blighted ovum是什么意思？

What causes a blighted ovum?
- Amber / Arkansas
Mayo Clinic obstetrician and gynecologist Roger Harms, M.D., and colleagues answer select questions from readers.
Answer
A blighted ovum is a common cause of early pregnancy loss. It occurs when a fertilized egg develops a placenta and membrane but no embryo. A blighted ovum usually occurs in the first few weeks of pregnancy — often before a woman even knows she's pregnant. An ultrasound will show an empty gestational sac. Blighted ovum is often due to chromosomal abnormalities in the fertilized egg.

With a blighted ovum, you may miss a period and have a positive pregnancy test. This is because the placenta secretes human chorionic gonadotropin (HCG), a pregnancy hormone. You may also experience some symptoms of pregnancy, such as fatigue and breast tenderness. But later when the placenta stops growing and hormone levels decrease, your pregnancy symptoms will subside. At this point, you may have m