We all know the excitement of a pregnancy announcement, at least in most cases. However, all this excitement quickly goes down the drain when concerns about miscarriage arise.
Thanks to medical technology, we have advanced tools like ultrasound scans, which help us assess the viability of a pregnancy and detect any potential complications early on.
In today’s article, we take a deeper look into the causes, signs, and symptoms of miscarriage, ultrasound diagnosis and accuracy, and more.
Understanding a Miscarriage
A miscarriage simply refers to the loss of pregnancy before 20 weeks into the gestation period. Most people experience miscarriages during the first trimester, which is between 0 to 12 weeks.
According to statistics, at least 1 in 4 pregnancies experiences a miscarriage.
While it can be caused by multiple factors, it doesn’t mean that it is your fault. Most miscarriages don’t happen intentionally. They are often beyond anyone’s control and only happen because the foetus isn’t growing anymore or developing as it should.
Understanding Early Ultrasound
The first ultrasound can be done between weeks 6 to 8. This is usually performed to determine your due date and measure the baby. Expectant mothers are also always impatient to see their babies and feel their heartbeat.
A private ultrasound is a medical imaging process that allows the pregnant woman and the healthcare professional to see the developing embryo or foetus within the uterus. It is usually performed using a special medical gel and a handheld device called a transducer.
During the procedure, you are required to start by lying on an examination bed. Your specialist will then apply the gel to your abdomen and then move the transducer around to capture images of your uterus.
Your practitioner will carefully examine these images to assess the development of the embryo, the presence of a gestational sac, and any other relevant features.
What Causes Miscarriages?
There are many reasons why a miscarriage may happen. Most of them, at least 3 out of 4, occur during the first trimester and are usually caused by issues with the foetus.
Miscarriages that happen during the second trimester are mostly caused by underlying health issues, while those that happen late into the pregnancy may be caused by infections, the womb opening too early, and more.
Let’s take a closer look;
First Trimester miscarriages
As mentioned above, they are normally caused by problems with the foetus. These problems may include;
Chromosome problems – These happen when there are errors in the baby’s genes or DNA that make it impossible for the foetus to develop normally. It can occur due to issues during fertilisation or as the cells divide and grow.
Placenta problems – Placenta is the organ that provides nutrients and oxygen to the developing baby. If it does not develop properly or becomes damaged, it can affect the foetus’s growth and survival.
Second Trimester miscarriages
The second trimester of pregnancy is between weeks 13 to 26. A miscarriage in this period may be caused by;
Long-term health conditions – Conditions such as uncontrolled diabetes, thyroid disease, or autoimmune disorders can increase the risk of miscarriage during the second trimester.
Infections – Infections such as HIV, syphilis, chlamydia, and bacterial vaginosis can also increase the risk.
Food poisoning – Eating contaminated foods by listeriosis, toxoplasmosis, and salmonella may cause miscarriages in this stage.
Medicines – Medicines such as misoprostol, retinoids, and non-steroidal anti-inflammatory drugs like ibuprofen may increase the risk too. Before using any drugs, always check with your healthcare provider first.
Womb structure – If you develop any problems in your womb, such as abnormalities in the shape or structure of your uterus, it may be a problem.
Weakened cervix – If the muscles of your cervix, also called the neck of the womb, become weaker, it may open too soon and lead to a miscarriage.
Ultrasound Diagnosis for Miscarriage
While many scans and tests can be done, ultrasound is the most accurate diagnosis for miscarriage. Different types of ultrasounds can be performed, including;
Transvaginal ultrasound – This involves inserting a small probe into the vagina to get a closer view of the uterus. It provides clearer images, especially in early pregnancy, making it one of the most accurate ultrasound scans for miscarriage.
Transabdominal ultrasound – During a Transabdominal ultrasound, your specialist will move a transducer over your abdomen to capture images of the uterus. This scan works well in both the early and late stages of the pregnancy.
Doppler ultrasound – Uses sound waves to measure the blood flow in the baby’s heart and blood vessels. It helps help detect a foetal heartbeat and assess the health of the pregnancy.
Generally, how these ultrasound procedures work is that they can help detect;
- The absence of a foetal heartbeat
- An empty gestational sac
- And a foetus that is not developing as expected
Types of Miscarriages
Your healthcare provider may diagnose you with different types of miscarriages, including;
Missed miscarriage – In this case, the miscarriage has happened, and you have lost the pregnancy, but you are not aware of it. This is because there are usually no symptoms such as bleeding or cramping. An ultrasound can confirm that there is no heartbeat in the foetus.
Complete miscarriage – Your specialist can also confirm a complete miscarriage with an ultrasound. It means that you have already experienced bleeding, passed the foetal tissue and your uterus is empty.
Incomplete miscarriage – This is when you have lost the pregnancy but not expelled all of the uterus tissue. It usually requires a medical procedure to remove the remaining tissue.
Recurrent miscarriage – As the name suggests, this type of miscarriage has occurred multiple times, usually three (or more) times consecutively. It requires medical intervention and thorough examination to determine the underlying cause.
Threatened miscarriage – When this happens, you will experience vaginal bleeding, but the cervix will remain closed, and the pregnancy will continue. Often, many women who experience a threatened miscarriage go on to have a healthy pregnancy.
However, your specialist will have to monitor you closely for the remainder of the pregnancy to ensure it develops properly.
Inevitable miscarriage – During an inevitable miscarriage, there is heavy bleeding and cramping as the cervix opens. This indicates that a miscarriage is in progress and cannot be stopped.
Signs and Symptoms of a Miscarriage
Vaginal bleeding is one of the most common signs of miscarriage. It ranges from light spotting to heavy bleeding and can be accompanied by clots. You may notice light bleeding at first, which can progress and become heavier over time.
It may also be continuous or intermittent. The amount and duration of bleeding can vary too, with some people experiencing it for a longer time.
Another common sign is abdominal pain and cramping. Many women experience cramping in the lower abdomen and pain in the lower back. This can be mild to severe and may feel like menstrual cramps or even more intense.
Other signs and symptoms include;
- Passing tissue or clots from the vagina
- A sudden loss of pregnancy symptoms, such as breast tenderness, nausea, and fatigue
- Feeling unusually weak or fatigued
- Fever and chills
Accuracy of Ultrasound Diagnosis for Miscarriage
The gestational sac should be detectable with transvaginal ultrasound by week 5 or 6 of gestation. If not, it could be an indication of an early pregnancy failure. Foetal heartbeat should also be visible.
However, it is important to carry out follow-up scans for confirmations. Your specialist might recommend this a week or two after the initial scan.
According to NHS guidelines, a diagnosis of miscarriage can only be made if there is an empty gestational sac with a mean sac diameter of at least 25 mm and no embryo visible. Or, if an embryo with no heartbeat is observed even after appropriate ultrasound evaluation.
Here are more factors that can affect the accuracy of the ultrasound diagnosis;
Operator skills – The accuracy of ultrasound results highly depends on your specialist’s skills and experience.
Gestational age – This refers to how far along the pregnancy is. The further along, the clearer the ultrasound images are, which makes it easier to see if everything is developing as it should.
Type of ultrasound scan – There are different types of ultrasound scans, each using different techniques. Some are done through the belly (abdominal), while others are done through the vagina (transvaginal). The type used can affect how clear the pictures are and how easy it is to see the pregnancy.
The quality of the equipment – It is important that your specialist uses a high-quality machine for the ultrasound, as this can make a significant difference. Simply put, the better the machines are, the clearer the images are, translating to a more accurate diagnosis.
Position of the pregnancy – The position of the pregnancy in the uterus can affect how well the ultrasound works. For example, it might be harder to see clearly if it is located in a tricky spot.
Uterine conditions – Issues in the uterus, such as fibroids, may change its shape, making it harder to see the pregnancy clearly on the ultrasound.
Can a Miscarriage be Prevented?
Most women end up blaming themselves for miscarriage. This is normal due to the overwhelming emotions of losing a baby. However, it is important to always remember that miscarriages are beyond anything you can do.
If you lose a pregnancy, it is not because you did or didn’t do something. The best thing you can do to ensure a healthier pregnancy is to take care of yourself, as this equals to taking care of your unborn child.
Here are some tips;
- Maintain a healthy lifestyle – This includes eating a balanced diet rich in nutrients, exercising regularly (as advised by your healthcare provider), and getting enough rest.
- Avoid harmful substances – Stay away from alcohol, tobacco, and illicit drugs, as these can increase the risk of pregnancy complications and ultimately lead to a miscarriage.
- Manage stress – Avoid stress by practising relaxation techniques such as deep breathing, yoga, and meditation.
- Attend prenatal care – Make sure to attend all your scheduled appointments. Regular prenatal check-ups help monitor the progress of your pregnancy and address any concerns early.
- Educate yourself – Stay informed and be aware of your situation. Ensure you understand the signs and symptoms of complications during pregnancy, so you can seek medical attention promptly in case of concerns, allowing for early treatment.
When to See a Specialist for an Ultrasound
Pregnancy is a delicate journey and experience, which makes it challenging to determine whether your pregnancy is safe and healthy.
It is crucial that you immediately contact a healthcare professional for a specialised ultrasound as soon as you notice something unusual or start experiencing concerning symptoms.
Here are some of the symptoms to watch out for;
Bleeding or spotting – If you notice any vaginal bleeding or spotting, especially if accompanied by cramping or pain, contact your specialist immediately
Severe abdominal pain – If you start experiencing severe or persistent abdominal pain, whether localised or spread across the abdomen, call your healthcare professional.
A sudden loss of pregnancy symptoms – Some common symptoms during pregnancy include nausea and morning sickness, fatigue, food cravings, mood swings, and more. If you stop experiencing these, it may not be a good sign. Consult a professional.
Fever and chills – Although rare, fever and chills may also signify miscarriage. If these symptoms persist, an ultrasound may be conducted to ensure that the baby is fine.
Frequently Asked Questions
How early can an ultrasound detect a miscarriage?
You can start ultrasound scans as early as 6 weeks into the pregnancy. During this period, you can already see the foetus and the heartbeat. This means the ultrasound can detect a miscarriage if it happens. However, follow-up scans may be needed for confirmation
What will an ultrasound show if there is a miscarriage?
Some signs of a miscarriage that an ultrasound will identify include an empty gestational sac, no fetal heartbeat, or abnormal fetal development.
Is an ultrasound always accurate?
Generally, ultrasounds are accurate and effective. However, this depends on various factors, such as the skill and experience of the specialist performing the ultrasound, the quality of the equipment used, and the stage of pregnancy.
In some cases, additional tests and follow-up ultrasounds may be necessary to confirm the initial diagnosis.
