Accuracy of time-to-pregnancy data from men

Purpose Occupational studies of fertility often rely on male report of time-to-pregnancy (TTP). We investigated the accuracy of male report compared with TTP derived from detailed data collected from female partners. Methods In a study designed to measure effects of prenatal diethylstilbestrol (DES) on male reproduction, exposed and unexposed men from the Chicago DES cohort were interviewed by phone to assess fertility. The female partner of each maleʹs most recent pregnancy was interviewed separately. The TTP derived from the female data was used as the gold standard. Kappa (κ) statistics were calculated to investigate male factors related to reporting accuracy. Results Of the 202 couples in which both partners reported a TTP, the male report was identical to the female-derived TTP in 36%, and in 75% it differed by no more than 2 months. Seventeen men had a high-school education or less, and their reporting was not as accurate (κ = 0.27) as that for those with higher education (κ = 0.48, 0.51, and 0.55, for some college, college, and > college, respectively). When the index pregnancy was the maleʹs first, his report was very good (κ = 0.72). Income had little association with male reporting accuracy. Conclusion The overall accuracy of male reporting of TTP was reasonably good, and that for first pregnancies was very good.