A miscarriage, also known as spontaneous abortion, is defined as the loss of a pregnancy during the first 23 weeks. Miscarriages are much more common than most people realise. Among women who know they’re pregnant, it’s estimated that about 1 in 8 pregnancies will end in miscarriage. Many more miscarriages occur before a woman is even aware that she has become pregnant. For many women the experience of a miscarriage can be devastating, with subsequent feelings of loss and bereavement which are very real.
In this article we look at the likelihood of miscarriage and subsequent pregnancy loss, and at how you can judge whether this is a one-off event or something you should be concerned about as a potential sign of infertility. We look at miscarriage signs and symptoms, as well as considering what steps can be taken in terms of miscarriage prevention.
Miscarriage symptoms: how can I recognise them?
Many instances of spontaneous abortion occur without any miscarriage signs at all except for the inevitable vaginal bleeding. This can vary from light spotting or brownish discharge to heavy bleeding and bright-red blood or blood clots. In some cases the bleeding can come and go over several days. The bleeding can be followed by cramping and pain in the lower abdomen. Other miscarriage symptoms may include a vaginal discharge of fluid, a discharge of tissue from the vagina, and an absence of the symptoms of pregnancy such as breast tenderness or feeling sick.
However, it is important to remember that light vaginal bleeding is fairly common during the first three months of pregnancy and is not necessarily a sign of miscarriage or an impending loss of pregnancy. If you suspect you are having a miscarriage, you should seek medical advice. A simple test with an ultrasound scan will be able to determine whether this is the case. Very often the pregnancy tissue will pass out naturally in 1 or 2 weeks. In some cases, medication to assist the process may be recommended, or you can choose to have minor surgery to remove it if you don’t want to wait.
What are the best methods of miscarriage prevention?
The majority of miscarriages can’t be prevented, but there are some measures you can take to reduce the risk. These include the long-standing advice which applies to all pregnancies not to smoke, drink alcohol or use drugs. Maintaining a healthy weight before becoming pregnant, minimising your risk of infection especially from diseases known to carry risks such as rubella and eating a healthy diet are also helpful.
Obesity increases your risk of miscarriage, but there is currently no evidence that losing weight during pregnancy, rather than beforehand, is beneficial. For exercise, you should keep up your normal level of exercise unless it’s very strenuous, in which case you should lower the intensity. However if you are not normally active, you should consult your medical adviser before taking up any new exercise regime.
What help is available when miscarriages lead to pregnancy loss?
For most women, a single miscarriage is not an indication of any underlying fertility problem and they can expect to go on to conceive again and have a successful pregnancy. Specialists usually suspect that after a third miscarriage there could be something amiss, and advise further testing. This normally involves testing for chromosomal abnormalities. The main way that these tests can be performed is through Pre-Implantation Genetic Testing (PGT).
This test is used to diagnose genetic and chromosomal alterations in embryos before they are implanted during the in-vitro fertilisation (IVF) process, in order to ensure that children are born free of hereditary diseases. This technique is used in conjunction with IVF treatment with sperm microinjection (ICSI). PGT is recommended for couples with a medical history of repeated miscarriages, those at risk of passing on chromosomal alterations or monogenic diseases and where there are issues with spermatozoa such as cell division abnormality (meiosis). A video about PGT is available in our IVI YouTube channel to help explain the process.
The best-known of the chromosomal diseases that can be screened out with PGT is Down’s Syndrome, but it is not the most common. In the majority of our clinics, the most common diseases in couples who come in for screening are Fragile X syndrome, Huntington’s disease and Muscular Dystrophy. Within PGT testing, there are two different techniques used in different cases.
A large number of patients, either because they have had a series of miscarriages or because they suspect that they might be carrying a chromosomal problem, are candidates for the ARRAYS CGH technique. This test makes it possible to study all 23 pairs of chromosomes in order to rule out any chromosomal abnormalities before implantation takes place.
FISH technique (fluorescence in situ hybridisation)
The FISH technique is recommended for couples who have suffered repeated miscarriages and couples who have not had any success with assisted reproduction due to a male factor anomaly, as well as patients who have an increased risk of passing on chromosomal abnormalities. The method allows the presence of chromosomal anomalies in the spermatozoa to be assessed and the risk of transmission to offspring to be determined. In these cases, chromosomes 13, 18, 21, X and Y are usually analysed, which if abnormal could lead to miscarriages or to chromosomal diseases in any babies born.
Clearly, both of these chromosomal testing techniques can prove invaluable for women and couples who have experienced multiple miscarriages leading to pregnancy loss, and where the cause of the problem is suspected to lie with chromosomal abnormalities.
How are PGT carried out?
These tests can be part of the well-known In Vitro Fertilisation (IVF) process. The purpose of PGT is to analyse pre-embryos in the laboratory following in vitro fertilisation and before they are transferred to the patient’s uterus. A biopsy is performed and the pre-embryos are analysed, allowing specialists to distinguish between sound ones and those which are affected by anomalies. The doctor can therefore transfer only those which are the most promising. The process is as follows:
- In the preliminary phase, genetic characterisation tests are carried out on the potential parents for the diseases to be diagnosed, with the objective of gaining as much information as possible prior to applying PGT.
- The next step involves obtaining the pre-embryos which will undergo diagnosis. They must be generated ‘in vitro’ using assisted reproduction techniques.
- A pre-embryo biopsy is performed on the third day after fertilisation when the pre-embryo has 6–8 cells. This consists of extracting one or two cells from the pre-embryo, without compromising its normal development. The pre-embryos are then put back into the incubator until the results of the diagnosis are known and the possibility of transferring them is assessed.
- Finally, the genetic diagnosis and pre-embryo transfer take place. The biopsy is prepared for analysis and a genetic study is carried out. Using the results of the genetic analysis the medical team decides, jointly with the patients, which pre-embryos will be transferred.
Is PGT always a remedy for recurrent miscarriages?
In the world of assisted reproduction there are no absolute guarantees and it is impossible to be certain before testing that chromosomal problems were originally the cause of repeated miscarriages in any particular case. But over the whole array of assisted reproduction treatments available, results improve all the time. Thanks to the technique of assisted reproduction with PGT, IVI achieved a world first in 2006 with the birth of a baby to a couple in which one partner was a carrier of lymphohistiocytosis.
In 2001, PGT allowed the chain to be broken in chromosomal hereditary diseases carried by 72% of the embryos analysed. As such, thanks to the study of chromosomal abnormalities through the FISH and ARRAYS techniques, around 50% of the embryos transferred resulted in pregnancy and PCR analysis of monogenic diseases led to a 54% pregnancy rate per transfer.
IVI: a record of continually growing success
If you have any concerns about miscarriage prevention or wonder what repeated miscarriage may mean for your future fertility, we would encourage you to browse our website which always has the most up-to-date information on the treatments and techniques available. You can also check the facts and figures relating to our audited clinical results by looking them up for yourself. Our overall result in a nutshell is that IVI is one of the European centres with the best pregnancy rates: 9 out of 10 couples that consult IVI due to problems with infertility and who put their trust in us achieve their goal.
Contact us at IVI
If you feel it’s time to seek help on any issue to do with miscarriage or fertility more widely, do get in touch with us at IVI. You can call us from the UK on 08 000 850 035 or from outside the UK, call +34 960 451 185. We look forward to discussing how we can help.
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