Phthalates Linked to Shorter Gestation - Summary - MDSpire
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Phthalates Linked to Shorter Gestation
Researchers linked several pregnancy urinary biomarkers—especially plasticizer and combustion-related chemical metabolites—to small shifts in gestational age and fetal growth measures in the ECHO Cohort.
To evaluate the association between urinary biomarkers of environmental chemical exposure during pregnancy and gestational length and birth weight-for-gestational-age z scores.
Approach:
Study Design: A prospective cohort study involving 5,318 mother-child pairs from 18 US sites, with urine samples collected at a median of 25 weeks gestation.
Analytes Measured: 113 analytes from 10 chemical classes, including phthalates, alternative plasticizers, and polycyclic aromatic hydrocarbons.
Statistical Analysis: Models adjusted for maternal age, race and ethnicity, prepregnancy BMI, education, parity, season and year of urine collection, and tobacco use.
Key Findings:
110 of 113 analytes were detected in at least one sample, with 43 detected in at least half of samples.
Phthalates and alternative plasticizers were associated with younger gestational age at birth.
Each interquartile-range increase in summed diisononyl phthalate metabolites was linked to about 0.6 fewer days of gestation.
Detection of phthalic acid was associated with about 1.1 fewer days of gestation.
15 analytes or sums from various chemical classes were associated with lower birth weight-for-gestational-age z scores.
Interpretation:
The study found associations between certain environmental chemicals, particularly phthalates, and shorter gestational length and lower birth weight-for-gestational-age z scores, but causation cannot be inferred.
Limitations:
Observational design limits causal inference.
Single midpregnancy urine sample may not reflect exposure throughout pregnancy.
Site selection and urine sample criteria may affect representativeness.
Long-term storage of urine samples could influence analyte measurement.
Potential for false-positive and false-negative findings due to the large number of analytes.
Conclusion:
The findings indicate that exposure to certain urinary analytes, especially phthalates and alternative plasticizers, is linked to shorter gestation and lower birth weight-for-gestational-age z scores, but these are associations and do not imply causation.
A Beyond the Guidelines discussion highlighted uncertainty around gastrointestinal evaluation and intravenous iron use in premenopausal women with iron deficiency.
