Table 4.

Sex difference for the occurrence of mortality and the prevalence of major neonatal morbidities, stratified by individual gestational age.

GA (weeks)	Mortality		BPD		IVH, grade ≥ 3		PVL		ROP, grade ≥ 3		NEC		Combined morbidities
	OR* (95% CI)	P	OR* (95% CI)	P	OR* (95% CI)	P	OR* (95% CI)	P	OR* (95% CI)	P	OR* (95% CI)	P	OR* (95% CI)	P
23	0.93 (0.44–2.07)	0.821	2.86 (0.57–14.54)	0.266	2.41 (0.97–5.30)	0.057	4.05 (1.06–15.5)	0.042	2.90 (0.83–10.02)	0.082	1.98 (0.73–5.40)	0.121	5.00 (1.10–55.67)	0.038
24	1.15 (0.62–2.15)	0.993	2.72 (1.18–6.25)	0.020	1.50 (0.77–2.66)	0.183	1.33 (0.50–3.54)	0.538	1.36 (0.65–2.86)	0.298	0.97 (0.61–2.13)	0.959	1.68 (0.58–4.90)	0.383
25	1.14 (0.63–2.04)	0.423	1.86 (1.05–3.29)	0.004	1.04 (0.58–1.93)	0.721	0.98 (0.49–1.93)	0.802	1.20 (0.68–2.11)	0.333	1.34 (0.64–2.75)	0.854	2.09 (1.07–4.09)	0.012
26	1.11 (0.62–1.97)	0.781	1.26 (0.77–2.05)	0.315	0.884 (0.47–1.65)	0.657	1.29 (0.67–2.48)	0.193	0.50 (0.27–0.92)	0.026	1.20 (0.56–2.57)	0.580	1.20 (0.71–2.03)	0.640
27	1.03 (0.48–2.23)	0.634	1.06 (0.67–1.68)	0.951	1.72 (0.84–3.53)	0.109	1.31 (0.64–2.68)	0.562	0.41 (0.19–0.88)	0.022	1.79 (0.83–3.89)	0.132	1.06 (0.67–1.67)	0.966
28	0.81 (0.35–1.86)	0.368	1.32 (0.86–2.03)	0.272	1.06 (0.46–2.46)	0.782	1.40 (0.70–2.80)	0.238	1.07 (0.49–2.31)	0.936	1.83 (0.70–4.76)	0.165	1.48 (0.99–2.23)	0.239
29	1.08 (0.39–3.00)	0.406	1.01 (0.61–1.65)	0.845	2.44 (0.74–8.05)	0.267	2.36 (1.11–5.02)	0.026	0.44 (0.13–1.54)	0.134	1.01 (0.27–4.00)	0.892	0.99 (0.64–1.55)	0.929

*Values are adjusted odds ratio and 95% confidence interval. Values are adjusted by histologic chorioamnionitis, intrauterine growth restriction, maternal diabetes, maternal hypertension, multiple births, delivery mode, and the use of antenatal steroid according to individual gestational age (GA).