What is a Blighted Ovum?

A blighted ovum is a fertilized egg which implants in the uterine wall, but does not develop. Typically, a blighted ovum results in a miscarriage, and this type of pregnancy is estimated to account for approximately half of first trimester miscarriages. While a blighted ovum technically doesn't even progress to the stage of becoming a fetus, it still feels like a pregnancy, and many women grieve the loss of the pregnancy, which is entirely appropriate. As a general rule, within one to three months, women can try for a new pregnancy.

The most common reason for a blighted ovum to develop is a catastrophic number of chromosomal abnormalities. The body recognizes that if the egg developed into a fetus and later into a baby, the baby would be extremely unhealthy, and its chances at life would be slim. Therefore, the egg is not allowed to develop, and within a relatively short period of time, the uterine lining is usually sloughed off, just like in a normal menstrual period, so that the body can prepare for another try at pregnancy.

This situation is also sometimes referred to as an “early pregnancy failure,” since “blighted” sounds rather pejorative, and “ovum” has a clinical tone. Sometimes, a blighted ovum miscarries before a woman is even aware that she is pregnant, and in other instances, the blighted ovum may be diagnosed when ultrasounds to track the progress of a pregnancy reveal a failure to develop on the part of the fetus.

In a typical blighted ovum, the placenta develops, and the levels of hormones associated with pregnancy go up. This means that a woman feels pregnant, which can make the loss of the fertilized egg traumatic. However, women should be aware that this complication of pregnancy is not at all preventable, and nothing that the mother does or doesn't do will affect the risk of having a blighted ovum.

When she receives the diagnosis of a blighted ovum, a woman can choose to allow the pregnancy to abort itself naturally. Others may opt for a medical abortion, for a variety of reasons. The primary advantage to having a medical abortion is that women can ask to have the egg tested to see which abnormalities caused the blighted ovum. Sometimes such tests can reveal potential problems which could be encountered with future pregnancies, such as the fact that one parent is the unwitting carrier of a genetic condition.