A second baby is happy news for parents, but for a first child it can raise a big worry: “Will I have to share Mom and Dad?” Many parents wonder when to tell and what words to use. This guide draws mainly on the American Academy of Pediatrics (AAP) HealthyChildren.org article “Preparing Your Older Child for a New Baby.”

When to Tell and the Signals to Watch For

The AAP material points to everyday moments rather than a fixed date. Starting to buy baby furniture or clothes, or your child asking about your growing belly, can be natural openings. A child who asks about your belly is often already noticing the change.

In practice, many families share the news once the early, uncertain weeks have passed and the pregnancy begins to show. Children aged 3 to 5 also tend to pick up on overheard phone calls and shifts in mood, so hearing it directly from a parent, rather than from someone else, can help protect trust.

How to Tell Step by Step

  • Start short and simple: “There’s a baby growing in my belly. In a few months, our family will have a new member.” One or two sentences is enough.
  • Translate time into seasons or events: Young children struggle with “in a few months,” so something like “the baby will come in summer” can work better.
  • Welcome questions: If your child asks the same thing repeatedly, answer with the same calm words each time.
  • Give a role: Choosing baby clothes, looking at ultrasound pictures, or reading a picture book together helps your child feel part of the preparation.
  • Finish big changes early: The AAP article suggests completing toilet training or the move from crib to bed before the baby arrives, and if that is not possible, putting it off until after the baby has settled in, so your child does not feel pushed out.
  • Plan the hospital days: Explain who will care for your child while you are away and that you will come home with the baby in a few days.

Common Mistakes

  • Telling too early or too late: A very long wait can feel endless, while a sudden announcement can feel like a shock.
  • Loading on expectations such as “You’ll be a big brother now, so you have to be mature”: This can add pressure.
  • Only soothing negative feelings: Helping your child put jealousy or sadness into words usually works better than brushing it aside.
  • Not expecting regression: The AAP article explains that after the baby arrives, a toilet-trained child may have accidents or ask for a bottle, and it describes this as one way a child checks that they are still loved.

What Can Differ From Child to Child

Reactions vary even at the same age. Some children are thrilled and tell everyone, while others stay quiet and show worry weeks later. Toddlers of 2 to 3 often do not fully grasp it until the baby is born, while children 5 and older tend to ask detailed questions and want a job. It helps to respect your child’s pace. Setting aside even 10 to 15 minutes a day of one-on-one time with your first child after the birth may help them feel secure.

When to Consider Talking with a Pediatrician

If, weeks after the news, your child sleeps poorly, eats much less, keeps returning to earlier behaviors, or becomes so aggressive or withdrawn that daily life and daycare are hard, it may help to talk with a pediatrician. This information isn’t a diagnostic tool and doesn’t replace advice from a medical professional.