This problem is worth discussing by modern people. Of course, it's never too late. It's better to keep it than not to keep it. When is the best time? At the very least, it is best to decline after the various functions of the body reach the peak; According to Huangdi Neijing, a woman's body can reach a peak at the age of 28. Therefore, it is best for women to have children before the age of 28; At the age of thirty-five, Yangming's pulse failed and the woman's face began to haggard. At the age of 42, she began to have white hair. July 49 years old, menopause, began to aging.