"What can I do with my two-year-old? Now that the new baby has arrived, he's gotten so immature, like he's a baby again," Lauren's face was filled with anxiety as she told her doctor how her young son had been acting ever since she brought his little sister home. "He has potty accidents and wants to drink his milk from a baby bottle - I thought he'd be proud to be a big brother!" she said. Sound familiar?

Lauren's son was doing what a lot of toddlers and preschoolers do when a new baby joins the family: regressing. Very young children are egocentrics who believe that they exist at the center of the universe and are entitled to all that position has to offer - lots of parental attention, to start with. When a new sibling comes on the scene, they wonder, "Wasn't I good enough? Is that why they brought another child home?" And of course, "Can we take her back to the hospital so I can be the baby again?"

Understanding the older child's dilemma and following these five important guidelines will help you to avoid typical parenting pitfalls and bolster your little one's sense of security.

• Don't tell the new sibling that he should act - or even feel - like a big boy now. Think about it from his point of view: Where's the benefit in being the big kid? The new baby is getting lots of attention while he's lost his position at the center of the universe. So, let him try on being a baby again if he wants, and he'll soon find that it no longer fits. Drinking from a baby bottle is much harder work than drinking from a cup, and diapers are uncomfortable.​
• Set aside time to spend with the older child so she can have that one-on-one attention from you that she's been missing. But don't wait for the baby to fall asleep. The best times for playing with the big sib are when the new baby is awake. This sends the message that good times with a parent come when the baby is there, too, and may encourage her to welcome the baby's presence. Plus, it stimulates the baby to be exposed to his active, verbal big sib. Second children have to compete for quality time, but they also have the advantage of the older child as a model, which may encourage earlier crawling, walking and talking.​
• Help your big kid adjust to the new baby by striving to give him more praise and attention every time he behaves kindly and lovingly—two habits you want to encourage him to use when interacting with his sibling. Some parents count the number of times they praise or compliment their older child and attempt to increase that number by two each day, which helps parents be aware of how much (or little) they reinforce positive behaviors. This praise and attention also serves to confirm the importance of your older child to the family - even though competition is under foot! By reinforcing your older child’s presence through attention and praise, you are helping him accept the newcomer in the household who adds to, rather than taking away, his parents’ love for him.​
• Enlist your older child to help with the baby. Even if she's very young, she can bring you a clean diaper or distract the baby with a squeaky toy while you change him. Whenever she helps out with the baby, make sure to tell her what a good big sister she is. Doing so will encourage her to be empathetic and increase her desire to be with you and the baby.​
• Don't try to do everything alone. Enlisting the help of your spouse or a grandparent and making them full members of the parenting team helps you both devote time to each child and can give both adults some coveted alone time. Plus, cooperative effort will help all the adults in your baby's life bond with both little ones and learn how to be “on the same page” with enforcing and establishing consistent discipline policies.