Table 3.
Cardiovascular, cerebrovascular and respiratory responses during the initial response phase of the modified Duffin CO2 rebreathe test.
| NP | TM1 | TM2 | TM3 | |
|---|---|---|---|---|
| Constant term | β Coef. | β Coef. | β Coef. | |
| (95% CI) | (95% CI) | (95% CI) | (95% CI) | |
| MAP (mmHg) | 0.69 | +0.06 | −0.08 | −0.14 |
| (0.21, 1.16) | (−0.57, 0.69) | (−0.87, 0.72) | (−0.68, 0.40) | |
| Heart rate (bpm) | −0.90 | −0.53 | +0.22 | +0.37 |
| (−1.47, −0.32) | (−1.49, 0.42) | (−0.66, 1.11) | (−0.42, 1.16) | |
| MCAvmean | 2.86 | +0.79 | +0.42 | +0.35 |
| (2.28, 3.45) | (−0.26, 1.84) | (−0.32, 1.17) | (−0.42, 1.12) | |
| PCAvmean | 1.61 | +0.42 | +0.30 | +0.25 |
| (1.19, 2.03) | (−0.36, 1.20) | (−0.31, 0.92) | (−0.32, 0.82) | |
| MCA resistance | −0.067 | −0.002 | −0.012 | +0.003 |
| (−0.09, −0.05) | (−0.03, 0.03) | (−0.05, 0.03) | (−0.02, 0.03) | |
| PCA resistance | −0.09 | −0.031 | −0.040 | −0.004 |
| (−0.12, −0.06) | (−0.09, 0.03) | (−0.10, 0.02) | (−0.05, 0.04) | |
| Tidal volume | 0.02 | −0.02 | −0.01 | +0.03 |
| (−0.04, 0.08) | (−0.11, 0.07) | (−0.09, 0.06) | (−0.04, 0.10) | |
| Frequency of breathing | 0.03 | −0.45 | +0.09 | +0.06 |
| (−0.22, 0.28) | (−1.05, 0.15) | (−0.33, 0.50) | (−0.50, 0.63) | |
| VE* | 0.21 | −0.46 | −0.07 | +0.62 |
| (−0.37, 0.80) | (−1.40, 0.47) | (−0.86, 0.73) | (−0.24, 1.48) |
Note: Data are presented as adjusted means (for reference term), β coefficients, and 95% confidence intervals. Analyses were adjusted for clustering by participant.
*Pregnancy phase significantly predicted values according to linear regression adjusted for clustering by participant (p < 0.05).
BP: blood pressure; MCA: middle cerebral artery; NP: nonpregnant; TM1: first trimester; TM2: second trimester; TM3: third trimester; PCA: posterior cerebral artery.