O-300 Human sperm selection using cumulus oophorus complexes compared with conventional sperm preparation method on sperm quality and ICSI outcomes: A pilot study
Authors: Ruvolo G , Camera I , Ermini B , Sapienza F , Manno M , Brucculeri A M , Biondo A , Lo Bue A , Falcone G , Simonaro C , Cefalù E , Ermini M , Cittadini E 
Published: June 2023

Study question

We compared a sperm selection protocol using cumulus oophorus complexes with a swim up preparation, evaluating the effects on sperm parameters and ICSI outcomes

Summary answer

Spermatozoa selected using cumulus oophorus complexes showed higher rates of normal morphology, good motility compared with basal semen and the traditional pellet swim up protocol.

What is known already

It is known that the head of a mature spermatozoa has a hyaluronan receptor that allows them to bind with hyaluronan acid. Cumulus oophorus complexs (COCs) extracellular matrix is made mainly by hyaluronic acid (HA). Various studies have confirmed the importance of COCs in fertilization, demonstrating that spermatozoa that are able penetrate through a layer of COCs are more likely to have a normal morphology and be more effective in producing acrosome reactions than spermatozoa that are not able to do. Moreover, these spermatozoa have been shown to have higher chromatin integrity and zona-binding capacity, resulting in increased fertilization competence.

Study design, size, duration

A prospective study was conducted between July and December 2022. A total of 50 participants were recruited for the study, randomly selected between patients attending ICSI. The patients were classified as group A when the sperms were selected using pellet swim up and COC selection and as group B when it was used pellet swim up treatment alone. Patients older than 39 years, with endometriosis or repeated IVF failure or severe male factor were excluded.

Participants/materials, setting, methods

3 drops of 30 mlt aligned and connected each other were prepared, covered with mineral oil. In group A, in the middle drop, was transferred COC fragments, while the central drop was empty in group B. In the left drop were added 20 mlt of sperm suspension after swim up, and from the right drops were recovered the sperms after passing the middle drop with or without COC, that were used for ICSI treatment.

Main results and the role of chance

The aim of the study was to verify the effectiveness of COCs, collected after ovarian stimulation, in selecting the best sperms to be used in ICSI procedure. No statistical difference was found between group A and B in the median age of female patients, FSH/LH units administred, E2 and endometrium thickness at triggering using hCG, in the sperm concentration, motility and normal morphology in the baseline seminal samples. We found a statistical difference in the traditional seminal parameters comparing the two different treatments. In particular, we found an higher rates of sperms with rapid and progressive motility and normal morphology in group A between basal semen sample and after sperm selection using COC filter (86.7 vs 31.3%; 8.2 vs 4.4 %). We found a lower sperm concentration in group A vs group B after sperm treatment (2.3 vs 4.7 M/ml), and an higher rates of rapid progressive motility and normal morphology in group A vs group B (86.7 vs 38.6 %; 8.2 vs 4.6%). We found an higher but not statistically significative pregnancy and implantation rates in group A compared with group B probably because of the limited number of patients analyzed (25 vs 19.2 %; 25 vs 20.6%)

Limitations, reasons for caution

The study was conducted on a small participant cohort. We analyzed the traditional sperm parameters, but it is necessary to evaluate the chromatine integrity of the sperms after COC selection to confirm that the higher sperm competence in fertilization and embryo development could be based on a better genetic pattern

Wider implications of the findings

Data seem to demonstrate that the use of COC allows to select higher competent sperms if compared with traditional pellet swim up treatment. The clinical and biological ICSI outcomes seem to be improved by COC treatment but it is necessary to increase the sample size in future experimental trial

Trial registration number

not applicable