Table 3.

Hemodynamics across the mouse fetoplacental tree

		CD1 Mice			B6 Mice
	Associated Variables/Calculations	E13.5	E15.5	E17.5	E13.5	E15.5	E17.5
Mean umbilical artery pressure drop (estimated), mmHg†	P	3	6	11	3	6	11
Mean umbilical artery blood velocity (estimated; Vmean), mm/s†	Vmean	25	25	31	30	30	34
Umbilical artery diameter from micro-CT data, mm	d	0.32 ± 0.02a	0.46 ± 0.01b	0.54 ± 0.01c	0.39 ± 0.02a,*	0.51 ± 0.02b	0.50 ± 0.01b
Umbilical artery flow (calculated), mm3/s	Q = Vmean[π(d/2)2]	2.0	4.1	7.1	3.6	6.1	6.8
Pressure drop across the arterial tree, mmHg	Parterial	1.06 ± 0.09a	1.69 ± 0.19a	2.97 ± 0.50b	1.42 ± 0.13a	1.85 ± 0.10b	1.28 ± 0.12b,**
Fetal placental resistance, mmHg·s·μl−1	Rtotal = P/Q	1.5	1.5	1.5	0.8	1.0	1.6
Resistance from micro-CT data, mmHg·s·μl−1	Rarterial	0.52 ± 0.04a	0.41 ± 0.05b	0.42 ± 0.07b	0.39 ± 0.04a	0.30 ± 0.02b	0.19 ± 0.02c,**
Capillary and venous resistance, mmHg·s·μl−1	Rcap+veins = Rtotal − Rarterial	1.0	1.1	1.1	0.4	0.7	1.4

Data are means ± SE; n = 7-10 placentas/group. micro-CT, microcomputed tomography.

^†Estimated from the literature.

^a,b,cDifferent letters show a significant difference between gestational ages (P < 0.05);

^*P < 0.05 and

^**P < 0.001, significant differences between strains at the same gestational age as determined by two-way ANOVA followed by Tukey post hoc tests. No statistical tests were performed on estimated values or calculated values that involved estimates.