What is primary ciliary dyskinesia?

Primary Ciliary Dyskinesia (PCD) is a rare genetic disease that can affect several organs. With PCD, the function of cilium (small, hair-like projections found on the surface of cells) is defective, known as ciliary dysfunction, and prevents the removal of mucus from the lungs, ears, and sinuses, allowing a build-up which can lead to infection.¹  

Overview of infertility in relation to PCD

Infertility is when a couple fails to achieve pregnancy after having regular unprotected sexual intercourse for more than 1 year.⁸

Cilia can also be found in the reproductive system, which means that ciliary dysfunction can affect other parts of the body.² Males affected by PCD are often infertile due to abnormal sperm movement.  Affected women are likely to have abnormal cilia motion within the fallopian tubes and endometrium that could impair the movement of a developing egg and embryo, interfering with the fertilisation and implantation of the egg.³

Understanding primary ciliary dyskinesia 

PCD is a rare genetic disease that is passed on from both parents that causing a mutation in the genes that create cilia and leads to the incorrect structure and function being produced. There have been over 35 genes discovered that cause PCD, with more yet to be found.⁴ 

Cilia are tiny, hair-like projections that line the airways of the respiratory system. They are especially important in propelling the movement of bacteria, mucus and other inhaled particles out of the airways by sneezing or coughing.⁵ When the cilia are defective, they are unable to perform these processes due to being the wrong size, shape, or being unable to move. 

Signs and symptoms of primary ciliary dyskinesia 

Depending on the severity of the disease, symptoms can be present hours after birth or can go undetected into adult life. PCD mainly affects the lungs, ears and sinuses; chronic infections of these areas are a sign of having PCD. Other symptoms include:

• Returning pneumonia 
• Bronchiectasis 
• Hearing loss
• Nasal polyps 
• Infertility 
• Kartagener’s Syndrome 

Kartagener’s Syndrome is a rare condition where the organs are flipped inside the body and are on the opposite side to where they normally are. This condition is a subset of PCD⁶ and is present in almost half of PCD sufferers.⁷

Diagnosis of primary ciliary dyskinesia 

PCD can be diagnosed by a specialist healthcare provider and is based on family history, symptoms and test results. A variety of tests can be used in the process of diagnosing PCD, such as:

• Genetic testing is carried out by a blood test that is then sent off to a lab to be analysed. There are many genes that are associated with PCD, and genetic testing can reveal any relevant genes that may be linked to the disease and aid in diagnosis
• Ciliary ultrastructural analysis, which uses a type of microscope called the electron microscope to check samples of cilia to check how they are functioning, These samples are taken via scraping or swabbing the inside of the nose
• Nasal nitric oxide measurement is a test that requires a sample of gas, which is taken when you breathe out. A low nitric oxide level is common in those who have PCD
• Semen analysis is used in adult men, as PCD can affect the cilia that help to make sperm move.  A low sperm count or abnormal sperm movement can be an indicator of PCD

Diagnosis of PCD can be time and labour-intensive due to the specialist equipment and training required, but is recommended as an early diagnosis and treatment of the disease is essential in maintaining lung function, and working towards a good prognosis.¹⁰ Testing for other autoimmune diseases and disorders with similar symptoms is common when testing for PCD in order to rule them out. 

The link between PCD and infertility 

As we know, PCD affects the cilia that line the cells of both the male and female reproductive organs.  Infertility affects around 83% of men and 61% of women with PCD,³ but they can receive assisted reproductive technologies (ART) to help them conceive. 

Researchers believe that the reason for male infertility with PCD is due to the cilia found in the small tubes between the testes being defective and unable to properly move sperm, causing the sperm to become agglutinated (clumped together). As a result of this, the sperm is unable to properly navigate the female reproductive tract.³ 

Women with PCD are typically affected by immotile (non-moving) cilia in the fallopian tubes and endometrium (inner lining of the uterus), making it hard for a fertilised egg to move and embed, however, this does not result in a higher number of ectopic pregnancies or miscarriages.⁹ As of now, there has not been a lot of research into the link between female infertility and PCD.

Infertility treatments and their effectiveness 

The use of ICSI has been demonstrated to be an effective treatment for men with PCD experiencing infertility.¹¹ One study reports that the use of ART was successful and beneficial in achieving pregnancy in 17 out of 20 women who took part. Another study tells that the use of ART helped 54 out of 65 men, which led to live births.³

Current studies have found that the level of respiratory tract cilia motility does not largely differ between individuals who were reported fertile or infertile, suggesting that the severity of respiratory tract abnormalities is not a predictor of fertility. However, it has been found that individuals with a mutation in one of these four genes: CCDC39, CCDC40, DNAAF1 or LRRC6⁹ are highly likely to be infertile.  

Pregnancy and reproductive health concerns FAQ

The decision to start a family is personal and has no right or wrong answer. It can be a difficult topic for those who suffer from PCD, as they have to take into consideration whether having a child is possible or safe for them to do so. This section will help answer some of the questions you may have.

Is pregnancy safe if I have PCD?

Pregnancy can put additional strain on the body, particularly in women with pre-existing health conditions such as PCD. Many women have had a successful pregnancy, but every situation and person is unique.  It is recommended to ask your healthcare provider and pulmonary advisor for advice, as they may want to give more frequent check-ups during your term.

Both parents should take into consideration the realities of caring for a baby, as added stress, lack of sleep, and missed appointments can be detrimental to the health of a parent with PCD. Having a support system of friends and family can be very helpful in maintaining your mental and physical well-being.

Can I continue with my PCD treatments during pregnancy?

Yes, however, this should be discussed with your healthcare provider to figure out what is best for you and your situation.  

Is it true that I can’t get pregnant with PCD?

No. It is possible to spontaneously conceive even if you are thought to be infertile.  Assisted reproductive technologies can be used to help you conceive, such as intracytoplasmic sperm injection, in vitro fertilisation, or an egg/sperm donor.

Will my child have PCD?

PCD is genetic and is passed from parent to child, but your child must receive two non-functioning copies of the same gene from each parent for them to express the disease and experience symptoms. If the child only receives one non-functioning gene, they will become a carrier for PCD, but will not be affected, This means that any child you have will become a carrier. If one parent has PCD and the other is a PCD carrier, the child has a chance of inheriting either the functioning or non-functioning gene.  

Summary

Primary ciliary dyskinesia is a rare disease affecting the cilia that line organs. The affected cilia are typically defective, being the wrong size or shape, immotile, or missing completely. Individuals who suffer from this disease experience chronic infections of the lungs, sinuses, and ears, along with infertility. Infertility as a result of PCD is due to the defective cilia, causing sperm and ova to be immotile in the reproductive organs.  

PCD can be managed if diagnosed early, treated, and reviewed regularly by a pulmonary specialist or healthcare provider. It is not impossible to conceive with PCD, as spontaneous conception can happen, or assisted reproductive technology can be used.