At my first egg retrieval, they got 26 eggs. But the next day they discovered that only four were mature and only one egg had been fertilized. I understand this is uncommon. What could cause this, and what is the treatment, if any?

Kit

Determining the factors resulting in poor egg quality or maturity is difficult. Let's look first at what maturity means, and then at what might go wrong.

All the eggs you will ever have were formed before you were even born, halfway through your mother's pregnancy. The eggs all started out with 46 chromosomes. But since we need just 23 chromosomes from the sperm and 23 from the egg, an egg must get rid of the extra 23 chromosomes, in a process called meiosis. Meiosis of all your eggs began while you were in your mother's uterus, but was not completed. The process was arrested, to resume in an egg after it receives a signal from your body's LH surge or the administration of hCG just prior to ovulation. For egg retrieval, hCG is administered approximately 36 hours before egg retrieval. It is the resumption of meiosis in response to that signal that determines egg maturity.

Unfortunately not all eggs receive the message and resume meiosis appropriately. Why? We don't really know. Possible factors include blood supply to the ovarian follicle in which the egg develops, hormone levels in the follicular fluid, the function of the hormone receptors on the egg, LH levels in the early follicular phase, the presence of normal egg chromosomes, ovulation medication schedules, and laboratory culture conditions. Much research is going on to determine the most important factors and to develop a culture environment that best supports maturation of the immature egg.