Premature infants

Premature infants are babies born before full-term gestation. Such babies account for a disproportionately high amount of neonatal morbidity and mortality, that is, when epidimiologic statistics on reported illness and deaths among newborns are compiled, premature infants are overrepresented among newborns. Prematurity is qualitatively different according to the extent of in utero (in the womb) development that the baby has undergone, the closer that the baby is to term, generally, the better his or her chances of survival and a normal life after survival.The "youngest" of premature newborns, those who have undergone the least amount of time in the womb, are generally worse off than the infants who have come closer to term gestation. There are other characteristics that are important in physicians' view of the health and care of these babies, but, as in all populations defined by medical criteria, the specific way that this term is applied is important in reviewing the known literature on prematurity. Just how is prematurity defined?

A fair percentage of babies who are pre-term by estimation of a calendar due date have characteristics of full term babies. One study 3 comparing sonographic with menstrual dates from a large database found that only 78% of pregnancies designated preterm (less than 37 completed weeks) by menstrual dates were actually preterm, according to a confirming sonogram. (Klebanoff MA. Gestational age: not always what it seems.[comment]. [Comment. Editorial] Obstetrics & Gynecology. 109(4):798-9, 2007 Apr. UI: 17400838). That de date is determined by the reported date of the last menstrual period, and in women who do not keep records, and for those who have irregular periods, the date given may be inaccurate.