Whether this is your 2nd baby or 5th baby, each pregnancy, birth and baby is different. Introducing the new baby to the other children can sometimes be challenging. Every family experiences some sort of adjustment at all levels when bringing in a new family member. Here is a list of behaviors for each age group to look for along with some ideas to make the transition a little easier.
Toddlers (1-3 years): Because this age group does not have a good concept of time yet, you may want to wait until you are in your second trimester to let them know a new family member will be arriving. Include the soon to be big brother or sister in preparing for the baby, i.e. shopping for the baby, setting up the nursery, participating in doctor visits, etc. If potty training needs to be done or the child is going to be moving to a bigger bed, take care of those things before the new baby comes. Read books and talk about the new baby as much as possible. Showing the child other babies and enrolling your child in a sibling's class can be very helpful.
After baby arrives, some behavioral issues that might come up are toileting accidents, asking for bottle/pacifier or use of baby talk. This age group will sometimes take more adjusting to sharing time, his things or your attention.
Preschool/School-age (4-12 years): Depending on the child's maturity level, this age group can be included in more detailed discussions about the pregnancy and taking care of a baby. Again, you want to include the child in as much preparation as possible for the baby. The more the child feels like he is apart of this big event the easier it will be for him to adjust to the changes.
This age group may experience increase in independence or even become more clingy during the pregnancy and/or after the baby comes home. Changes in sleep, appetite, language and playtime might occur after baby comes. The younger children of this age group might show aggressive behavior towards the baby, i.e. taking baby's bottle or hitting. The school age child might show changes more at school, i.e. homework, friends, and disciplinary problems.
For all ages: Let the child interact with the baby at his own pace. Don't be offended if the child doesn't want to touch, hold or talk to the baby at first. They will learn by your example and will get more comfortable with doing these things with the baby.
Have family members and friends acknowledge the older child or children first when they come to see the baby. It will help the older child not feel like everything is revolving around the baby and the baby won't know the difference.
Have some extra little gifts so that when you do have a visitor that brings the baby a gift, then you can have something for your older child too. You may even ask that people bring a gift for your older child.
Have a gift from the older child to the baby and vice versa - this can make for a very special moment.
