Recurrent Pregnancy Loss: Understand its Causes

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MH speaks to the experts on why it happens and what can be done to reduce its risk. 



Miscarriage. It is the one thing that every pregnant mother out there definitely doesn’t want to go through at any time during her pregnancy. It is extremely heartbreaking when a mother finds out that she has lost her baby; it is even more heart-wrenching when it happens more than once – an occurrence known as recurrent pregnancy loss.

More specifically, recurrent pregnancy loss refers to “two or more consecutive pregnancy losses/miscarriages”, according to Associate Professor Tan Thiam Chye, head and senior consultant of the Department of Obstetrics and Gynaecology, KK Women’s and Children’s Hospital.



Unfortunately, in up to 50 per cent of recurrent pregnancy loss cases, there is no explainable cause for the loss, says Dr Chua Yang, obstetrician and gynaecologist at A Clinic For Women, Mount Alvernia Medical Centre.


In other cases of recurrent pregnancy loss, Dr Chua Yang says that there are a few possible causes including:


Autoimmune causes – which make up 20 per cent of recurrent pregnancy loss cases – such as antiphospholipid antibody syndrome (APS). APS is an autoimmune disorder whereby the immune system produces antibodies that mistakenly attack healthy tissues, resulting in blood clots. The blood clots then cause the foetus to receive insufficient nutrients for its development, hence resulting in a miscarriage.


Endocrine or hormonal factors cause up to 20 per cent of recurrent pregnancy loss cases. “Women with pre-existing hormonal imbalance, like luteal phase defects or polycystic ovary disease, may be at higher risks for pregnancy loss,” says Dr Chua Yang.


Luteal phase defects refer to a medical condition that disrupts a woman’s menstrual cycle. The luteal phase is a part of the menstrual cycle in which the uterus lining will thicken, in preparation for a potential pregnancy. However, if a woman has a luteal phase defect, this lining doesn’t develop correctly, which makes it hard for her to conceive or carry the baby to term.



Women with polycystic ovary disease typically have irregular menstruation,

an excess amount of the male hormone, androgen, and/or ovaries that may develop

small sacs of fluid – known as follicles – that are unable to release eggs frequently.



Apart from hormonal disorders, there are other pre-existing medical issues that may increase the risk of recurrent pregnancy loss as well. “Diabetics and women with hyperprolactinemia or thyroid disorders are similarly at risk. It is important to control these pre-existing conditions before trying for pregnancy,” says Dr Chua Yang.


In hyperprolactinemia, the non-pregnant woman has higher-than-normal levels of prolactin – a hormone produced by the pituitary gland that is usually present in low levels. Women who have hyperprolactinemia prior to pregnancy may experience fertility problems.


Anatomical factors, such as congenital uterine anomalies, or fibroids and polyps, make up 10 per cent of cases and are usually detected during ultrasound scans.


Congenital uterine anomalies refer to defects of the woman’s uterus during its development in the embryonic stage. According to Columbia University Medical Center, these anomalies “occur in less than 5 per cent of all women, but have been noted in up to 25 per cent of women who have had miscarriages and/or deliveries of premature babies”.


Fibroids are growths that develop in the uterus. These growths are made up of muscle cells and fibrous tissue, and they vary in size.



The presence of fibroids during pregnancy can sometimes result in complications such as

labour difficulties, and in rare cases, miscarriage.



Polyps are also growths that develop in the uterus, but unlike fibroids, polyps grow on the uterus lining. Large polyps may result in fertility problems as well as increase the risk of miscarriage.


Genetic factors, such as chromosomal abnormalities, and infections, may also cause recurrent pregnancy loss.


Besides the above causes, there are certain factors that may increase the risk of recurrent pregnancy loss, as listed below by A/Prof Tan:

  • Progesterone hormone deficiency
  • Womb anomalies
  • Uncontrolled diabetes or thyroid problems
  • Obesity


It’s Not Your Fault

When mothers experience one or multiple miscarriages, it is not unusual for them to blame themselves for the loss of their baby. Some may wonder what they did wrong during their pregnancy, or if they could have done something to prevent the miscarriage from happening.

However, it is important for parents to know that they are not at fault for the loss of their baby. As A/Prof Tan explains, “The pregnancy that miscarries is probably abnormal from the beginning. At the time of conception, the baby receives half the genes from the sperm and half from the egg. For unknown reasons, at this crucial time of the baby’s development, some of the genetic information is lost. This results in genetic anomalies and eventually results in a miscarriage.”

“What is certain is that a miscarriage does not result from eating specific foods, exercise or sexual intercourse. In short, a miscarriage does not occur as a direct result of something you or your partner has done during the pregnancy,” he adds. 



Thanks for sharing!