Table 3. Demographic and clinical characteristics of study participants according to the need of h-CPAP.

Variables	Room air or oxygen only	h-CPAP application	p-value
	N = 31	N = 10
Timing of infection
1st wave (Mar-Aug 2020)	10 (32.2)	0	0.040
2nd wave (Sept-Dec 2020)	16 (51.6)	3 (30.0)	0.205
3rd wave (Jan-Mar 2021)	5 (16.1)	7 (70.0)	0.003
Demographic and obstetric variables
Maternal age (years)	31.6 ±4.9	33.3 ± 6.4	0.397
BAME	7 (22.6)	3 (30.0)	0.683
Pregestational BMI ≥30 Kg/m2	4 (12.9)	4 (40.0)	0.082
Comorbidities	6 (19.4)	1 (10.0)	0.660
Nulliparity	10 (32.3)	4 (40.0)	0.712
Pregnancy complications	15 (48.4)	6 (60.0)	0.719
GA at hospital admission (weeks)	31.4 ± 5.6	29.4 ± 5.0	0.318
Laboratory data at hospital admission
White blood cells (10^3/uL)	7.93 ± 3.3	9.49 ± 4.3	0.260
Lymphocytes (10^3/uL)	1.2 ± 0.6	1.1 ± 0.7	0.560
Platelets (10^3/uL)	202.1 ± 68.5	253.8 ± 125.3	0.125
D-dimer (ng/mL)	713.4 ± 801.5	651.0 ± 539.5	0.858
	(n = 28)	(n = 8)
Fibrinogen (mg/dL)	512.6 ±144.2	524.8 ± 157.4	0.839
ALT (U/L)	29.7 ± 34.8	38.9 ± 28.1	0.478
LDH (U/L)	185.3 ±39.3	213.0 ± 55.3	0.111
CRP (mg/dL)	3.0 ± 2.9	6.1 ± 4.4	0.021
Chest X-ray findings upon hospital admission
Involvement of ≥3 lobes	3 (9.7)	8 (80.0)	<0.001
Bilateral involvement	14 (45.2)	10 (100.0)	0.002
Lobe involvement
• Right Lower	19 (61.3)	10 (100.0)	0.021
• Left Lower	13 (41.9)	10 (100.0)	0.002
• Right middle	7 (22.6)	9 (90.0)	<0.001
• Lingula	8 (25.8)	9 (90.0)	<0.001
• Right Upper	1 (3.2)	3 (30.0)	0.039
• Left Upper	5 (16.1)	2 (20.0)	1.000

Footnotes: Data shown as mean ± standard deviation or number (percentage).

BAME, Black, Asian, and minor ethnicity; BMI, Body Mass Index; h-CPAP, helmet continuous positive airway pressure; GA, gestational age.