The Study Of Phthalate Exposure During Pregnancy And Its Effects On Pregnant Outcomes

ObjectiveAs one of the important plastic plasticizer, phthalates acid esters (PAEs) were used worldwide. A large number of studies have shown that pregnant women exposured to PAEs not only could cause complications during pregnancy, but affect intrauterine fetal growth and development. This study discussed the relationships between PAEs exposure during pregnancy and fetal growth and development, gestational age and male sex hormones in cord blood. The objective is to provide a scientific basis for prevention of the potential effect of fetal growth and reproductive systems induced by PAEs exposure during pregnancy.MethodsBetween2010and2011, we recruited232pregnant women who met our study eligibility criteria in Tianjin Center Hospital of Obstetrics and Gynecology and were able to provide adequate amounts of biological samples for analysis. Five phthalate metabolites including monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), and mono-2-ethylhexyl phthalate (MEHP) were measured in urine samples of pregnant women using liquid chromatography-tandem mass spectrometry. In mother-newborns cohort, the associations between urinary concentrations of creatinine-adjusted phthalates metabolites and fatal growth indexes (birth weight and length) were assessed by multivariate liner regression models. The case-control studies about PAEs exposure and preterm birth was assessed by1:2matched conditional logistic regression models. Associations of phthalate exposure and sex hormones in the cord blood among male fetuses were determined by multiple liner regression model analysis.ResultsThe medians of five phthalate metabolites (MMP, MEP, MBP, MBzP and MEHP) concentrations were49.51μg/L、13.19μg/L、7.22μg/L、0.30μg/L、30.03μg/L, respectively. The median of the creatinine-adjusetd phthalate monoester was:MMP (110.40μg/g), MEP (27.61μg/g), MBP (16.90μg/g), MBzP (0.53μg/g), MEHP (56.23μg/g). The detection rates of MMP, MEP, MBP, MBzP and MEHP ranged from63.8%to99.4%. In Pearson’s correlation analysis between the concentrations of five phthalate metabolites and fetal growth indexes among211fetuses(including premature infants), we found MMP,MEP and∑PAEs were significantly negatively correlated with birth weight (r=-0.28, P<.05; r=-0.14, P<0.05; r=-0.25, P<0.001), MEP was significantly negatively correlated with birth length (r=-0.14, P=0.05); After excluding preterm birth or adjusting for covariates, we found insignificant association between PAEs exposure during pregnancy and birth weight or birth length. In single-factor and multi-factor conditional logistic regression models, log-unit increases in MEHP concentration was associated with reduced odds of preterm delivery (OR95%CI:0.17-0.57;0.08-0.64). For the hormones, the means of T, E2, P, FSH, LH, INSL3and SHBG were182.76ng/dl,5078.62pg/ml,779.18ng/ml,1.50IU/L,3.11IU/L,135.29pg/ml and98.78nmol/L in the umbilical blood of male fetuses. There was significant association between MBzP and E2(β=0.083, P=0.03). The negative correlation existed between T/E2and BBzP exposure during pregnancy(β=-0.065, P=0.07).ConclusionThe detection rates of five phthalate metabolites (MMP, MEP, MBP, MBzP and MEHP) ranged from63.8%to99.4%. Pregnant women in Tianjin were ubiquitously exposed to PAEs. PAEs exposure during pregnancy has led to the potential damage of fetal development and reproductive system, which contained that MMP and MEP could affect birth weight and length, DEHP exposure during pregnancy reduced the risk of preterm birth and BBzP exposure has affect on male newborn sex hormone levels.