Table 2.

Accuracy of gestational age assessment by method

Method of Gestational Age Assessment	Accuracy Correctiona,b,c	Accuracy Scaled
Ultrasound before 14 gestational weeks	±5 days	1 (most accurate)
Ultrasound between 14 and 28 gestational weeks	±2 weeks	2
Ultrasound after 28 gestational weeks	±3 weeks	3
Ballard score within 7 days of birth	±2 week	4
LMP	±4 weeks	5
Fundal Height	±6 weeks	6 (least accurate)

^a[37]

^b[38]

^c[39]

^dGestational age was be assessed using the most accurate technique available