. 2020 Mar 13;49(2):572–586. doi: 10.1093/ije/dyaa017

Table 3.

Adjusted effect measure of exposures on birth weight by offspring sex (ExWAS approach)

Exposure	Exposure family	Transformation	IQR	ICC	Interaction P-value	Sex	Estimate (95% CI)^a	P-value
Ethyl-paraben	Phenols	Log₂	3.7	0.44	0.0060	Female	−43 (−135; 49)	0.36
Ethyl-paraben	Phenols	Log₂	3.7	0.44	0.0060	Male	112 (31; 193)	0.007
Propyl-paraben	Phenols	Log₂	3.0	0.44	0.0062	Female	−61 (−142; 20)	0.14
Propyl-paraben	Phenols	Log₂	3.0	0.44	0.0062	Male	92 (11; 173)	0.026
Molybdenum	Metals and essential elements	Log₂	0.4	^b	0.046	Female	−19 (47; 8.2)	0.15
Molybdenum	Metals and essential elements	Log₂	0.4	^b	0.046	Male	24 (−8.6; 56)	0.17
N-Butyl-paraben	Phenols	Log₂	4.3	0.51	0.055	Female	−14 (−114; 86)	0.78
N-Butyl-paraben	Phenols	Log₂	4.3	0.51	0.055	Male	100 (5.6; 195)	0.038
Cadmium^b	Metals and essential elements	Log₂	0.7	0.78	0.060	Female	1.0 (−57; 59)	0.97
Cadmium^b	Metals and essential elements	Log₂	0.7	0.78	0.060	Male	−55 (−107; 3.6)	0.036
Lead ^b	Metals and essential elements	Log₂	0.5	0.73	0.092	Female	−6.0 (−73; 61)	0.86
Lead ^b	Metals and essential elements	Log₂	0.5	0.73	0.092	Male	−76 (−128; −24)	0.0041
Arsenic	Metals and essential elements	Log₂	2.3	0.42	0.11	Female	−133 (−258; −6.6)	0.039
Arsenic	Metals and essential elements	Log₂	2.3	0.42	0.11	Male	−24 (−149; 101)	0.71
PFOS^b	Per- and poly-fluoroalkyl substances	Log₂	0.7	^b	0.14	Female	−54 (−98; −10)	0.015
PFOS^b	Per- and poly-fluoroalkyl substances	Log₂	0.7	^b	0.14	Male	−15 (−57; 28)	0.50
PM_2.5 absorbance in 3rd trimester of pregnancy	Atmospheric pollutants	Ln	0.4	^b	0.38	Female	−35 (−91; 20)	0.21
PM_2.5 absorbance in 3rd trimester of pregnancy	Atmospheric pollutants	Ln	0.4	^b	0.38	Male	−62 (−114; −10)	0.019
DDT^b	Organochlorine compounds	Log₂	1.4	^b	0.31	Female	−15 (−66; 36)	0.56
DDT^b	Organochlorine compounds	Log₂	1.4	^b	0.31	Male	−46 (−90; −2.8)	0.037

CI, Confidence interval of the coefficient estimate; DDT, dichlorodiphenyltrichloroethane; IQR, inter-quartile range of the (normalized and corrected for measurement error) exposure variable; PFOS, perfluorooctane sulfonate.

Estimates are given as a change in mean birth weight (g) for each inter-quartile range (defined over all observations) increase in (normalized and corrected for measurement error) exposure. Only exposures with an uncorrected sex interaction or sex-specific P-value < 5% are reported. Associations were adjusted for gestational duration (simple and quadratic terms), sex of the newborn, parity, maternal height, maternal weight before pregnancy (using a broken stick model with a knot at 60 kg), maternal smoking during the second trimester of pregnancy, maternal education, season of conception and cohort (fixed effect variable).

Atmospheric pollutants were not assumed to suffer from classical-type measurement error; for biomarker-based exposures, no ICC was available in the literature.