Transvaginal oocyte retrieval (TVOR) is a technique used during in vitro fertilization (IVF) to remove eggs from the ovary. Also called oocyte retrieval (OCR), this procedure allows for fertilization to occur outside the body in the laboratory setting. TVOR was developed by Pierre Dellenback of France in 1984, and was introduced in the U.S. at the Genetics and IVF Institute in 1985.
Preparing for TVOR
Before the procedure, the ovaries are stimulated with injections of medication. This causes the follicles to develop. Once the ovarian follicles reach full development, an injection of human chorionic gonadotropin (hCG) is given, which will make the eggs mature. When you arrive at the fertility center, a nurse will go over the procedure and ask you to sign a consent form. After you change into a gown, an IV line is placed in your arm to administer anesthesia and necessary medications. An embryologist will ask you questions to confirm your name, partner’s name, and identification numbers. This is done to ensure no mix up of the eggs or sperm occurs.
After you are changed into a gown, and positioned on the table, anesthesia is given. Using ultrasound guidance, the doctor inserts a needle through the vaginal wall and into the ovarian follicle. Outside the body, the other end of the needle attaches to a special suction device. After entering the follicle, the doctor gently applies suction to pull out follicular fluid containing eggs. Several follicles are targeted with TVOR during one session. Once fluid is obtained from the follicles, the needle is withdrawn, and the procedure is repeated on the other ovary. After collecting from the follicles, the fluid is sent to the laboratory to identify and count the eggs (ova). Usually, 15-25 eggs are removed, especially if hyperstimulation medication was taken.
Risks and Side Effects
There is a risk of ovarian hyperstimulation syndrome with the administration of hCG for ovulation. This is more common for women with polycystic ovary syndrome. While complications of TVOR are rare, they include bleeding, infection, and organ damage. Side effects to anesthesia and medications used during the procedure could occur, including rash, itching, low blood pressure, and breathing problems.
The Number of Eggs Retrieved
During one TVOR session, 10-15 eggs are usually removed, but this can vary from woman to woman. Not all eggs will be fertilized, so the number of eggs removed is no indication of how many embryos will result after fertilization.
While you are undergoing TVOR, your partner is asked to provide a fresh semen sample. This way the sperm can be concentrated and “washed” in the laboratory setting. If you are using a sperm donor, the clinic will thaw your selected donor sperm to coincide with your egg retrieval procedure.
After the egg retrieval procedure, you will feel groggy as the sedative wears off. Expect some soreness and mild swelling of the lower abdomen. These side effects will pass after a few hours, and you can gradually return to usual activities in 1-2 days. The fertility doctor will prescribe some antibiotics for you to take for a few days. If you are prone to yeast infections, acidophilus may help, which is an over the counter supplement.
In addition, you must take progesterone, either by suppository or injection. This prepares the lining of the uterus (endometrium) for receiving the resulting embryos. If you do test positive for pregnancy, you may continue the progesterone for up to 12 weeks. Side effects are mild and include constipation, bloating, and nausea.