# Medically indicated preterm birth before 35 weeks (CHAP definition)

Outcome · id `maternal:outcome-chap-medically-indicated-preterm-birth-before-35-weeks` · Maternal & Newborn Atlas · release `15708f235d73cd42` (public)

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## In plain language

Whether the baby was born before 35 weeks of pregnancy because the mother or the baby was ill, and not because labor started on its own or the waters broke. It is one of the four parts of the CHAP primary combined outcome.

## Technical summary

One of the four components of maternal:outcome-chap-primary-composite, worded as the CHAP paper's Methods words it. The paper counts the event per patient. It concerns the whole pregnancy: the birth is the baby's, and the stated reason is illness in the mother or the fetus. The paper does not say whose outcome it is, so this record assigns no single recipient. It is not the same as any preterm birth, because spontaneous labor and membrane rupture do not count.

## Provenance

Content hash: 588ad7efcd3e85b7c5bf64cdb51e8072ed4b33c471dd5586a8be8efeec57904d
Last substantive edit: 2026-10-12
Evidence last checked: Not recorded