The present study aims to elucidate if the FSH and LH activity contained in hMG preparations is comparable to the recombinant FSH and LH administration in a 1:1 ratio. The mean outcome is the corresponding ovarian response in terms of oestradiol increase during stimulation and number of mature follicles the day of hCG administration. The patients will be included and randomized into two groups and stimulated either by HMG injections started on day 3 at a dose of 75 IU every day and fixed for the first 5 days, and in the second group, rFSH and rLH injections be started on day 3 at a dose of 75 UI/day of rFSH + 75UI/day of rLH. Serum estradiol levels will be measured on stimulation day 1, day 6 and the day of hCG injection. All follicles greater than 14 mm of diameter will be recorded on hCG day Intrauterine insemination is performed during two consecutive days starting the day after the human chorionic gonadotrophin (Ovitrelle) injection. Secondary outcomes are Days of stimulation, Total doses of gonadotrophins administrated, Clinical pregnancy , Ongoing pregnancy and Miscarriage rate, and Cancellation rate.

Inclusion Criteria:

• Esterility > 1 year duration
• < 39 years old
• REM > 3 millions/ml
• 1 or 2º IUI cycle

Exclusion criteria:

• Ovarian policystic syndrome
• Severe Endometriosis
• Uterine disease (polyps, myomas, intracavitarios, malformations…)