Fig. 2
The association between overall metal mixture exposure and spontaneous preterm birth (A) and the independent effect of each metal (B). A The effect was estimated by fixing all scaled log10-transformed metal concentration(log10C) at the same quantile. B The effects were estimated by comparing the effect for each metal at the 75th percentile versus the 25th percentile of scaled log10C while holding the scaled log10C for other metals fixed at the 25th, 50th, and 75th percentiles