Oocyte Vitrification
The techniques of vitrification of oocytes and the subsequent warming process being used today are now producing results far superior to the results that are obtained with slow-freezing techniques, and it would seem that this is the method of female fertility preservation that will be widely used in the near future. The reported success of the use of this method should stimulate a renewed debate on oocyte storage for fertility preservation without a medical indication. (Fertil Steril® 2008. ©2008 by American Society for Reproductive Medicine.)
While men are capable of manufacturing 1000 sperm in the space of one heartbeat up to a ripe old age, the female of the species steadily but surely loses her eggs from birth to menopause, with an accelerated loss from the mid-thirties onward. Accompanying this loss of eggs is an equally severe decline in egg quality with age. Consequently, female fertility potential rapidly dwindles from the age of 37 on.
In addition, the vitrification process is considerably less complicated than slow freezing, avoids the complication of intracellular ice crystallization, and is less expensive and time-consuming. The initial worry that the use of the high concentrations of cryoprotectants needed would cause toxic and osmotic effects have so far proved unfounded as long as the eggs are only left in the highest concentration of cryoprotectant for less than 60 seconds.
We believe that the time has come to consider redressing the balance between the male and female fertility potential now that we apparently have the technology to do so. While sperm may be naturally capable of inducing a pregnancy even up to the age of 80, the limited reproductive life span of oocytes has restricted women to conceiving and delivering a baby up to the age of 45 at the best but with increasing difficulties from the mid to late thirties onward.
The successful preservation of oocytes by vitrification will provide the ''aging'' woman who has had to delay her childbirth, for any reason, the opportunity to conceive and deliver using her own oocytes at the time she decides.
Society dictates the widespread use of medical advances, and society is seemingly presently intent on women delivering at later ages. The laws of the country will dictate the age limit up to which ET may be performed after the fertilization of previously vitrified oocytes in the same way that the age limit after ovum donation is applied.
While ovum donation has been highly successful in providing a solution for women with incompetent oocytes, the preference of using their own genetic material is overwhelming. Legal, ethical, and logistic problems of ovum donation may also be overcome with the use of the subject's own vitrified oocytes.
