Method Development for Effect-Directed Analysis of Endocrine Disrupting Compounds in Human Amniotic Fluid

Abstract

The developing fetus represents a highly sensitive period of exposure to endocrine disrupting compounds (EDCs). However, risk assessment of EDCs is hampered by the lack of data on direct in utero exposure. In this study, we developed a robust analytical methodology for the identification of a wide range of known and unknown EDCs in full-term amniotic fluid (AF). First, a method for extraction and fractionation of a broad range of polar and nonpolar EDCs was developed and validated. Maximal recoveries of reference compounds and minimal interference from the matrix were achieved with a combination of solid phase extraction and dispersive liquid/liquid extraction. Bioassay analysis using cell-based reporter gene assays revealed estrogenic, androgenic, and dioxin-like activity in AF extract corresponding to 1.4 nmol EEQ/L, 76.6 pmol DHT-EQ/L, and 10.1 pmol TEQ/L, respectively. Targeted analysis revealed 13 xenobiotics, phytoestrogens, and endogenous hormones in the AF extract that partly contributed to the bioassay activity. Separation of the complex mixture of chemicals in the AF extract with reversed-phase chromatographic fractionation and subsequent bioassay analysis revealed activity in fractions over a wide range of polarity, indicating diverse (unidentified) substances with potential ED activity. The method developed here represents the first methodological step in an effect-directed analysis approach to identify unknown biologically active compounds in the fetal environment.

Oestrogenic Endocrine Disruptors in the Placenta and the Fetus

“…Pregnant women are a unique population who are exposed to endocrine disruptors during pregnancy that can affect the baby through body fluids. Liquids such as urine, maternal milk, serum, and amniotic fluid are currently the most commonly used substances to assess the EDCs in the body [16,23]. Its widespread use has led to the detection of BPA in low doses in pregnant women.…”

A Critical Review on Transplacental Transfer of Per- and Polyfluoroalkyl Substances: Prenatal Exposure Levels, Characteristics, and Mechanisms

“…The occurrence of PFASs in placenta, , umbilical cord blood, , amniotic fluid, , and infant serum indicated their prenatal exposure. Numerous studies have shown that there are extensive prenatal exposures to PFASs among pregnant women and infants.…”

“…Concentration and Geographical Distribution of PFASs in Various Matrices. The occurrence of PFASs in placenta, 47,48 umbilical cord blood, 49,50 amniotic fluid, 50,51 and infant serum 52 studies have shown that there are extensive prenatal exposures to PFASs among pregnant women and infants.…”

“…However, the levels of most PFASs in amniotic fluid were very low and below the detection limit. 50,51 Amniotic fluid is the dialysis fluid as maternal serum enters the amniotic cavity through the placenta in the first trimester, and mainly comes from the urine excreted by the fetus after the second trimester. 59 Low levels of PFASs in amniotic fluid indicate the amniotic fluid is not the main route of intrauterine exposure, nor is it the main route of fetal excretion of PFASs.…”

The effect of endocrine-disrupting chemicals on placental development

“…The placenta must develop for a pregnancy to be successful. This delicate organ comprises multiple layers of tissue that must develop normally during pregnancy to function correctly, which could have devastating consequences for the fetus ( 13 ). Different EDCs may indirectly influence the fetus through the placenta.…”