Objective　Artificial insemination with husband’s sperm（AIH）is widely used to treat infertility. However, whether AIH is necessary before trying in vitro fertilization（IVF）, and whether an optimal number of AIH cycles exists, remain controversial. Therefore, to determine the optimal number of AIH cycles before switching to IVF, we examined AIH cases in our department. Subjects　Ninety-two couples who had undergone AIH in our department between January 2008 and December 2010（total cycle number: 256）were examined. Results　AIH was successful in 16 cases, and the pregnancy rate per cycle and per patient was 6.0％ and 17.4 ％ , respectively. In successful cases, the lowest amount of seminal fluid was 0.1 ml, and the lowest sperm concentration and lowest sperm motility were 25 x 106/ml and 34％ , respectively. There was a significant difference in sperm concentration, but not in motility or total sperm count, between successful and unsuccessful AIH cases. In successful cases, pregnancy was achieved with an average of 2.5 attempts, and the cumulative pregnancy rate after four and five cycles was 93.8％ and 100％ , respectively. The pregnancy rate in patients aged 20–24 was 11.1％ , while that in patients aged 40–44 was 3.7％ . Conclusion　A maximum of five AIH cycles before switching therapy to assisted reproductive technology（ART）appeared appropriate. An earlier switch to ART may be suitable when sperm test
findings are less than optimal and/or female patients are old.