Infant, postmature

Medical Definition of Infant, postmature

Infant, postmature: A baby born 2 weeks (14 days) or more after the usual 9 months (280 days) of gestation. The gestation (length of the pregnancy) is calculated from the date of the last menstrual period (LMP). This is an important calculation since, if delivery is delayed 3 weeks beyond term, the infant mortality rate skyrockets to 3 times normal.

The definition of a postmature infant has evolved. A few sources still consider a baby postmature if it is born a week after the usual 9 months' gestation but the current trend is to consider a baby postmature ONLY if it is born 2 weeks (14 days) or more after the usual 9 months of gestation.

The terms "postmature infant" and "post-term infant" are interchangeable.


Quick GuideBrain Foods: Healthy Food for Kids' Brains

Brain Foods: Healthy Food for Kids' Brains

Subscribe to MedicineNet's Children's Health & Parenting Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Reviewed on 7/1/2016

Health Solutions From Our Sponsors