Role of the total progressive motile sperm count (TPMSC) in different infertility factors in IUI: a retrospective cohort study
A retrospective cohort study was carried out to identify the optimal total progressive motile sperm count (TPMSC) required in couples undergoing intrauterine insemination (IUI) with different infertility factors.
The study included a total of 2647 couples who underwent 5361 IUI cycles, at the Reproductive Centre, Sun Yat-sen Memorial Hospital, from January 2015 to December 2018. Only 4 main infertility factors was analysed; 1) oligo-ovulation/anovulation, 2) unexplained infertility, 3) mild male factor, 4) mild endometriosis.
Unexplained infertility in couples was classified as normal ovulation, bilateral patent tubes and normal semen analysis. In contrast, mild male factor was defined as a single semen parameter below the normal range, for total sperm count (< 15M/mL), progressive motility (< 32%) or normal morphology (≤ 4%). Diagnosis of mild endometriosis was confirmed via laparoscopy or the presence of a small endometriosis cyst < 4cm.
Semen was collected following 3 to 7 days of abstinence and prepared using the density-gradient centrifugation method. The female partner was then inseminated with 0.5mL of sperm, within 2 hours of original collection for maximum results, followed by 2 weeks of dydrogesterone supplementation. Semen was examined as per WHO guidelines with prewash and postwash TPMSC calculated accordingly.
In patients with oligio-ovulation or anovulation, ovarian stimulation was carried out using clomiphene citrate, letrozole and gonadotrophins, either independently or combined. Depending on luteinizing hormone (LH) levels, insemination was then performed on the LH positive day or the day following a HCG/rHCG trigger shot.
Alternatively in women with regular cycles, follicle growth was monitored by ultrasound from cycle day 10-12 onwards, followed by insemination on the LH positive day or the day following a HCG trigger shot.
Clinical pregnancy was then confirmed by the presence of one or more gestational sacs, whilst live birth was defined by successful delivery after 28 weeks gestation.
Of the 5361 IUI cycles, only 5171 were included in the final analysis after a number of cycles were converted to IVF due to multifollicular development, while other cycles had data missing. According to the infertility diagnosis: 1542 cycles was due to unexplained infertility, 1228 cycles for anovulation, 122 featured mild endometriosis and 1120 because of mild male factors. Unsurprisingly cycles involving multiple infertility factors or other known infertility factors were excluded from the study (n=1159).
Initial baseline characteristics of participants showed that couples with unexplained fertility or mild male factor had a higher median age compared to those with anovulatory cycles (female: 31 vs 29; male 33 vs 32). Interestingly, female BMI was also significantly higher in those diagnosed with oligo-ovulation/anovulation (22.0 vs 20.7-19.5) while prewash and postwash total progressive motile sperm counts (TPMSCs) was significantly lower in couples with unexplained or mild male factor (34.76 million vs 54 million or 36 million vs 60 million) respectively.
Preliminary analysis showed that clinical pregnancy rate (CPR) and live birth rate (LBR) was significantly higher for couples with oligo-ovulation/anovulation, with a CPR of 18.0% and LBR of 14.5% per IUI cycle. On the other hand, CPR and LBR in couples with unexplained, mild male factor or mild endometriosis was not significantly different to each other, with CPR between 7.4 to 8.4% and LBR of 5.4 to 6.6%.
Surprisingly, in women older than 40 years of age, only one clinical pregnancy was recorded from 78 IUI cycles and no live birth.
To evaluate the effect of pre and post wash total progressive motile sperm count (TPMSC) on CPR and LBR, the data was broken down further into quartiles of TPMSC. In couples with unexplained infertility or anovulation, pre and postwash TPMSC did not significantly improve the CPR or LBR. However in couples with mild male factor infertility, postwash TPMSC > 65.10 million had significantly higher CPR (14.0% vs 11.2%) and LBR (10.0% vs 8.3), compared to prewash TPMSC > 75 results. Similarly, in couples with mild endometriosis, pre-wash TPMSC > 90 and post-wash TPMSC > 81 achieved an identical CPR and LBR, of 10.3% prewash and 11.1% postwash.
Advanced statistical analysis confirmed that total progressive motile sperm count (TPMSC) correlated significantly with live birth rates in couples with mild male factor infertility and that postwash TPMSC was better than prewash TPMSC, based on area under the curve analysis.
Finally the overall LBR of 8.5% was consistent with previous studies. The authors noted that therefore consecutive ejaculates maybe beneficial to improve semen quality, and IUI outcomes, particularly in cases of mild male factors or endometriosis.
SUMMARY: NUMBER OF SPERM NEEDED FOR IUI
A total progressive motile sperm count, greater than 75 million (prewash) or 65.10 million (postwash), achieved the highest clinical pregnancy rate (11.2% or 14.0%) and live birth rate (8.3% or 10.0%) per intrauterine insemination (IUI) cycle in couples with only mild male factor type infertility.
- Retrospective study
- Single centre study and results may not translate to other populations
Atasever M, et al. (2016). Factors affecting clinical pregnancy rates after IUI for the treatment of unexplained infertility and mild male subfertility. https://dx.doi.org/10.5152/jtgga.2016.16056
Ganguly I, et al. (2016). Pregnancy Predictors after Intrauterine Insemination in Cases of Unexplained Infertility: A Prospective Study. https://doi.org/10.1155/2016/5817823
Isa A M, et al. (2014). Accurate diagnosis as a prognostic factor in intrauterine insemination treatment of infertile saudi patients. https://www.ncbi.nlm.nih.gov/pmc/articles/pmc4227975/
Ashrafi M, et al. (2013). The role of infertility etiology in success rate of intrauterine insemination cycles: an evaluation of predictive factors for pregnancy rate. https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3850345/
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