Serum Concentrations of Polychlorinated Biphenyls in Relation to in Vitro Fertilization Outcomes

Abstract

Background: Human exposure to polychlorinated biphenyls (PCBs) remains widespread. PCBs have been associated with adverse reproductive health outcomes including reduced fecundability and increased risk of pregnancy loss, although the human data remain largely inconclusive.Objective: Our goal was to explore the relationship between serum PCB concentrations and early pregnancy loss among a large cohort of women undergoing in vitro fertilization (IVF) between 1994 and 2003.Methods: Concentrations of 57 PCB congeners were measured in serum samples collected during 827 IVF/intracytoplasmic sperm injection cycles from 765 women. Joint statistical models that accommodate multiple outcomes and multiple cycles per woman were used to assess the relationship between serum PCB quartiles and implantation failure, chemical pregnancies (human chorionic gonadotropin level > 5.0 mIU/mL) that did not result in clinical pregnancy, or spontaneous abortion, while also adjusting for confounders.Results: PCB-153 was the congener present in the highest concentration (median, 46.2 ng/g lipid). Increasing quartiles of PCB-153 and the sum of all measured PCB congeners (ΣPCBs) were associated with significantly elevated dose-dependent odds of failed implantation. Adjusted odds ratios (95% confidence interval) for highest versus lowest quartile were 2.0 (1.2–3.4) for PCB-153 and 1.7 (1.0–2.9) for ΣPCBs. There were suggestive trends for increased odds of implantation failure for PCB-118 and cytochrome P450–inducing congeners (p-values for trend = 0.06). No statistically significant associations between PCBs and chemical pregnancy or spontaneous abortion were found.Conclusions: Serum PCB concentrations at levels similar to the U.S. general population were associated with failed implantation among women undergoing IVF. These findings may help explain previous reports of reduced fecundability among women exposed to PCBs.

Anxiety-like behaviors in adulthood are altered in male but not female rats exposed to low dosages of polychlorinated biphenyls in utero

“…When improperly stored or disposed of, PCBs entered the environment in soil, water, and air, and were subsequently incorporated into the food chain. Although banned in 1979 (McFarland and Clarke, 1989), nearly all humans and wildlife have measurable amounts of PCBs in their bodies (Meeker et al, 2011; Quinn et al, 2011). …”

PCB-153 Shows Different Dynamics of Mobilisation from Differentiated Rat Adipocytes during Lipolysis in Comparison with PCB-28 and PCB-118

“…The fact that cellular NL levels were similar between our experimental conditions is most probably at the origin of the identical accumulation of PCBs within adipocytes. While PCB concentrations in the culture medium were in the same range than those measured in the human serum [29], [30], the PCB levels found in cultured adipocytes after 12 hours of incubation (data from Table 1 are equivalent ∼175 ng PCB congeners per mg NLs) were much higher than those measured in vivo , in the human adipose tissue (from 0.02 to 0.66 ng total PCBs per mg lipids) [34]–[38]. It reflects a high propensity of differentiated rat adipocytes to store PCBs [4].…”

“…The PCBs were added to the culture medium as ethanolic solution and four conditions of PCB contamination were tested: ( i ) 2,4,4′-trichlorobiphenyl (PCB-28); ( ii ) 2,3′,4,4′,5-pentachlorobiphenyl (PCB-118); ( iii ) 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153); ( iv ) an equimolar mixture of three PCB congeners (PCB-28, -118 and -153), also called cocktail of PCBs. In all conditions of contamination, each PCB was added to the culture medium at a concentration of 300 nM, which is within the range of concentrations found in in vivo and in vitro studies [4], [29], [30]. Impact of the ethanol vehicle was tested earlier [4].…”

Role of Environmental Factors and Gonadotoxin Exposure in Unexplained Female Infertility

“…Maternal serum PCB concentrations have been documented during critical windows of development, including the periconception interval and early pregnancy [104], and PCB levels are detectable within human follicular fluid [105,106]. More recently, follicular fluid and serum PCBs have been associated with reduced oocyte fertilization [107] and with reduced embryo implantation during IVF [108], although a systematic review concluded that the epidemiologic evidence to date is insufficient to support a causal association [109].…”