A summary of the conclusions regarding the evidence of a causal association between ETS exposure and reproduction from the 1997 OEHHA

The study of reproductive toxicity includes measures of: female fertility and fecundability; other female reproductive effects, such as lowered age at menopause and menstrual disorders; and male reproductive effects, including altered sperm parameters, which may influence a couple’s fertility and/or fecundability. Very few studies prior to the 1997 review (Cal/EPA, 1997) or since have investigated the effects of ETS exposure on male and female reproductive function. Of these, most have examined delay to conception in women who eventually achieve pregnancy as an indication of sub-fecundability. Many of these studies were designed to look at the woman’s active smoking, not ETS exposure, but also reported the husband's smoking status, a surrogate for ETS exposure used in studies of other outcomes. It should be noted that although husband’s smoking can be a surrogate for ETS exposure of the wife, the direct effects of active smoking on sperm complicate the analysis of effects on female reproductive function. Three of the studies reviewed for the 1997 report and one published since then (Table 5.1) examined the possibility of an effect on women’s fertility occurring earlier in development by trying to ascertain childhood and in utero exposure to ETS. Unlike the 1997 review, this report also includes two studies of the effect of ETS on pregnancy rates in women enrolled in assisted reproductive technology programs such as in-vitro fertilization and gamete intrafallopian transfer (GIFT).