Muscular Dystrophy and Infertility

Muscular dystrophy is a broad term used to label gene-related disorders that affect muscles throughout the body. There are more than 20 specific genetic disorders considered to be muscular dystrophy, and in South Africa, it affects 1:1 200 people. Most conditions are progressive, causing the muscles gradually to weaken over time. It can either be inherited or occur out of the blue where there is no family history.

What about infertility?

Unfortunately, muscular dystrophy can lead to infertility by causing impotence and testicular atrophy in males; in women, it may cause irregular periods and infertility. Some patients may have difficulty having sexual intercourse due to physical disability such as spinal deformity or contracture.

In particular, women with myotonic dystrophy are at risk of a number of complications which include increased risk of miscarriage, increased fluid around the baby (hydramnios) which may cause premature labour, heavy bleeding either before or following delivery and retained placenta or afterbirth. Many of these complications are particularly evident when the baby has congenital myotonic dystrophy. The incidence of diabetes is slightly increased in myotonic dystrophy and the bodily changes associated with pregnancy may precipitate diabetes during pregnancy, which will bring its own complications.

Muscle weakness may cause physical difficulty in assuming the appropriate position, or maintaining the physical exertion required for the sexual act. These types of problems may result in incomplete penetration or maintenance of the sexual act. Those making love infrequently may not perform the act at the time when the female’s eggs are available for fertilisation. If the woman has a regular monthly menstrual cycle of 28 days (while not on the oral contraceptive pill) ovulation occurs 14 days after the start of the period, and fertilisation may occur following intercourse about 2-3 days before or after this date. Males with myotonic dystrophy may have reduced fertility. This is associated with changes in the testes, but the exact causes of these are not yet known.

Of course, infertility is potentially a problem for anyone, and couples may have trouble conceiving for unrelated reasons. Most couples who have regular unprotected intercourse will have conceived within one year, if this is not the case then you should consult with a fertility specialist.

What about the genetic implications?

There are different forms of inheritance in muscular dystrophy. The confirmation of your precise diagnosis may help the doctors advise you as to the risks of your baby having the same problem as you. Sometimes the form of inheritance may be worked out from the pattern of inheritance in your family. There may be variation in the severity of affected individuals between families and within increase is more marked when a mother passes on the condition. Myotonic dystrophy tends to get more severe when it is passed from parent to child. This increase is more marked when a mother passes on the condition.

Males with sex or X-linked conditions such as Duchenne and Becker will not have affected sons. Their daughters will all be carriers and are at risk of having affected sons.

If the condition is genetic what are the options for prenatal diagnosis?

Gene tests are now possible for many types of muscular dystrophy. You need to discuss this with your doctor to find out exactly what could be available for you. Some families may need to have the specific form of the alteration identified within their family. If a specific test is available, then you may opt for a test on the pregnancy to see if the baby is affected or not. This may not be entirely straight forward as tests may not always be able to predict how severe the baby’s problems will be, so you really need to talk through the issues relevant to your own particular case.

What kinds of tests are available?

Chorionic Villus Sampling/Biopsy (CVS/CVB)

This test involves removing a small portion of the placenta or afterbirth from within the womb by inserting a needle through the abdominal wall just below the belly button or umbilicus (occasionally this test is done via the vagina). The needle goes through the muscles of the womb and is guided using an ultrasound scan. The procedure is performed from 11-12 weeks of pregnancy and takes about 20 minutes. Only specialised centres perform this test. The miscarriage risk is about 1 in 50. The test results are generally available within two weeks. Some tests including sexing for sex or x-linked conditions may be available within a couple of days. It is important that you check details of the testing including the miscarriage risk with your local centre.


This is performed in a similar fashion to a CVS, but it involves the removal of a small amount of fluid from around the developing baby within the womb. It is performed from 15 weeks with a miscarriage risk of about 1 in 100. The results take about three weeks.

Scans for sex determination

For sex-linked conditions, these scans may be performed from about 20 weeks. Sexing the baby depends on the development of the external genitals of a male. Occasionally these may be underformed and the sex may not be accurate at this stage.

Preimplantation Genetic Diagnosis (PGD)

PGD is a screening process that enables us to test the embryos of a couple who carry a known genetic marker for a specific inherited disorder so that only healthy embryos are selected to be replaced/transferred to the woman’s uterus in order to attempt to achieve a pregnancy.

PGD testing has been a common practice for more than 20 years and is very successful in detecting genetic alterations in the embryos of couples known to be at risk of passing on an inherited disease to their children. Amongst infertile couples, PGD testing enables the identification of chromosomally normal embryos for transfer which improves IVF pregnancy rates. PGD is of great benefit to women with a history of miscarriage, failed IVF cycles and in those of an older maternal age.

Previously, couples carrying the risk for transmitting genetic disorders were only able to diagnose the health of their unborn child after conception had occurred by amniocentesis. Subsequently, if the pregnancy is affected with the abnormality, couples are faced with the dilemma of having to decide whether they would terminate or continue with the pregnancy. For couples who carry the known risk for a serious inherited disorder, PGD offers an alternative to prenatal testing and pregnancy termination by screening embryos (fertilised eggs) before pregnancy is established.

PGD is performed using a high-powered microscope. One or more cells are removed from the embryo and tested for the genetic trait of interest. The unaffected embryos are identified, separated from the affected embryos, and transferred into the uterus.

Egg/Sperm Donation

Women or men with a condition may wish to avoid having a child with their particular condition by asking for a donation of eggs or sperm from a donor woman or man. The resulting child will not be at risk of the relevant condition as they will not be the genetic offspring of the relevant parent.

Content sourced from The Muscular Dystrophy Campaign

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