Relationship between PCBs, dioxins, chlorinated pesticides, and fertility problems in young women

Abstract

Background: Persistent polychlorinated aromatic compounds have been reported to adversely affect fertility, both in men and women. Methods: In a Flemish environmental health study, we included 1187 women and their newborns. Hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (p,p′-DDE, a metabolite of DDT), dioxine-like compounds (measured with the Calux assay), and the sum of marker PCB 138, 153, and 180 were determined in cord blood. Data on lifestyle(smoking, nutrition, etc...) and fertility problems in the current and former pregnancies were colleced through self-assessment questionnaires. We used logistic regression analysis to calculated dose-response relations between exposure data and the odds of a fertility disorder. Results: The mean (SD) of the mothers was 29.6 (4.3) years. Sixty-one percent delivered their first baby, while 27% had a second and 9% had a third baby. Thirty-six percent were former smokers and 16% continued smoking during their pregnancy. In total, 111 (9.4%) women reported that they had experienced fertility problems and had received medical assistance to get pregnant. About 49% received hormonal treatment, 40% in vitro fertilization and 12% reported other treatments. Women with assisted pregnancies were significantly older (31.5 vs. 29.4 years; P < 0.001) and smoked less (9.9% vs. 16.8%; P = 0.06) than women who became pregnant spontaneously. After adjustment for age and smoking, women who became pregnant after medical assistance had significantly higher values of HCB (22.2 vs. 18.2 ng/g fat; P = 0.02), dioxin-like compounds (27.1 vs. 22.2 pg TEQ/g fat; P = 0.02) and PCBs (81.4 vs. 60.3 ng/g fat; P = 0.001) in cord blood. For a doubling of the serum concentration of HCB, dioxin-like compounds, and PCBs, the odds ratio for fertility problems was 1.21 (95% CI, 1.01-1.45; P = 0.04), 1.40 (1.09-1.80; P = 0.008), and 1.29 (1.04-1.59; P = 0.02), respectively. From the 939 mothers who answered the questions on miscarriages, 157 (16.7%) reported to have had a miscarriage. The chance of a miscarriage was negatively associated with dioxin-like compounds in cord blood, ie, for a doubling of the calux assay, the odds ratio of having a miscarriage ever equaled 0.81 (0.65-0.99; P = 0.04) after adjustment for age and smoking. Conclusions: Higher exposure to HCB, dioxin-like compounds, and PCBs was associated with an increased risk of fertility problems, but not with an increased risk for miscarriage.