Table 2.

Doppler ultrasound measurements of fetal and placental hemodynamics.

	Nonsmokers (n=33)	Placebo-treated smokers (n=26)	Vitamin C-treated smokers (n=29)	p-value nonsmoker vs. placebo	p-value nonsmoker vs. vitaminC	p-value vitamin C vs. placebo
Umbilical vein Doppler velocity (Vmax), cm/s	28.00 ± 1.31	23.49 ± 1.10	27.88 ± 1.21	0.05	0.92	0.04
Umbilical vein volume blood flow (cQUV), mL/min	254.9 ± 14.2	209.4 ± 14.6	249.2 ± 16.0	0.17	0.71	0.09
Umbilical artery pulsatility index (UAPI)	0.90 ± 0.02	0.99 ± 0.03	0.99 ± 0.03	0.07	0.05	0.95
IAUV—intraabdominal umbilical vein diameter (IAUV), cm	0.62 ± 0.02	0.61 ± 0.02	0.61 ± 0.01	0.85	0.78	0.93
Cross sectional area of the umbilical vein (CSA), cm2	0.31 ± 0.02	0.30 ± 0.02	0.30 ± 0.01	0.83	0.75	0.94
Fetal heart rate (FHR), beats/min	143.0 ± 1.6	137.3 ± 1.9	141.3 ± 2.0	0.02	0.59	0.06

Data shown as mean ± SE. CSA calculated as π(UV diameter (cm)/2)²; cQUV calculated as 0.5 × Vmax × CSA × 60. P-values for F-test using mixed linear model per measurement adjusted for gestational age at ultrasound and BMI. Logarithmic transformation were performed for the following measurements to reduce skewness of residuals: IAUV, CSA, cQUV, and FHR.