Newborn's Basic Growth Status

Newborn's Basic Growth Status

01 Newborn's Height and Weight

Newborns have an excess of body fluids at birth, and as these fluids are excreted, infants typically lose about 10% of their birth weight within the first 7 days. Starting from the 5th day after birth, a newborn's weight should steadily increase. Around 2 weeks old, a newborn's weight usually returns to its birth level.

Most newborns experience rapid weight gain, especially during two growth spurts: one between days 7-10 and another between weeks 3-6.

On average, a newborn's weight increases by 20-30 grams per day, reaching around 4.5 kilograms at one month old, but these values may vary. In the first month, a newborn's height increases by 4.5-5 centimeters. Male infants tend to be slightly heavier than female infants (by about 350 grams) and generally taller than female infants of the same age (by approximately 1.25 centimeters).

02 Newborn's Head Growth and Development

Special attention is needed for the head growth of newborns, as it reflects their brain development. The skull of a newborn is not fully closed, and the first 4 months are the period of fastest skull growth. The average head circumference of a newborn is about 35 centimeters, reaching around 38 centimeters at one month old. Male infants tend to have larger head circumferences, but the average difference is not significant. If a newborn's head is slightly misshapen at birth, it typically corrects itself quickly. Scalp abrasions and eyelid swelling from the birth process usually diminish within 1-2 weeks. Blood spots on the whites of the eyes disappear within about 3 weeks.

Newborns may develop temporary flat spots on the back of their heads due to lying on their backs, but other areas of hair are unaffected. These flat spots do not affect health and new hair grows in those areas after a few months.

03 Newborn's Limb Growth and Development

Fetuses in the womb are accustomed to a curled-up posture, and newborns initially maintain this posture but gradually start stretching their bodies within a few weeks. They begin to reach out their hands, kick their legs, and straighten their backs.

Infant legs and feet may still appear bowed, resembling O-shaped legs, which typically improve on their own within the first year. If leg bowing is severe or there is significant curvature of the feet, pediatricians may recommend corrective measures such as splints or casts, although this situation is rare.

04 Newborn's Facial Acne

One developmental phenomenon is infantile acne—pimples that usually appear on a newborn's face around weeks 3-5. Doctors previously attributed this acne to stimulation of the newborn's skin by maternal hormones, but it is now widely believed to be a normal skin response to bacteria, and it's termed "neonatal pustulosis."

If a child has acne, you can gently wash their face once a day with mild baby soap and a soft, clean towel underneath their head while they are awake to remove any milk or residue. If the condition is severe, pediatricians may recommend using a cream.

05 Newborn's Temperature Regulation Development

Newborns' hands and feet often feel colder than other parts of their bodies and may have a bluish tint because the blood vessels in these areas are more sensitive to temperature changes and contract in response to cold air. Moving their limbs can quickly make their hands and feet redder.

Newborns have temperature regulation capabilities such as sweating or shivering, but their temperature regulation center is not fully functional right after birth. Additionally, due to insufficient fat content, newborns cannot retain warmth well when exposed to sudden temperature changes.

Therefore, dressing newborns appropriately is crucial—keep them warm enough in cold weather and dress them lightly in hot weather. As a rule of thumb, newborns should wear one layer more than adults nearby. Avoid overdressing newborns, thinking they need to be tightly wrapped up.

06 Newborn's Umbilical Cord Falling Off

The remaining part of a newborn's umbilical cord dries and falls off around 10 days to 3 weeks, leaving a fully healed belly button. Occasionally, a small amount of blood-like discharge may occur after the cord falls off.

Keeping the area clean and dry helps the wound heal naturally. Consult a pediatrician if the wound remains moist or doesn't fully heal after 3 weeks.

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