Adverse neonatal outcome and veno-arterial differences in umbilical cord blood pH (ΔpH) at birth: a population-based study of 108,629 newborns

Table 3 Relative risk of adverse neonatal outcome with Small ΔpH (≤0.02; 10th percentile) or Large ΔpH (≥0.15; 90th percentile) as compared to ΔpH between 10th–90th percentiles. Modified Poisson regression model with 95% confidence intervals and P-values were calculated for term pregnancies. N = 108,629

	Total cases	108,629	%	Apgar 0–6 at 5 minutes			CPAP^a			NICU^b admission
	Total cases	108,629	%	P-value	RR ^c	95% CI^d	P-value	RR	95% CI	P-value	RR	95% CI
UApH < 7.05	Small ΔpH	135	6.1%	0.62	1.12	0.71–1.77	0.457	0.800	0.44–1.44	0.89	0.98	0.74–1.30
	Large ΔpH	813	36.9%	0.71	0.95	0.75–1.22	0.199	0.833	0.63–1.10	0.15	0.90	0.78–1.04
	Total	2204	100%
UApH 7.05–7.099	Small ΔpH	178	5.1%	0.58	1.24	0.58–2.66	0.404	0.708	0.32–1.59	0.71	0.93	0.64–1.36
	Large ΔpH	1208	34.9%	0.76	0.94	0.63–1.40	0.082	0.730	0.51–1.04	0.00	0.75	0.62–0.91
	Total	3466	100.0%
UApH 7.10–7.149	Small ΔpH	456	5.5%	0.55	1.23	0.62–2.44	0.380	0.728	0.36–1.48	0.36	1.14	0.86–1.50
	Large ΔpH	2577	30.9%	0.41	0.85	0.57–1.25	0.924	1.015	0.75–1.37	0.24	0.91	0.79–1.06
	Total	8345	100.0%
UApH 7.15–7.199	Small ΔpH	901	5.7%	0.01	1.96	1.15–3.37	0.411	0.755	0.39–1.47	0.99	1.00	0.78–1.28
	Large ΔpH	3452	21.7%	0.01	0.48	0.27–0.84	0.048	0.679	0.46–1.00	0.01	0.82	0.70–0.95
	Total	15,920	100.0%
UApH ≥ 7.20	Small ΔpH	10,345	13.1%	0.00	1.65	1.26–2.1	0.918	1.013	0.78–1.31	0.01	1.13	1.04–1.24
	Large ΔpH	4211	5.4%	0.01	0.29	0.12–0.71	0.022	0.549	0.30–0.92	0.01	0.81	0.69–0.95
	Total	78,694	100.0%

^a CPAP continuous positive airway pressure, ^b NICU neonatal intensive care unit, ^c RR relative risk, ^d CI confidence interval

ISSN: 1471-2393