A blighted ovum is an early type of miscarriage. In fact, it can happen so early you don’t even know you’re pregnant.
It is also referred to as anembryonic pregnancy, embryonic demise, embryo loss, or the term preferred by the Royal College of Obstetricians and Gynaecologists, early foetal demise.
It happens when a fertilised egg implants in the uterus, the pregnancy sac forms and grows, but the embryo doesn’t develop. Anembryonic pregnancy means a pregnancy without an embryo.
What causes a blighted ovum?
Miscarriages from a blighted ovum are often, like most early miscarriages, down to chromosome abnormalities, which can occur because of poor-quality egg or sperm. It may also be down to the cells that form the embryo dividing in an abnormal way. Your body stops the pregnancy because it recognises this abnormality. It’s not down to anything you may or may not have done and it almost certainly could not have been prevented.
For most women who have a blighted ovum, it occurs only once and they go on to have a successful pregnancy in future.
Signs of a blighted ovum
You may already have experienced signs of pregnancy, like a missed period or positive pregnancy test.
Then you may experience signs of miscarriage, such as:
- Vaginal spotting or bleeding
- A period that is heavier than usual
- Abdominal cramps.
If you're experiencing any of these symptoms, you may be having a miscarriage.
Despite this you may continue to feel pregnant because hormone levels can remain high for some time after the embryo has stopped developing. It means you may have a blighted ovum but a pregnancy test, which is based on hormone levels, can still be positive.
Seek medical advice if you have any signs of miscarriage.
Diagnosing a blighted ovum
Because a pregnancy test may still be positive, and a woman may still feel pregnant, the only way to diagnose a blighted ovum is to confirm by ultrasound, that the pregnancy sac is empty.
What happens after diagnosis?
You need to have a discussion with your doctor about what to do next, but you don’t have to do anything straight away. It’s a very personal decision.
Some women choose to miscarry naturally and let their body pass the tissue by itself. This can take some weeks.
Other women choose to have a surgical procedure called a D&C (dilation and curettage) also known as an ERPC (evacuation of retained products of conception). This involves dilating the cervix and removing the contents of the uterus. Because this immediately removes any remaining tissue, it may help some women with mental and physical closure. It may also be helpful if you want a pathologist to take a look at the tissue to confirm the reason for the miscarriage.
The other option is medication to bring on a miscarriage. With this method it can take several days for your body to expel all tissue and you may experience more bleeding and side-effects like cramping.