Many families who are planning or expecting their second child ask themselves questions about what it will be like after they become four; how will the first child react to the appearance of the baby; is there a possibility that everything will go smoothly and there will be no jealousy; how to make this transition easier for everyone involved, and much more. The truth is that this is a huge change for the family system and it brings with it reactions from everyone, and that's how it should be. Let's answer a few basic questions on the topic:
1. When and how is it good to announce the news of the first child in the family?
The answer to this question is simple - as soon as possible. Regardless of how big the first child is, it is good when you are already sure and know that there will be a new baby, to start preparing it with explanations. Of course, in appropriate language for the child's age. It is not good to start from the thought that it does not understand, because children may not understand with their minds, but they feel. When something happens in the family, children register it intuitively, and if you don't name it, it is possible to introduce unnecessary tension. The arrival of a new baby in the family is a big event and the brother/sister is one of the most significant figures for this new life. It is not desirable to deprive them of the opportunity to participate in the process of expecting the baby, and it is good that they themselves have enough time to prepare for this big change.
2. How to care for the first child related to the process of expectation? 
By telling him/her, explaining and answering all the questions he/she asks. Ask the child what he needs to know and give an accessible, understandable explanation. The bond between the two children begins during the mother's pregnancy, just as the bond between the parents and the baby begins. The first child begins to adapt and imagine different things related to the new member of the family. Our job as parents is to clear up the confusion (as much as possible), create realistic expectations where possible, and ensure that the relationship between our children is there and ease the transition for the older child. If your child is willing and the time is right, there is nothing worrisome about even attending an examination with the mother so that he can see his brother/sister while still in the womb.
3. What can we expect as emotions from the first child after birth?
Any reactions are possible and can vary in a wide range, depending on the temperamental characteristics of the child. Usually noticeable changes appear with a delayed start, reactions within the first, even the second month are unlikely, in most cases this is still the period of "love". The first child needs to "brave and make sense" of the new situation, to get used to what it means to have a new person at home and that this new person "will not go away", i.e. when the baby begins to be more actively and sustainably present in the family's life and everyday life, then it is natural for reactions from the older child to appear. Keep in mind that it is impossible not to have a reaction, even after 6 months of the appearance of the baby, expect changes in the behavior of your older child (related to food, to sleep, to the daily routine, to tantrums and higher irritability, depression, absent-mindedness at school or kindergarten, indifference to the baby, etc.). It is always better for the reaction to be visible than for it to appear that everything is smooth sailing.
It is an illusion to think that the first child does not experience the appearance of his sibling, just as it is an illusion to believe that if he reacts more violently it means that he does not love the baby. Moments of almost absent attention and attitude towards the baby can be expected, not surprisingly. There may also be times when he/she acts like a baby himself or exhibits behaviors that are not age appropriate but more like those from earlier stages. These are also attempts to cope and draw attention only to themselves, as it was before the baby appeared. Children have a right to these reactions, they are a sign of their attempts to process this spectacular change in their lives and adapt to the new family system. It's always better to have any visible reaction than none at all! Jealousy in this case is the most normal, natural and explainable feeling that a child can experience. Let's honor it first by validating it for our child and then maybe try to help overcome it. Keep in mind that brotherly jealousy never completely disappears. The arrival of a sibling is both one of the greatest sources of love, bonding and support for children, but it is also one of the greatest sources of competition for everything – for mom and dad, for other loved ones, for belongings, for games, for room, etc. There are psychological explanations according to which, on an unconscious level, the older child experiences "dethronement" and needs time and space to cope with this difficult task. Relax, it's a period and it passes. When and how depends on the reactions of those closest!
4. What should our reactions be to the new behavior of the older child? 
How parents react to the first child's behaviour is key. Most often, the reactions of the first-born are aimed precisely at the parents. To be fair, more often than not, children become more reactive to the mother and/or may be more clingy to the father. Spend time alone with your child, talk, show them your love. Expect questions like: "When I'm at school/kindergarten, are you going to be staying home with the baby now?". Expect more violent reactions like: "Make him stop crying!"; "How long will this baby be with us?"; "You don't love me any more and you only pay attention to the baby!" and other similar remarks. It is a difficult task for a child for a child to share his parents with another. Approach with calmness and certainty, try to validate the child's feeling and avoid expressions like: "You are already big, you should act your age."; "You're the older one, give in/give him/do..." Such remarks addressed to the older child not only do not help, but may even make them more competitive and increase behavioural manifestations. Try to objectively (as far as possible) reflect the new situation and do not falter in making it seem that nothing has changed. Forcing yourself into paying as much attention to the first child as before is also not feasible - your attention is now divided and it should be equal between the two children. Be authentic and don't avoid the topic, if you are experiencing difficulties or exhaustion, it is better to name them, because most likely your child is experiencing similar things, he just can't put them into words. Also name your new positive experiences, tell stories to your older child, what you remember when they were born and what it was like then to create a sense of normalcy in the whole situation. Explain to them that it may seem that you pay more attention to the baby, but that's just because babies are defenceless and can't handle anything on their own, which is why they need your help. Hug and caress both your children equally. And most importantly, if you want to be as helpful as possible, put yourself in your child's place, don't think about what they might be experiencing through your own eyes, but really make an effort to see through his point of view - it will give you quite a few courses of action.