A blighted ovum (also called an anembryonic pregnancy) is a type of early miscarriage that occurs when a fertilized egg implants into the uterus but does not develop into an embryo. The embryo will stop growing, but the gestational sac (where the embryo would develop) continues to grow. The placenta and empty gestational sac will release pregnancy hormones — even without an embryo present. This causes you to have early symptoms of pregnancy or even have a positive pregnancy test. Sometimes it occurs so early in pregnancy that you don't know you're pregnant.
A blighted ovum causes an early miscarriage in the first trimester of pregnancy. During fetal development, a fertilized egg turns into a blastocyte. At around four weeks of pregnancy, this blastocyte implants in the wall of the uterus and develops into an embryo. When you have a blighted ovum, the gestational sac that would hold the embryo continues to grow, even without an embryo present. The following can occur:
. A blighted ovum happens so early in pregnancy, that you never realize you are pregnant.
. You have a positive pregnancy test and signs of pregnancy only to discover a blighted ovum at your first ultrasound.
. You have a positive pregnancy test and signs of pregnancy but then experience a miscarriage.
A blighted ovum is the number one cause of first trimester miscarriages.
A blighted ovum can occur so early in pregnancy that you never knew you were pregnant. In other cases, you may experience signs of pregnancy such as a missed menstrual period or a positive pregnancy test. You can have symptoms of early pregnancy, such as breast tenderness and morning sickness.
Other times your symptoms will resemble those of a miscarriage:
. Vaginal bleeding: Spotting (light bleeding), bleeding or passing light gray tissue or blood clots.
. Cramping: Mild to moderate cramping in your pelvic and abdominal region.
The only way to confirm a blighted ovum is through an ultrasound. It will show a gestational sac that is missing an embryo inside.
A blighted ovum is usually caused by chromosomal or genetic problems during cell division. During conception, the egg will begin to divide shortly after being fertilized by sperm. Around ten days later, the cells have formed an embryo. With a blighted ovum, the embryo never forms or stops growing after it’s formed.
A blighted ovum miscarriage will cause vaginal bleeding and abdominal cramping. A miscarriage usually feels more intense than your regular menstrual period. You can take an over-the-counter medicine like acetaminophen to relieve cramping. Avoid lifting anything heavy or any strenuous exercise as it can increase your bleeding. You may experience spotting for several weeks after a miscarriage.
Your healthcare provider will diagnose a blighted ovum using transvaginal ultrasound. This happens in the first trimester, usually between seven and nine weeks of pregnancy. An embryo should be visible at this time in pregnancy. With a blighted ovum, the gestational sac will be empty.
. You will lie back on an exam table and place your feet in stirrups like you do for a pelvic exam. Your healthcare provider will put an ultrasound wand into your vagina to see the contents of your uterus.
. A blighted ovum will appear as an empty sac — almost like a bubble.
People are often unaware that they have a blighted ovum. This is because your placenta continues to give off hormones, making your body think you are pregnant. This is also why you can still have symptoms of pregnancy, including a positive pregnancy test.
If you’ve already experienced bleeding or signs of a miscarriage, your healthcare provider will use ultrasound to look at the contents of your uterus to diagnose a blighted ovum.
Some healthcare providers will collect a series of blood samples that check the levels of hCG (human chorionic gonadotropin) in your body. HCG is known as the pregnancy hormone because it's only produced if you are pregnant. The level of hCG in your blood increases rapidly in early pregnancy and reaches its peak around weeks eight to ten. If it's not rising quickly, it can indicate a miscarriage or other complication. Your provider may decide to test your hCG levels over the course of several days to evaluate how your hCG levels are rising. This can be an effective tool for diagnosing blighted ovum.
Complications of a blighted ovum are uncommon, but the possible complications could include:
. Excessive bleeding or hemorrhage.
. Scarring (from the D&C procedure).
. Tears in the uterus (from the D&C procedure).
A blighted ovum can’t be prevented. Some couples may want to do genetic testing on the tissue inside the uterus. This checks for underlying causes of your miscarriage and can be helpful to couples who have experienced multiple pregnancy losses.
For some people, there may be no treatment needed, because your body passes the embryo through your vagina (a miscarriage). If your body does not miscarry the embryo, there are other options to remove the contents of your uterus. Your healthcare provider will talk you through possible treatments:
. Dilation & Curettage (D&C): This is a surgical procedure to remove the contents of your uterus. Your healthcare provider will dilate, or open, the cervix and use medical tools and suction to remove the pregnancy tissues from your uterus. This is done under sedation or general anesthesia.
. Natural miscarriage: If it's safe, you may be able to watch and wait to see if your body eventually releases the pregnancy tissues. It can sometimes take days or weeks for this to start. Your healthcare provider will let you know if this is an option for you. You will experience cramping, abdominal pain and bleeding once the miscarriage begins.
. Medication-induced miscarriage: You may be given a medication called misoprostol to trigger your body to miscarry. This moves the process along and eliminates the time waiting for a miscarriage to start on its own. You will have cramping, abdominal pain and bleeding within 30 minutes to ten hours of taking the medication.
A follow-up appointment is usually scheduled four to six weeks after a miscarriage or D&C. You may be given another ultrasound to confirm the uterus is empty. Your healthcare provider will check for signs of infection and make sure there were no complications.
Recovering from a blighted ovum miscarriage or D&C can last from one or two weeks to a month. Cramping generally lasts up to a week, but bleeding can last several weeks. Your bleeding should get lighter until it stops completely.
You can resume normal activities when you feel comfortable. Bleeding can increase with strenuous activity or exercise. Hormones may remain in your body and delay your menstrual cycle. Most people will get their period within four to six weeks after a blighted ovum.
It may take longer to recover emotionally from a blighted ovum miscarriage. You may have feelings of sadness, anger or confusion. It’s OK to take time to grieve. Ask your friends and family for support.
Most healthcare providers recommend having one or two regular menstrual cycles before trying to conceive again after any type of miscarriage.
Your chances of having another blighted ovum are low. Most people go on to have healthy, full-term pregnancies. If you experience more than one blighted ovum, your healthcare provider may suggest testing to determine if there is an underlying cause.
Call your healthcare provider right away if you have any of these symptoms:
. Excessive bleeding from your vagina.
. Dizziness or fainting.
. Fever that does not go away.
. Symptoms that get worse over time.
. Severe pain that isn’t helped with pain medicine.
Go to the nearest ER If you experience heavy vaginal bleeding — more than two pads per hour for two consecutive hours — or have symptoms of anemia like dizziness, palpitations or paleness.
Yes, a blighted ovum is a miscarriage. A miscarriage is a loss of pregnancy before 20 weeks. A blighted ovum is considered an early miscarriage because it occurs before 13 weeks of pregnancy.
The amount of time you can carry a blighted ovum varies. Your placenta will continue to grow and release hormones without an embryo. For some people, a miscarriage can occur within a few days or weeks. Others may still believe they are pregnant only to discover a blighted ovum at their first ultrasound.
No, an empty gestational sac will not turn into an embryo. The formation of the embryo occurs within two weeks of conception. By the time the gestational sac is formed, the cells should have already formed the embryo. Your healthcare provider will be able to examine your gestational sac to confirm that no embryo has developed.
Yes, most of the time hCG levels will rise, giving you a positive pregnancy test and symptoms of pregnancy. This is because the placenta continues to give off hCG even if an embryo is not present. The hormone hCG is sometimes called the pregnancy hormone because it is only produced if you are pregnant.
A blighted ovum is not more common with IVF (In Vitro Fertilization). Your chances of having a blighted ovum with IVF treatment are about the same as they would be with a natural conception.