Basic Growth Patterns of Infants at 1-3 Months Old

01 Newborn Height and Weight

From the time they are a month old until they reach three months, babies continue to grow rapidly at the pace seen in the first few weeks after birth. Generally, infants gain around 0.7 to 0.9 kilograms in weight each month, grow 2.5 to 4 centimeters in height, and their head circumference increases by 1.25 centimeters. However, these figures are averages, and actual growth can vary from person to person.

Most newborns experience rapid weight gain, especially during two growth spurts: one occurring between days 7-10, and another between weeks 3-6. On average, newborns gain 20-30 grams per day, reaching a weight of around 4.5 kilograms by the end of the first month, although this can vary. During the first month, a newborn's height typically increases by 4.5 to 5 centimeters. Male infants are slightly heavier than female infants (about 350 grams heavier) and generally taller than female infants of the same age (approximately 1.25 centimeters taller).

02 Newborn Head Growth and Development

At two months old, a baby's fontanelle, or soft spot on the head, remains open and flat to the touch, but it should close by around three months. Additionally, their head still appears relatively large compared to their body due to faster head growth. This is a normal phenomenon, and their body development will catch up quickly.

03 Growth and Development of Newborn Limbs

At two months old, babies may appear chubby and round, but as they become more active with their limbs, their muscles will start to grow. Their skeletal development also progresses rapidly, and as they learn to relax their limbs and stretch their bodies, they will appear taller and leaner than before.