Patient's question:
My wife is pregnant. Today at the hospital, the doctor said the embryo did not divide. Could you please tell me what could be the reason for this?Doctor's answer:
The rapid mitotic division of the fertilized egg is called cleavage. During cleavage, the cells do not grow but are simply divided into many small cells. The hollow spherical structure composed of these small cells is called a blastula. Since fertilization of the oocyte can occur at any stage of maturity (such as primary oocyte, metaphase I, secondary oocyte, metaphase II, or after meiosis is completed), if the oocyte is fertilized before it is fully mature, the fertilization process triggers the completion of meiosis, and cleavage occurs only after meiosis is finished.