Frozen sperm is just as effective as fresh for insemination treatments, a new study says. Photo courtesy of the National Institute of Allergy and Infectious Diseases
July 5 (UPI) -- Frozen sperm is just as effective as fresh for insemination treatments, though frozen may take "slightly longer" to work, a new study says.
"Patients undergoing [intrauterine insemination] should be counseled about the non-inferiority of frozen sperm," Dr. Panagiotis Cherouveim, who conducted the study, said in a news release.
Cherouveim, a research fellow at Massachusetts General Hospital and Harvard Medical School, presented the study's findings this week Monday at the 38th annual meeting of the European Society of Human Reproduction and Embryology.
He analyzed 5,335 intrauterine insemination cycles performed at his center between 2004 and 2021, and explained that cryopreservation has become the preferred method of sperm storage.
However, he said, despite its widespread use, and required quarantine and screening, there are concerns among patients that cryopreservation might reduce the viability of the frozen-thawed sperm cells, affecting their motility, structure and DNA content.
"Contemporary data from intrauterine insemination cycles are still scarce," he noted.
The new study analyzed a range of outcomes following intrauterine insemination treatments with either fresh or frozen sperm, including a positive pregnancy test, clinical pregnancy and miscarriage rate.
The study also controlled for the type of ovarian stimulation either given or not given to women before such treatment.
Cherouveim found similar clinical pregnancy rates between individuals using fresh and frozen samples. He noted there were some minor differences in a subgroup of patients having pretreatment ovarian stimulation with oral medications -- either clomiphene citrate or letrozole -- but these differences were no longer evident when the analysis was limited to a first cycle of treatment.
According to the news release, "The only lasting difference was that time-to-pregnancy was slightly longer in the frozen sperm group than in the fresh."
Cherouveim added: "Although, specific subgroups might benefit from fresh sperm utilization and time-to-pregnancy might be shorter with fresh than frozen sperm, patients should be counselled about the non-inferiority of frozen sperm.
"No detrimental effect of sperm cryopreservation on [intrauterine insemination] outcomes was noted."
Cherouveim said the study's findings might be "especially welcome in single-mothers-by-choice and same sex couples" for whom intrauterine insemination with a cryopreserved sperm sample might represent the only opportunity for conception in any given menstrual cycle.
He noted that most of the cryopreserved sperm samples in the study came from an anonymous donor, reflecting the everyday practice of most fertility centers.