Newborn in 2016: Fourth trimester

The first 28 days after birth — physiology, bonding, feeding rhythms, and the shift from womb to world. The newborn period spans roughly the first four weeks after birth — a time of rapid physiological adaptation, establishing feeding, and early attachment. Research from Bowlby and Ainsworth onward treats these weeks as foundational for stress regulation and caregiver synchrony, though individual trajectories vary widely.

Global guidance from WHO and national pediatric societies emphasises skin-to-skin contact, safe sleep, and responsive feeding rather than rigid schedules. Most clinicians use 28 days; some extend to six weeks when colic and feeding patterns stabilise. Roughly 14–17 hours in 24, in short bouts — wake cycles are normal and not a sign of poor sleep training need.

Yes, especially evenings in the first weeks; it supports milk supply and growth spurts rather than indicating insufficient milk alone. Fever in infants under three months, poor feeding, fewer wet nappies, yellowing skin, or breathing difficulty warrant urgent review. Strong evidence links immediate and ongoing skin-to-skin with temperature stability, breastfeeding success, and parent-infant synchrony.