What are the Thresholds of Sperm Concentration and Total Motile Count Required to Achieve Pregnancy in IUI Cycles?

Introduction

The fertility community has not yet reached a consensus regarding the required minimal sperm concentration and Total Motile Count (TMC) associated with successful IUI. This debate concerns both untreated ejaculated sperm and post separation sperm.

Aims

The study is designed to establish the minimal TMC threshold prior to and after sperm separation that correlated with successful ovulation induction and IUI cycles in terms of pregnancy rates.

Materials and methods

This study included 1134 IUI consecutive cycles examined between 2009 and 2012. The choice of sperm preparation method depended on the characteristics of the semen sample. Separation methods complied with WHO guidelines.

Results

Higher pregnancy rates (PR) were observed in IUI cycles using initially normal sperm parameters according to WHO criteria. The following PR were calculated in relation to the subsequent parameters: normal vs. abnormal concentration (6.9% vs. 2.2% p=0.007), normal vs. abnormal motility (7.1% vs. 2.4% p=0.003) and normal vs. abnormal progressive motility (7.1% vs. 3.0% p=0.008). When the TMC prior to sperm separation was below 10X10⁶ the PR was 1.0% compared to 6.9% when the TMC was ≥10X10⁶, p=0.005. The PR when the TMC values after treatment were: 0.1-1.9, 2.0-4.9 and ≥5X10⁶ was 1.4%, 6.3% and 9.1% respectively, p<0.001.

Conclusions

We may conclude that a final TMC below 2x10⁶ sperm cells is not effective in terms of achieving conception. It is our recommendation that couples are referred to IUI treatment only when the TMC is least 10X10⁶ prior to sperm treatment and at least 2.0X10⁶ after.