Many parents have asked me similar questions in the clinic: neither of the couple has polydactyly, but the baby is born with polydactyly. There are many such cases in the clinic, not only polydactyly, but also many other hand deformities, why? There are many reasons for the development of polydactyly. Genetic factors are certainly involved, but they are not only traced back to the parents’ generation, but also to the grandparents’ generation. As long as there is a precedent of polydactyly in the family of both parties, the child born may be polydactyly, and this is about the odds, not that if there has been a precedent of polydactyly in the family, the child will have it for sure. In addition to genetic factors, it may also be related to the physical condition of the parents during the preparation period, the health of the mother during pregnancy, and external environmental stimuli, and like genetic factors, it is all about chances. To have a healthy baby, parents have to be prepared from the beginning of preparation for pregnancy, try to maintain physical and mental pleasure, avoid illness, and stay away from second-hand smoke and formaldehyde and other harmful substances, which can effectively reduce the chances of having a baby with polydactyly. In addition, the timing of polydactyly surgery is also a concern for many parents. Usually, as long as the baby is healthy and weighs more than 6kg, we can do the polydactyly surgery.