Human urinary/seminal phthalates or their metabolite levels and semen quality: A meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of observational studies
PubMed 26275958 · doi:10.1016/j.envres.2015.07.008
What was done
Authors searched PubMed and Web of Science through October 2014, including cited references, for studies quantitatively evaluating associations between human phthalates or metabolite levels in urine or semen and semen quality. Random-effects models were used to calculate pooled effect estimates across eligible studies.
What was found
Twenty studies met inclusion criteria and 14 were included in the meta-analysis: - Monobutyl phthalate (MBP, 7.4–25.3 µg/L) was associated with reduced sperm concentration (pooled OR = 2.60, 95% CI = 1.32–5.15). - Monobenzyl phthalate (MBzP, 14.0–540.2 µg/L) was associated with reduced sperm concentration (pooled OR = 2.23, 95% CI = 1.16–4.30). - Straight line velocity (VSL) was inversely associated with MBP (24.6–14,459.0 µg/L; pooled β = -2.51, 95% CI = -4.44 to -0.59) and MEHP (3.1–208.1 µg/L; pooled β = -1.06, 95% CI = -1.99 to -0.12). - An IQR increase in MBzP (IQR = 11.35 µg/L) and MEP (IQR = 449.4 µg/L) was associated with increased comet extent DNA damage (MBzP pooled β = 3.57, 95% CI = 0.89–6.25; MEP pooled β = 4.22, 95% CI = 1.66–6.77). - No associations were observed between monomethyl phthalate and any semen parameters.
Why it matters
This meta-analysis quantitatively consolidates conflicting epidemiological data, demonstrating consistent associations between specific phthalate metabolites and markers of reduced semen quality and sperm DNA damage.
Limits
The review pools observational studies, preventing causal inference. The abstract does not report the total participant sample size, population details (e.g., fertile vs. infertile cohorts), heterogeneity metrics, or adjustment for confounders such as other endocrine disruptors.
Cited by
- supports High exposure to BPA and phthalates reduces sperm count, sperm motility, and normal sperm morphology.