In Vitro Fertilization (IVF)

In natural conception, the fallopian tube provides three functions: it picks up the ovulated egg, it provides an environment in which fertilization can occur and it transports the resulting embryo to the uterus for implantation. In cases where the fallopian tube is not functional or other impediments to fertility are present, the function of the fallopian tube can be replaced by in vitro fertilization (IVF).

IVF is the most technologically advanced and successful form of fertility therapy available. The pregnancy rates associated with IVF are the highest of all fertility treatments across every age bracket. This is because IVF optimizes all of the steps associated with the reproductive process. In a natural cycle, only one egg is ovulated, fertilized and implanted in the uterus. IVF augments these processes by stimulating multiple eggs to grow, fertilizing them directly in the laboratory (in vitro) and placing multiple embryos into the uterus.

The IVF cycle has three phases: ovarian stimulation and egg retrieval; fertilization and embryo culture; and embryo transfer and progesterone support. A description of these three main principles follows.

For a description of the procedure in greater detail, please see The IVF Cycle.

Ovarian stimulation and egg retrieval

Injectable fertility medications are used to stimulate the ovaries, making multiple eggs available for retrieval. An ultrasound-guided needle is inserted through the vagina to suction the fluid and the egg from the follicle.

Fertilization and embryo culture

In the laboratory, the eggs are isolated from the fluid and each is placed in a dish filled with culture media. Sperm are then added to each dish, or if warranted, each egg is injected with one sperm in a procedure called intracytoplasmic sperm injection (ICSI).

Embryo transfer and progesterone support

Once the eggs have been fertilized, the embryos are maintained in the laboratory before being transferred to the uterus. Typically, embryo transfer takes place after three days. A blastocyst transfer occurs after five days, and in the case of a tubal embryo transfer, the embryos are placed into the fallopian tube 24-48 hours after aspiration. Typically, embryos are placed in the uterine cavity using a catheter in a procedure similar to that used in intrauterine insemination (IUI).

The transfer process is critical to the success of IVF. If an embryo is not placed in the correct location, or if a uterine contraction causes it to move once it has been placed inside the uterus, the embryo may fail to implant. We have a great deal of experience in this delicate process, and we utilize special catheters and ultrasound to assist us in the transfer. Additionally, the embryo transfer is practiced twice in advance of the actual procedure. In some circumstances, we may recommend a tubal embryo transfer.

In most cases, progesterone supplementation is used during the second half of the cycle (the luteal phase). This assists in preparing the endometrium for embryo implantation. The most common dose is 200 mg vaginally twice daily. The progesterone is continued until the end of the first trimester if the pregnancy is successful, or until the second negative pregnancy test.

For more details, see The IVF Cycle.