Miscarriage refers to the loss of a pregnancy. Most miscarriages occur at a very early stage of pregnancy, before 12 weeks gestation. Miscarriages after the end of the first trimester of pregnancy (second trimester miscarriages) are known as late miscarriages. If a baby is lost after 20 weeks of pregnancy, this is considered a still birth.
Why does miscarriage happen?
Miscarriages are very common. For the most part, there is nothing that can be done to prevent most miscarriages and nothing that a woman has done to provoke a miscarriage.
Miscarriages happen for a variety of reasons but in over 50% of cases there is a chromosomal (DNA) error in the embryo or baby. This kind of problem happens during the DNA exchange in cell divisions that occur in the egg and early cells of the embryo and is called aneuploidy. Aneuploidy mistakes happen much more frequently as a woman gets older, due to the oocyte (egg) aging process. However, aneuploidy mistakes can happen at any age.
Miscarriages also occur when embryos and babies with normal DNA make structural mistakes during early development. They have the right DNA instructions, but serious mistakes can still be made as the baby tries to carry out those instructions. There is nothing a mother can do to prevent this kind of miscarriage, except ensuring her good nutrition and folate supplementation so that all the right building blocks are there.
What is recurrent miscarriage?
Recurrent miscarriage is a medical term used when more than three miscarriages occur in a row consecutively, or if two babies are lost after the point where a baby’s heart beat has been seen on ultrasound. In these cases, rare medical causes of miscarriage need to be fully investigated and review by a CREI specialist is encouraged.
How many women suffer recurrent miscarriages?
Less than 10% of women suffer from recurrent miscarriages based on the formal definition. However, most women who have had babies have also had miscarriages and it is not common over time to suffer more than one miscarriage during a woman’s reproductive years. However, it is unusual to suffer three consecutive miscarriages. If this has happened to you, it is more than reasonable to seek professional help.
I have had two consecutive miscarriages. Should I be investigated for factors causing multiple miscarriages?
While women in this circumstance, having had two consecutive early miscarriages, do not meet the formal criteria for “recurrent miscarriage”, it is more than reasonable to seek help and undergo formal testing:
- If you are stressed
- If you have suffered delay to natural conception
- If you have suffered infertility and needed medical help to conceive (e.g. IVF or other assisted reproductive treatment)
- If you fit the category of advanced maternal age, being over the age of 35 years
What factors can cause recurrent miscarriages?
Medical problems responsible for recurrent miscarriages include:
- Anatomical problems such and uterine fibroids and other structural abnormalities of the uterus such as a uterine septum.
- Autoimmune problems causing poor placental function. This can include blood clotting disorders such as the Anti-Phospholipid Syndrome. Other autoimmune conditions such as thyroid disorders (Hashimoto’s thyroiditis and Grave’s disease) have been associated with an increased risk of miscarriage.
- Folate methylation disorders and women carrying MTHFR mutations may be at increased risk of miscarriage without adequate folate supplementation.
- It has been hypothesised that Natural Killer Cell prevalence in the endometrium and peripherally may be a marker of other autoimmune dysfunction in women who suffer recurrent pregnancy losses that has yet to be further characterised.
- Genetic problems including Karyotype imbalances causing chromosome rearrangements. This problem can arise from egg or sperm – both male and female partners require testing for this cause of recurrent pregnancy loss.
- Sperm DNA fragmentation: poor quality sperm and older fathers are more likely to be associated with miscarriages.
- Advanced maternal age: spontaneous chromosome problems occur in 9 out of 10 eggs if a woman is aged over 40 years, a very common cause of recurrent miscarriages. IVF with genetic testing of embryos can be very helpful to some women facing this problem.
- Diabetes control: unrecognised or poorly managed diabetes is a serious cause of recurrent miscarriages.
- Hormonal imbalances: thyroid problems causing both under and overactive states (Hyper or hypothyroidism) and low progesterone levels in cases of luteal phase deficiency can be associated with recurrent miscarriages.
- Lifestyle factors: Women and men who smoke and report illicit drug use are more likely to suffer miscarriages.
The impact of miscarriages:
To a woman and her partner, miscarriage is devastating. This is especially true when it happens again and again. It is normal to have feelings of hopelessness and despair.
Furthermore, anxiety cannot help but carry over into future pregnancies. The hormonal changes that occur with a pregnancy starting and ending contribute to the emotional toll that a woman suffers with miscarriage.
In our society, it is not unusual to keep early pregnancies a secret. This can enhance the feelings of grief, sadness and loneliness couples feel, as they feel they cannot share their experience with their usual support networks. Accessing professional support through counselling can be really helpful in this circumstance.
Miscarriage: who is at risk?
Every woman who tries to conceive is at risk of suffering miscarriages. Miscarriages are very common, affecting at least 20% of women who recognise an early pregnancy.
The statistics are even higher for embryo transfer at the blastocyst stage where at best 50% of embryos will implant while the remaining embryos will fail. These statistics for early pregnancy loss in both IVF and naturally conceived pregnancies increase dramatically as a woman ages. What are the signs and symptoms of recurrent miscarriage? At age 43 years, more than 90% of pregnancies will miscarry due to spontaneous genetic problems that a woman cannot control. However, only 1% of over all aged <35 years will suffer three consecutive miscarriages. In this group of women and male partners, a medical underlying cause for recurrent miscarriages is much more likely to be found.
What is meant by the term “threatened miscarriage”?
Threatened miscarriage is a term used to describe bleeding in early pregnancy that may or may not lead to a miscarriage. Bleeding in early pregnancy occurs quite commonly and thankfully does not always lead to miscarriage. It is important to seek immediate help when this happens. If you have a Rhesus factor negative blood group, getting in touch with your doctor is especially important any time that you experience bleeding during a pregnancy. You will need to have an Anti-D injection every time this happens and also any time that a miscarriage happens.
How is a miscarriage diagnosed?
Some miscarriages present with bleeding. Other cases present with “missed miscarriage” where the fact that the baby has died is diagnosed by an ultrasound. Sometimes serial ultrasound assessments over a few days are needed to know for sure that a pregnancy loss has occurred. In this circumstance, your doctor would like to be absolutely sure that there is no chance the pregnancy could be viable before offering you choices to bring on or end the miscarriage.
How is recurrent miscarriage diagnosed?
To diagnose the underlying causes behind recurrent miscarriages, you may be referred to see a CREI fertility specialist. Both you and your partner will need to attend investigations including karyotype analysis. Preconception genetic screening of parents for rare recessive conditions may also be recommended.
Advanced uterine imaging or hysteroscopy will be arranged to evaluate the structure of your uterus and to identify anatomical concerns that may contribute to your miscarriages. Further tests may be recommended at the time of miscarriage, including karyotype analysis of your baby. Autoimmune disease screening can involve a wide variety of blood tests. A hormonal and metabolic assessment will also be conducted via blood tests.
If you are aged over 35 years, and no other cause of recurrent miscarriages is suspected after thorough testing, embryonic aneuploidy (spontaneous age related DNA problems arising in your embryos) may be to blame for recurrent miscarriages. In this circumstance, IVF and preconception genetic screening of embryos, testing for aneuploidy (technology known as PGT-A, formally called PGD) can be very helpful and may be recommended to help you achieve an ongoing pregnancy. A strategy of “euploid” or genetically normal embryo banking can be used to help you and your partner to build your family further over time.
Will I ever be able to have a baby?
Some couples have just been unlucky and even after suffering three consecutive miscarriages may go on to conceive naturally and carry a healthy baby to full term without medical help.
Other couples may never be able to have a baby without some form of help. Effective treatment of recurrent miscarriages requires individualisation of care. Your doctor will do their best to recognise and exclude important underlying factors, each of which may have a larger or smaller part to play in reducing your risk of having future miscarriages.
In 50% of couples who have suffered recurrent miscarriages, no sure single reason can be determined. In these couples, IVF and PGT-A will be able to help in the majority of occasions. In some patients, immune and anticoagulant treatments may be of assistance, as can progesterone support. It is important that any treatment is targeted to underlying concerns that affect you. In some couples, egg, sperm or embryo donation may represent further options to build their families.
At Women’s Health Melbourne, we work in a holistic team. You can make an appointment to see Dr Raelia to investigate causes of miscarriage. You can also see Georgia to help you with emotional support and to address any diet and lifestyle factors that may help you to achieve a healthy pregnancy. You can also see Wendy our clinical dietician to address any nutritional deficiencies that may have arisen because of blood loss suffered from multiple miscarriages and to address lifestyle factors like blood sugar control that may contribute to miscarriage risk in patients with PCOS and diabetes. An anti-inflammatory diet may be a very relevant intervention for women and men diagnosed with coeliac disease, thyroid concerns, antiphospholipid syndrome and any other autoimmune conditions associated with miscarriages.
We are here to support you and to help build your family. Reach out if our message resonates and you need help.