A Firstborn Younger Than 2
If your child isn't even 1, obviously there's not a lot you can do to explain the situation. But if she's past her first birthday, she probably grasps more than you think. "Kids under 2 understand much more than they can say," Korfmacher says. "If you explain that there's a baby in your tummy and that one day it will come out, they get it. You don't have to say or do much more."
Sometime after 18 months, most kids will want to "mother" a doll or stuffed animal. Give your child his own "baby" if he doesn't have one already; this will let your child mimic you when the real baby arrives. Imitation is a toddler's favorite game and can help him absorb what's going on. In addition, you can introduce age-appropriate books about new siblings, even if your child mostly chews them. He may not get the gist of the stories yet, but when the new baby arrives, the scenarios you've been reading about will start to make sense.
Begin transitioning your child into new routines well before her sibling's birth. For instance, I knew I'd want Kate to be with a sitter for a few hours a week, so I started sending her a few months before Sara was born. It helped me get some rest, and it also established a routine for Kate in advance of the baby's arrival, preventing her from seeing the sitter as someone she was stuck with because of her new sister. If you have hand-me-down toys or gear that you're going to give the baby, make sure your firstborn has parted ways with them a few months before the birth.
Overall, the most important thing you can do is reassure your child, says Caroline Clauss-Ehlers, PhD, an assistant professor of counseling psychology in the graduate school of education at Rutgers University in New Brunswick, New Jersey. Certain aspects of pregnancy, such as morning sickness, can be scary to a toddler. I remember once scooping up Kate as I ran to the bathroom to be sick; as I plopped her down and made it to the toilet, she burst into tears. Once I was able, I picked her up and held her close. "Keep letting them know that everything's okay," Clauss-Ehlers says. "They'll understand the emotion." And try not to stress too much about how your child will react to the baby. Children this age quickly forget life without a sibling.