Table 2.

Maternal and fetal whole blood gasses and oximetry and plasma metabolites from ewes receiving compressed air (CON) or nitrogen (HOX) gas at late gestation

	CON (n = 7), Day of Treatment				HOX (n = 13), Day of Treatment					P value*
	0	1	4	9	0	1	4	9		TRT	DAY	INT
	Whole blood gasses and oximetry
O2 content, mM
Maternal artery	5.30 ± 0.26a,b	5.37 ± 0.27a,b	5.38 ± 0.23a,b	4.93 ± 0.21b,c	5.58 ± 0.20a	5.05 ± 0.15b	4.54 ± 0.14c,d	4.32 ± 0.21d		0.17	<0.0001	0.0005
Umbilical vein	5.03 ± 0.11	4.64 ± 0.27	5.05 ± 0.25	4.44 ± 0.19	4.90 ± 0.19	4.15 ± 0.18	4.01 ± 0.34	3.39 ± 0.22		0.009	<0.0001	0.07
Fetal artery	3.34 ± 0.08	2.94 ± 0.18	2.52 ± 0.21	2.45 ± 0.16	2.93 ± 0.20	2.22 ± 0.18	1.65 ± 0.13	1.55 ± 0.17		0.001	<0.0001	0.37
So2, %
Maternal artery	92.85 ± 1.02a,b	94.77 ± 1.02a,b	95.32 ± 1.60a,b	93.75 ± 1.02a,b	95.91 ± 0.69a	89.24 ± 1.87b	81.58 ± 3.08c	75.98 ± 2.91d		0.0004	<0.0001	<0.0001
Umbilical vein	79.14 ± 3.01a	76.84 ± 5.52a	74.73 ± 4.27a	67.15 ± 4.99a,b	76.48 ± 3.02a	64.45 ± 3.15b,c	59.23 ± 3.92c,d	53.16 ± 3.06d		0.006	<0.0001	0.04
Fetal artery	51.76 ± 2.32	47.03 ± 2.58	36.27 ± 3.91	43.42 ± 5.85	43.35 ± 3.74	34.78 ± 3.18	24.73 ± 1.92	23.46 ± 2.38		0.002	<0.0001	0.20
Hematocrit, %
Maternal artery	29.83 ± 1.47	29.36 ± 1.49	29.30 ± 1.65	27.19 ± 1.34	30.16 ± 1.10	29.41 ± 0.84	28.98 ± 1.01	29.24 ± 1.05		0.69	0.002	0.28
Umbilical vein	32.95 ± 1.38	31.30 ± 1.50	34.52 ± 0.80	31.90 ± 1.36	32.92 ± 0.87	33.03 ± 0.89	34.34 ± 1.42	32.74 ± 1.70		0.83	0.10	0.96
Fetal artery	33.14 ± 1.43	31.77 ± 1.27	35.10 ± 0.91	32.19 ± 1.33	33.06 ± 0.90	32.68 ± 0.88	33.93 ± 1.17	32.96 ± 1.22		0.85	0.06	0.70
pCO2, mmHg
Maternal artery	36.17 ± 0.91	36.59 ± 1.38	34.62 ± 0.96	35.06 ± 1.15	33.71 ± 1.22	31.45 ± 0.96	30.08 ± 1.04	31.52 ± 0.73		0.01	0.004	0.17
Umbilical vein	43.58 ± 1.25a	44.40 ± 1.55a	44.68 ± 0.74a	43.33 ± 1.38a,b	44.07 ± 0.98a	41.30 ± 0.80b,c	40.17 ± 1.22c	40.61 ± 1.36c		0.03	0.05	0.003
Fetal artery	50.71 ± 1.89a,b	52.04 ± 1.19a	54.17 ± 1.23a,b	51.46 ± 1.74a,b	51.39 ± 1.32a,b	48.65 ± 1.15b,c	47.23 ± 1.32c,d	45.48 ± 1.31d		0.02	0.07	0.003
Bicarbonate, mM
Maternal artery	26.30 ± 1.03	26.11 ± 1.31	25.50 ± 1.08	24.70 ± 0.87	24.92 ± 0.77	23.27 ± 0.52	22.27 ± 0.69	21.56 ± 0.59		0.01	0.0001	0.08
Umbilical vein	25.97 ± 0.44a	26.20 ± 0.46a	25.98 ± 0.65a	25.43 ± 0.54a,b	26.65 ± 0.44a	25.65 ± 0.52a	23.84 ± 0.79b	22.26 ± 1.22c		0.05	<0.0001	0.002
Fetal artery	27.41 ± 0.60a,b,c	27.93 ± 0.39a,b	27.83 ± 0.74a,b	26.63 ± 0.37a,b,c	28.05 ± 0.43a	26.22 ± 0.91b,c	25.42 ± 0.62c	23.78 ± 0.89d		0.03	0.003	0.052
pH
Maternal artery	7.49 ± 0.02	7.48 ± 0.01	7.50 ± 0.01	7.48 ± 0.01	7.49 ± 0.01	7.49 ± 0.01	7.48 ± 0.01	7.46 ± 0.01		0.65	0.14	0.32
Umbilical vein	7.40 ± 0.01	7.42 ± 0.02	7.39 ± 0.01	7.40 ± 0.01	7.41 ± 0.01	7.42 ± 0.01	7.39 ± 0.02	7.38 ± 0.02		0.64	0.04	0.89
Fetal artery	7.37 ± 0.01	7.37 ± 0.01	7.35 ± 0.01	7.35 ± 0.01	7.38 ± 0.01	7.38 ± 0.01	7.37 ± 0.01	7.36 ± 0.02		0.20	0.09	0.76
	Plasma metabolites
Glucose, mM
Maternal artery	3.34 ± 0.15	3.67 ± 0.20	3.56 ± 0.13	3.78 ± 0.11	3.38 ± 0.12	3.53 ± 0.07	3.54 ± 0.08	3.75 ± 0.13	0.76		0.006	0.86
Umbilical vein	1.18 ± 0.08	1.23 ± 0.16	1.35 ± 0.07	1.18 ± 0.09	1.24 ± 0.06	1.3 ± 0.05	1.37 ± 0.06	1.39 ± 0.11	0.21		0.31	0.70
Fetal artery	0.98 ± 0.06	1.04 ± 0.09	1.09 ± 0.06	0.98 ± 0.09	1.05 ± 0.05	1.07 ± 0.04	1.12 ± 0.05	1.17 ± 0.08	0.19		0.56	0.55
Lactate, mM
Maternal artery	0.64 ± 0.03	0.77 ± 0.10	0.77 ± 0.05	0.83 ± 0.10	0.68 ± 0.05	0.69 ± 0.06	0.85 ± 0.08	0.89 ± 0.08	0.69		0.03	0.54
Umbilical vein	2.05 ± 0.15	1.82 ± 0.12	2.93 ± 0.44	2.29 ± 0.15	2.47 ± 0.34	4.06 ± 0.61	5.94 ± 1.03	7.83 ± 2.33	0.002		0.02	0.06
Fetal artery	1.92 ± 0.17	1.93 ± 0.20	2.74 ± 0.43	2.11 ± 0.14	2.31 ± 0.34	3.53 ± 0.50	5.34 ± 0.84	7.04 ± 1.87	0.008		0.02	0.08

Data are means ± SE. CON, control; DAY, day of treatment; HOX, hypoxemia; INT, interaction between DAY and treatment group; TRT, treatment group.

^*Data were analyzed by 2-way ANOVA for the fixed effects of TRT, DAY, INT.

^a,

^b,

^c,

^dWithin a row, means with different superscripted letters are different (P ≤ 0.05).