How long after marriage does a couple not get pregnant do they need to be tested? The World Health Organization reports that the cumulative probability of spontaneous conception for the woman 1 year after formal cohabitation is 91. 67% . The greatest clinical pregnancy rate occurs within 3 years of trying to conceive, and if left untreated, the subsequent pregnancy rate decreases significantly. If a couple has not conceived after one year of cohabitation it is time to undergo tests related to infertility. If a woman is older than 35 years old, the ovarian function will decline rapidly and the pregnancy rate will decrease accordingly. The cause of infertility should be detected early, treated and conceived as early as possible so as not to miss the time to get pregnant, and for this group of women if they do not get pregnant for half a year, it is time to do the examination. Ma|, Infertility Treatment Center, Qilu Hospital of Shandong University