P-001 Comparing two monomorphic teratozoospermia syndromes in terms of ICSI outcomes - Round vs. pin-head
Authors: Kalantari H , Sabbaghian M , Vogiatzi P , Hosseini S  H , Colpi G  M , Sadighi Gilani M  A 
Published: July 2024

Study question

Whether ART clinical outcomes are affected at extremes of morphological presentations, in samples where typical forms are unavailable for ICSI.

Summary answer

The study found no correlation between the severity of sperm defect and ICSI results.

What is known already

One of the challenging topics in the field of Andrology is the predictive role of monomorphic teratozoospermia, specifically head defects, in assisted reproductive technology (ART) outcomes. The definitive requirement of conducting intracytoplasmic sperm injection (ICSI) is the presence of at least one motile spermatozoon. Two schools of thought provide contradicting views; some believe that sperm morphology can significantly predict fertilization, clinical pregnancy, and live birth rates in fresh ICSI cycles and others support that the degree or nature of sperm morphological dysfunction lacks a significant impact on the outcome of ICSI outcomes.

Study design, size, duration

This retrospective cohort study was included 7,881 couples with male factor infertility who underwent 11,536 IVF/ICSI cycles at a tertiary referral fertility center over a 13-year period.

Participants/materials, setting, methods

From this cohort, 10 cases were identified with &gt;90% acephalic sperm syndrome and 11 patients had &gt;90% globozoospermic sperm. The implantation rate, pregnancy, and live birth rates per initiated cycle (iC) and per patient were compared between the two groups. The rates were also compared between each group with the general ICSI population.

Main results and the role of chance

The data analysis suggests no statistically significant differences between the two patient groups. Implantation was 20% versus 15.1% (95% CI, 0.33 to 5.97; OR, 1.4) for round and pin-head groups. The pregnancy per iC and patient were 25% vs 23.1% (95% CI, 0.25 to 9.5; OR, 1.55) and 27.3% vs 30% (95% CI, 0.13 to 5.8; OR, 0.87) for round-head and pin-head groups, respectively. The live birth rates matched the pregnancy rates. For the general ICSI population the rates were as follows: implantation rate was 17.3%; pregnancy rate (per iC and per patient) was 27.2% and 44.7%; and live birth rate (per iC and per patient) was 23.2% and 38.2%. The study found no significant differences between the outcomes for the general ICSI population and the two groups.

Limitations, reasons for caution

It is uncertain whether this lack of association is genuine or whether it is affected by the limited number of cases with extreme monomorphic abnormalities. The absence of evidence should not be taken as evidence of absence.

Wider implications of the findings

Conducting such studies should be encouraged to provide insight by informing systematic reviews. A significant portion of existing literature on teratozoospermia comprises of case reports, which are rationally excluded from systematic reviews and meta-analyses. Additional research is warranted to definitively establish the investigated relationships.

Trial registration number

not applicable