Table 3.
Associations between prenatal exposure to individual phthalates and offspring Social Responsiveness Scale (SRS) raw scores in HOME and EARLI: linear regression models (N = 437).
| Phthalate, log2(ug/g creatinine) | Unadjusted modela | Adjusted model | ||||
|---|---|---|---|---|---|---|
|
|
|
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| HOME (N=271) | EARLI (N=166) | Pooled (N=437) | HOMEb (N=271) | EARLIc (N=166) | Pooledd (N=437) | |
| MBP | 0.24 (−2.1, 2.6) | −1.3 (−5.3, 2.6) | −0.85 (−2.8, 1.1) | −0.17 (−2.3, 2.0) | 0.52 (−4.5, 3.4) | −0.23 (−2.3, 1.8) |
| MBzP | 2.1 (0.24, 3.9) | 1.5 (−1.5, 4.5) | 1.5 (−0.08, 3.1) | 0.15 (−1.6, 1.9) | 0.89 (−2.1, 3.8) | 0.47 (−1.1, 2.1) |
| MCPP | −0.37 (−3.1, 2.4) | −1.9 (−4.1, 0.28) | −1.4 (−3.0, 0.19) | 1.9 (−0.64, 4.5) | −0.75 (−3.0, 1.5) | −0.12 (−1.7, 1.4) |
| DEHPc | 0.21 (−1.4, 1.8) | −3.6 (−7.4, 0.14) | −1.0 (−2.5, 0.40) | 1.9 (0.43, 3.4) | −2.8 (−6.5, 0.87) | 0.53 (−1.0, 2.1) |
| MEP | 0.68 (−0.72, 2.1) | −2.0 (−4.5, 0.53) | −0.62 (−1.7, 0.48) | 0.36 (−0.91, 1.6) | −1.6 (−4.2, 1.0) | −0.59 (−1.8, 0.64) |
| MiBP | 2.2 (−0.25, 4.7) | −2.2 (−6.2, 1.8) | 0.88 (−1.1, 2.9) | 1.8 (−0.41, 4.1) | −1.6 (−5.4, 2.3) | 0.18 (−1.9, 2.2) |
Included di(2-ethylhexyl) phthalate (DEHP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono-3-carboxypropyl phthalate (MCPP), monoethyl phthalate (MEP), and mono-isobutyl phthalate (MiBP) as the independent variables. DEHP (ug/g creatinine) was calculated as ΣDEHP (ug/g creatinine) = [MEHP (ug/g creatinine)/278 (g/mol) + MEOHP (ug/g creatinine)/292 (g/mol) + MEHHP (ug/g creatinine)/294 (g/mol) + MECPP (ug/g creatinine)/308 (g/mol)] × 308 g/mol where 278, 292, 294, and 308 are the molecular weights of mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), respectively.
Included DEHP, MBP, MBzP, MCPP, MEP, MiBP, maternal age at delivery (years), three dummy variables for maternal race/ethnicity (Hispanic or Latino, Non-Hispanic black, Non-Hispanic white, Other/multiple races), maternal parity (0–2, >2), pre-pregnancy BMI (kg/m2), household annual income ($), child sex at birth (male, female), and child age at Social Responsiveness Scale (SRS) administration (months) as the independent variables.
Included DEHP, MBP, MBzP, MCPP, MEP, MiBP, maternal age at delivery (years), three dummy variables for maternal race/ethnicity (Hispanic or Latino, Non-Hispanic black, Non-Hispanic white, Other/multiple races), maternal parity (0–2, >2), pre-pregnancy BMI (kg/m2), household annual income ($), child sex at birth (male, female), child age at Social Responsiveness Scale (SRS) administration (months), and three dummy variables for study site (Drexel, Johns Hopkins University, Kaiser Permanente, UC Davis) as the independent variables.
Included DEHP, MBP, MBzP, MCPP, MEP, MiBP, maternal age at delivery (years), three dummy variables for maternal race/ethnicity (Hispanic or Latino, Non-Hispanic black, Non-Hispanic white, Other/multiple races), maternal parity (0–2, >2), pre-pregnancy BMI (kg/m2), household annual income ($), child sex at birth (male, female), child age at Social Responsiveness Scale (SRS) administration (months), and 4 dummy variables for study site (HOME, Drexel, Johns Hopkins University, Kaiser Permanente, UC Davis) as the independent variables.
All values are regression coefficients (95% confidence intervals) unless otherwise specified. All the phthalates were imputed with the lower limit of detection (LLOD) divided by a square root of two if lower than the LLOD and corrected for urinary dilution using urinary creatinine concentrations.
DEHP, di(2-ethylhexyl) phthalate; MBP, mono-n-butyl phthalate; MBzP, monobenzyl phthalate; MCPP, mono-3-carboxypropyl phthalate; MEP, monoethyl phthalate; MiBP, mono-isobutyl phthalate.