Do phthalates and their metabolites cause poor semen quality? A systematic review and meta-analysis of epidemiological studies on risk of decline in sperm quality.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational epidemiological studies
PubMed 36504299 · doi:10.1007/s11356-022-24215-x
What was done
Researchers conducted a systematic review and meta-analysis of epidemiological literature published up to June 30, 2022, searching PubMed, EMbase, and Web of Science. Two reviewers independently screened literature, extracted data, and assessed risk of bias. A meta-analysis of 12 studies was performed using RevMan 5.3 and Stata 11 to evaluate associations between various phthalate metabolites in urine and semen with semen concentration, sperm motility, and sperm morphology.
What was found
Urinary monobutyl phthalate (MBP) and monobenzyl phthalate (MBzP) were significantly associated with reduced semen concentration (MBP: pooled OR = 2.186, 95% CI [1.471, 3.248], P < 0.05; MBzP: pooled OR = 1.882, 95% CI [1.471, 3.248], P < 0.05). Semen di-(2-ethylhexyl) phthalate (DEHP) was negatively correlated with semen concentration (pooled r = -0.225, 95% CI [-0.319, -0.192], P < 0.05). In contrast, MBP and MBzP were not significantly associated with sperm motility or morphology (P > 0.05). Monoethyl phthalate (MEP), monomethyl phthalate (MMP), and mono-2-ethylhexyl phthalate (MEHP) showed no statistically significant correlations with semen concentration, motility, or morphology (P > 0.05).
Why it matters
This review synthesizes human epidemiological data identifying specific phthalate exposures (MBP, MBzP, and DEHP) linked to poorer semen concentration, helping prioritize environmental chemical targets for reproductive toxicology and policy.
Limits
Total participant count across the included studies was not reported in the abstract. Only 12 studies met criteria for quantitative meta-analysis, with multiple studies excluded due to heterogeneous effect size metrics. All underlying studies were observational, preventing causal inference, and residual confounding or exposure misclassification could not be ruled out.
Cited by
- partial High exposure to BPA and phthalates reduces sperm count, sperm motility, and normal sperm morphology.