Table 2. Incidence of IVH for all neonatal treatment cases and for infants <1500 g or <32 weeks’ gestation categorized according to severity, with associated mean gestational age (full weeks) and birth weight (g).

Grade of hemorrhage (Papile classification)	Total n = 26 609	<1500 g or <32 gw n = 1782
n grade 1	417 (1.57%)	112 (6.29%)
	34.4 ± 4.1 weeks	29.1 ± 2.5 weeks
	2314 ± 926 g	1195 ± 391 g
n grade 2	143 (0.54%)	93 (5.22%)
	30.3 ± 5.1 weeks	27.1 ± 2.4 weeks
	1630 ± 944 g	1048 ± 390 g
n grades 3 + 4	193 (0.73%)	151 (8.47%)
	28.3 ± 4.9 weeks	26.1 ± 2.3 weeks
	1294 ± 885 g	886 ± 311 g
n grades 1–4	753 (2.83%)	356 (19.97%)
	37.3 ± 3.2 weeks	29.3 ± 2.7 weeks
	2947 ± 822 g	1255 ± 392 g

IVH, intraventricular hemorrhage; GW, gestational week; n, number