Miscarriage is the unsolicited loss of pregnancy before the foetus reaches viability. It includes all pregnancy losses from the time of conception until 24 weeks of gestation.

Recurrent miscarriage, often referred to as recurrent pregnancy loss or habitual abortion which occurs when a woman has consecutive pregnancy losses.

What is the probability of having repeated miscarriages?

The probability of having a recurrent miscarriage is small, especially in young women. Studies have shown that about 5% of women have two or more consecutive miscarriages and 1%  will have three or more. Recurrent miscarriage risk is higher in women above 35 or who have had previous miscarriages compared to younger women.

It is not all incidences of miscarriage that is reported, because some women may have miscarriages before they even knew they were pregnant without experiencing any sign or symptoms of the miscarriage. In this case, your GP can diagnose a miscarriage by using an ultrasound. Vaginal bleeding, tenderness of the breasts, and the loss of foetal movement or sound are some of the signs women will likely experience when having a miscarriage. Such signs should be reported to your GP or midwife to keep track of the amount of bleeding that occurred.

What causes recurrent miscarriage?

Researches have shown that the majority of recurrent miscarriages results from genetic abnormalities. The age of a woman can contribute to recurrent miscarriages because the risk of miscarriage due to genetic abnormalities increases from 15-20% at age 35 to more than 50% at 40 years old. Apart from genetic abnormalities, other causes of recurrent miscarriages may be anatomic abnormalities or medical conditions.

Genetic abnormalities

Genetic abnormalities occur when an embryo receives an abnormal number of chromosomes during fertilisation. This condition happens by chance and has no medical remedy. It happens when one of the couples develop chromosome translocation, a condition where a piece of chromosome breaks off and re-attaches to a second chromosome.

Anatomic abnormalities

An anatomic abnormality occurs in the septate uterus, in which a wall of tissue divides the uterus into two sections resulting in recurrent miscarriage. It has not been clarified why this causes recurrent miscarriage, but some specialists believe that poor vascularity in the septum stops the growth of the embryo if it’s implanted there. Weakened cervix muscles can also lead to miscarriage because it might not be able to support growing foetus when it reaches a certain weight.

Medical conditions

Various types of medical conditions can lead to an increase in the risk of recurrent miscarriage and they include;

  • Antiphospholipid syndrome (APS) – this is referred to as an autoimmune disorder which takes place when a person’s immune system makes antibodies mistakenly to certain substances that are necessary for blood clotting.
  • Thyroid/hormonal issues – this is a hormonal imbalance that results from an overactive or underactive thyroid. These hormonal imbalances cause a miscarriage because it raises prolactin levels which alter proper development of the uterine lining for implantation and nourishment of embryo.
  • Fibroids and polyps – These are non-cancerous growths that can grow in the uterus and also invades the uterus.
  • Asherman’s syndrome – this is a situation in the uterus where scar tissue is formed and may result in miscarriage.

Diagnosing recurrent miscarriage

To diagnose the cause of recurrent miscarriages, a fertility specialist will need to review the medical history and past pregnancies of the patient. Your GP will recommend a complete physical examination, including a pelvic examination. Your GP may recommend you perform a karyotype to identify and evaluate the size, shape and number of chromosomes if he suspects recurrent miscarriages resulted from a genetic error.

If a uterine problem is suspected to be the cause of recurrent miscarriage, you may be required to perform imaging tests, such as an MRI or an ultrasound. A hysterosalpingogram (HSG) which is an X-ray of the fallopian tubes and uterine cavity or ultrasound will help to show if a woman has a problem with the shape of her uterus. In cases where recurrent miscarriage is caused by immune system such as APS, then blood tests can be suggested to detect the problems.

Treatment for recurrent miscarriage

Treatments for recurrent miscarriage may include medications, surgery or genetic tests to increase the chances of a successful pregnancy. Medical and surgical treatment is the solution to recurrent miscarriage caused by anatomical conditions.

Problems like septate uterus can be fixed with surgery which can also eliminate some fibroids or scar tissue irregularities. Surgical correction is the best treatment choice for anatomical issues since it improves live birth rates.

An autoimmune problem like APS can be treated with blood thinning medications such as aspirin or heparin during pregnancy to reduce the rate of miscarriage, but your GP must be informed so as to reduce the chances of serious bleeding problem.

A chromosomal problem such as translocation may employ genetic counselling in its treatment. In-vitro fertilisation (IVF) may be suggested in couples with translocation after which the embryo is genetically tested using preimplantation genetic diagnosis (PGD) technique before transferring to the uterus.