A blighted ovum refers to a miscarriage that occurs in the first few weeks of pregnancy.
It is estimated that only about 2/3 of female eggs that are fertilized result in detectable pregnancies. The other 1/3 of fertilized eggs spontaneously abort or die. Another name for a female egg is an ovum. A blighted ovum usually occurs before a woman even knows she is pregnant.
A blighted ovum is abnormal. Nature selects those people that are able to survive. Many of the fertilized eggs that die this early have severe genetic defects. These eggs cannot develop properly and end up dying. This condition seems to occur more often in older women. Older women have a higher risk of delivering children with genetic disorders, such as Down syndrome.
The main risk of this condition is usually the mental distress caused by discovery that the woman is or was pregnant. Repeated early egg deaths may indicate a genetic or physical disorder in the parents. Rarely, a specific problem may be causing multiple early egg deaths, such as low hormone levels.
A blighted ovum often causes no symptoms at all. Symptoms and signs may include:
Because women usually don't know they are pregnant at the very early stage of pregnancy, a diagnosis is not made. Menstrual periods usually return to normal quickly. In some cases, the diagnosis is made because a pregnancy test is positive and the woman misses her period. A special x-ray test will usually show either an empty womb or an empty birth sac.
In most cases, nothing can be done to prevent this condition. In the case of repeated early egg deaths, both partners may want to get genetic testing and genetic counseling.
The main long-term effects are related to mental distress. This is more often a problem if the condition occurs more than once, in which case it is very emotionally distressful to the people involved.
There are no risks to others, as this condition is not contagious. Those women with repeated early egg deaths might have a genetic problem. This problem may sometimes be passed on to the child if a regular pregnancy occurs.
Rarely, a treatable condition is found to be the cause of the blighted ovum. For example, a low hormone level may rarely cause early egg death. In these cases, hormone pills such as progesterone may work.
If repeated early egg deaths occur, artificial fertilization may be effective in producing pregnancy. Genetic testing may also be advised to rule out genetic problems. While these are not treatable, they may indicate the need for a sperm or egg donor in order to have children.
Hormones can cause side effects, such as headaches, mood swings, and others. Artificial fertilization is expensive and does not always work. The risk of multiple births is often higher.
In most women, the diagnosis is never made and treatment is never needed. Most women who have a blighted ovum go on to have a healthy child the next time they get pregnant.
If treatment occurs and is successful, a regular pregnancy occurs. Adoption is another option for many couples.
Most cases require no monitoring unless the woman or couple desires it. The abnormal pregnancy will eventually be aborted if no treatment to clean the uterus is performed.
Author:Eva Martin, MD
Editor:Planko, Christa, MA
Reviewer:Carlos Herrera, MD
Williams Obstetrics, 1997, Cunningham et al.
Danforth's Obstetrics and Gynecology, 1999, Scott et al.