Table 1 Clinical characteristics of the study population.

	Group 1(n = 26)	Group 2(n = 50)
Male:female	12:14	24:26
Gestational age, weeks	30.2 (2.8)	30.2 (2.9)
Birth weight, g	1465 (615)	1480 (540)
Apgar score at 1 min,	5 (1–9)	6 (1–10)
Apgar score at 5 min,	8 (4–10)	8 (5–10)
Number of punctures	23 (6–126)	22 (5–117)
Day of placement of reservoir	15 (1–49)	15 (1–86)

Values are mean (SD) or median (range) as appropriate.