I was first told that my aorta is slightly dilated at 4.0 cm. There is some variation in the way the term aneurysm is used. For the thoracic aorta, most agree that at a diameter of 4.0 cm it has reached a size that is considered an aneurysm. The word dilated refers to the enlargement of the aorta.
Called also neonate and newborn. premature infant (preterm infant) one born before a gestational age of 37 completed weeks (259 days). The duration of gestation is measured from the first day of the last menstrual period and is expressed in completed days or weeks.
A newborn is an infant who is only hours, days, or up to a few weeks old. In medical contexts, newborn or neonate (from Latin, neonatus, newborn) refers to an infant in the first 28 days after birth; the term applies to premature infants, postmature infants, and full term infants. Before birth, the term fetus is used. In the UK, infant is a term that can be applied to school children aged between four and seven. As a legal terminology, infancy continues from birth until age 18. An infant is usually called a baby in simple English, as many people use the term 'baby' instead of infant.