Hypocalcemia is a total serum calcium concentration of less than 8 mg/dL (less than 2 mmol/L) in full-term infants and less than 7 mg/dL (less than 1.75 mmol/L) in preterm infants. It is also defined as an ionized calcium level of less than 3.0-4.4 mg/dL (less than 0.75-1.10 mmol/L) depending on the method (electrode type) used.
Hypercalcemia is defined as a total serum calcium level greater than 12 mg/dL (3 mmol/L) or ionized calcium greater than 6 mg/dL (1.5 mmol/L). The most common cause is iatrogenia.
A premature baby is a baby born before 37 weeks of gestation. The full gestational age is 40 weeks. Babies born before 37 weeks of gestation have an increased incidence of complications and mortality, which is approximately proportional to the degree of prematurity.
A post-term baby is a baby born after 42 weeks of gestation. The reasons for a baby being post-term are usually unknown. Very rarely, it may be due to abnormalities that affect the fetal pituitary-adrenal system (such as anencephaly or adrenal agenesis).
Intracranial hemorrhage into the brain tissue or surrounding tissue can occur in any newborn, but is especially common in premature infants; about 20% of premature infants with a birth weight of less than 1500 g have intracranial hemorrhage.
Approximately 10% of newborns require some degree of resuscitation during birth. The reasons for this are numerous, but most involve asphyxia or respiratory depression. The incidence increases significantly with birth weights less than 1500 g.
Sleep disturbances in children after this age take many forms, including difficulty falling asleep at night, frequent night awakenings, atypical daytime sleepiness, and dependence on feeding or being held in order to fall asleep.
Separation anxiety is characterized by a child crying when the parents leave the room. It usually begins at 8 months, reaches its peak intensity between 10 and 18 months, and usually disappears by 24 months.
