The WHO definition of gestation should be used. This states: 'The period of gestation is measured from the first day of the last menstrual period (LMP). Gestational age is expressed in completed weeks; eg events occurring 280-286 days after the onset of the last menstrual period are considered to have occurred at 40 weeks gestation'.

Alternative methods of assessing gestation are:

a.	Clinical assessment of uterine size
b.	Ultrasonic measurements, and/or
c.	Retrospective clinical assessment of the new born by a paediatrician

 

This attribute is also known by these names:

Context	Alias
plural	GESTATION LENGTH (LABOUR ONSET)