When a fertilized egg implants itself in the uterus but doesn’t become an embryo, it’s known as a blighted ovum. Most lead to miscarriage. Treatments may include medication, waiting for a natural miscarriage, or surgery.

A blighted ovum is a fertilized egg that implants itself in the uterus but doesn’t become an embryo. The placenta and embryonic sac form, but remain empty. There’s no growing baby. It’s also known as anembryonic gestation or anembryonic pregnancy.

Even though there’s no embryo, the placenta still produces human chorionic gonadotropin (hCG). This is a hormone designed to support pregnancy. Blood and urine pregnancy tests look for hCG, so blighted ovum can result in a positive pregnancy test even though the pregnancy isn’t actually proceeding. Pregnancy-related symptoms, such as sore breasts and nausea, may also occur.

A blighted ovum eventually leads to miscarriage. It’s not able to turn into a viable pregnancy.

What are the symptoms?

A blighted ovum sometimes ends before you realize you’re pregnant. When this happens, you may just think you’re having a heavier-than-normal menstrual period.

A blighted ovum may have the same symptoms associated with pregnancy, such as:

  • a positive pregnancy test
  • sore breasts
  • a missed period

As the pregnancy ends, symptoms may include those of miscarriage. These can include:

  • vaginal spotting or bleeding
  • abdominal cramping
  • disappearance of breast soreness

Pregnancy tests measure hCG levels, so a blighted ovum can continue to result in positive test results before the tissues are passed.

What are the causes?

This condition isn’t caused by anything that you did or didn’t do, either during or before your pregnancy.

The exact cause of blighted ovum isn’t known. It’s thought to be caused by chromosomal abnormalities occurring within the fertilized egg. This may be the result of genetics, or of poor-quality eggs or sperm.

Blighted ovum may be linked to abnormalities within chromosome 9. If you have repeated blighted ovum pregnancies, consider talking to your doctor about a chromosomal analysis of your embryos.

You may be at a significantly higher risk of blighted ovum than the general population if your partner is biologically related to you.

A blighted ovum can occur so early that it goes unrecognized. However, many women who receive a diagnosis of this condition go on to have subsequent healthy pregnancies. It’s not clear if blighted ovum occurs most typically in first-time pregnancies or if they sometimes occur more than once. Most women who have a blighted ovum do go on to have successful pregnancies and healthy babies.

How is this diagnosed?

A blighted ovum is often discovered on the first ultrasound given during a prenatal appointment. The sonogram will show the placenta and empty embryonic sac. A blighted ovum usually occurs between the 8th and 13th weeks of pregnancy.

What are the treatment options?

If blighted ovum is discovered during a prenatal appointment, your doctor will discuss treatment options with you. These may include:

The length of your pregnancy, medical history, and emotional state will all be taken into account when you and your doctor are deciding upon a treatment option. You’ll want to discuss the side effects and the standard risks associated with any type of medication or surgical procedure, including a D and C.

Even though there wasn’t a baby, there has been a loss of a pregnancy. Miscarriages can be emotionally difficult, and waiting for the pregnancy to end can take longer than anticipated. For this reason, some women decide to terminate surgically or with medication. Other women are uncomfortable with these choices and prefer to let the miscarriage happen on its own.

Discuss all of your options with your doctor. Let them know if you’re uncomfortable with any of the options available to you.

Can this be prevented?

A blighted ovum can’t be prevented.

If you’re concerned about this condition, talk to your doctor about possible genetic causes and testing procedures, which might help you avoid it. Also discuss with your doctor about exposure to toxins in the environment. It may be linked to blighted ovum and miscarriage.

Are there any complications with future pregnancies?

Just as with any miscarriage, your body and emotional well-being need time to heal. It’s important to remember that most women who go through a blighted ovum go on to have successful pregnancies.

You and your doctor will discuss how long you should wait before trying to conceive again. It’s typically recommended that you wait three full menstrual cycles so that your body has time to recuperate fully and is ready to support pregnancy. During this time, focus on healthy lifestyle habits for your body and mental health, such as:

Having a blighted ovum once doesn’t mean you’re destined to have another one. However, there are factors associated with this type of miscarriage that you should discuss with your doctor. These factors include genetics, egg quality, and sperm quality. Your doctor may recommend testing for these types of conditions. Tests may include:

  • preimplantation genetic screening (PGS), a genetic analysis of embryos that can be done prior to implantation into the uterus
  • semen analysis, which is used to determine sperm quality
  • follicle stimulating hormone (FSH) or anti-mullerian hormone (AMH) tests, which can be used to help improve egg quality

The takeaway

The specific cause of blighted ovum is unknown, but chromosomal anomalies appear to be a main factor. Having a blighted ovum doesn’t mean you’ll have another one. Most women who experience this go on to have healthy pregnancies.