Spinal Anesthesia Superior for Egg Retrieval

Women who had spinal anesthesia (SA) for egg retrieval for in vitro fertilization (IVF) had a significantly higher overall pregnancy rate (50%) than those who opted for general anesthesia (GA, 33%), a study has found. The study was conducted at Massachusetts General Hospital.

The differences in pregnancy rates could be related to the different ways the two types of anesthesia affect the body, said anesthesiologist Bobbie Jean Sweitzer at the American Society of Anesthesiologists annual meeting. Some laboratory studies suggest the anesthetic agents used for GA can affect an egg's ability to be fertilized in vitro. In addition, GA enters the bloodstream quickly, reaching the brain and the ovaries within about 10 minutes. In contrast, SA enters the blood stream very slowly, a smaller amount of drug is used, and the medication stays in the spinal region for a relatively long time. "By the time the drug enters the bloodstream, the oocytes have been retrieved,” said Dr. Sweitzer.

SA also helps surgeons, according to Dr. Sweitzer, because oocyte retrieval is an extremely delicate procedure that places an ultra-fine needle into a follicle to retrieve a microscopic egg. "Some patients may move slightly under GA, and even tiny movements can make it harder to retrieve the eggs.” In contrast, SA temporarily immobilizes patients from the waist down.