Exposure to a Mixture of Polychlorinated Biphenyls and Polychlorinated Dibenzofurans Resulted in a Prolonged Time to Pregnancy in Women

Abstract

BackgroundPolychlorinated biphenyls (PCBs), dibenzofurans (PCDFs), and dibenzodioxins (PCDDs) may affect the female reproductive system in animals and humans. In 1978–1979, a mass poisoning occurred in central Taiwan due to PCB/PCDF-contaminated cooking oil; this incident was called Yucheng (“oil disease” in Chinese).ObjectiveThe purpose of our study was to determine whether PCB/PCDF exposure affected fertility in exposed women.MethodsAfter the event, we followed the exposed individuals and a reference group who were sex-, age-, and community-matched. In 2003, we obtained fertility histories from Yucheng and reference women by telephone interview. We used Kaplan–Meier survival curves and multivariable Cox regression to compare time to pregnancy (TTP) between Yucheng and reference women, and we performed multiple logistic regression to determine whether PCB/PCDF exposure caused infertility.ResultsIn total, 412 women responded, with a median TTP of 4 months in Yucheng women and 3 months in reference women (p = 0.019). After adjusting for confounders by Cox regression, we found a fecundability ratio of 0.90 [95% confidence interval (CI), 0.80–1.00] for Yucheng women. Among the 408 women who had noncontraceptive sexual activity for > 12 months, 19.7% of Yucheng women and 9.7% of reference women did not become pregnant (i.e., they were infertile). After we adjusted for confounders by logistic regression, the infertility odds ratio was 2.34 (95% CI, 1.23–4.59) for Yucheng women compared with the reference group.ConclusionsWe found prolonged TTP and reduced fertility among women previously exposed to PCBs/PCDFs. Because of the limited sample size and the relatively small decrease in the fertility rate, these effects require cautious interpretation and further investigation for confirmation.

Persistent organic pollutants have dose and CAG repeat length dependent effects on androgen receptor activity in vitro

“…Exposure to persistent organic pollutants (POPs) has been suggested as potential cause of reproductive disturbances including reduced semen quality [1], testicular cancer [2], prolonged waiting time to pregnancy [3], imbalanced sex ratio [4][5] and altered age of sexual maturation [6]. These compounds are resistant to abiotic as well as biotic degradation and exposure therefore results in bio-accumulation.…”

Serum Dioxin Concentrations and Time to Pregnancy

“…The study of these outcomes with exposure most similar to ours examined the women of Yucheng in Taiwan, who were poisoned by PCB-contaminated cooking oil in 1979. 11 Serum samples from a subset of the population taken more than a decade later revealed high levels of polychlorinated dibenzofurans and total PCBs. The authors compared 186 Yucheng women to 226 unexposed controls, and found that fecundability decreased by about 10% in the Yucheng women and that the odds of infertility doubled (OR= 2.3).…”

“…8–11 To address the potential biases and inadequacies of this type of study, Joffe et al 41 recommended a number of steps, including the use of discrete-time survival analysis, sensitivity analyses, a study sample representative of the underlying population, and a well-designed questionnaire. We have attempted to adopt these recommendations.…”

“…Of these, most have suggested an association between higher exposure to polychlorinated biphenyls (PCBs) and longer TTP. 8–11 However, most did not specifically examine the dioxin-like compounds nor use a direct measure of exposure.…”

Prolonged time to pregnancy in residents exposed to ionising radiation in cobalt-60-contaminated buildings

“…Data on TTP collected using a brief questionnaire are believed to be valid at a group level 27. We used the same collection methods in our semiconductor study,22 in a study on paternal lead exposure and fertility23 and in a study of exposure to a mixture of polychlorinated biphenyls and polychlorinated dibenzofurans in women 24. Disadvantages, however, include susceptibility to recall and selection biases,28 and the need for data on several potential confounders 38.…”