Premature infants

Premature infants are babies born before full-term gestation.

A fair percentage of babies who are pre-term by estimation of a calendar due date have characteritics 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.