SERUM DIOXIN CONCENTRATIONS AND TIME TO PREGNANCY

摘要

On July 10, 1976, as a result of a chemical explosion, residents of Seveso, Italy, experienced the highest levels of TCDD in a human population. Twenty years later, we initiated the Seveso Women's Health Study (SWHS), a retrospective cohort study of the reproductive health of the women. We examined the association between TCDD exposure and fertility as measured by time to pregnancy (TTP). The SWHS cohort comprises 981 women who were 0 to 40 years in 1976, resided in the most contaminated areas, and had adequate archived sera collected soon after the explosion. Individual serum TCDD exposure was measured by high-resolution mass spectrometry. We examined the relation of serum TCDD with TTP using a discrete-time analogue of the Cox proportional hazards model. Of 981 women, 472 attempted pregnancy post-explosion, and 278 had a planned or non-contracepted pregnancy resulting in a live birth. A 10-fold increase in serum TCDD was associated with a 25% increase in TTP (adjusted–fecundability Odds Ratio = 0.75, 95%CI: 0.60, 0.95), and suggests TCDD exposure may be associated with reduced fertility in the Seveso cohort.