President, Academy of Medicine Specialties and Secretary-General of the International Federation of Fertility Societies, Prof Oladapo Ashiru, says there are no significant differences between fresh sperm and frozen sperm used for Assisted Reproductive Technology.
Prof Ashiru said frozen sperm would not interfere with the fertilisation and clinical pregnancy rates.
He said with intrauterine insemination and in vitro fertilisation, one has a better chance of clearing hurdles along the path to pregnancy.
Speaking with Newsmen, Ashiru said studies have also shown no difference between fresh sperm and frozen sperm in ART.
“It was reported by a group from Mayo Clinic Rochester in 2004 that couples using in vitro fertilisation have the same likelihood of successful pregnancy whether the sperm used is frozen or fresh.
“A study from Egypt in 2021 showed that using frozen testicular sperm from men with non-obstructive azoospermia results in fertilisation and clinical pregnancy rates similar to those of fresh sperm. It may encourage fertility centres to use frozen testicular sperm samples, as this policy has certain advantages that would help organise their workflow.
“Another study from New York in over 6,000 couples showed that using fresh compared to frozen ejaculated sperm has no impact on fresh embryo transfer cycle reproductive outcomes.
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“In a study conducted using first fresh embryo transfer cycles at a single high-volume academic institution between 2013 and 2019. In our Medical Art Center Clinic, we have observed no significant difference between frozen and fresh samples since 1994,” he said.
According to the fertility expert, the sperm freeze procedure freezes sperm cells to preserve them for future use.
“To begin, the embryologist verifies that the sample belongs to the appropriate patient and evaluates the volume of the sample, along with the sperm concentration, motility, and progression. The sample is then placed into a tube and combined with a sperm cryopreservation media.
“Once the sample is equilibrated, it is evenly distributed among pre-labelled cryopreservation vials, including a test thaw vial, and placed into a liquid nitrogen vapour, and later, into liquid nitrogen storage. Once the samples have been frozen, the test vial is thawed to ensure the survivability of the sperm. The process enables the sperm to be safely stored in liquid nitrogen for many years.
“The procedure that makes it possible to stabilise the cells at cryogenic temperatures is called cryopreservation, also known as an applied aspect of cryobiology or the study of life at low temperatures. Many advances in cryopreservation technology have led to the development of methods that allow for low-temperature maintenance of various cell types, including male and female gametes, tiny multicellular organisms, and even more complex organisms such as embryos.
“Cryopreservation of human spermatozoa introduced in the 1960s has overcome many space and time limitations and now forms an integral part of assisted reproduction technologies.”
He said this technique becomes important in cases of male fertility preservation before radiotherapy or chemotherapy, which may lead to testicular failure or ejaculatory dysfunction.
“Semen cryostorage seems to be the only proven method that may offer these couples a chance to have future children. Cancer therapy could lead to damage, resulting in sub-fertility or sterility due to gonad removal or permanent damage to germ cells caused by adjuvant treatment.
“In particular, the risk associated with therapy depends on several factors: the patient’s age at the time of treatment, the dose, site, and type of treatment. Also, some non-malignant diseases, such as diabetes and autoimmune disorders, may lead to testicular damage. Cryopreservation is also advisable in these conditions. In countries where heterologous (donor egg)) fertilisation is allowed by law, and in donor insemination programmes, cryopreservation is necessary to have enough time to screen donors for infectious agents, such as the HIV and hepatitis B viruses, before the cryopreserved semen is used for clinical purposes. In azoospermic patients, who have undergone testicular sperm extraction or percutaneous epididymal sperm aspiration, sperm cryostorage is also used to avoid repeated biopsies or aspirations.
“Furthermore, cryopreservation is routinely performed in patients who have to start ART and decide to preemptively freeze the semen sample to avoid inconveniences due to failed ejaculation often associated with ‘semen collection stress,’ certain emotional states, or other commitments at the time of oocyte retrieval,” he noted.
He added that male gamete freezing is primarily recommended to preserve fertility in those subjects who, for one reason or another, are exposed to potentially toxic agents, which may interfere with the sperm production mechanism.
