Spinal Cord Injuries and Male Infertility
Injuries to the spinal cord can impact ejaculation in different ways, depending on the level of the injury as well as its severity. In general, about 90 percent of spinal cord injury patients experience some form of ejaculatory dysfunction.
Level of Injury
If there are spinal cord lesions at or below T10–L2 (10th thoracic to 2nd lumbar vertebral levels), generally the man can achieve an erection (though without the normal sensation of sexual pleasure), but commonly there is a complete loss of ejaculation.
Men with spinal cord lesions above T10 (10th thoracic vertebral level) generally have an intact nerve reflex arc. These men are often able to get erections, and are also often able to ejaculate.
Men with lesions at about the 6th thoracic vertebral level are prone to autonomic dysreflexia with genital stimulation. This can manifest as bradycardia, sweating, chills, headache, and increased blood pressure, which if not managed properly can lead to stroke, seizures, and death. Autonomic dysreflexia can typically be avoided with pretreatment using oral calcium channel blockers, such as nifedipine 20 mg orally or under the tongue. Men with high (T6 and above) lesions should also have continual blood pressure monitoring during any procedure. Men with very high (cervical level) lesions are at extremely high risk for autonomic dysreflexia, have a higher chance of not responding to nifedipine, and should therefore ideally have all procedures performed under general anesthesia.
Fertility Management of Spinal Cord Injury Patients
Several fertility options are available for men with spinal cord injuries who are not able to ejaculate on their own. Since sperm quality is often decreased in these men (discussed later in this section), it is recommended to try and improve the environment for sperm production as much as possible (with the Sperm Boot Camp techniques) before attempting the use the man's sperm.
Penile vibratory stimulation (PVS)
PVSis considered to be the first-line therapy for men with spinal cord injuries, as it is generally safe, effective, and not too expensive. Devices that have vibratory amplitude of at least 2.5 mm are the most effective. Examples of commercially available PVS devices include Ferticare and Viberect. PVS involves holding a vibrating device against the frenulum (underside) of the penile head for two to three minutes, or until antegrade ejaculation occurs. If no ejaculation has occurred by this time, stimulation is stopped for one to two minutes and then resumed. This can be repeated for up to a total of about ten minutes of stimulation. However, 89 percent of spinal cord injury patients who respond usually do so within the first two minutes of stimulation.
Success rates for PVS depend upon the level of spinal injury. With an injury below T10, there is a 15 percent success rate. PVS is not effective if sacral cord or parasympathetic nerves are affected. Above T10, PVS has an 85 percent success rate.
Several techniques have been developed for use when PVS has not been successful. These include using two vibrators, one on the dorsum and the other on the frenulum of the penis (note that the Viberect device has two vibrating heads), simultaneous abdominal muscle stimulation, and the addition of an oral PDE-5 inhibitor (see the "Erectile Dysfunction" section of this website for more information on these medications).
It is always important to watch for autonomic dysreflexia in men with T6 or higher injuries, and to consider pretreatment with oral calcium channel blockers for these men.
EEJ involves direct stimulation of the penile nerves with an electric probe through the rectum; it can result in ejaculation in most men with spinal cord injuries. EEJ is successful in about 95 percent of cases, although the ejaculation often goes retrograde (into the bladder), so the bladder needs to be catheterized, emptied, and washed out with a buffering solution prior to EEJ, and then the semen must be collected by catheterization following EEJ. As with PVS, It is always important to watch for autonomic dysreflexia in men with T6 or higher injuries and consider pretreatment with oral calcium channel blockers.
Although EEJ is felt to be the treatment of choice in men who are not successful with PVS, several important caveats exist for its use:
1) Retrieved sperm can be used in combination with intrauterine inseminations, although success rates can be variable due to the common findings of decreased sperm quality (see below).
2) Not all regions of the country have an EEJ machine available for use nearby.
3) EEJ is extremely painful in men who have sensation below the waist. In men with no sensation below the waist, this procedure can be performed under local anesthesia. However, in men who have fairly normal sensation below the waist, general anesthesia needs to be used. The cost of doing this procedure under general anesthesia can be prohibitively expensive in some cases.
Sperm can be extracted (typically under local anesthesia) and used for IVF/ICSI. It is always important to watch for autonomic dysreflexia in men with T6 or higher injuries and consider pretreatment with oral calcium channel blockers. See the "Fertility Following Vasectomy" for more information on sperm extraction options.
Erectile Dysfunction and Spinal Cord Injury
Most men with spinal cord injuries (about 85 percent) do regain some level of erectile function by about two years after the injury. However, these erections are not always well-timed or sustained, and only about 10 percent of men with spinal cord injuries are able to successfully ejaculate with sexual intercourse or masturbation. Most men with spinal cord injuries at T10 or above respond well to standard ED treatments, such as PDE-5 inhibitors. These medications can be tried in men with lower (below T10) lesions, but they have a significantly decreased chance of success. Muse intraurethral pellets do not tend to work well in spinal cord injury patients, and this may be due to decreased absorption of this medication in men who perform routine intermittent catheterization. Penile injections and vacuum erection devices can be used effectively, but men with impaired hand function may need assistance.
For more detailed information on these treatments, please see the "Erectile Dysfunction" section of this website.
Sperm Quality in Spinal Cord Injury Patients
If sperm are able to be successfully obtained from ejaculate in men with spinal cord injuries, semen parameters are normal only about 7.5 percent of the time. About 10 percent of these men will be completely azoospermic. There are multiple potential reasons for decreased sperm production and quality in men with spinal cord injuries, including:
1) Scrotal hyperthermia from sitting in a wheelchair for extended periods (although this is controversial)
2) Infrequent ejaculation
3) Problems associated with bladder management
4) Accessory gland (seminal vesicle and prostate) dysfunction
6) Endocrine abnormalities
It is therefore always recommended to check a hormone panel (FSH, testosterone levels, etc.) on spinal cord patients before any fertility-related procedures.
Cumulative pregnancy rates for PVS followed by home intracervical inseminations (ICI) are generally around 20–25 percent. When intrauterine insemination (IUI) is used in conjunction with either EEJ or PVS, per-cycle pregnancy rates are usually around 8–9 percent, although rates as high as 18 percent per cycle have been reported in men with high sperm counts (total motile count over 40 million). Cumulative IUI pregnancy rates are generally around 30–35 percent. Higher pregnancy rates are associated with sperm extractions combined with IVF/ICSI, but these cost more and are more invasive.