Interest of Clomiphene Citrate in Patients With Non-obstructive Azoospermia on the Quantity of Sperm Cells

In the absence of sperm in the semen (azoospermia), there is no chance of natural paternity. It is found in about 1% of men and is either due to an obstruction of the seminal tracks (obstructive azoospermia (OA)) in 1/3 of the cases, or a spermatogenic failure (non-obstructive azoospermia (NOA)) in 2/3 of the cases. To date, no medical treatment had proved its efficiency to induce spermatogenesis in case of NOA.

The development of Intracytoplasmic sperm injection (ICSI) in 1992 allowed to obtain pregnancies from a small number of spermatozoa. The next year, testicular sperms were extracted from testicular tissue obtained surgically in cases of OA , allowing paternity for azoospermic men. In case of NOA, TESE allowed to obtain few sperms in an unexpected number of cases. It was shown that spermatogenesis remains active in rare portions of seminiferous tubules, a phenomenon called focal spermatogenesis, which allows to extract testicular sperms with an average SRR of 50%, and to obtain pregnancy by ICSI. Thus, TESE-ICSI revolutionized the prognosis of NOA, however, half of the cases of NOA had no sperm extracted and remained sterile . Since sperm donation and adoption are unacceptable for several of these couples, there is a real demand for additional treatment.

Two ways to improve chances of paternity in case of NOA are currently discussed:

1. Proceed to a second attempt of TESE. Since the first attempt could have missed a focus of active spermatogenesis, the chance for a positive second TESE is not null even. Reviewing the few articles published on this issue , the SRR for the second attempt, after a first negative attempt averaged 25%.

2. Based upon the decrease of testosterone production within the testis in case of NOA and the potential increased of the focal spermatogenesis by gonadotropins, few reports of hormonal therapy in case of NOA have been published and suggested a positive effect of hormonal therapy.

This prompted us to develop this clinical trial to investigate the effect of Clomiphene Citrate versus placebo on the results of a second TESE in NOA.

Results of hormonal therapy in case of NOA were heterogeneous and of poor methodological quality, none was randomized versus placebo: Anti-aromatases or Gonadotropins administered before the first TESE or the second TESE gave positive results. Hussein at al in 2013, suggested a positive effect of Clomiphene citrate (CC), administrated before the first TESE (57% of the CC treated group versus 33.6% in not treated group) but with drop out of patient positive to sperm analysis. However, in these positive studies, sample sizes were small or selected patients on hormonal status or histology criteria suggesting subgroup of favourable NOA. Thus, there is no strong evaluation of the interest of hormonal treatment in NOA, after a negative first TESE.

The investigators decided to evaluate the effect of the CC, the most convincing and convenient hormonal treatment, in patients with negative first TESE for NOA. It is of main interest to known if CC could enhance the SRR of a second TESE, that is the ultimate possibility to have their own child for these patients.