. Author manuscript; available in PMC: 2015 Dec 1.

Published in final edited form as: J Perinatol. 2014 Dec 18;35(6):428–433. doi: 10.1038/jp.2014.225

Table 4.

Sleep-wake cycling by PMA¹

	Group 1 <27 weeks (n=8)	Group 2 27–29 weeks (n=16)	Group 3 29–31 weeks (n=21)	Group 4 >31 weeks (n=19)
SWC² absent	2	2	0	0
SWC² intermediate	6	14	16	6
SWC² mature	0	0	5	13

PMA denotes post-menstrual age.

SWC denotes sleep-wake cycling.