When a baby is about to appear in the house, then you should think about how to prepare your older children for this event. Your child can be extremely stressed if you don't do this beforehand.
Initially, the child should be told how his life can change when the baby appears. Answer all the questions that interest him and try to explain the most important thing, that your love for him cannot become less. It is especially difficult for children to believe this, as they perceive love as something finite. In their understanding, love is a big and tasty cake, and with the birth of a baby, a piece of this cake that belongs to him will pass to the baby. Explain to him that there is enough love for everyone, and it cannot suddenly come to an end.
Do not add fuel to the fire or scold your child for his negative reaction. He needs to be given time to get used to. Praise him often for good behavior and show how much you love him by any means, despite the fact that another baby has appeared in the house.
When, on the occasion of the birth of a baby, all relatives come to visit you, then ask first to show attention to the elder, and only after that, go to the newborn. The situation is the same with gifts. Many people forget to bring a gift to an older child, so all thoughts will be occupied exclusively by the little one. Try not to change your habits too much, because an older child may think that you are distancing from him.
Remember the truth that it is impossible to be afraid of what you are laughing at. Therefore, joke with the older child about the baby as often as possible. Don't forget about the time you spent with your child. Let him feel that he is still special to you. Encourage your child to take on the responsibilities of caring for the toddler. Let the help be small in the beginning, this is not the most important thing. The main thing is that the child will be as before with his mother, and will also feel needed.
At first, after the birth of a baby, try not to put pressure on the baby, emphasizing his connection with the baby at every opportunity. Eliminate phrases from your vocabulary: big sister or big brother. Your older child is not yet accustomed to the idea that the baby is now also a part of your large family, and moreover, it will be simply unpleasant for him.