Medical Health Encyclopedia

Use of Donor Eggs. Older women are more likely to use donor eggs. In a 2002 study, success rates were the same for women who used donors with an age range of 20 to 40. There were also no differences in delivery rates for recipients up to age 45. Women over 45, however, increasingly had problems with implantation, pregnancy, and delivery.

Use of Frozen Eggs. Frozen eggs tend to have lower success rates because of toxins released by cells damaged in the freezing and thawing tissues. An interesting study in 2002 suggested that the use of lasers to remove these dead cells may increase the chances of success in the thawed embryos.

Other IVF Techniques

In Vitro Maturation. A new technique called in vitro maturation allows fertilization without the use of fertility drugs. In this process, follicles are harvested a few days before ovulation. In such cases, up to 50 have already begun to mature. At this time, about 15 of these maturing follicles can be removed, out of which two or three can produce healthy embryos.

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Blastocyst Transfer. Blastocyst transfer is very promising. Instead of implanting the standard two- or three-day-old embryos in the uterus, the procedure implants blastocysts, which are more complex, five-day-old embryos. Fewer blastocysts than embryos need to be implanted, reducing the risk for multiple births. (There is, however, a higher risk for identical twins compared to other procedures.) Offspring may be more likely to be males than females. Pregnancy rates are about 36% with a first attempt but then drop significantly. The procedure is more likely to be successful in younger than older women.

In Vitro Fertilization with Intracytoplasmic Sperm Injection (ICSI). Intracytoplasmic sperm injection (ICSI) is one of a highly sophisticated group of techniques referred to as micromanipulation. ICSI injects one single sperm into an egg using microscopic instruments. It is used for couples who have failed IVF or when the man has severe infertility problems. It is proving to be effective even in some severe female fertility cases, and pregnancy rates are now equivalent to other ART techniques. The procedure itself is deceptively simple.

• A tiny glass tube (called a holding pipet) stabilizes the egg.
• A second glass tube (called the injection pipet) is employed to penetrate the egg's membrane and deposit a single sperm into the egg.
• The egg is released into a drop of cultured medium.
• If fertilized, the egg is allowed to develop for one or two days and then is either frozen or implanted.