{"doi":"10.1101/2025.08.01.25332639","title":"Prenatal exposure to polycyclic aromatic hydrocarbons and birth outcomes in a pregnancy cohort in Nairobi, Kenya","abstract":"Prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to lower birth weight (BW) and shorter gestational age (GA) at delivery. Most research has focused on populations in high-income countries, leaving low- and middle-income countries (LMICs) understudied. We examined associations between pregnancy urinary PAH metabolites and birth outcomes in a prospective cohort in Nairobi, Kenya. The study population was drawn from women and their newborn babies enrolled in a pregnancy cohort in Nairobi, Kenya. Third-trimester urinary mono-hydroxylated PAH metabolites (OH-PAH) were measured and infant BW and GA were ascertained using medical record abstraction and self-report; BW-for-GA z-scores were computed. Linear and modified Poisson regression models were used to estimate the effects of five OH-PAHs on birth outcomes; Weighted Quantile Sum regression was used to explore OH-PAH mixture effects. Among 353 mother-infant pairs, the median infant BW was 3.2 kg and 10.7% were born preterm. All OH-PAH metabolites were present in urine of >99% of mothers. Individual OH-PAH concentrations were not associated with BW or BW-for-GA z-scores. One metabolite, 2-hydroxyphenanthrene, was associated with shortened gestation (RR = -1.6 day per doubling in concentration, 95% confidence interval: -3.1, -0.1). This association was attenuated after adjusting for self-reported exposure to household fuel and outdoor combustion and was strengthened among female infants, but not male infants, in sex-stratified analyses. Other metabolites and the OH-PAH mixture were not associated with birth outcomes. Our findings suggest that exposure to 2-hydroxyphenanthrene may have a modest adverse effect on pregnancy duration, with potential sex-specific differences in association. No associations were observed for markers of fetal growth. These results highlight need for further studies on sex-specific vulnerabilities and the role of environmental co-exposures in impacting birth outcomes in LMICs.","journal":"medRxiv","year":2025,"id":556623,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9366,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1455851,"name":"Priscillah Wanini Edemba","orcid":"0000-0002-1084-6902","position":1,"is_corresponding":false},{"id":405907,"name":"Anne M. Riederer","orcid":null,"position":2,"is_corresponding":false},{"id":1425468,"name":"Judy Adhiambo","orcid":null,"position":3,"is_corresponding":false},{"id":1456315,"name":"Lewis Olweywe","orcid":null,"position":4,"is_corresponding":false},{"id":980485,"name":"Prestone Owiti","orcid":null,"position":5,"is_corresponding":false},{"id":325491,"name":"Catherine J. Karr","orcid":"0000-0002-4683-2270","position":6,"is_corresponding":false},{"id":299054,"name":"John Kinuthia","orcid":"0000-0001-6571-8927","position":7,"is_corresponding":false},{"id":407491,"name":"Barbra A. Richardson","orcid":"0000-0001-9564-1828","position":8,"is_corresponding":false},{"id":390879,"name":"Christopher D. Simpson","orcid":"0000-0001-7122-371X","position":9,"is_corresponding":false},{"id":636952,"name":"Christopher Zuidema","orcid":"0000-0002-2233-2706","position":10,"is_corresponding":false},{"id":376368,"name":"Elizabeth Maleche‐Obimbo","orcid":"0000-0001-7871-3367","position":11,"is_corresponding":false},{"id":421617,"name":"Sarah Benki‐Nugent","orcid":"0000-0002-3034-8257","position":12,"is_corresponding":false},{"id":326967,"name":"Allison R. Sherris","orcid":"0000-0002-7858-2608","position":0,"is_corresponding":true}],"reference_count":64,"raw_metadata":null,"created_at":"2026-07-19T02:55:08.896385Z","pmid":"40766158","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}