What Is a Blighted Ovum Pregnancy?

A blighted ovum is a fertilized egg that attaches to the uterine wall, as in a normal pregnancy, but never goes on to develop into an embryo. The gestational sac, which contains the egg, continues to form and grow, but the embryo itself does not. This is also known as an anembryonic pregnancy and will ultimately end in a miscarriage, sometimes before a woman even knows she is pregnant.

Causes of Blighted Ovum

In a normal pregnancy, the egg starts dividing within hours after being fertilized. Around 10 days later, these cells have formed an embryo, which implants itself in the uterus. From there, the placenta begins to develop and hormone levels begin to surge. With a blighted ovum, the cells never divide to the point of forming an embryo, or the embryo stops growing very shortly after it implants in the uterus.

A blighted ovum is most often the result of chromosomal abnormalities in the fertilized egg. This may be due to abnormal cell division or poor-quality egg or sperm that make the pregnancy non-viable from the start. When the body recognizes this, it discontinues the pregnancy via miscarriage.

There is no evidence that a blighted ovum is caused by anything parents do or do not do. Most cases of blighted ovum are one-off events and are unlikely to occur in future pregnancies. If you do experience more than one anembryonic pregnancy, your doctor may want to do tests to make sure there are no underlying causes, such as hormone imbalance or genetic mutation. 

Symptoms of Blighted Ovum

Symptoms of a blighted ovum may be non-existent, leading to what's known as a missed miscarriage. Alternatively, you may experience the typical symptoms of miscarriage, including:

• Vaginal spotting or bleeding
• Abdominal cramps
• Blood clots or grayish tissue passing from the vagina

Diagnosis

In cases of a blighted ovum, early blood tests and pregnancy tests will usually indicate that the pregnancy is progressing normally. This is because levels of human chorionic gonadotropin (hCG), a hormone produced by the placenta during a normal pregnancy, will continue to rise as the placenta develops, even if an embryo is not present.

Typically, your healthcare provider will do a routine ultrasound when you are roughly six weeks pregnant. In a normal pregnancy, an embryo should be visible at this time. With a blighted ovum, the gestational sac will be empty.

Treatment

If you have a blighted ovum, your doctor may recommend a procedure known as dilation and curettage (D&C). This surgical procedure involves the dilation of the cervix followed by the removal of the contents of the uterus using a looped tool called a curette. Vacuum aspiration, in which excess tissue is removed by suction, may also be performed.

The alternative is to wait for a natural miscarriage to occur. This can sometimes take weeks and requires a doctor to monitor the process to ensure that all the tissue in the uterus has been expelled. If tissue remains in the uterus after the miscarriage, a D&C may still be required. If the tissue is not removed, an infection can occur and lead to a potentially serious complication called a septic miscarriage.

Post-Miscarriage Care

Following a D&C or a natural miscarriage, you may have mild cramping for a day or two. Over-the-counter pain medication such as acetaminophen or ibuprofen may be an option. You may return to normal activity if you feel well enough to do so, but avoid heavy exercise until the bleeding stops. Call your doctor if you experience any of the following:

• A temperature above 100 F
• Cramping after the first two or three days
• Any severe pain
• Heavy bleeding that is more than the heaviest day of a normal period

Use a pad (not tampons) for the bleeding. You may experience spotting for several weeks. Avoid douching and sexual intercourse until bleeding stops.

A Word From Verywell

Suffering a miscarriage as a result of a blighted ovum—or for any other reason—can be very difficult, even though there's nothing you or your partner did to cause it, nor anything you could have done to prevent it. If you are struggling, consider seeing a counselor or joining an online support group. Remember that the majority of women who have a blighted ovum go on to have a healthy full-term pregnancy.