Intrauterine insemination: pregnancy rate and its associated factors in a university hospital in Iran

Objective: To determine pregnancy rate and its associated factors in Intrauterine Insemination (IUI) in a University ART center in Tehran, Iran. Materials and Methods:A retrospective descriptive study was conducted on all available records of infertile patients (200 cases) who had undergone IUI treatment for their infertility problems in Mirza Koochak Khan ART center, between 1999 and 2000. The necessary data were collected and then analyzed with Chi-square test with a significant level of 0.05. Results: 200 infertile couples did 575 IUI cycles. Pregnancy rate was 19.5% per couple and 6.8% per cycle (39 cases). The pregnancy rate in couples with secondary infertility was significantly higher than those with primary infertility (47.4% vs. 8.4%, P<0.0001) and patients with more than 60% normal sperm morphology (NSM) had higher pregnancy rate than those with less than 60% NSM (24.3% vs. 7.7%, P=0.0052). Pregnancy rate tended to increase when the number of large follicles increased at the time of IUI (From 6.7% in 1-2 oocytes to 15.7% in >5 oocytes, P=0.0095). As the numbers of IUI treatment cycles increased, the success rate per cycle decreased. There was a significant difference in pregnancy rate according to kind of drug used for ovarian stimulation. Pregnancy rate was 11.5% with HMG, compared to 7.2% with clomiphene citrate and HMG (P=0.052). Pregnancy rate with twice IUI per cycle was significantly higher than those who had one IUI per cycle (24.1% versus 11.8%, P<0.05). The highest pregnancy rate was seen in 21-30 years old patients (46.5%) and the lowest in women with more than 36 years of age, while no pregnancy occurred in patients less than 20 years of age. The frequency of twin pregnancy and low birth weight infants was 25.6% (10 subjects) and 14.3% (7 subjects) respectively. Conclusion: It seems that IUI provides better results in patients with secondary infertility, with >60% NSM and with >5 large follicles at the time of treatment. Pregnancy rate does not increase with increasing the number of treatment cycles and ovarian stimulation with HMG is associated with relatively higher pregnancy rate.