Associations between exposure to cadmium, lead, mercury and mixtures and women’s infertility and long-term amenorrhea

Table 2 Unadjusted medians and log transformed means of blood heavy metal concentrations and heavy metal mixture scores in ever-infertile or fertile/pregnant women

	Main group sample (ever-infertile vs fertile n = 1999)				Sub-group sample (ever-infertile vs pregnant n = 297)
Metal	Total Sample	Ever- infertile¹	Fertile²	p-Value⁴	Total Sample -	Ever- infertile¹	Pregnant³	p-Value⁴
Lead, median, IQR (ug / dL)	0.53 (0.34-0.78)	0.56 (0.42-0.79)	0.53 (0.38-0.78)	0.19	0.54 (0.36-0.74)	0.56 (0.42-0.79)	0.36 (0.26-0.53)	0.001
Log Transformed Lead, Mean, SE	-0.57 ± 0.02	-0.49 ± 0.04	-0.58 ± 0.03	0.11	-0.58 ± 0.05	-0.49 ± 0.04	-0.99 ± 0.06	< .001
Cadmium, median, IQR (ug / L)	0.25 (0.16-0.44)	0.26 (0.15-0.47)	0.25 (0.60-0.44)	0.68	0.25 (0.14-0.44)	0.26 (0.15-0.47)	0.19 (0.11-0.35)	0.21
Log Transformed Cadmium, Mean, SE	-1.25 ± 0.03	-1.24 ± 0.07	-1.25 ± 0.03	0.91	-1.30 ± 0.07	-1.24 ± 0.07	-1.54 ± 0.10	0.07
Mercury, median, IQR (ug / L)	0.61 (0.33-1.26)	0.60 (0.37-1.15)	0.61 (0.32-1.27)	0.72	0.59 (0.35-1.16)	0.60 (0.37-1.15)	0.55 (0.26-1.14)	0.051
Log Transformed Mercury, Mean, SE	-0.37 ± 0.03	-0.36 ± 0.08	-0.37 ± 0.03	0.89	-0.40 ± 0.07	-0.36 ± 0.08	-0.58 ± 0.12	0.21
Weighted Mixed Metal, median, IQR	3.01 (2.12 – 4.39)	3.10 (2.27 – 4.31)	2.10 (2.98 – 4.39)	0.19	2.94 (2.03 – 4.23)	3.10 (2.27 – 4.31)	1.39 (2.04 – 2.79)	0.001
Log Transformed Mix, Mean, SE	1.14 ± 0.02	1.21 ± 0.04	1.13 ± 0.02	0.15	1.12 ± 0.04	1.21 ± 0.04	0.73 ± 0.06	< .001

Blood metal distributions were skewed. Therefore, we presented the median and IQR (25^th and 75^th percentile) and the mean of the Log Transformed blood heavy metal levels. These results are weighted to account for NHANES survey design
¹ ‘Ever-infertile’ if participant responded ‘yes’ to the following question: “Have you ever attempted to become pregnant over a period of at least a year without becoming pregnant?”
² ‘Fertile’ if answered “No” to the following question: "Have you ever attempted to become pregnant over a period of at least a year without becoming pregnant?"
³ ‘Pregnant’ if women answered “Yes” to the question “Are you pregnant now?”
⁴ p-values represent a t-test to determine if there is a significant difference between the means of ever-infertile vs. fertile or pregnant

ISSN: 2049-3258