Objective To understand the lifestyle and behavioral factors influencing the time-to-pregnancy (TTP) among the pre-pregnancy population who received the National Free Pre-conception Health Examination.

Methods Couples who received the National Free Pre-conception Health Examination in Baiyun District of Guangzhou from January to June 2022 were selected. At the 13th to 15th month after the examination, the pregnancy status and life behavior factors were investigated by telephone questionnaire, and the influencing factors of TTP of pre-pregnancy couples were analyzed by multivariate Cox regression model.

Results A total of 1 684 couples completing the final follow-up. Among them, 1 127 couples (66.92%) achieved pregnancy. The conception rates were 49.39% at 6 months and 78.68% at 12 months of TTP. The results of multivariate Cox proportional hazards regression model analysis showed that the life behavior factors affecting female fertility decline included overweight/obesity (FR = 0.79, 95% CI: 0.65 − 0.96, P = 0.018), poor sleep quality (FR = 0.67, 95% CI: 0.55 − 0.81, P < 0.001), overweight/obesity in spouse (FR = 0.87, 95% CI: 0.77 − 0.98, P = 0.029).The lifestyle factors influencing the improvement of female fertility included long sleep duration (FR = 1.17, 95% CI: 1.09 − 1.25, P < 0.001) and exercising more than 3 times per week (FR = 1.15, 95% CI: 1.03 − 1.28, P = 0.010).

Conclusions Overweight/obesity, sleep and exercise are the influencing factors of the time to pregnancy. Health education and guidance on life behavior should be strengthened in the content of pre-pregnancy health care for couples preparing for pregnancy.