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Newborn baby (0–6 weeks): sleep, feeding and diaper size

Stage: 0–6 weeks · newborn

Sleep

no fixed rhythm yet — naps are spread across the day

Feeding

Breastfeed on demand — no schedule needed. If formula feeding, start small and build up gradually per feed.

Formula: 8–12 feeds a day, 1–3 oz (30–90 ml), building up. A newborn tummy is tiny — small, frequent feeds are normal. Around day 7–10 many babies cluster-feed during a growth spurt.

Diaper size

Size N (newborn, up to 10 lb / 4.5 kg); some babies move to size 1 (8–14 lb) within weeks.

Development at this stage

• Startles at loud noises (Moro reflex)
• Briefly fixes on faces 8–12 inches away
• Rooting and sucking reflexes active
• Recognizes parents' voices

Care & things to watch

• Bathing: 2–3 times a week is plenty (even once is fine) — more often dries out delicate skin; sponge-bathe until the cord stump falls off. Water around 98–100°F, never leave your baby unattended
• Vitamin K: given as a single injection at birth (standard in US hospitals)
• Vitamin D: breastfed and partially breastfed babies need 400 IU (10 micrograms) daily from the first days; fully formula-fed babies drinking about 32 oz a day get enough from formula (AAP)
• Newborn screening: heel-stick blood test at 24–48 hours and a hearing screen, usually before hospital discharge; first pediatrician visit at 3–5 days old
• RSV protection: babies entering their first RSV season (roughly October–March) are recommended an RSV antibody immunization (nirsevimab or clesrovimab), unless mom had the maternal RSV vaccine during pregnancy — ask your pediatrician what applies
• Safe sleep ABCs (AAP): Alone, on the Back, in a Crib — firm flat surface, no pillows, blankets, bumpers or soft toys; room-share (not bed-share) ideally for the first 6 months; dress for room temperature to avoid overheating, a SIDS risk factor
• Hepatitis B vaccine: offered at birth — the AAP recommends it for all newborns; since late 2025 the CDC leaves the timing to parents and pediatrician when mom tested negative for hepatitis B. Discuss it before delivery
• Watch for jaundice — if in doubt, call your pediatrician
• Car seat: rear-facing infant seat, properly installed, from the very first ride home — have the fit checked (NHTSA offers free inspection stations)
• Extra feeding, fussier behavior and shorter naps around a growth spurt (often day 7–10) are normal and settle within days

Other ages: 6–12 weeks · 3–4 months · 4–6 months · 6–9 months · 9–12 months · 12–18 months · 18–24 months · 2–3 years · 3–4 years · 4–5 years