Knowing that miscarriage is common, occurring in one in four pregnancies, doesn’t make the loss any less heartbreaking. Couples understandably want to find out why it occurs and what can be done to prevent the risk of it happening again.
Many women who have experienced a miscarriage will go on to have a healthy baby. Sadly, about 2% of women trying to conceive will experience more than one pregnancy loss.
Following three consecutive miscarriages in the first trimester, it is recognised that there may be a specific or recurring cause of a woman’s pregnancy loss. However, in many couples, no reason can be found.
In this article, we look at some of the potential causes, plus the care and support that is available to women experiencing recurrent first trimester pregnancy loss.
Causes of recurrent first trimester pregnancy loss
According to IVF Australia, some of the causes of miscarriage include:
- Random chromosome variations
- Genetic variations
- Parental chromosome variations
- Uterine variations
- Immune causes
- Blood clotting disorders
- Other medical conditions
- Hormone imbalances
- Age is also an important factor. After a woman has turned 43, there is a 50% chance a pregnancy will spontaneously miscarry.
One of the most common reasons miscarriages occur is chromosomal variations in the embryo.
Up to 70% of embryos are lost, usually within the first 3 months of pregnancy, but most often before implantation. This can be a result of the cells of the embryo containing the wrong number of chromosomes, or sometimes pieces of chromosomes break off and attach to the ends of other chromosomes.
In some cases, these genetic abnormalities occur randomly, but for 2-5% of couples, one of the partners carries a chromosomal abnormality.
Care and support for couples experiencing recurrent miscarriage
Firstly, couples will need to speak to their GP, who will likely refer them to a fertility specialist for investigative testing. An in-depth history will be taken from both partners, followed by some tests, and then a management plan once the results are reviewed. Below is a list of what is generally tested during investigations (from The Pink Elephants):
- Male and female karyotype
- AMH, LH, FSH, oestradiol
- TSH Prolactin, Testosterone
- Full Blood Count
- Cardiolipin antibodies, Lupus anticoagulant
- Protein C, Protein S, antithrombin III
- Factor V Leiden
- Prothrombin gene mutation
- MTHFR mutation
- Fasting glucose, insulin, homocysteine
- Thyroid antibodies
- Peripheral blood activated natural killer cells
- Uterine natural killer cells and other endometrial pathology
- Pelvic ultrasound scan
- Hysteroscopy (and sometimes laparoscopy)
- Semen analysis and sperm DNA fragmentation
- Causes of Recurrent Pregnancy Loss
Treatment for recurrent pregnancy loss
If a chromosomal abnormality is detected, the couple can proceed to IVF, or they may choose to conceive naturally, but undertake chorionic villus sampling (CVS) testing in any future pregnancy. CVS is a pregnancy test that checks the baby for genetic or biochemical abnormalities, in which a small sample of the placenta (which is made up of the same cells as the baby) is taken to be tested.
If an anatomical cause of pregnancy loss is detected, such as uterine fibroids or a septate uterus (when the uterus is divided into two parts by a membrane), surgical treatment could be an option to improve pregnancy outcomes.
If endocrinological investigations reveal that thyroid function, PCOS, or glucose metabolism, for some examples, are contributing to pregnancy losses, there are often treatments that can be beneficial.
Finally, there are the unexplained causes, which makes up about 50-75% of cases of recurrent pregnancy loss. This can be incredibly difficult on couples, so specialist treatment and advice will be recommended, along with counselling.
The good news is that most women (over 70%) who experience recurrent miscarriages are still able to have successful pregnancies. Unfortunately, for women over 38, the chance of pregnancy is lower.
Going through recurrent miscarriage can be isolating, and emotionally and physically traumatising. Please seek support from any of the following organisations: