What is a blighted ovum?

What is a blighted ovum?

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.