The materials from which baby’s clothes are made is not a minor concern, particularly concerning head coverings. Why? The brain of a baby represents 12 percent of its body weight, and the head is a major source of heat during infancy. It is, therefore, important to keep the baby’s head protected from the cold, especially when the child is not with his or her mother or if there are no available incubators or radiant heat.
Few previous studies have assessed the quality of materials used to make babies’ hats and their ability to maintain heat. So, a group of researchers evaluated the effect of wool or cotton hats on infants’ body temperature. This study, entitled “The Effect of Wool vs. Cotton Head Covering and Length of Stay with the Mother Following Delivery on Infant Temperature,” was carried out at the Department of Neonatology at Hadassah University Hospital in Israel and first published by the International Journal of Nursing Studies in 2004.
The study included 126 full-term, singleton newborn infants who were vaginally delivered following an uncomplicated course of pregnancy and labor. All infants weighed more than 2,500 grams at birth, with Apgar scores higher than 7 at both one and five minutes, and they showed no signs of respiratory distress.
Measurements were taken of the infants delivered during the morning shift on regular weekdays. After delivery, infants were dried off, and their umbilical cords were clamped and cut. They were then left with their mothers and bundled in a single cotton blanket before being weighed. Initial examinations were performed by the attending nurse. Then, the babies’ heads were covered with either a cotton diaper that loosely covered the head or a woolen hat.
The infants wearing cotton head coverings were assigned to the control group. On alternating weekdays, knitted woolen hats were used for head coverings instead of cotton diapers. The hats covered the upper half of the forehead and both ears. The newborns in woolen hats were assigned to the study group. All infants were returned to their mothers for a period of up to three hours postdelivery and then transferred to the newborn nursery, where their rectal temperature was measured.
No radiant warming was applied in the delivery room, where the infants’ temperatures were recorded each morning. The time lapse between delivery and admission to the nursery was measured for each baby.
There were fifty-nine infants in the study group and sixty-seven in the control group. There were no significant statistical differences between the groups regarding birth weight, gestational age, gender, temperature measured in the delivery area, and time lapse between delivery and admission to the nursery. The newborns who wore woolen hats were warmer upon admission to the nursery than the infants who wore cotton hats, and fewer infants among the study group arrived with a rectal temperature less than 36 degrees Celsius.
However, the most important finding is the effect that the amount of time spent with the mother has on the rectal temperature of infants. Beyond the material with which the hat is made, the most significant factor that affects infant body temperature is physical contact with the mother. The results of the study suggest that prolonged stays with the mother following delivery not only helped adequately maintain the body temperature of babies who wore woolen hats, but they also helped warm infants with cotton head coverings.
Pediatricians can provide more information regarding the materials of baby clothes and make suggestions about how to avoid hypothermia in infants.