Exposure to organophosphate flame esters during early pregnancy and risk of spontaneous abortion: A case-control study

Prenatal exposure to organophosphate flame retardants (OPFRs) has been associated with adverse pregnancy outcomes including low birth weight and preterm birth. However, no study has addressed the impacts of OPFRs exposure on spontaneous abortion (SAB) and fetal chromosome abnormalities. We examined whether prenatal exposure to OPFRs was associated with increased risk of SAB and fetal chromosome abnormalities. A total of 272 pregnant women, including 136 SAB cases and 136 healthy controls, were enrolled in this case-control study. Urinary concentrations of 3 OPFRs metabolites (diphenyl phosphate (DPHP), bis (1,3-dichloro-2-propyl) phosphate (BDCIPP) and bis (1-chloro-2-propyl) phosphate (BCIPP)) were measured using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). More than 70% of the urine samples detected quantifiable levels of 3 OPFRs metabolites. Concentrations of BCIPP were significantly higher in SAB cases than in healthy controls. Higher urinary BCIPP levels were associated with increased risk of SAB. Per unit increase in ln-transformed BCIPP concentrations was associated with 103% (OR = 2.03, 95% CI, 1.57, 2.63) increase in the odds of SAB. While higher BDCIPP levels were associated with increased risk of fetal chromosome abnormalities and the corresponding OR associated with a unit increase in ln-transformed BDCIPP concentrations were 2.34 (95% CI, 1.14, 4.81). Our results suggested the potential developmental toxicity and teratogenicity of some OPFRs.