Now that the three-child policy has been opened, many people who are planning to get pregnant or are already pregnant are worried about whether their future children will have congenital hand and foot deformities after reading the popular science about congenital hand and foot deformities. At the same time, they would like to know how to reduce the chance of their children having congenital hand and foot deformities? First of all, don’t worry too much, the chance of hand and foot deformity is not as high as you think. The causes of hand and foot deformities are broadly related to three factors, the first one is heredity, the incidence of which is uncontrollable and the child may or may not have it, it is impossible to say. The other two factors are the mother’s physical health during pregnancy and the stimulation of the external environment during pregnancy, which brings us to our second question, how can we reduce the chances of the child developing hand and foot anomalies? Some time ago, a pair of twins came to the clinic and both of them had polydactyly. I asked the mom how her health was during pregnancy. Did she take any medication? Did she move to a new house? Any family history of heredity? But in the end it was all denied. If it was occasionally the case with one child, we would have speculated on a variety of reasons, but as both children were multi-fingered, we assumed that the individual child’s factor was relatively less strong. We later found a suspicion in the mom’s account that the dad was still smoking while this mom was pregnant with the baby, which is a very suspicious and sensitive factor. We would like to remind you that if you are planning to get pregnant or are already pregnant, you should not take any chances and think that it is okay to smoke once or twice in a while. Later on, this mom asked me if she had another child, would she also have hand and foot deformities like her first two babies. My answer was that if you can try to avoid the influence of the external factors mentioned above, and then have good health during pregnancy, it is not very likely that another similar deformity will occur.