Table 3 Estimated change in Z-score fetal biometric measurements (95% confidence interval) based on an increase of 1 μg/L of maternal urinary arsenic concentration according to fetal sex and maternal arsenic metabolism
| Â | Â | Head measures | Body measures | ||
|---|---|---|---|---|---|
| Â | Estimated fetal weighta | Head circumferencea | Biparietal diametera,b | Abdominal circumferencea,b | Femur lengthb,c |
All | -0.003 (-0.061, 0.055) | -0.019 (-0.050, 0.013) | -0.005 (-0.042, 0.033) | 0.006 (-0.027, 0.037) | 0.001 (-0.031, 0.033) |
By fetal sex | Â | Â | Â | Â | Â |
 male | 0.013 (-0.052, 0.078) | -0.016 (-0.052, 0.021) | 0.021 (-0.022, 0.065) | 0.011 (-0.025, 0.048) | 0.014 (-0.023, 0.051) |
 female | -0.041 (-0.171, 0.089) | -0.047 (-0.115, 0.021) | -0.072 (-0.151, 0.007) | -0.014 (-0.085, 0.057) | -0.016 (-0.085, 0.053) |
By arsenic metabolism (ratio of urinary arsenic metabolites) | |||||
First methylation step (MMA/iAs) | Â | Â | Â | Â | |
 below median | -0.025 (-0.107, 0.056) | -0.023 (-0.077, 0.017) | -0.007 (-0.066, 0.052) | -0.009 (-0.056, 0.038) | -0.003 (-0.047, 0.041) |
 above median | 0.023 (-0.066, 0.111) | -0.005 (-0.050, 0.040) | 0.003 (-0.049, 0.056) | 0.021 (-0.027, 0.069) | 0.008 (-0.040, 0.057) |
Second methylation step (DMA/MMA) | Â | Â | Â | Â | |
 below median | -0.023 (-0.166, 0.121) | -0.057 (-0.137, 0.023) | -0.010 (-0.193, -0.006)* | -0.019 (-0.098, 0.061) | 0.018 (-0.061, 0.098) |
 above median | 0.012 (-0.058, 0.082) | -0.007 (-0.044, 0.029) | 0.027 (-0.014, 0.069) | 0.021 (-0.017, 0.060) | 0.001 (-0.036, 0.038) |