What Is a Blighted Ovum?

A blighted ovum describes what happens when a fertilized egg fails to develop into an embryo. A woman's body will usually naturally miscarry early in the first trimester when this happens. While it may be a sad or confusing event for a woman, it's her body's way of ensuring that only a viable embryo is developing and will result in a healthy baby.

Definition Of Blighted Ovum
When a fertilized egg attaches to the uterine wall, it begins to divide its cells and start the process of growing and developing into an embryo. When the cells develop in a way that is not viable or the egg has an abnormal amount of chromosomes, the body stops nurturing the cells. The body's natural reaction to the condition is to eliminate the damaged cells from the body.

Symptoms Of Blighted Ovum
The result of a blighted ovum is a miscarriage. The body expels the mass of cells in order to prepare the uterus for the next cycle. Some miscarriages are no more painful than menstrual cramps and, when the tissue is passed, it is generally not much different from a regular menstrual period. Other miscarriages result in frequent cramps and, occasionally, the doctor may perform a D&C to analyze the tissues for genetic or other reasons to try to identify any preventable conditions.

If a blighted ovum does not pass, it is usually discovered via ultrasound at one of the early doctor visits. The ultrasound will reveal an empty birth sac or simply no evidence of a viable pregnancy. However, the pregnant woman may still feel the symptoms of early pregnancy, such as morning sickness, tender breasts and fatigue. In that case, it might seem as if she is going through misdiagnosed miscarriages, but that's because it may take a while for the pregnancy hormones to leave the body and levels to return to a normal pre-pregnancy condition.

Frequency Of Blighted Ovum
A woman may experience a blighted ovum only once in her lifetime, or possibly never. Because many are never recognized or reported, there may be more than estimated. Other women may have a hard time conceiving and experience blighted ovum multiple times. In those cases, doctors generally try to gather samples of tissue for testing in order to determine a cause of frequency.