Weeks of gestation

Record the best estimate of gestational age at birth in weeks and days using the following hierarchy:

• Obstetrical measures based on last menstrual period, obstetrical parameters, and prenatal ultrasound as recorded in the maternal chart.
• Neonatologist’s estimate based on physical criteria, neurologic examination, combined physical and gestational age exam (Ballard or Dubowitz), or examination of the lens.

The best estimate should be recorded in weeks and days. In instances when the best estimate of gestational age is an exact number of weeks, enter the number of weeks in the space provided for weeks and enter “0” in the space provided for days. Do not leave the number of days blank.