Conclusion
Our study provides a comprehensive estimation of the TTP among Chinese couples of reproductive age. Over half of women aged <35 years would conceive within 1 year, the proportion of which increased to 80% at 2 years. Conversely, the probability of natural conception among women older than 35 years was only half that within 2 years. Along with the TTP distribution in Chinese couples, this study also detected related risk factors for fecundity such as age, toxic exposure, and socioeconomic status. Although the diagnosis and treatment of subfertility or infertility are becoming more accurate and less invasive, there remains a need to explore the overall fecundity of couples in order to guide clinicians toward the appropriate timing of treatment. Hence, the results of our study provide important information for policy makers to improve sexual health education for couples of reproductive age.