Gestational dating ultrasound
The authors examined whether early ultrasound dating (≤20 weeks) of gestational age (GA) in small-for-gestational-age (SGA) fetuses may underestimate gestational duration and therefore the incidence of SGA birth.
Harland, Injury Prevention Research Center and Department of Epidemiology, University of Iowa, 200 Newton Road, 2188 WL, Iowa City, IA 52242-5000 (e-mail: [email protected]).
Some women will deliver on their due date, others before, and others after.
The body is not on a clock counting down to delivery; natural variation will introduce uncertainty.
In normal state, each body tissue type, such as liver, spleen or kidney, has a unique echogenicity.
Features include the forehead at 10 o'clock, the left ear toward the center at 7 o'clock and the right hand covering the eyes at .
Accurate gestational age (GA) dating of pregnancies is vital to public health surveillance and research investigating the causes of small-for-gestational-age (SGA) birth and preterm delivery (PTD).