Table 2.

Detection frequencies, limits of detection, and distributions of pregnancy-average OPE biomarker concentrations (ng/mL), and intraclass correlation coefficients in the LIFECODES Fetal Growth Study (n = 900, 2007–2018)

Abbreviation	Chemical Name	n (%) > LOD^a	LOD	GM	Percentiles					ICC^b
Abbreviation	Chemical Name	n (%) > LOD^a	LOD	GM	5^th	25^th	50^th	75^th	95^th	ICC^b
BCEP	Bis(2-chloroethyl) phosphate	812 (90)	0.10	0.32	0.09	0.17	0.28	0.54	1.61	0.50
BCIPP	Bis(1-chloro-2-propyl) phosphate	577 (64)	0.10	0.17	0.05	0.09	0.14	0.24	1.02	0.51
BDCIPP	Bis(1,3-dichloro-2-propyl) phosphate	892 (99)	0.10	0.75	0.20	0.39	0.71	1.34	3.46	0.50
DNBP	Di-n-butyl phosphate	568 (63)	0.10	0.11	0.05	0.08	0.11	0.15	0.26	0.27
DPHP	Diphenyl phosphate	900 (100)	0.10	1.05	0.38	0.65	1.00	1.60	3.42	0.33
iPPPP	2-((isopropyl)phenyl)phenyl phosphate	135 (15)	0.05	-	-	-	-	-	-	-
tBPPP	4-((tert-butyl)phenyl)phenyl phosphate	350 (39)	0.05	-	-	-	-	-	-	-
TBBA^c	2,3,4,5-tetrabromobenzoic acid	58 (6)	0.05	-	-	-	-	-	-	-

Abbreviations: GM = geometric mean; ICC = intraclass correlation coefficient; LOD = limit of detection; OPE = organophosphate ester. The numbers (%) correspond to the of participants for each biomarker with at least one detectable concentration. Percentages are rounded to the nearest integer.

Computed using a survey-weighted linear mixed model with random intercept for each participant.

TBBA is a biomarker of exposure to 2-ethylhexyl-2,3,4,5-tetrabromobenzoate.