Guide to Sperm Freezing

Sperm-producing transgender individuals may want to have biological children in the future, using their sperm to fertilize either a partner’s egg or a donated egg. Sperm freezing makes this possible, and is recommended before undergoing gender-affirming hormone therapy (typically estrogen and androgen-blockers).

A 2017 review looked at nearly 40 years of research on the impact of cross-sex hormones on the sperm quality and testicular function of trans women. The review found that, in the majority of cases, estrogen and/or anti-androgen treatment caused reduced or halted spermatogenesis, as well as physical changes to the testicles.

The effect seems to be dose-dependent; in one study, a low-dose estrogen therapy had no impact on sperm concentration or motility, while a higher-dose regimen resulted in reduced sperm motility after a few days and reduced sperm concentration after 2 weeks.

In some cases, sperm count and quality can be recovered. One study suggested that, within 6 months of stopping estrogen therapy, 67% of subjects returned to a normal sperm count.

However, the impact of medical gender transition on fertility, as well as the capacity for spermatogenesis to recover if estrogen treatment is paused, seem to be variable and individual. Case studies demonstrate that, while some patients continued spermatogenesis through gender-affirming hormone treatment, others stopped producing sperm altogether, and several experienced azoospermia for 4–5 months after pausing therapy.

Sperm freezing prior to hormone therapy offers an option for trans women to preserve their ability to become a genetic parent, and to avoid the need for long-term cessation of their hormone treatment later on.

Historically, many trans people did not get adequate counseling on their fertility prior to starting hormone therapy. That seems to be changing. A study in 2018 analyzed sperm samples in a sperm bank, finding that the number of transgender sperm bankers increased by 18% relative to cisgender sperm bankers from 2006 to 2016.

Although vasectomy reversal surgery is an option, the success rate isn’t guaranteed. Dr. Honing of Yale Medicine says that success rates are 80–90% when performed by an experienced microsurgeon. However, some estimates of pregnancy rates after vasectomy reversal are as low as 30%.

The procedure can take 3–4 hours, substantially longer than the typical 15-minute vasectomy, because reversals are technically challenging surgeries. During a vasectomy, the vas deferens, which is the tube that stores sperm and carries it out of the scrotal sac, is severed. Those severed ends have to be reconnected with a great deal of precision during a vasectomy reversal to allow the sperm to once again enter ejaculate.

Research says that factors such as your surgeon’s skill level, secondary obstruction in the epididymis, or scar tissue in the vas deferens can contribute to ineffective vasectomy reversal.

Sperm freezing is significantly less expensive and invasive than attempting vasectomy reversal. Sperm freezing and sperm storage before a vasectomy provides you with a back-up plan, just in case you change your mind. With this option, you can choose to have another biological child without having to undergo vasectomy reversal surgery.

In addition to military service, there are a number of professions that pose an increased risk of male infertility. People in these occupations may consider sperm freezing and sperm storage to preserve their fertility early in their careers.

Research shows that sperm-producing people who work in following industries may see a negative impact on their fertility, including reduced sperm count and increased risk of miscarriage and birth defects:

• Agriculture
• Herbicides
• Construction
• Machining
• Plastic production
• Printing
• Tobacco processing
• Welding

The evidence points towards exposure to toxic substances, such as pesticides, lead, metals, petrochemicals, and more. 

Exposure to radiation can also negatively impact male fertility. A study that analyzed 90 male radiographers against 90 men not exposed to x-ray radiation showed that there was significant association between exposure to radiation and miscarriage, congenital anomalies, still birth, and infertility.

Although men have been known to father children well into their 60s and beyond, it is known that sperm quality decreases after the age of 35. This includes a significant decrease in pregnancy rate, an increase in time to conception, an increase in miscarriage risk, and an increase in potential adverse pregnancy outcomes.

All of this occurs because sperm quality parameters (count, motility, morphology, and DNA fragmentation) naturally change with age. On average, a male can expect to see a 0.8% decrease in sperm motility, 0.65% decrease in sperm morphology, and a 0.3% increase in sperm DNA fragmentation each year.

Sperm freezing in your 20s or 30s can help provide assurance for when you’re ready to have children later in life — especially if you don’t foresee starting a family until you reach your 40s.

This quality test is a critical step in sperm freezing and sperm storage. The post-thaw analysis involves freezing and then thawing a small portion of your sample, simulating the thawing conditions your sperm will experience in the future when it’s ready to be used. From there, we re-analyze sperm quality parameters to see if the sperm in your sample is viable after thawing.

According to research, it is normal to expect parameters like sperm motility to decrease a bit after being frozen and thawed. A recent study demonstrated that, on average, around 80% of sperm will survive the thaw.

This slight drop in numbers does not affect pregnancy rates significantly. For successful intrauterine insemination, data shows that around 10 million sperm is usually required. Those with normal, healthy sperm quality parameters usually produce at least 40 million sperm per ejaculate.

A post-thaw analysis gives you a realistic idea of the quantity and quality of sperm you may have after thawing, which is important information for the healthcare provider who may be working with the sample in the future.

A post-thaw analysis is conducted as part of every Legacy analysis, to determine whether or not a sample is eligible for cryostorage. In fact, Legacy offers the only at-home sperm freezing kit with a post-thaw analysis.

Frozen sperm is stored in cryogenic vials within liquid nitrogen or nitrogen vapor storage tanks, called dewars. The safest place for frozen sperm storage is a dedicated cryogenic storage facility, with security and ongoing monitoring of liquid nitrogen levels in the sperm storage tanks. That’s exactly where they’ll go after sperm freezing with Legacy.

Legacy’s state-of-the-art cryogenic sperm storage facilities are monitored around the clock, with backup emergency power sources and equipment redundancy to mitigate the risk of a blackout or natural disaster.

To further mitigate any risk, Legacy offers multi-site frozen sperm storage as a default for all clients. That means your frozen sperm samples will be shipped to multiple cryo storage facilities, just in case.

Cryo storage facilities are highly secure locations. For example, Legacy’s cryo storage partner facility employs a 24/7 video monitoring surveillance system along with motion detectors. Card-controlled access areas admit only trained and certified staff.

Cryostorage facilities must be HIPAA-compliant. HIPAA is a federal law that protects sensitive patient health information, so that means your samples cannot be released to anyone other than you or an individual that you have authorized (such as your spouse). Clinics and labs also cannot share your sample or storage details with third-parties, and must protect your health data and any associated personally identifiable data from unauthorized parties.

There are a number of options for using frozen sperm, including intrauterine insemination (IUI), in vitro fertilization, and IVF with intracytoplasmic sperm injection.