An Overview of the Possible Reasons For Miscarriage

By December 6, 2017Obstetrics

The loss of a child during a pregnancy can be an overwhelming and very upsetting experience. Most of the time, miscarriage occurs for reasons outside your control and your obstetrician will likely tell you nothing could have been done to prevent it.
reasons for miscarriage

The loss of a child during a pregnancy can be an overwhelming experience. Here we take a look at the possible reasons for miscarriage. If you have any further questions, please don’t hesitate to get in touch.

However, if you’ve had a miscarriage, chances are you want to know what caused it, and what you can do to prevent it from happening again. The same goes if you are looking to get pregnant, or if you have just fallen pregnant. Let’s take a look at some of the possible reasons for miscarriage.

What Is A Miscarriage and How Common Is It?

A miscarriage is the loss of a fetus before the 20th week of pregnancy. These early miscarriages are, sadly, very common. Up to 20 percent of confirmed pregnancies end in miscarriage before 20 weeks. An even greater number end in miscarriage before women even realise they are pregnant.

The loss of a baby after 20 weeks is called a late pregnancy loss, or stillbirth, and is less common. Fortunately, most miscarriages are a one-time occurrence; most women who have had a miscarriage once will have a healthy pregnancies in the future.

Possible Reasons For Miscarriage

Early pregnancy loss usually occurs because the embryo is not developing as it should. The reason behind these miscarriages is usually a chromosomal abnormality that is entirely unrelated to the mother. There are myriad other reasons a miscarriage may occur. These include:

Chromosomal Abnormalities

Chromosomal abnormalities in the mother or father account for a large percentage of miscarriages. To develop properly, a fetus requires the right number of chromosomes; 23 pairs, one set from the mother and one set from the father. Disruptions to a chromosome’s structure, or an abnormal number of chromosomes, may cause genetic development to cease, resulting in a miscarriage.

Uterine Abnormalities

An abnormal uterine environment, such as an divided uterus or abnormally shaped uterus, may result in a miscarriage. This is usually because the embryo can’t implant properly, or can’t receive the nutrients it needs to survive.

Uterine conditions such as fibroids may also cause a miscarriage. The good news is that many uterine abnormalities are treatable, and after diagnosis and surgery, the chances of a healthy pregnancy increase significantly.

Thyroid Disorders

Thyroid disorders can cause both problems with fertility, and be the reason behind a miscarriage. For example, low thyroid function may result in the production of hormones that can actually suppress ovulation. High thyroid function, on the other hand, can result in the production of hormones than can interfere with oestrogen function, which is crucial during pregnancy.

Lifestyle Factors

There are a number of lifestyle factors that can lead to miscarriage at any time during a pregnancy. These include drinking alcohol, smoking, and taking recreational drugs. Each have their own detrimental effects on a pregnancy, and should all be cut out of the lifestyle of any woman who is pregnant or looking to get pregnant.

For example, nicotine from cigarette smoke interferes with the placenta, blood, oxygen and nutrient supply, and, in turn, fetal growth. Smoking during pregnancy doubles the chance of miscarriage.


Pregnant women who suffer from diabetes are more likely to have a miscarriage due to poorly controlled blood glucose levels. However, a healthy pregnancy is very likely with planning, multidisciplinary care and meticulous control of blood glucose levels.

You may have heard of gestational diabetes too, which is a condition that develops during pregnancy, and usually goes away after the baby is born. You can read about it here.


There are a number of infections that can result in complications during pregnancy. Two of the most common are mycoplasma and ureaplasma infections, which result in inflammation of the endometrium (the lining of the uterus), making it inhospitable for the growth of an embryo. Other infections that can lead to miscarriage include STIs like gonorrhea, and chlamydia, as well as diseases like mumps, rubella, measles, cytomegalovirus, and parvovirus.

We understand that a miscarriage can be devastating. If you have any questions regarding issues with a pregnancy, and would like to book an appointment, please don’t hesitate to get in touch.

We will strive to give you guidance and compassionate care in every way possible. Dr Bevan Brown is one of the most trusted gynaecologists and obstetricians in the Hills District.