A miscarriage is something that happens more often than we would all like to see. It is incredibly difficult to let go and move on after a miscarriage. And for many couples, their most dreaded question is: “Why do miscarriages happen, and am I at high risk for it?”

In this blog, we will be talking about the different types of miscarriages, why they may occur, and the risk factors of miscarriages.

What are miscarriages and recurrent miscarriages?

Miscarriage is the term used to describe a spontaneous pregnancy loss. It is estimated to occur in 10-20% of all pregnancies, 80% of which is during the first trimester.

If a woman has two or more miscarriages, she is said to experience recurrent miscarriages, a condition that occurs thankfully, in only 1% of population.

Types of miscarriages

Blighted ovum miscarriages

This is a type of miscarriage that happens early in the pregnancy. The baby’s supporting materials, sac and placenta, grow whereas the baby does not. Since a blighted ovum still produces hormones, it will show up as a positive pregnancy test.

Usually during 7 to 12 weeks of pregnancy, the woman’s body will realise that the pregnancy is not progressing normally. This is when the uterus sheds blood and makes it more obvious to the woman that she has had a miscarriage.

When this happens, you can choose to allow the natural miscarriage to finish its course in the coming days and weeks. But if the bleeding is heavy and painful, your doctor may recommend a termination of pregnancy by medications or surgery.

Biochemical pregnancies

A biochemical pregnancy is another type of early pregnancy loss shortly after implantation. This is most likely just one or two weeks since a woman finds out about a positive pregnancy test, which can be devastating.

Biochemical pregnancies do not typically have symptoms, and some women have a miscarriage without realising that they were pregnant. For others that do have symptoms, they may experience stomach cramping and vaginal bleeding within days after getting a positive pregnancy result.

Notably, a biochemical pregnancy occurs more often in pregnancies through in vitro fertilisation (IVF). Although a blood test may indicate that implantation has taken place, abnormalities with the embryo could cause a biochemical pregnancy shortly thereafter.

Of course, for couples in the long haul for assisted reproduction, a biochemical pregnancy will be devastating after just being given some hope. But on the bright side, it is also a sign that you can get pregnant, and more attempts may eventually yield to a successful pregnancy!

Ectopic pregnancies

Ectopic pregnancies are implantations that have occurred outside the uterus, mostly in the fallopian tubes. Unfortunately, a normal pregnancy will never develop in such conditions, and ectopic pregnancies can even be life-threatening. In many cases, the woman will need to have the tube surgically removed for her own health.

Notably, women with blocked fallopian tubes caused by past infections or surgical scarring are more likely to experience an ectopic pregnancy.

Early detection of an ectopic pregnancy is very important to prevent complications. This is why your first few doctor appointments in the pregnancy are key, as they can confirm the location of your pregnancy.

Late miscarriages

Although it is much less common to miscarry after the first 13 weeks of pregnancy, late miscarriage is still possible. This condition is when a baby dies between 14 and 24 weeks of pregnancy, which is different to if a baby dies before 14 weeks, but the miscarriage happens later. The latter scenario is considered a missed or silent first-trimester miscarriage.

There are a number of reasons why a late miscarriage may occur, most of which are to do with abnormal foetal development. These include genetic or structural issues, such as a chromosomal abnormality or heart defect.

In addition, trauma, weak cervix and the mother’s chronic conditions are also possible factors for losing the pregnancy.

Risk factors for miscarriages

Maternal age is a prominent risk factor for not only getting pregnant but also sustaining it. 34 year old women have a roughly 20% risk of miscarrying, whereas 40 year olds have 40% chance. When a woman is past 40 years old, the risk of miscarrying can be as high as 80%.

Apart from age, poor lifestyle behaviours may also contribute to miscarriage, including smoking, drug use, environmental exposure to toxins, and radiation.

For more information regarding your risk of miscarriages, feel free to contact Melbourne-based obstetrician and fertility specialist, Dr Alex Polyakov here.