Neonatal period

Neonatal period refers to the first 28 days of life, from the moment of birth until the end of the fourth week. This period is characterized by rapid physiological changes and adaptation to the external environment. The neonatal period is divided into two phases: the early neonatal period, which covers the first seven days of life, and the late neonatal period, which covers the rest of the month.

Physiology

During the neonatal period, the newborn undergoes several physiological adaptations. The most significant of these is the transition from fetal to neonatal circulation. Other important physiological changes include the initiation of breathing, thermoregulation, and the establishment of feeding.

Circulation

In fetal circulation, the placenta provides oxygen and nutrients to the fetus. After birth, the umbilical cord is clamped, and the newborn must transition to neonatal circulation. This involves the closure of the ductus arteriosus and the foramen ovale, two structures that allow blood to bypass the lungs in fetal circulation.

Breathing

The initiation of breathing is a critical adaptation that occurs immediately after birth. The first breaths inflate the lungs and help establish functional residual capacity. The newborn's respiratory rate is much higher than that of an adult, and the pattern of breathing may be irregular.

Thermoregulation

Newborns are at risk of hypothermia due to their large surface area relative to their body mass and their limited ability to generate heat. To maintain body temperature, newborns use several mechanisms, including non-shivering thermogenesis in brown adipose tissue.

Feeding

Feeding is established during the neonatal period. Newborns have a strong sucking reflex and can start breastfeeding immediately after birth. Colostrum, the first milk produced by the mother, provides essential nutrients and antibodies to the newborn.

Health issues

The neonatal period is a critical time for the newborn, and several health issues can arise during this time. These include neonatal jaundice, neonatal sepsis, and neonatal respiratory distress syndrome.

See also

• Infant
• Childbirth
• Pediatrics

Neonatal period Resources
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