. 2007 Sep 27;7:22. doi: 10.1186/1471-2393-7-22

Table 3.

Incidence Rate Ratios of miscarriage comparing different biomarkers of lead exposure. Mexico City, Mexico, 1997–2004

Biomarker	IRR*	p
Plasma Pb	1.12	0.22
Blood Pb	0.93	0.56
Plasma/Blood Pb ratio	1.18	0.02
Patella Pb^†	1.15	0.39
Tibia Pb^‡	1.07	0.56

Comparison of incidence of spontaneous abortion rate ratios per increase of one standard deviation of several biomarkers of lead exposure. Note: Each line features an effect estimate obtained by separate Poisson regression models.

* Incidence Rate Ratio, adjusted for age and schooling.

^†n = 95

^‡n = 153