RESUMEN
<p><b>OBJECTIVE</b>To study the association between phthalate esters (PAEs) metabolites in maternal urine and 11beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2 ) enzyme activity, explore the possible mechanism of PAEs effect on fetal development.</p><p><b>METHODS</b>All of 33 cases of intrauterine growth retardation (IUGR) newborn were selected by random sampling in 2012. And 33 cases of normal control newborn were enrolled, use high performance liquid chromatography-tandem mass spectrometry method was used to detect 4 kinds of phthalate esters (PAEs) metabolites in maternal urine: mono-n-butyl phthalate ester (MBP), mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) and three kinds of cortisol corticosterone metabolites, tetrahydrocortisol (THF), allo-tetrahydrocortisol (allo-THF), tetrahydrocortisone (THE), and analyze the association between phthalate esters (PAEs) metabolites in maternal urine and 11β-HSD2 enzyme activity.</p><p><b>RESULTS</b>MBP, MEHP, MEHHP, MEOHP metabolites can be detected in 98% (65 cases) , 89% (59 cases), 91% (60 cases), 91% (60 cases) of all 66 maternal urine samples, respectively. The median concentrations of test material in case group were 31.20 ng/ml for MBP, 24.61 ng/ml for MEHHP, 11.72 ng/ml for MEOHP and 48.67 ng/ml for SumDEHP which were significantly higher than those of the control group (were 17.32, 12.03, 5.68 and 28.64 ng/ml); 11β-HSD2 activity in case group ((THF+allo-THF)/THE = (0.79 ± 0.09) ng/ml) was significantly lower than that of the control group((THF+allo-THF)/THE = (0.58 ± 0.04) ng/ml); PAEs metabolites MBP (β' = 1.12), MEHHP(β' = 1.14), MEOHP(β' = 1.10), SumDEHP(β' = 1.08) in baby boy mother's urine was reversely correlated to 11β-HSD2 activity.</p><p><b>CONCLUSIONS</b>PAEs could affect fetal development by inhibit 11β-HSD2 activity.</p>