Definition of Premature infant:

A premature infant is a baby born before 37 weeks gestation.

Causes, incidence, and risk factors:

At birth, a baby is classified as one of the following:

• Premature (less than 37 weeks gestation)
• Full term (37 to 42 weeks gestation)
• Post term (born after 42 weeks gestation)

If a woman goes into labor before 37 weeks, it is called preterm labor. Often, the cause of preterm labor is unknown. Multiple pregnancy (twins, triplets, etc.) makes up about 15% of all premature births.

The following health conditions and events in the mother may contribute to preterm labor:

• Diabetes
• Heart disease
• Infection
• Kidney disease
• Lack of prenatal care
• Poor nutrition
• Preeclampsia --the development of high blood pressure and protein in the urine after the 20th week of pregnancy
• Substance abuse
• Young age (a mother age younger than 18)

A woman who has had any of the following is at increase risk of preterm labor:

• Premature rupture of the membranes or placenta previa
• Previous preterm delivery
• Problems with the uterus or cervix
• Unexplained high alpha-fetoprotein level in the second trimester
• Untreated disease or infection (such as urinary tract infection or infection of the amniotic membranes)