Data from the Early Pregnancy Study (EPS) (A.Wilcox, PI) provide a resource for ongoing research into reproductive hormones, fertility, &early pregnancy. During field work for this study in 1982-1985, women enrolled at the time they stopped using birth control in order to conceive. We followed them through their 8th week of pregnancy. They collected daily first morning urine specimens and these were analyzed for human chorionic gonadotropin and steroid metabolites. Women with known fertility problems were excluded, so the sample represents normal unassisted reproduction. We conducted a pilot study to test the stability of hormones in urines stored from the Early Pregnancy Study. A subsample of urine specimens from the EPS have been analyzed for phthalates, and bisphenol A to see if those toxicants can be evaluated in these stored samples. Analysis shows similar distributions of these toxicants as reported for more recently-collected samples and similar within-woman reproducibility measures. This supports analysis of specimens from the complete EPS study in order to examine the relationship between these exposures and fertility and early pregnancy. We have designed the further exposure outcome analysis and further specimens will be analyzed. We also would like to look further at hormonal changes during early pregnancy with the EPS urines, but do not know how well they can be measured after long-term storage. We collected a sample of new daily urine specimens during early pregnancy to serve as a reference to evaluate the quality of hormone data from the stored samples. Estrogen and progesterone metabolite as well as hCG measurements from a sample of the stored urines will be compared to these hormones measured in newly collected urine samples. We enrolled 44 women, 26 of whom became pregnant and collected daily first morning urine specimens. Urine samples from the new collection and stored EPS samples are being analyzed for estrogen and progesterone metabolites as well as for hCG by Jim Kesner at NIOSH. There is methodologic interest in quality of self-reported reproductive data, and there have been several efforts to evaluate the validity of such reports. We have evaluated the validity of self-reported cycle characteristics by comparing interview data to prospective daily recording of menstrual bleeding and pain. We have also examined the validity of self-report of bleeding during pregnancy. In another methodologic project, we are using available data to determine how well women can report the timing of their positive pregnancy test. Bias arises in spontaneous abortion &time-to-pregnancy studies when comparing exposed and unexposed groups that differ in timing of pregnancy testing. Those who tend to have delayed pregnancy testing will recognize fewer spontaneous abortions, and they will have longer times to pregnancy. We continue our research into factors affecting fertility. In addition to solvents and male BMI, we are looking at pesticide exposure using data from the Agricultural Health Study. Organochlorines accumulate in tissue so that a single measure may be useful as a surrogate for years of exposure. We evaluated change in DDE and PCB levels in reproductive age women and the factors that affect the rates of change. There was a strong correlation between measurements over twenty years apart for both toxicants, and data on breast feeding, initial BMI, and weight gain allowed for further predictive precision. Using the data on loss of these environmental contaminants over time, we estimated the exposure at age 40 for members of a cohort of women and examined its relationship to their age of menopause. There was no significant association. We are also studying other effects on age of menopause using data from the Sister Study.
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