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Conception Success with Congenital Bilateral Absence of the Vas Deferens
There is a common assumption that when a couple is experiencing difficulty in achieving pregnancy, it is typically attributable to a problem with the female. This is not at all the case, and in fact, male infertility accounts for 40 to 50 percent of all infertility cases. In some instances the issue centers on factors such as hormonal insufficiencies, environmental factors or poor general health, while in others the complications are caused by the male’s reproductive system in its ability to produce viable sperm. I recently treated a couple for whom this was the issue; they were married for four years and had spent the previous two years casually trying to get pregnant – they hadn’t used any birth control for the first year, just hoping that things would happen naturally, and then during the second year they had increased attention to her cycle, used an ovulation predictor, all to no avail. After their initial assessment and work-up, we ran a standard semen analysis, only to find that the husband had a zero sperm count. This is referred to azoospermia, a condition that only affects about 1% of males. On physical examination he was noted to have normal testis but no vas deferens were palpable bilaterally. The couple was immediately relieved to learn from me that normal sperm production was present but due to a congenital condition, known as congenital bilateral absence vas deferens, a blockage was present. Most importantly we discussed on the initial visit that via sperm retrieval and IVF with ICSI, their hope of having a family can be fulfilled.
Congenital bilateral absence of the vas deferens, or CBAVD, is responsible for approximately thirty percent of cases of obstructive azoospermia. It is a genetic condition in which part of the male reproductive organs known as the vas deferens fail to develop properly. The sperm is still being produced, but it does not travel the expected pathway to facilitate release, leaving the male in much the same situation that he would be if he’d had a vasectomy – only the condition is not reversible. It is not possible to reconstruct an organ that was not there in the first place, which means that the only way the problem can be resolved is by undergoing sperm retrieval through testicular or epididymal sperm extraction. Following this procedure the sperm can be used immediately in an in vitro fertilization procedure and or sperm can be cryopreserved for future cycles if needed.
Identifying the problem is often great news because we know what to do to fix it, but in the case of CBAVD, knowing the source of the failure to conceive is only half the process: it is essential that we have a good understanding of the cause of the CBAVD because the condition is sometimes genetically linked to cystic fibrosis, a genetic disease that causes problems with the lungs and the pancreas. More than half of men who have CBAVD also have a mutation on their CFTR gene – the same gene that causes CF. It is important to determine whether either the male or his partner carry the genetic mutation that causes CBAVD because the condition is inheritable, and if both partners have a CFTR mutation it could result in a child being born with cystic fibrosis. If the genetic mutation is identified in both partners then it is advisable for a couple to undergo genetic counseling and preimplantation genetic diagnosis (PGD), which will test the embryo prior to implantation.
All of that is difficult for a couple to digest, especially because the condition causing the issue is something that so few have ever heard of. The recommended treatment plan in this case involved having the couple meet with a geneticist and conducting a genetic panel run on the husband and wife. As a result, the husband had the most common CF mutation, delta 508, associated with CBAVD. As for the wife, it was determined that she was not a carrier and therefore we were able to proceed with percutaneous testicular sperm aspiration. Our reproductive endocrinologist and embryology team were then able to perform IVF and ICSI, and their efforts resulted in a successful, singleton pregnancy with the birth of a healthy baby girl.
In this case, further genetic testing was not necessary, but it is reassuring that even in cases of no sperm in the ejaculate and complex genetic scenarios, couples have a wide array of highly advanced sperm retrieval techniques and associated proven fertility treatments available to them.