Missed miscarriage: how to tell if you’re having one
What is a missed miscarriage?
A missed (or silent) miscarriage happens when the embryo stops developing and instead of being expelled from the body remains in the uterus.
There are often no typical miscarriage signs associated with a missed miscarriage and as a result they regularly go unnoticed. Missed miscarriage is usually discovered during the first routine scan in early pregnancy.
How likely is a missed miscarriage?
How do you know if you have a missed miscarriage?
What are the symptoms of a missed miscarriage?
There are often very few obvious signs of a missed miscarriage. Although the embryo has stopped growing your placenta may still be producing hormones that cause early pregnancy symptoms which can mask the pregnancy loss.
It is important to remember however that pregnancy symptoms may come and go as part of a normal pregnancy, and a lessening of symptoms is not necessarily any cause for concern.
What are the first signs of a missed miscarriage?
Missed miscarriage often goes unnoticed because of a lack of symptoms. This means that the first signs of a missed miscarriage are usually discovered during the first pregnancy scan.
How is a missed miscarriage diagnosed?
Missed miscarriage is usually diagnosed by ultrasound. Your doctor will not be able to detect a heartbeat, or the embryo will appear too small for the date of the pregnancy. It is common for the diagnosis to be confirmed by a repeat scan at a later date, usually seven to 14 days later.
Hormone measurements do not tend to be used to diagnose missed miscarriage. The pregnancy hormone hCG normally doubles every 24 – 48 hours during the first 8 weeks of pregnancy, peaking at 10 weeks. Slower doubling times of hCG in the first trimester can be associated with an increased risk of miscarriage.
Studies have found that the doubling time of hCG can vary widely between women which means hCG measurements alone are not reliable enough to diagnose miscarriage.
If you are less than 10 weeks pregnant however your doctor may monitor the level of hCG in your blood for a few days and use this information in combination with your ultrasound scan to confirm your diagnosis.
Missed miscarriage after heartbeat
Although it is possible, the risk of any type of miscarriage after the detection of a fetal heartbeat is very rare. Following a healthy scan at eight weeks the chance is less than 2%. The risk of miscarriage continues to decrease as pregnancy continues, falling to less than 1% at 10 weeks.
How long can missed miscarriage go undetected?
Because the symptoms tend to be very mild, a missed miscarriage can go undetected for several weeks. Missed miscarriage is usually discovered at the first trimester scan between 11 and 14 weeks.
How does a missed miscarriage happen?
What happens when you have a missed miscarriage?
Missed miscarriage may occur because of a condition known as a blighted ovum. A blighted ovum is a fertilized egg which implants into the uterus forming a gestational sac but fails to develop. On ultrasound it is detected as an empty gestational sac.
Sometimes the implanted embryo will begin to form but then development stops. In these cases, a fetal pole or fetus can be observed in the gestational sac but will no fetal heartbeat will be detected.
What are the reasons for a missed miscarriage?
Like other types of miscarriage chromosomal abnormalities are the most common cause and contribute to over 50% of miscarriages.
In a viable pregnancy each parent contributes one set of chromosomes which contains the genetic material. Abnormalities occur if the sperm or egg that have fused to form the embryo do not have the correct amount of genetic material. These abnormalities can either be genetically inherited or occur spontaneously.
The risk of spontaneous chromosomal abnormalities increases with maternal age. A number of studies now suggest that paternal age may play a small part too but this has only recently become a focus of research.
Other less common risk factors for miscarriage include:
- Lifestyle choices, including smoking and excessive alcohol and caffeine intake
- Structural abnormalities of the uterus
- Poor eating habits (malnutrition, obesity or being underweight)
- Poorly managed endocrine disorders such as polycystic ovary syndrome, thyroid disease, and type I diabetes
Can I prevent missed miscarriage?
It is important to remember that miscarriage caused by chromosomal abnormalities accounts for the highest number of pregnancy losses and this cannot be prevented.
You can however increase your chances of a healthy pregnancy. Before conceiving again focus should be on ensuring good general health and well-being and making sensible lifestyle choices. This means eating well, taking regular exercise, managing stress, and maintaining a healthy weight.
Sometimes couples experience recurrent miscarriage (three or more consecutive pregnancy losses). If you have experienced this your doctor will usually carry out further investigations.
This may involve examining the structure of your uterus, looking at blood hormone levels, as well as genetic tests of both you and your partner. There is also recent research to suggest that sperm quality could be linked to recurrent miscarriage.
If you have experienced multiple previous pregnancy losses and have become pregnant again you may be offered an earlier ultrasound scan at seven or eight weeks gestation to reassure you that the pregnancy is progressing normally.
Can stress cause missed miscarriage?
There is limited evidence to suggest stress is linked to missed miscarriage. When looking to conceive again focus should be on maintaining good physiological and mental well-being.
What are the treatment options for a missed miscarriage?
Unfortunately, once a miscarriage has started there is nothing that can be done by you or your doctor.
Following diagnosis, the next steps will be focussed on ensuring the embryo is passed or removed from the body, as well as ensuring the miscarriage does not lead to further complications such as uterine infection.
Your doctor will outline several possible treatment options for you:
Expectant management involves waiting for the tissue to pass naturally out of your body. You will experience symptoms similar to a heavy period. Once started, the bleeding usually slows down within a week although spotting may continue for another week or so.
Studies have shown that expectant management is not always successful and can have a higher rate of complications compared to other treatments. Women can also find the uncertainty of not knowing when the bleeding will start difficult to manage.
You may also choose to take a medication—either orally or vaginally—called misoprostol. Misoprostol triggers the body to expel the tissue by causing the cervix to open and the uterus to contract. The process will usually start within hours of taking the pill.
Misoprostol does not work for all women and sometimes a second dose is required. Some studies have also shown that combining misoprostol with a drug called mifepristone can be more effective.
If the tissue does not pass naturally or with medication a small surgical procedure called dilatation and curettage (D&C) can be performed. After dilating your cervix, your doctor will use a spoon-shaped object called a curette to remove tissue from the inner lining of your uterus.
Surgery can be more effective than expectant management and misoprostol if you are further along in your pregnancy.
Trying again after a missed miscarriage: how long to wait?
If you have suffered a miscarriage it is natural to feel apprehensive about trying to conceive again.
Having one miscarriage however does not affect your chances of getting pregnant again or your risk of miscarriage.
There is no medical reason to delay trying again after a missed miscarriage. Assuming you feel emotionally ready it is perfectly safe have sex again once the miscarriage bleeding has stopped.
One study has even shown that trying to conceive within three months may increase your chances of having a full-term pregnancy. Another study suggests that women who conceive within six months are less likely to have miscarriage than those who wait longer.