Newborn refers to infants aged up to 4 weeks after birth. This is a stage with normal conditions not found in other ages. These conditions may cause parents to worry and it is also a period with high rates of illness and mortality because the environment changes from being inside the mother’s womb, and the infant’s immune system is still not strong, making them prone to illness. Therefore, care and prevention of various complications are important to ensure the baby’s good health. Parents need to know about the “general characteristics of newborns” to be able to quickly observe any abnormalities.
Weight of the Infant or Newborn
Normally, the average weight is about 3,000 grams (for Thai infants) with a length of about 50 centimeters. The head is relatively large compared to the body. The infant can move all muscle parts. If placed prone, the infant can turn the head to either side without difficulty breathing. If there is a loud noise or impact, the infant will startle, simultaneously spreading the arms out and then bringing them together while crying loudly. This reaction is considered normal and natural. Conversely, if the infant lies still or is lethargic, it may indicate brain abnormalities.
Head Characteristics of the Infant or Newborn
Usually, the head appears large with a head circumference of about 35 centimeters and is fully covered with hair. In the first few days, the hair may appear quite long due to compression during passage through the birth canal. The front middle part of the head above the forehead has a soft, square-shaped area called the fontanelle, which must be carefully protected because the brain lies beneath it without a hard bone covering. This anterior fontanelle closes when the infant is about 1 year and 6 months old.
Skin of the Infant or Newborn
Generally, the skin is thin, sometimes allowing capillaries to be seen. The color is usually red or deep pink. Fine hair may be present on the shoulders and back. In some premature infants, this fine hair may cover the entire body. Around the 3rd day after birth, some infants may develop jaundice, observed as yellowing of the whites of the eyes and the skin, which was red at birth, turning orange. All infants with jaundice should consult a doctor for evaluation to identify the cause of the jaundice.
Characteristics of Stool of the Infant or Newborn
Normal infants pass stool within 24 hours after birth. This stool is grayish-black called meconium and is odorless. After the infant starts feeding, the meconium gradually changes to dark gray, green, greenish-yellow, and finally yellow, which takes about 4-5 days. Normally, infants pass stool almost every time they feed, so they may have 3-6 bowel movements per day.
Umbilical Cord of the Infant or Newborn
In the first days, the umbilical cord appears whitish opaque with visible dried black blood vessels inside. It gradually dries, turning yellow and black, and usually falls off around 7-10 days after birth, though it may fall off earlier or later. This is not dangerous.
Breathing of the Infant or Newborn
Normal infants breathe mainly using the abdomen, with more abdominal movement than chest movement. They breathe about 30-40 times per minute, which is about twice as fast as older children. If there is no coughing, wheezing, or cyanosis, this is considered normal.
Breasts of the Infant or Newborn
Normal infants, whether male or female, if full term, usually have palpable breasts. Some may have 2-3 drops of milk secretion, which is a natural change. It should not be squeezed as this may cause harm and inflammation. If left alone, the breasts will shrink back to normal.
Vaginal Bleeding of the Infant or Newborn
It may be seen in full-term female infants due to hormonal changes after birth from the mother to the infant. At 3-4 days old, slight bleeding may occur. This is not dangerous and does not require treatment.
