Urinary phthalate exposure and reproductive outcomes in U.S. women: evidence of dose-response associations in NHANES 2003-2014

Phthalates are a group of endocrine-disrupting chemicals widely used in consumer products and consistently detected in human populations. Although experimental studies suggest that phthalate exposure may affect reproductive function, evidence in women at the population level remains limited and not fully consistent. This study examined the relationship between urinary phthalate metabolites and reproductive outcomes among women aged 18 to 44 years using data from the National Health and Nutrition Examination Survey (NHANES) 2003–2014 (N = 1,806).Survey-weighted logistic regression models were used to evaluate associations between log-transformed urinary phthalate metabolites and parity, adjusting for age, body mass index, socioeconomic factors, and urinary creatinine. For most metabolites, the estimated associations were close to no meaningful effect. However, mono-benzyl phthalate (MBzP) showed a modest positive association with parity in the fully adjusted model (1.19 (1.02, 1.37)). In quartile-based analyses, higher MBzP exposure levels were associated with increasing odds of parity, with evidence of a linear trend (p-trend = 0.029). These findings were generally consistent across sensitivity analyses, including alternative methods of creatinine adjustment and exclusion of extreme values. A cumulative exposure index for phthalates did not demonstrate stronger associations than individual metabolites, suggesting that individual compounds may be more informative than the composite exposure summary for this outcome. Secondary analyses of subfertility and menstrual irregularity were more limited due to smaller sample sizes and reduced statistical power. MBzP showed a modest positive association with parity that warrants cautious interpretation and replication in longitudinal studies using more proximal reproductive endpoints.

Name thesis:degree_name

M.S. (Master of Science)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Bioinformatics (UMKC)

Grantor

University of Missouri--Kansas City

Year dc:date.issued

2026

Author dc:creator

• Thondepu, Anusha

Advisor dc:contributor.advisor

• Bhattacharyya, Sudeepa

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10355/112357

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/112357