preterm

American  

[pree-turm] / priˈtɜrm /

adjective

1. occurring earlier in pregnancy than expected; premature.

   preterm labor.

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noun

1. a baby born prematurely, especially one born before the 37th week of pregnancy and weighing less than 5½ pounds (2.5 kilograms).

preterm British  

/ ˌpriːˈtɜːm /

adjective

1. (of a baby) born prematurely

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adverb

1. prematurely

Etymology

Origin of preterm

First recorded in 1925–30; pre- + term

Example Sentences

At a routine 20-week checkup, however, she learned that she was suffering from preterm premature rupture of membranes and that her baby would not survive.

From Slate • May 4, 2026

Compared to pregnancies in adulthood, adolescent pregnancies have been associated with higher rates of low birth weight, preterm birth, and early neonatal mortality among infants.

From Salon • Apr. 18, 2026

Abbott faces more than 1,700 ongoing lawsuits linking its cow’s milk-based formula, Similac, to necrotizing enterocolitis in preterm infants.

From Barron's • Apr. 16, 2026

Researchers still do not fully understand what causes preterm birth.

From Science Daily • Feb. 21, 2026

"Understanding brain activity patterns in both term and preterm infants can help us identify those most vulnerable to injury at an early stage."

From BBC • Nov. 6, 2025