Week-by-week library · 4 months old
Month 4: your checklist
Quick answer
What should I actually do at 4 months old?
Sleep patterns can shift noticeably around now, which trips up a lot of routines that were working. 4 concrete tasks below, grouped by what they're for.
What's going on this week
A well-known stretch around four months is often described informally as a sleep regression, tied to a real shift in how babies cycle through sleep stages. It usually settles with some routine adjustment and is not a sign of a problem. A second vaccine round is also typically due around this age.
Your checklist
Night-shift logistics
- If sleep has gotten noticeably worse this month, treat it as an expected phase to adjust to, not a routine failure to fix overnight.
Appointments & paperwork
- Attend the four-month well visit and the associated vaccine round.
Household & gear
- If solids are on the horizon per your pediatrician's guidance, start researching a high chair and feeding gear now, ahead of the actual start date.
Partner care
- A rough sleep month wears on both of you; keep the overnight rotation honest rather than letting it silently drift to one person.
Sourced to
- American Academy of Pediatrics (HealthyChildren.org)
- CDC, recommended immunization schedule
Last reviewed by the First Dad Guide editorial team.