The idea of having a new baby in the family is indeed exciting but this is also a major transition for the older sibling and could be a bit challenging for him (or her).
The key is to engage your child with the experience of taking care of the new member of the family... But, he wouldn't engage if he feels threatened with the new baby.
Here are things you can do to let your preschooler embrace his/her journey of being a big brother/sister.
Some kids easily assume that ALL the attention will be poured on the new baby. Assure him that your love will stay the same even when the new baby is born. Constant reassurance that his place in your heart won't ever be replaced could help. Sing him a lullaby while letting him feel the baby's kicks and movements. You could also let him listen to the baby's heartbeat which will be a great bonding experience between your child and the unborn baby.
Encourage your child to help out or engage in activities with the baby. Teach your child to prepare the baby’s milk or even with diaper changing. Aside from implanting responsibility to the older sibling, engaging him will make him feel a sense of belonging and not left out. Though it could take a while longer to finish something, trust me, it'll be worth it.
Expect bad times. In any relationship, it won't always be a good time. Prepare yourself for some emotional meltdown. On days that your child acts up, understand what he's going through and encourage your child to open up with what he feels.
Seek help from relatives and friends. Believe it or not, some relatives would tease other children for not being the only child anymore. Though their only intention was to make fun, little do they know that it creates a negative impact on the child’s feeling. When this happens, just tell them that you’d appreciate if they would help you make the older sibling feel that he/she is as special as the new baby.
Spend some alone time with the older sibling. Though it is understandable that your schedule will be so hectic and your body will cry out loud and beg for some sleep, it is essential that you allow a special time with him/her. Play the same games that you used to play, bake some goodies or even learn a new musical instrument. This will help ease any jealousy towards the new baby.
Playing favorites destroys the core value of what family is all about. Do not compare as well as it creates a feeling of needing to compete with each other. Over time, constant comparison between them has a potential to turn them into siblings who despise each other.