To investigate the effects of age combinations and fertility assessment results on the clinical pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET) / intracytoplasmic sperm injection (ICSI).

A retrospective cohort was established based on the data of 5 104 cycles of IVF-ET/ICSI transplantation from 11 assisted reproductive institutions in the east, central, and west regions. According to the age registered at the first fertility evaluation, the couples were divided into group A (female < 35, male < 40), group B (female < 35, male ≥ 40), group C (female ≥ 35, male < 40), and group D(female ≥ 35, male ≥ 40). The results of clinical pregnancy rate and first fertility among the four groups were compared by Chi-square test and one-way ANOVA.

The clinical pregnancy rates of the four age groups treated with IVF-ET were 58.23%, 54.12%, 40.57%, and 30.70%, respectively (χ²=167.214, P < 0.001), and those of ICSI were 59.29%, 62.5%, 49.07%,and 34.31%, respectively (χ²=23.834, P < 0.001). There was no significant difference in the clinical pregnancy rate between the two treatments of IVF-ET/ICSI between group A and group B (χ²=0.574, P_IVF-ET=0.449, χ²=0.099, PICSI=0.754) but the clinical pregnancy rate of group C was significantly higher than that of group D in the two treatments of IVF-ET/ICSI, which was (χ²=11.581, P_IVF-ET=0.001; χ²=4.695, P_ICSI=0.03).

When the woman is less than 35 years old, the age of the man has no significant effect on the clinical pregnancy rate treated with IVF-ET/ICSI. When the woman is ≥ 35 years old, the clinical pregnancy rate of the man < 40 years old receiving IVF-ET/ICSI is significantly higher than that of the man ≥ 40 years old, which suggests that if the couple with fertility intention is in the age range of ≥ 35 years old for woman and < 40 years old for man, they should actively evaluate the fertility and choose the appropriate medical treatment plan in time.