My baby weight is 7+kg and wearing a Miezuu diaper size S. Normally for other diapers if baby weighing 5kg above wearing size M or L. No worries for a big baby wearing size S (4-9kg) because it have a wider side leak barrier, no leakage or uncomfortable thigh marks. 12hours wearing at night with no worries because the absorbency really good, no skin irritations. It also have wet indicator so you can change when the indicator turns blue it means the diaper already full. I really recommend it to all moms especially new mom so we could get more sleep at night! Thank you for this premium diaper. Love it so much ?