A blighted ovum is not a baby in the biological sense. It is a pregnancy where a fertilized egg implanted in the uterus and a gestational sac began to grow, but an embryo never developed inside it. The sac is empty. That said, for many people this experience still represents a real pregnancy loss, and how you think about it personally is a separate question from the biology.
What Actually Happens in a Blighted Ovum
In a typical early pregnancy, a fertilized egg implants in the uterine lining and begins dividing into the structures that will become both the placenta and the embryo. In a blighted ovum, that process starts but then stalls. The gestational sac and placenta keep growing, but the cells that would have become an embryo stop developing entirely. On ultrasound, this looks like an empty bubble inside the uterus.
The medical term is “anembryonic pregnancy,” which literally means “pregnancy without an embryo.” No embryonic tissue forms, no heartbeat develops, and there is no fetus. The European Society of Human Reproduction and Embryology actually recommends abandoning the old term “blighted ovum” because it’s poorly defined and can be confusing. The preferred clinical language is “anembryonic miscarriage” or “empty sac miscarriage.”
Why It Still Feels Like a Pregnancy
One of the most disorienting parts of a blighted ovum is that your body acts pregnant. You may have nausea, sore breasts, fatigue, and a positive pregnancy test. This happens because the growing gestational sac and placental tissue produce pregnancy hormones regardless of whether an embryo is present. Your body responds to those hormones the same way it would in any early pregnancy. Many people don’t learn anything is wrong until their first ultrasound, often around six to eight weeks.
This disconnect between feeling pregnant and learning there was never an embryo is part of what makes the experience so difficult. You weren’t imagining the pregnancy. The implantation was real, the hormones were real, and the loss is real.
What Causes It
About half of blighted ovum cases involve chromosomal abnormalities in the fertilized egg. The most common is an extra copy of chromosome 16, found in roughly 15% of abnormal cases. Extra copies of chromosomes 22, 15, and 19 account for smaller percentages. In these cases, the genetic instructions were too scrambled for an embryo to form, and development stopped very early.
The other half of cases show a normal chromosome profile, which means the cause isn’t always clear. What is clear is that a blighted ovum is not caused by anything you did or didn’t do. It reflects a problem at the very earliest stage of cell division, before most people even know they’re pregnant.
How the Diagnosis Is Confirmed
Doctors diagnose a blighted ovum through ultrasound, but they’re careful not to rush the call. Current guidelines require the gestational sac to reach at least 25 millimeters in diameter with no visible embryo or yolk sac before a definitive diagnosis is made. If the sac is smaller than that, it’s possible the pregnancy is simply earlier than expected.
When there’s any uncertainty, a follow-up ultrasound is recommended at least 14 days after the first one. This waiting period protects against misdiagnosis in cases where dates are off or the pregnancy is developing slowly. The wait can feel agonizing, but it exists because the consequences of a wrong diagnosis are irreversible.
What Happens After the Diagnosis
Once a blighted ovum is confirmed, there are three paths forward. Some people choose expectant management, which means waiting for the body to recognize the loss and pass the tissue on its own. This can take days to weeks and is unpredictable in timing. Others use medication to speed up that process, which typically works within a few days. A third option is a minor surgical procedure to remove the tissue, which is the fastest and most predictable approach. The right choice depends on personal preference, how far along the pregnancy measured, and individual health factors.
Physically, recovery from any of these options is usually complete within one to two weeks. Emotionally, recovery takes as long as it takes. Some people feel ready to move forward quickly. Others grieve deeply, especially if the pregnancy was planned or long-awaited.
Is It Considered a Miscarriage?
Yes. A blighted ovum is classified as an early miscarriage, specifically one that occurs before 10 weeks. Medical organizations place it in the same category as other early pregnancy losses, just with the distinction that no embryo was ever visible on ultrasound. Research on pregnancy loss terminology has found that patients generally prefer the word “miscarriage” over clinical alternatives, and knowing specifically when and how the pregnancy stopped developing can help with emotional processing.
The fact that no embryo formed doesn’t make the experience less valid as a loss. You had a positive test, pregnancy symptoms, and expectations for the future. How you choose to define what was lost is personal, and there’s no single correct way to frame it.
Chances of a Healthy Pregnancy Afterward
A blighted ovum does not mean future pregnancies will have the same outcome. Even among people who experience recurrent miscarriages, about 85% eventually have a successful pregnancy. A single blighted ovum is common enough that most doctors don’t recommend additional testing or intervention before trying again. Miscarriages of all types occur in up to 40% of pregnancies, many before the person is even aware they’re pregnant.
Most people can try to conceive again after one normal menstrual cycle, though some prefer to wait longer for emotional reasons. If you experience two or more consecutive losses, that’s when further evaluation for underlying causes becomes appropriate.