Female (pregnant)—estimated gestational age

Guide for use:

The duration of gestation is measured from the first day of the last normal menstrual period. Gestational age is expressed in completed days or completed weeks (e.g. events occurring 280 to 286 completed days after the onset of the last normal menstrual period are considered to have occurred at 40 weeks of gestation).

The World Health Organization identifies the following categories:

• Pre-term: less than 37 completed weeks (less than 259 days) of gestation
• Term: from 37 completed weeks to less than 42 completed weeks (259 to 293 days) of gestation
• Post-term: 42 completed weeks or more (294 days or more) of gestation.

Context:

Perinatal statistics