Table 3.
Adjusted difference in blood pressure (mmHg) at < 20 weeks of pregnancy, difference in highest blood pressure (mm Hg) at ≥ 20 weeks of pregnancy, and relative risk for pregnancy-induced hypertensive disease (gestational hypertension, preeclampsia, HELLP syndrome or eclampsia) according to terciles of creatinine-normalized urinary MBzP concentrations*
| MBzP Tercile and Timing of Urine Sample | Cases/Total | Median (Range) MBzP Concentration (μg/g Cr) | Difference in Diastolic BP at <20 Weeks (95 % CI) a | Difference in Systolic BP at <20 Weeks (95 % CI) a | Difference in Diastolic BP at ≥20 Weeks (95 % CI)b | Difference in Systolic BP at ≥20 Weeks (95 % CI)b | RR for pregnancy-induced hypertensive disease (95 % CI)c |
|---|---|---|---|---|---|---|---|
| 16 Week-1st | 6/122 | 3.9 (0.5, 6.5) | Ref | Ref | Ref | Ref | Ref |
| 16 Week-2nd | 8/122 | 9.8 (6.5, 13) | 0.5 (−1.1, 2.1) | −1.0 (−3.4, 1.5) | 0.6 (−1.2, 2.4) | −0.3 (−3.0, 2.4) | 1.44 (0.51, 4.02) |
| 16 Week-3rd | 19/122 | 22 (13, 331) | 2.2 (0.5, 3.9) | 2.1 (−0.5, 4.7) | 2.8 (0.9, 4.7) | 2.3 (−0.3, 4.9) | 2.92 (1.15, 7.41) |
| P-value for trend | <0.01 | 0.05 | <0.01 | 0.05 | 0.01 | ||
| 26 Week-1st | 10/118 | 3.9 (0.1, 6.0) | Ref | Ref | Ref | ||
| 26 Week-2nd | 7/119 | 9.0 (6.1, 14) | 0.9 (−1.0, 2.9) | 1.0 (−1.8, 3.8) | 0.91 (0.35, 2.42) | ||
| 26 Week-3rd | 15/118 | 23 (14, 178) | 1.1 (−0.7, 3.0) | 0.6 (−2.2, 3.4) | 1.65 (0.76, 3.60) | ||
| P-value for trend | 0.29 | 0.80 | 0.12 | ||||
| Pregnancy Average-1st | 8/123 | 4.5 (0.2, 6.4) | Ref | Ref | Ref | ||
| Pregnancy Average-2nd | 9/123 | 9.0 (6.4, 13) | 1.0 (−0.8, 2.8) | 1.1 (−1.5, 3.8) | 1.30 (0.55, 3.09) | ||
| Pregnancy Average-3rd | 17/123 | 21 (13, 137) | 2.1 (0.3, 3.9) | 0.5 (−2.1, 3.1) | 2.21 (0.96, 5.09) | ||
| P-value for trend | 0.03 | 0.86 | 0.04 |
*- Adjusted for maternal race, age at delivery, household income, education, marital status, serum cotinine concentrations, parity, BMI at 16 weeks gestation, and previous use of medication for high blood pressure. The blood pressure models were additionally adjusted for the week of pregnancy that the blood pressure measurement was taken
a-n = 369 with 719 repeated observations
b-n = 371 with 736 repeated observations for 16 weeks, n = 360 with 714 repeated observations for 26 weeks, and n = 374 with 742 repeated observations for average
c-n = 366 for 16 week, 355 for 26 week, and 369 for average