Table 3.

Bivariate associations (r) for nocturnal sleep parameters (n = 74)

Variables	Sleep duration	Sleep efficiency	WASO	Arousal index	Stage N1 sleep	Stage N2 sleep	Stage N3 sleep	REM sleep	NREM sleep
Evening CRP, ng/mL	0.02	0.03	−0.02	0.12	−0.06	0.20§	−0.24*	0.05	−0.07
Evening IL-6, pg/mL	0.09	0.14	−0.08	0.16§	0.10	0.01	−0.06	−0.09	0.09
Evening sIL-6R, pg/mL	0.05	0.06	−0.05	0.06	−0.06	0.14	−0.07	−0.09	0.06
Age, years	−0.07	−0.07	0.19§	0.36**	0.10	−0.06	0.11	−0.13	0.11
Gestational age, weeks	−0.16§	−0.17§	0.17§	0.14	0.01	0.10	−0.11	−0.03	0.08
Prepregnancy BMI, kg/m2	−0.12	−0.13	0.10	0.24*	0.03	0.07	−0.14	−0.02	0.03
Pregnancy BMI, kg/m2	−0.11	−0.12	0.10	0.30**	0.04	0.11	−0.16§	−0.08	0.09
Neck circumference, cm	−0.27*	−0.29*	0.23*	0.28*	0.19	0.07	−0.23§	−0.14	0.12
PHQ-9	0.19§	0.21§	−0.14	0.02	−0.05	0.09	−0.19§	0.10	−0.09

Note:

^§P < 0.2;

^*P < 0.05;

^**P < 0.01;

BMI, body mass index; NREM, nonrapid eye movement sleep; PHQ-9, Patient Health Questionnaire-9; REM sleep, rapid eye movement sleep; SD, standard deviation; WASO, wake after sleep onset; natural log of IL-6, sIL-6R, and arousal index and square root of CRP were used.