic (ultrasound) guidance, and into the follicle (fluid collection) so the egg and follicular fluid may be aspirated. The egg itself can be seen only under the microscope once the fluid is taken into the laboratory (see Figure 3). Spinal anesthesia or IV sedation will be used for these procedures.

A laparoscopic retrieval will only be used under special circumstances with in vitro fertilization. During laparoscopy, an instrument which permits the telescopic viewing of the follicles is inserted through the abdomen. A needle is introduced through a second incision and placed into the follicle. The egg and the follicular fluid can then be aspirated.

Transvaginal Oocyte Retrieval Procedure


The oocytes are retrieved in one of two ways: through a surgical procedure called laparoscopy or through transvaginal retrieval by ultrasound guidance. Ultrasound-guided retrieval has become the standard for almost all procedures.

For premier in vitro fertilization services in Wyoming,  North Dakota, South Dakota and Colorado, Rocky Mountain Fertility has an Award Winning doctor and caring, dedicated staff for personalized treatment. RMFC helps build families… everyday!

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