Table 1.

Numbers of successful measurements per variable, according to age. Values are percentages (absolute number of children)

Kidney measurement	Successful measurements, % (n)
	Gestational age 30 weeks	Age 6 months	Age 24 months
	(n = 1,215)	(n = 901)	(n = 856)
Left kidney
Length	94.9 (1,153)	81.2 (732)	78.2 (669)
Width	95.2 (1,157)	77.2 (696)	72.8 (623)
Depth	95.1 (1,155)	76.8 (692)	76.9 (624)
Volume	94.4 (1,147)	76.6 (690)	72.9 (615)
Right kidney
Length	94.7 (1,151)	82.9 (747)	81.9 (701)
Width	95.4 (1,159)	82.4 (742)	80.6 (690)
Depth	95.4 (1,159)	82.2 (741)	80.6 (690)
Volume	94.5 (1,148)	82.1 (740)	80.4 (688)