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PubMed This is a summary of 19 peer-reviewed journal articles Updated
Urology · Congenital Bilateral Absence of the Vas Deferens

Understanding Congenital Bilateral Absence of the Vas Deferens (CBAVD)

At a Glance

CBAVD is a condition where a man is born without the tubes that transport sperm, causing infertility. Because sperm production typically remains normal, men with CBAVD can usually still father biological children using specialized sperm retrieval procedures and IVF.

Receiving a diagnosis of Congenital Bilateral Absence of the Vas Deferens (CBAVD) can be an overwhelming and unexpected shock. Many men only discover they have this condition when they begin investigating why they are having trouble conceiving [1]. It is natural to feel a range of emotions, from confusion to grief, but it is important to know that this diagnosis does not mean you cannot have biological children [2][3].

What is CBAVD?

The vas deferens is a pair of muscular tubes that serve as the transport system for your sperm. They carry mature sperm from the epididymis (the storage area behind the testes) to the urethra so they can be part of the ejaculate [4][5].

In men with CBAVD, both of these tubes are missing from birth (congenital) [1]. This creates a physical “disconnection” in the reproductive tract. While your body continues to produce semen, it does not contain any sperm—a condition known as obstructive azoospermia [6][7].

How Common Is It?

While CBAVD is rare in the general population, it is a well-recognized cause of male infertility:

  • General Population: Approximately 0.1% of men are born with CBAVD.
  • Infertile Men: About 1% to 2% of men seeking fertility treatment are diagnosed with this condition.
  • Obstructive Azoospermia: Among men who have a physical blockage preventing sperm from entering the ejaculate, CBAVD accounts for roughly 6% of cases.

Sperm Production is Usually Normal

One of the most important facts for you to know is that your body is likely still producing sperm correctly. In most men with CBAVD, spermatogenesis (the biological process of making sperm) is completely intact [1][6][8].

Your testes are typically still functioning as “factories,” creating healthy sperm that just happen to be trapped because the “delivery trucks” (the vas deferens) are missing [2]. Because your sperm production is usually normal, doctors can often bypass the blockage by retrieving sperm directly from the testes or the epididymis using minor surgical procedures [9][10].

The Genetic Link

CBAVD is often linked to the CFTR gene, which is the same gene associated with Cystic Fibrosis (CF) [11][12]. Many men with CBAVD carry mutations in this gene but do not have any of the classic symptoms of Cystic Fibrosis, such as severe lung or digestive issues [7][13].

Because of this link, genetic counseling and testing are essential steps in your journey [14]. Testing helps determine the risk of passing a CFTR mutation to your children, especially if your partner is also a carrier of a CFTR mutation [13][15].

Other Considerations

In some cases, the same developmental “hiccup” that caused the vas deferens to be missing can affect other organs.

  • Kidney Health: Roughly 11% to 12% of men with CBAVD are also missing one kidney (unilateral renal agenesis) [16][17].
  • Screening: Your doctor may recommend a simple ultrasound of your abdomen to ensure your kidneys are healthy and present [18][16].

Understanding your diagnosis is the first step toward building your family. With modern fertility techniques like ICSI (intracytoplasmic sperm injection), the chances of successful biological fatherhood remain very high for men with CBAVD [9][19].

Common questions in this guide

Can I still have biological children if I have CBAVD?
Yes. In most cases, men with CBAVD still produce healthy sperm in their testes. A fertility specialist can retrieve this sperm directly from the reproductive tract using a minor surgical procedure, which can then be used for treatments like IVF and ICSI.
Do I need genetic testing if I am diagnosed with CBAVD?
Yes, genetic testing is highly recommended because CBAVD is strongly linked to mutations in the CFTR gene, which is the same gene that causes cystic fibrosis. Testing you and your partner helps determine the risk of passing a CFTR mutation to your future children.
Why did my doctor order a kidney ultrasound for my CBAVD diagnosis?
Because the vas deferens and the kidneys develop at the same time before birth, a developmental issue can sometimes affect both. About 11% to 12% of men with CBAVD are also born missing one kidney, so an ultrasound is a simple way to confirm your kidney health.
Does having CBAVD mean my body isn't making any sperm?
No. For the vast majority of men with CBAVD, the body continues to produce sperm normally. The condition simply causes a physical blockage, meaning the healthy sperm are trapped and cannot travel out of the testes to mix with your semen.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Does the fact that I am missing my vas deferens mean my testes are still producing sperm normally?
  2. 2.Should I (and my partner) undergo genetic testing for CFTR mutations before we proceed with fertility treatments?
  3. 3.Since CBAVD is sometimes associated with kidney issues, should I have a renal ultrasound to check if I am missing a kidney?
  4. 4.What sperm retrieval procedure—like PESA or TESE—do you recommend for my specific situation?
  5. 5.What are the success rates for IVF and ICSI for couples where the male partner has CBAVD?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (19)
  1. 1

    Compound heterozygous mutations in CFTR causing CBAVD in Chinese pedigrees.

    Yang B, Wang X, Zhang W, et al.

    Molecular genetics & genomic medicine 2018; (6(6)):1097-1103 doi:10.1002/mgg3.486.

    PMID: 30450785
  2. 2

    Reproductive Urologist Preferences for Sperm Extraction in Congenital Bilateral Absence of the Vas Deferens.

    Passarelli R, Moore K, Islam R, et al.

    Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists 2026; doi:10.1016/j.eprac.2026.02.012.

    PMID: 41720344
  3. 3

    A step-by-step guide to office-based sperm retrieval for obstructive azoospermia.

    Coward RM, Mills JN

    Translational andrology and urology 2017; (6(4)):730-744 doi:10.21037/tau.2017.07.15.

    PMID: 28904906
  4. 4

    High-resolution imaging of the actin cytoskeleton and epithelial sodium channel, CFTR, and aquaporin-9 localization in the vas deferens.

    Sharma S, Kumaran GK, Hanukoglu I

    Molecular reproduction and development 2020; (87(2)):305-319 doi:10.1002/mrd.23317.

    PMID: 31950584
  5. 5

    Ultrasound of the Normal and Abnormal Vas Deferens.

    Kerr DM, Middleton WD

    Ultrasound quarterly 2022; (38(3)):224-236 doi:10.1097/RUQ.0000000000000588.

    PMID: 35129151
  6. 6

    Genetic diagnosis and sperm retrieval outcomes for Chinese patients with congenital bilateral absence of vas deferens.

    Wang H, An M, Liu Y, et al.

    Andrology 2020; (8(5)):1064-1069 doi:10.1111/andr.12769.

    PMID: 32020786
  7. 7

    Male partners of infertile couples with congenital unilateral absence of the vas deferens are mainly non-azoospermic.

    Mieusset R, Bieth E, Daudin M, et al.

    Andrology 2020; (8(3)):645-653 doi:10.1111/andr.12749.

    PMID: 31872980
  8. 8

    Intact spermatogenesis in an azoospermic patient with AZFa (sY84 and sY86) microdeletion and a homozygous TG12-5T variant in CFTR.

    Sun Y, Zhong B, Meng Z, et al.

    Basic and clinical andrology 2025; (35(1)):13 doi:10.1186/s12610-025-00260-7.

    PMID: 40169970
  9. 9

    Percutaneous epididymal sperm aspiration as a method for sperm retrieval in men with obstructive azoospermia seeking fertility: operative and laboratory aspects.

    Esteves SC

    International braz j urol : official journal of the Brazilian Society of Urology 2015; (41(4)):817; discussion 818 doi:10.1590/S1677-5538.IBJU.2015.0064.

    PMID: 26401878
  10. 10

    Relationship of sperm motility with clinical outcome of percutaneous epididymal sperm aspiration-intracytoplasmic sperm injection in infertile males with congenital domestic absence of vas deferens: a retrospective study.

    Jixiang Z, Lianmei Z, Yanghua Z, Huiying X

    Zygote (Cambridge, England) 2022; (30(2)):234-238 doi:10.1017/S0967199421000587.

    PMID: 34313208
  11. 11

    Prevalence of CBAVD in azoospermic men carrying pathogenic CFTR mutations - Evaluated in a cohort of 639 non-vasectomized azoospermic men.

    Fedder J, Jørgensen MW, Engvad B

    Andrology 2021; (9(2)):588-598 doi:10.1111/andr.12925.

    PMID: 33095972
  12. 12

    Andrological findings in infertile men with two (biallelic) CFTR mutations: results of a multicentre study in Germany and Austria comprising 71 patients.

    Rudnik-Schöneborn S, Messner M, Vockel M, et al.

    Human reproduction (Oxford, England) 2021; (36(3)):551-559 doi:10.1093/humrep/deaa348.

    PMID: 33374015
  13. 13

    Congenital Bilateral Absence of the Vas Deferens.

    Cai Z, Li H

    Frontiers in genetics 2022; (13()):775123 doi:10.3389/fgene.2022.775123.

    PMID: 35222530
  14. 14

    Congenital bilateral absence of the vas deferens as an atypical form of cystic fibrosis: reproductive implications and genetic counseling.

    de Souza DAS, Faucz FR, Pereira-Ferrari L, et al.

    Andrology 2018; (6(1)):127-135 doi:10.1111/andr.12450.

    PMID: 29216686
  15. 15

    Mutations of the cystic fibrosis transmembrane conductance regulator gene in males with congenital bilateral absence of the vas deferens: Reproductive implications and genetic counseling (Review).

    Cui X, Wu X, Li Q, Jing X

    Molecular medicine reports 2020; (22(5)):3587-3596 doi:10.3892/mmr.2020.11456.

    PMID: 33000223
  16. 16

    Unilateral Kidney Agenesis and other Kidney Anomalies in Infertile Men with Congenital Bilateral Absence of Vas deferens: A Cross-Sectional Study.

    Pahlavan F, Niknejad F, Sajadi H, Vosough A

    International journal of fertility & sterility 2022; (16(3)):152-155 doi:10.22074/ijfs.2021.535148.1166.

    PMID: 36029049
  17. 17

    Congenital absence of vas deferens: Anatomical and embryological inputs from a series of autopsies reported in Europe throughout the 18th and 19th century.

    Bendayan M, Boitrelle F, Maurens-Hamdi S

    Andrology 2024; doi:10.1111/andr.13815.

    PMID: 39648616
  18. 18

    Scrotal Ultrasonic Features of Congenital Bilateral Absence of Vas Deferens.

    Liu J, Wang Z, Zhou M, et al.

    Ultrasound quarterly 2017; (33(2)):153-156 doi:10.1097/RUQ.0000000000000278.

    PMID: 28541268
  19. 19

    Sperm Extraction in Obstructive Azoospermia: What's Next?

    Akerman JP, Hayon S, Coward RM

    The Urologic clinics of North America 2020; (47(2)):147-155 doi:10.1016/j.ucl.2019.12.003.

    PMID: 32272986

This page provides educational information about CBAVD and male fertility. It is not a substitute for professional medical advice, diagnosis, or treatment from a qualified urologist or reproductive specialist.

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