Relationship between donor sperm parameters and pregnancy outcome after intrauterine insemination: analysis of 2821 cycles in 1355 couples

The aim of this study was to investigate whether sperm parameters can affect the pregnancy outcome of artificial intrauterine insemination with cryopreserved donor spermatozoon (AID). A total of 1355 couples received 2821 AID treatment cycles in the Reproductive Medicine Center of the Tongji Medical College between January 2010 and December 2013, and the data were collected and retrospectively analysed. The relationship between pre-freezing, post-thawing as well as optimised sperm parameters and AID pregnancy outcome was investigated. Clinical pregnancy rate and cumulated pregnancy rate were also calculated. A total of 728 cycles from 2821 treatment cycles achieved pregnancies, and cumulated pregnancy rate was 25.81%. Pre-freezing progressive sperm motility in pregnant cycles was higher than that in nonpregnant cycles (P = 0.001); logistic regression analysis also indicated that pre-freezing progressive sperm motility was the only parameter affecting pregnancy outcome (P = 0.0001). Our study also showed that the cumulated pregnancy rate increased progressively and reached a plateau after the fifth cycle. In conclusion, pre-freezing progressive sperm motility should be a valuable predictor for AID pregnancy outcome. Female fertility factors should be considered, or IVF/ICSI should be recommended when couples received more than 5 AID cycles without pregnancy.