Week 31 old
Week 31 (month 8): what to expect with feeding, sleep, and development for your 8-month-old, with safety-first guidance for anxious parents.
In short
At 31 weeks (about 8 months), many babies are sitting steadily, eating solids two to three times a day alongside breast milk or formula, and sleeping roughly 11-12 hours at night plus two to three naps. Every baby moves at their own pace, so treat these as ranges, not deadlines.
🍼 Feeding
Breast milk or formula is still the main nutrition source, typically around 24-32 oz of formula per day (or nursing roughly 4-6 times), plus two to three solid meals offered each day. Solids are for practice and variety, not replacing milk yet.
😴 Sleep
Most 8-month-olds sleep about 12-15 hours total per day: roughly 11-12 hours at night plus two to three naps adding up to about 3-3.5 hours of daytime sleep. Wake windows usually stretch to about 2.5-3.5 hours, and some babies begin shifting from three naps toward two.
What's happening this week
- •Around this age many babies sit without support and may rock on hands and knees, lean to reach toys, or start to scoot or army-crawl
- •Hand skills are growing: many 8-month-olds rake or pick up small pieces of food and pass objects from one hand to the other
- •Babbling often gets longer and more varied around now, with strings like "bababa" or "dadada" and clearer responses to their own name
- •Separation anxiety and stranger wariness commonly show up in this window as babies grow more attached to familiar caregivers
Milestones to keep in mind
- ✓By the 9-month checkup, the CDC notes many babies sit without support, look for objects they see you hide, and babble with strings of sounds like "mamama"
- ✓Around this age many babies bear weight on their legs when held standing and pass a toy between hands
- ✓Many babies respond to their own name and turn toward familiar voices by the 9-month checkpoint
- ✓These are ranges, not a weekly schedule; if your baby isn't doing all of these at exactly 31 weeks, that is usually normal
Growth
💡 Tip for this week
Now that your baby is more mobile, do a floor-level safety sweep: secure furniture and TVs to the wall, cover outlets, move cords and small choking hazards out of reach, and use gates at stairs. For sleep, keep placing baby on their back in a bare crib with no pillows, blankets, or bumpers.
⚠️ When to call your pediatrician
Call your pediatrician if your baby has fewer wet diapers than usual or signs of dehydration, isn't gaining weight or is losing weight, has a fever, refuses to eat or drink, isn't making eye contact or responding to sounds and voices, has lost skills they previously had, or seems very floppy or very stiff. Trust your instincts and reach out with any worry.
Frequently asked
How much should my 8-month-old eat at 31 weeks?
Breast milk or formula remains the main source of nutrition: about 24-32 oz of formula a day, or nursing around 4-6 times, plus two to three small solid meals. Offer a variety of soft, mashed, or appropriately soft finger foods and let your baby decide how much to eat. Talk to your pediatrician if you have feeding concerns.
Is it normal for my baby to suddenly be clingy this week?
Yes. Separation anxiety and wariness of strangers commonly appear around 8-10 months as babies form stronger attachments and start to understand that you exist even when you leave the room. Quick, calm goodbyes and consistent routines help. It is a normal sign of healthy development, not a setback.
My baby isn't crawling yet at 31 weeks. Should I worry?
Usually not. Crawling has a wide normal range, and some babies skip it entirely and go straight to pulling up and cruising. There is no per-week milestone for crawling. The CDC checkpoint is at 9 months, and even then sitting and exploring matter more than crawling. Mention any concerns at your next visit.
Looking for the bigger picture? See the month 8 overview →
General guidance, not medical advice. Every baby develops at their own pace — talk to your pediatrician with any concerns.