Making babies: having a family, the HD way
Making babies: HDBuzz's feature article – updated for 2024 – on fertility technologies that can help at-risk people to have HD-free children
For people at risk of Huntington’s disease, having a baby who might inherit HD can make decisions around planning a family extremely difficult. This article explains the options available, and how modern reproductive science can make a difference right now to families touched by HD.
Content warning This article describes issues of fertility, tough choices, and medical procedures including termination of pregnancy.
Not all techniques described here are available everywhere, and in some countries, they can involve major expense. So, if you’re thinking about any of them, we recommend you contact a specialist genetic counsellor for individual advice. The earlier you do, the more options you’ll have.
Introduction
Many people with Huntington’s disease, or at risk of it, would like to know if there are ways to have children without passing the disease on to the next generation. The short answer is yes!
Genetic science and reproductive technologies mean that several choices are available to people who are at-risk of Huntington’s disease, to ensure that future children won’t be at risk of developing HD. This includes people who have had testing and carry a HD gene expansion, but there can also be options for some people who choose not to have a HD genetic test themselves.
First things first: nothing has to change
Although a lot of this article focuses on the options for having HD-free children, it is important to know that having a child without doing any genetic testing is very much an option for parents at risk of the condition.
As every HDBuzz article confirms, scientists are making real progress towards finding treatments for Huntington’s disease. While we cannot guarantee anything or promise a firm timeline, we firmly believe a time will come when at-risk children are born into a world where HD is a treatable condition.
Additionally, there is always a chance that the child won’t inherit HD gene expansion in the first place, and therefore will never develop HD.
Some people may want to guarantee HD-free children, but options may not be available to them, for example based on location, financial support, or religious beliefs.
Having a child at risk of HD is something that can be a point of discussion and debate within the HD community. While people may not agree with the decisions that others make, it is important to remember that everybody has the right to be respected when making their own decisions.
The Huntington Disease Youth Organisation has some resources available to help discuss HD and genetic risk to children in an age-appropriate way:
Some people feel that they don’t want to take any chances and would like to avoid the risk of passing on HD at all. That’s where genetic testing techniques come in. These options are available whether it is you or your partner who is at risk of HD.
What are my genetic testing options?
Thanks to genetic testing. we can identify the risk of HD for a fetusfetus a developing baby in the womb during a pregnancy, or in embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells in the lab.
Testing a fetusfetus a developing baby in the womb during pregnancy is called prenatal testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated.. Testing embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells in the lab is a form of in-vitro fertilisation or IVFIn vitro fertilization A medical procedure where eggs and sperm are combined in the laboratory, then embryos are implanted in the mother's womb., and is called pre-implantation genetic testing or PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb..
If you or your partner have had genetic testing that confirms you carry an HD gene expansion, you would be able to have direct testing during pregnancy or via PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb., to confirm whether or not the pregnancy or embryoembryo the earliest stage during the development of a baby, when it consists of just a few cells has inherited the HD gene expansion.
Some people want HD-free kids without getting the gene test themselves. There are options for this, too! They involve more complicated versions of the same methods. So first we’ll discuss how it works for couples where one partner has already had a positive HD gene test.
Pre-implantation Genetic Testing (PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb.)
Pre-implantation genetic testing is one way of having an HD-free kid without having to consider terminating a pregnancy. It can be a long, challenging and expensive process though.
PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. involves using eggs and sperm to create embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells in a lab, then performing the HD test on the embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells, and putting only the HD-negative embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells into the womb.
The PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. Process
PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. is IVFIn vitro fertilization A medical procedure where eggs and sperm are combined in the laboratory, then embryos are implanted in the mother's womb. with an added step of genetic testing. IVFIn vitro fertilization A medical procedure where eggs and sperm are combined in the laboratory, then embryos are implanted in the mother's womb. is a medical procedure which involves a hormonehormone Chemical messengers, produced by glands and released into the blood, that alter how other parts of the body behave medication to cause the egg provider to produce more eggs than normal. Hormonehormone Chemical messengers, produced by glands and released into the blood, that alter how other parts of the body behave medication can involve injections to deliver the medications into the body.
The eggs are then collected and fertilised using a sperm sample.
The fertilised eggs develop into embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells, which are grown in the laboratory for up to five days until they are a small bundle of cells. One or two cells are removed from each embryoembryo the earliest stage during the development of a baby, when it consists of just a few cells at this stage and sent for genetic testing while the embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells are frozen and stored. Removing cells at this early stage of development doesn’t affect the way the embryoembryo the earliest stage during the development of a baby, when it consists of just a few cells develops.
Any embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells found to be not at risk of developing HD will continue to be stored. Depending on the country you are in, one or two of these risk-free embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells are then transferred to the womb.
About two weeks after the embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells are transferred, a pregnancy test is run on a blood sample. If the transfer has been successful, pregnancy then carries on like normal.
The downside of PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb.
The process of stimulating egg release, collecting eggs, fertilising them outside the body and returning embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells to the womb – is always a time-consuming and exhausting process. It can also be dangerous, carrying risks of the person becoming unwell.
Various things can go wrong, like not enough eggs or embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells being produced. There’s also more chance of having twins with PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb., which is harder work and riskier.
On top of the risks of the procedure, things can go wrong with the genetic bit of PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb.. Embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells can be damaged when cells are removed, and sometimes the HD test doesn’t work because there isn’t enough DNA. Bad luck can mean that all the embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells have the HD mutation.
Image credit: @gcnotes
In the end, sometimes only one embryoembryo the earliest stage during the development of a baby, when it consists of just a few cells is available for implantation – and sometimes none at all. To top it off, a pregnancy can fail after implantation. Overall, each attempt at PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. gives a 20-30% chance of an HD-free pregnancy. This success rate varies per PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. centre and is dependent on a number of factors.
Women under the age of 35 have the highest success rates – another reason to think ahead about fertility. Unfortunately, the chances of success over the age of 40 are small.
How much does PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. cost?
PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. is expensive. The cost is somewhere in the region of US $20,000 (£15,000 or €18,000) for each attempt.
Health insurance usually doesn’t cover the cost of PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb./PGDPre-implantation genetic diagnosis A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the mother's womb.. In some countries the public health care system will fund some PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. attempts – for instance, three attempts in the UK – but even this can vary within individual countries, and may be limited to couples with no existing children.
Any additional embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells that are not at risk of HD may be stored. However, this also comes with a cost that varies depending on the length of storage.
If this is an option you are considering, we recommend contacting your local genetic service to have a discussion regarding eligibility, referral, and associated costs.
Testing during Pregnancy
It is possible to perform a genetic test during pregnancy to see whether the developing baby (fetusfetus a developing baby in the womb) carries the gene expansion that causes HD. This is called prenatal testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated..
Deciding whether to test a fetusfetus a developing baby in the womb is a difficult decision. It is important to understand that prenatal testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated. in HD is only performed on the understanding that if the result showed that the fetusfetus a developing baby in the womb carries the HD gene expansion, the pregnancy will be terminated. This is an immensely challenging and personal choice.
It’s important to think carefully about prenatal testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated. for HD, and how you feel about pregnancy termination, in advance of getting pregnant.
Once pregnant, there is very little time to absorb the information about the prenatal test and make these important decisions, as the testing has to be carried out early during a pregnancy.
Testing a pregnancy, but not going ahead with a termination after a positive test result, would take away the child’s right to choose whether to have the genetic test, later in life. After all, most people at risk of HD choose not to have the test before they develop symptoms. We know that big problems can occur when a child is identified, from birth, as someone who will develop HD.
In addition, most testing in pregnancy can only be done if tests have been carried out on the couple or other family members beforehand. Often, there is not enough time to do this background work when a pregnancy has already started.
Invasive Prenatal Testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated.
Most commonly and reliably, a procedure called chorionic villus samplingchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. or CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. is performed during early pregnancy to test the fetusfetus a developing baby in the womb. CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. involves collecting a small sample of the placentaplacenta the 'afterbirth', which supplies the fetus with oxygen and nutrients via the umbilical cord. The placenta's DNA is the same as the fetus's. which represents the DNA in the fetusfetus a developing baby in the womb.
CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. is a quick procedure in the outpatient clinic, and in some countries, it is done under local anaesthetic. Depending on where the placentaplacenta the 'afterbirth', which supplies the fetus with oxygen and nutrients via the umbilical cord. The placenta's DNA is the same as the fetus's. is attached to the wall of the uterusuterus womb, a very fine needle is passed either through the cervixcervix the neck of the uterus (womb) or through the skin of the abdomen, using an ultrasound scanner to guide it. A small sample of cells is then collected from the placentaplacenta the 'afterbirth', which supplies the fetus with oxygen and nutrients via the umbilical cord. The placenta's DNA is the same as the fetus's..
These cells can be used to test for the HD gene expansion. Some genetic centres will also offer testing for three common chromosome syndromes as part of the CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. genetic test.
CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. is usually carried out between 11 and 12 weeks into a pregnancy but no later than 15 weeks. An early dating scan is often required prior to a CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. taking place.
The main complication of this procedure is a small risk of miscarriage. Each centre will have specific information on the risk of miscarriage following a CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta.. Please contact your local centre if you wish to learn more.
An amniocentesis is another type of invasive prenatal testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated. technique, similar to a CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta., but takes a sample of amniotic fluid rather than placentaplacenta the 'afterbirth', which supplies the fetus with oxygen and nutrients via the umbilical cord. The placenta's DNA is the same as the fetus's.. This can be carried out from 16 weeks. This therefore provides a result at a much later gestation and can make decisions around termination of pregnancy even more challenging.
If the genetic test is positive, a termination can usually be carried out under general anaesthetic until about 12-13 weeks depending on the country’s laws. Unfortunately, there can sometimes be a waiting list for this procedure.
In some countries termination of pregnancy may be carried out later on by inducing labour; however the availability of this option is again dependent on the country’s laws.
What if I don’t want to get the gene test myself?
There are ways to have HD-free kids without the at-risk partner getting tested themselves.
They use the same basic methods we’ve described – prenatal testingprenatal testing A technique for preventing HD from being passed to children. A DNA sample is taken during pregnancy and tested genetically. If the HD mutation is found, the pregnancy is terminated. or PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. – with a genetic twist to identify ‘high risk’ pregnancies or embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells without revealing the HD gene status of the at-risk partner.
The twist is a couple of methods called exclusion testingexclusion testing an optional add-on to prenatal testing, where DNA from parents and grandparents is compared with the DNA of the embryo or fetus. Exclusion testing means that the at-risk parent doesn't have to have an HD genetic test to have HD-free children. or non-disclosureNon-disclosure an optional add-on to PGD, where an HD genetic test is performed on an at-risk parent but the result is kept secret. Non-disclosure PGD enables HD-free embryos to be implanted without the at-risk parent having to learn their HD status. testing. These involve more preparation and planning, and there are some situations where it isn’t possible, so if this sounds like the right option for you: get expert advice early.
How does exclusion testingexclusion testing an optional add-on to prenatal testing, where DNA from parents and grandparents is compared with the DNA of the embryo or fetus. Exclusion testing means that the at-risk parent doesn't have to have an HD genetic test to have HD-free children. work?
Exclusion testingexclusion testing an optional add-on to prenatal testing, where DNA from parents and grandparents is compared with the DNA of the embryo or fetus. Exclusion testing means that the at-risk parent doesn't have to have an HD genetic test to have HD-free children. involves at least three blood samples. One each from the couple wanting to extend their family and ideally one each from both the mother and father of the person at-risk of developing HD. This technique may sometimes not be an option without a blood sample from the parent affected with HD.
We know that each of us will inherit one copy of the HD gene from each parent. The affected grandparent will have one normal copy of the HD gene and one expanded copy of the HD gene. We can label these genes ‘AA’. We do not know which one of these has been passed onto their adult child – and that person does not want to get tested to find out.
Image credit: @gcnotes
The unaffected grandparent will have two normal copies of the HD gene. We can call these ‘BB’.
The adult at risk will have some combination of A and B, with the A gene having a 50% chance of carrying the mutation.
If they wish to have a family without having genetic testing to determine their own risk, we can use exclusion testingexclusion testing an optional add-on to prenatal testing, where DNA from parents and grandparents is compared with the DNA of the embryo or fetus. Exclusion testing means that the at-risk parent doesn't have to have an HD genetic test to have HD-free children. during a prenatal test or PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. to identify if the fetusfetus a developing baby in the womb or embryoembryo the earliest stage during the development of a baby, when it consists of just a few cells has inherited an A-gene from the affected grandparent, or a B-gene from the unaffected grandparent. This tells us whether the pregnancy would be high-risk or low-risk.
Crucially, exclusion testingexclusion testing an optional add-on to prenatal testing, where DNA from parents and grandparents is compared with the DNA of the embryo or fetus. Exclusion testing means that the at-risk parent doesn't have to have an HD genetic test to have HD-free children. identifies the grandparent of origin, without telling us whether the expanded HD gene has been inherited. If we found out the answer to that, it could tell us the results of the at-risk parent – which is what we are trying to avoid!
The flip side of this is that some high-risk embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells don’t carry an HD mutation, which would mean potentially ending a pregnancy or discarding embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells that may not have been at risk of HD in the first place.
Non-disclosureNon-disclosure an optional add-on to PGD, where an HD genetic test is performed on an at-risk parent but the result is kept secret. Non-disclosure PGD enables HD-free embryos to be implanted without the at-risk parent having to learn their HD status. PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb.
Non-disclosureNon-disclosure an optional add-on to PGD, where an HD genetic test is performed on an at-risk parent but the result is kept secret. Non-disclosure PGD enables HD-free embryos to be implanted without the at-risk parent having to learn their HD status. is a twist on PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. that enables at-risk people to have HD-free children without finding out their own genetic status. This option is not available in every country, so it is important to contact your local genetic service to know if this is an option that is available in your area.
If an at-risk couple opt for non-disclosureNon-disclosure an optional add-on to PGD, where an HD genetic test is performed on an at-risk parent but the result is kept secret. Non-disclosure PGD enables HD-free embryos to be implanted without the at-risk parent having to learn their HD status. PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb., the blood sample of the at-risk person would be tested for the HD mutation. The at-risk person would not be told the result of this test, and neither would any of the healthcare professionals that the at-risk person meets – only the professionals at the fertility lab would know the result.
The PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb. then begins, with egg collection and generation of embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells. If the at-risk person’s ‘secret’ test result showed they had a HD gene expansion, the embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells are the tested for HD, and only those without the HD gene expansion are transferred for a potential pregnancy.
The couple isn’t told how many eggs are harvested, how many are successfully fertilised, or how many embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells are implanted. If there are no embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells without a HD gene expansion, the cycle stops there, and the couple are told that the fertilisation failed, but not why.
IVFIn vitro fertilization A medical procedure where eggs and sperm are combined in the laboratory, then embryos are implanted in the mother's womb. can fail for many reasons, so a failure to get pregnant can’t be interpreted to mean the at-risk person has the HD gene.
Other options
One way to have HD-free kids is to use donor eggs or sperm instead of those of the at-risk person. Deciding to have a child with the help of a donor is a difficult decision but avoids the need to consider termination of a pregnancy. It can be done for people who’ve had a predictive test showing they carry an HD gene expansion, as well as those at risk who don’t want to be tested themselves.
Like all choices, this is complicated. The child won’t be genetically related to the at-risk parent, and careful thought will need to be given to how and when to share the information with the child. A parent doesn’t need to be genetically related to their child in order to fulfil a complete and loving parental role. There is plenty of support available to people who decide to go down this route, and this can be discussed before deciding to embark on the process.
Many couples think about adopting children. In many places, couples with one partner at risk of HD may have difficulty adopting a child. This is due to the disease being in the family and the adoption agency have to ensure the child has a stable home to go to. However, each case is individually assessed, so it is worth looking into adoption as an option. If you have been turned down for adoption, at-risk couples may be able to be foster carers for children as this is often a short-term option, caring for children over weeks or months at a time. The time you spend with foster children while short, can still often have a positive impact on the child’s life.
Future Directions
Non-invasive Prenatal DiagnosisNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. is a newer way of testing in pregnancy without doing an invasive test, and so avoiding the small risk of miscarriage. Instead of an invasive test that takes a sample from the placentaplacenta the 'afterbirth', which supplies the fetus with oxygen and nutrients via the umbilical cord. The placenta's DNA is the same as the fetus's. or amniotic fluid, NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. takes a blood sample from the parent carrying the pregnancy. This test looks for tiny bits of DNA from the fetusfetus a developing baby in the womb that float around in the parents’ blood.
NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. can take place from around 10 weeks of pregnancy. NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. usually involves some workup by the lab in advance of a pregnancy. It requires samples from the couple looking to extend their family and may require a sample from an affected relative.
NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. is already available in the clinic for some inherited disorders and is in development for HD but not currently widely available. There are a number of instances where NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. would not be appropriate, for example during twin pregnancies. If and when NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD. for HD is available, it is likely that a result indicating a pregnancy is at risk of HD may still be followed up with an invasive test to confirm the test results, before booking a termination.
What about LGBTQIA+ people?
All the options discussed above are likely to be available for LGBTQIA+ couples, with a family history of HD, that are looking to start a family. There would be the additional step of finding a sperm or egg donor as well as a surrogate, if necessary, which will come with its own additional cost and legal paperwork.
In many countries being LGBTQIA+ is unlikely to prevent you from accessing the family planning option that’s right for you and your partner. There will be specific information for the family planning techniques available in your country for LGBTQIA+ couples that wish to have a family.
Summary
There are a number of options available to people at risk of HD who wish to start a family.
Not everyone chooses to go through genetic testing to start a family, and this is a completely valid option.
For those who wish to remove the risk of their child inheriting HD, they may not need to know their own risk for HD. Direct testing can take place when we know the result of the at-risk parent and they are shown to have the HD gene expansion. Whereas exclusion or non-disclosureNon-disclosure an optional add-on to PGD, where an HD genetic test is performed on an at-risk parent but the result is kept secret. Non-disclosure PGD enables HD-free embryos to be implanted without the at-risk parent having to learn their HD status. testing can be carried out for at-risk couples who do not wish to find out their own test results.
Direct and non-disclosureNon-disclosure an optional add-on to PGD, where an HD genetic test is performed on an at-risk parent but the result is kept secret. Non-disclosure PGD enables HD-free embryos to be implanted without the at-risk parent having to learn their HD status. testing can take place during pre-implantation genetic testing (PGTPreimplantation genetic testing or PGT A technique for preventing HD from being passed to children. Eggs and sperm are combined in a laboratory, and the embryos are tested genetically for the mutation. Only embryos without it are implanted into the womb.) where embryosembryo the earliest stage during the development of a baby, when it consists of just a few cells are created in the lab and tested for their risk of developing HD, or a fetusfetus a developing baby in the womb can be tested during pregnancy. Testing in pregnancy can be invasive via chorionic villus samplingchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta. (CVSchorionic villus sampling A medical procedure used to get a sample of DNA from a developing baby during pregnancy. A needle passed through the skin of the abdomen, or through the cervix, is used to collect tissue from the placenta.) or non-invasive (NIPDNon-invasive prenatal diagnosis A technique for preventing HD from being passed to children. A blood sample from the mother is taken, and DNA from the fetus is found in the blood and genetically tested for the risk of HD.), but both of these are only options for those who would consider ending a pregnancy at risk of developing HD.
There are other options available for at-risk couples that include using donor eggs/sperm or adoption/fostering of children.
Expert advice, in the form of genetic counselling, will help you understand the exact options available to you locally and help explore which option feels right for you. Your country’s HD Association can tell you how to get in touch with a genetic counsellor. As with so many things in life, forward planning and understanding all the options in advance is key.
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