Types of Miscarriage

There are several different types of miscarriage. Depending on your symptoms and the stage of your pregnancy, your doctor will diagnose one of the following:

Chemical Pregnancy

A chemical pregnancy is a very early miscarriage that normally ends before 5 weeks.  More often than not you will have a positive home pregnancy test, but start bleeding within a few days. Even though this loss happens so early on, it can still cause great sadness for the couple experiencing it. 

Threatened Miscarriage

Sometimes you may get some bleeding that settles down within a day or so and the pregnancy then continues as normal. This is known as a threatened miscarriage. Normally it is wise to take it easy and perhaps have a scan to see if there was a cause for the bleeding, such as a sub-chorionic hematoma.

Missed Miscarriage (also called a ‘silent’ miscarriage)

This is where the baby has died or failed to develop but is still in your uterus and as a result, you have no reason to believe that anything is wrong. A missed miscarriage is usually not diagnosed until a routine scan. You may still feel pregnant or your pregnancy symptoms may have begun to subside. 

Incomplete Miscarriage

When an incomplete miscarriage occurs, some but not all of the pregnancy tissue is miscarried. You may have pain and heavy bleeding that does not subside. In some instances a D&C will be required to remove the remaining pregnancy tissue.

Blighted Ovum

A blighted ovum is usually not discovered until an early ultrasound, where no embryo can be detected in the uterus. When a blighted ovum occurs, it generally means that an embryo was conceived, hence a pregnancy sac was formed, but it did not develop and was reabsorbed into the wall of the uterus.

Types of Pregnancy Loss

Miscarriage is only one kind of pregnancy loss. Here we look at two other kinds of loss that result in a pregnancy ending, even though they may not typically be classified as a miscarriage. Grief surrounding these types of losses will be just as intense and the women experiencing them, will also require lots of support and love.

Ectopic Pregnancy

An ectopic pregnancy occurs when an embryo implants somewhere other than the uterus - most commonly in one of the fallopian tubes. Very sadly, there is no way a pregnancy can grow and survive in this case. This is even more heartbreaking when the embryo itself is perfectly healthy. 

Initially an ectopic pregnancy will seem like a normal pregnancy. You will have a positive test, and experience normal pregnancy symptoms. If you have an early dating scan, the absence of the embryo in the uterus will be the first indication that it has implanted elsewhere. In other cases, you may start to have some light bleeding, cramping or even shoulder tip pain which indicates blood loss from the tube. 

In extreme cases, an undiagnosed ectopic pregnancy can be life threatening, if the fallopian tube ruptures and blood starts pooling in your abdomen. If you become extremely light-headed or faint, you should present immediately to your hospital emergency department. 

Treatment of an Ectopic Pregnancy

In order to remove the embryo from the tube, provided there is no extreme bleeding, you will be given an injection of Methotrexate which stops cell growth and will dissolve existing tissue. In some cases the embryo can be removed from the tube laparoscopically, but there is a risk that the tube may become damaged and need to be removed.

If an emergency situation arises, and the fallopian tube has ruptured, you will be given emergency surgery and it is likely the tube will be removed along with the embryo.

Molar Pregnancy

Unfortunately if you have been diagnosed as having a molar pregnancy (Hydatidiform Mole), there is no chance that your pregnancy can survive. Affecting 1 in 1200 pregnancies¹, when a molar pregnancy has occurred, your baby won’t have developed properly." The trophoblast - which later forms part of the placenta - abnormally overgrows in the uterus, producing very high amounts of HCG, which in turn gives you normal pregnancy symptoms, and little sign that anything might be wrong. 

While these unusually high hormone levels can sometimes be a red flag to a potential issue, a molar pregnancy is generally diagnosed via ultrasound. In some cases, if a pregnancy has already miscarried, diagnostic testing can also reveal it as the cause. 

Complete Molar

 In the case of a complete molar pregnancy, an egg with no genetic material is fertilised, meaning that a baby cannot be formed. All that grows is the trophoblast.

Partial Molar

When a partial molar pregnancy occurs, two sperms fertilise an egg, and as a result there is too much genetic material. In this case, a baby may or may not form, but even so, it would be severely abnormally developed and would not survive. 

Treatment of a Molar Pregnancy

Once diagnosed, a molar pregnancy will be removed via D&C and the tissue sent away for testing. You will generally be followed up after the surgery, with regular blood tests to ensure that your HCG is dropping. 

In the case of a partial mole, once your HCG reaches zero, no more follow up is necessary. For a complete mole, blood tests will be conducted monthly for 6 months, to ensure that your hormone levels remain low, and that no molar tissue is regrowing. 

1. Fact Sheet: Molar Pregnancy (Hydatidiform Mole) [Internet]. The Royal Womens Hospital [updated 2020 Aug; cited 2023, Sept 25]. Available from: https://thewomens.r.worldssl.net/images/uploads/fact-sheets/Molar-pregnancy-Hydatidiform-Mole.pdf