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. Author manuscript; available in PMC: 2020 May 31.
Published in final edited form as: Fertil Steril. 2018 Nov;110(6):1137–1144.e1. doi: 10.1016/j.fertnstert.2018.06.045

Table 4.

Risk Ratios (RR) and 95% Confidence Intervals (CIs) for biochemical pregnancy loss and total pregnancy loss across quartiles of urinary organophosphate flame retardant metabolite concentrations using 339 cycle-specific samples from 179 pregnancies in the Environment and Reproductive Health (EARTH) Study.

Biochemical Lossa Total Pregnancy Lossb
PFR Metabolite Quartile (ng/ml) N RR (95% CI) Unadjustedc Model RR (95%CI) Adjustedd Model RR (95% CI) Unadjusted Model RR (95% CI) Adjustedd Model
BDCIPP
Q1 (0.21) 45 REF REF REF REF
Q2 (0.46) 44 0.73 (0.25, 2.10) 0.70 (0.25, 2.00) 0.83 (0.45, 1.55) 0.87 (0.50, 1.54)
Q3 (0.94) 45 0.71 (0.25, 2.07) 0.71 (0.24, 2.06) 0.81 (0.45, 1.47) 0.83 (0.47, 1.49)
Q4 (2.49) 45 0.57 (0.18, 1.79) 0.52 (0.17, 1.58) 0.75 (0.40, 1.39) 0.70 (0.39, 1.26)
p-trende 0.34 0.23 0.37 0.27
DPHP
Q1 (0.34) 44 REF REF REF REF
Q2 (0.58) 45 0.78 (0.23, 2.69) 0.81 (0.23, 2.77) 0.73 (0.39, 1.40) 0.71 (0.37, 1.35)
Q3 (0.92) 45 0.98 (0.33, 2.94) 1.06 (0.36, 3.10) 0.67 (0.35, 1.30) 0.84 (0.44, 1.46)
Q4 (1.88) 45 1.37 (0.49, 3.84) 1.64 (0.61, 4.39) 0.92 (0.53, 1.59) 1.15 (0.68, 1.93)
p-trende 0.49 0.30 0.94 0.67
ipPPP
Q1 (0.028) 44 REF REF REF REF
Q2 (0.068) 45 0.81 (0.28, 2.42) 0.86 (0.28, 2.68) 0.75 (0.37, 1.51) 0.79 (0.40, 1.57)
Q3 (0.12) 45 0.81 (0.27, 2.45) 0.91 (0.29, 2.88) 1.28 (0.71, 2.30) 0.91 (0.82, 2.40)
Q4 (0.28) 45 0.82 (0.29, 2.32) 0.81 (0.29, 2.27) 1.05 (0.56, 1.96) 0.81 (0.56, 1.88)
p-trende 0.71 0.76 0.71 0.76
ΣPFR (mol/ml × 10–9)f
Q1 (0.0038) 44 REF REF REF REF
Q2 (0.0060) 45 1.47 (0.45, 4.76) 1.61 (0.49, 5.23) 1.39 (0.72, 2.64) 1.41 (0.75, 2.65)
Q3 (0.0087) 45 0.98 (0.27, 3.50) 1.05 (0.30, 3.84) 1.06 (0.54, 2.09) 1.10 (0.58, 2.10)
Q4 (0.018) 45 1.71 (0.56, 5.24) 1.89 (0.64, 5.58) 1.14 (0.60, 2.18) 1.19 (0.63, 2.24)
p-trende 0.48 0.65 0.82 0.70

Metabolite Abbreviations: BDCIPP: [bis(1,3-dichloro-2-propyl) phosphate; DPHP: diphenyl phosphate; ip-PPP: isopropylphenyl phenyl phosphate

a

Biochemical pregnancy loss was defined as the demise of a non-visualized β-hCG confirmed pregnancy.

b

Pregnancy loss <20 weeks’ gestation was defined as the loss of any pregnancy (including biochemical losses) of less than 20 weeks gestation (<=139 days).

c

Unadjusted and adjusted models estimated risk ratios and 95% CIs with repeated measures log- binomial regression.

d

Adjusted models included age (categorical), BMI (continuous), smoking status (never/ever).

e

Tests for trend were performed using the urinary PFR metabolite concentration quartile as an ordinal level indicator variable in the regression model, adjusted for covariates.

f

ΣPFR is the molar sum of the three organophosphate flame retardant metabolite concentrations with high detection frequencies: (BDCIPP*(1/319.91) + (DPHP*(1/250.04) + ipPPP*(1/292.09). Concentrations shown in mol/ml X10–9.