The Human Parvo Virus B19 Infection is present in almost every place. One of the diseases it produces is called the 'Fifth disease", a common infection experienced during childhood or adolescence. Thus, the National Center for Infectious Diseases has estimated that approximately 50% of all adults have experienced the fifth disease. After recovering from the disease, a person will most likely have developed immunity against further attacks of the B19 parvovirus.

A woman who is pregnant can be attacked by the B19 parvovirus. This occurrence is usually not life-threatening since many pregnant women are already immune to the virus. This immunity will also protect the unborn child. But sometimes, the pregnant woman will be easily fatigued and have mucous discharges from her nose. Aside from this, there are no serious human parvovirus symptoms that could endanger the lives of both mother and child. The B19 was never linked to mental retardation or any birth defects.

But there are a few cases of pregnant women who, after being infected by the B19 parvovirus, suffered miscarriage in the first half of pregnancy. The cause of the miscarriage is the severe anemia that happens to the unborn baby. The National Center for Infectious Diseases estimated these few cases to be about 5% of all B19-infected pregnant women.

If a pregnant woman has been known to be exposed to the B19 parvovirus, she should immediately inform her personal doctor about it. Usually, the physician will perform blood tests in order to know the medical situation of the pregnant woman with regards to the B19 parvovirus infection. The blood test will reveal one of the following:

· The pregnant woman is already immune to the B19 parvovirus and her body is not suffering any infection - This means that she has nothing to worry about the presence of the virus. Her immune system can easily handle the B19 parvovirus.

· The pregnant woman had a recent infection, most probably within the last three months - This means that the pregnancy must be closely monitored. There are no specific steps established to monitor a pregnant woman who recently had a B19 parvovirus infection, but the doctor can perform ultrasound examinations and more blood tests to make sure that the unborn baby is developing as he/she should be.

· The pregnant woman has no B19 parvovirus infection but she has no immunity against it - This means that the woman must avoid exposure to the B19 parvovirus. There is no vaccine yet against the B19 infection.

If the blood results revealed that the pregnant woman has no immunity against the B19 parvovirus infection, and she believes that she has been exposed to this virus, the doctor cannot provide medications to stop the infection. All the doctor and the pregnant woman can do is to weather the infection, which could last for one to two weeks. The unborn baby will be frequently examined for any signs of anemia.