What Pregnant Women Should Know About Fifth Disease

This common childhood illness is usually mild in kids, but it can pose a serious danger to pregnant women and their unborn babies. Here's what you should know.

By Kathy Sena

A Playground Illness

During school outbreaks (late winter and early spring), 10 to 60 percent of students may get fifth disease. It is spread like most colds, via coughing, sneezing and inadequate hand-washing. However, most children generally don't get very ill.

"Oftentimes, the symptoms are so similar to the flu, which is why it's important to have a doctor diagnose it if we suspect a child has it," says veteran school nurse Fetheresa Maderazo, R.N.

Maderazo says fifth disease is not common in all schools, but there are some schools that experience recurrent outbreaks.

"It's not one of those diseases that we can explain why it happens more at certain schools," she says. "But once we know that fifth disease is present, we send a school-wide notice home to parents, educating them about the disease. We take special precautions with the kids who have low immune systems. And," she adds, "if we have a staff member who's pregnant, we send her home, too."

The most important step that schools can take is to educate parents about getting a proper diagnosis and treatment - especially families with moms who are pregnant, Maderazo says.

Despite its strange name, fifth disease is no big deal for most kids. But it can lead to serious, and even fatal, complications for an unborn child if the mother contracts this disease.

Every pregnant woman should be aware of the risks of contracting fifth disease and should see her doctor promptly if she thinks she may have been exposed, experts say. If an expectant mom was exposed to an infected person during the contagious stage of the illness (generally 24 to 48 hours before symptoms begin to manifest), her doctor may recommend a blood test to determine whether she has had fifth disease in the past and is immune, or if she currently has it.

Fifth disease is a usually mild illness spread by airborne respiratory droplets, according to the March of Dimes. The illness is caused by human parvovirus B19. It got its name years ago when it appeared fifth in a list of what were considered the common causes of childhood rash and fever.

In a household, as many as 50 percent of susceptible persons exposed to a family member with fifth disease may become infected. ("Susceptible," in this case, means the person hasn't already had fifth disease and become immune.) Symptoms appear between four and 14 days after exposure. Fifth disease causes a distinctive "slapped-cheek" rash and, less commonly, a mild fever, cold-like symptoms, headache, sore throat and joint pain. Infected adults often experience joint pain and swelling, and they are less likely to develop a rash. Sometimes they experience mild flu-like symptoms.

Half of all women have already had fifth disease by the time they become pregnant; therefore, they and their pregnancy would be unaffected, says Susan Bostwick, M.D., chief of general pediatrics at Cornell University's medical college. And most fetuses are unaffected even if their mothers contract fifth disease, according to the March of Dimes. However, fifth disease does cause a 9-percent risk of fetal death, with three-fourths of those cases resulting in miscarriage or stillbirth.

If a pregnant woman becomes infected with fifth disease, her doctor will monitor the pregnancy carefully for signs of fetal problems. The virus can disrupt fetal ability to produce red blood cells, leading to a dangerous form of anemia and heart failure. Serious fetal complications, such as abnormal pooling of fluid around the heart, lungs or abdomen (which may result from the anemia) can be detected through repeated ultrasound examinations.

Most fetal complications develop within 10 weeks of the mother being infected, according to the March of Dimes. If an ultrasound does not show any problems during this time, no further testing is recommended.

Fetal deaths are more likely when a pregnant woman contracts the infection in the first 20 weeks of pregnancy rather than later in the pregnancy. The March of Dimes notes that some fetuses with severe complications from parvovirus B19 infection have recovered without treatment and appear normal at birth.

Minimizing Risk

As with most viruses, maintaining an extremely clean environment is the best way for pregnant women to lessen their degree of exposure.

"Because the disease is spread by droplets and secretions, keep washing your hands during the day," says Jamie McGregor, M.D., a visiting assistant professor in the department of obstetrics and gynecology at the University of Southern California School of Medicine. "It's quite difficult if you work in a daycare, school or have school-age kids. Pregnant moms should be especially careful around smaller children and try not to kiss too many people. It's hard, but use your own cup and don't share your cup with your kids," Dr. McGregor warns.

Although this "hands-off" approach may appear somewhat overcautious, McGregor says, expectant women could greatly limit the amount of germ exposure not just during a fifth disease outbreak, but throughout their pregnancy.

Treatments on the Horizon

About 20 percent of infected people have no symptoms and about 60 percent of adults have had the infection in childhood, often without knowing it, according to the March of Dimes. Currently, there is no vaccine for fifth disease. But a simple blood test can determine if someone has already been infected and, therefore, is not at risk.

There is no specific drug to treat fifth disease, says Cornell's Dr. Bostwick, but symptoms of fever or malaise can be treated with acetaminophen or ibuprofen. "If the child is otherwise healthy, the disease is often resolved in seven to 10 days," she says. By the time the child has the rash, when fifth disease is usually diagnosed, he is no longer contagious and may return to school, she adds.

"Unfortunately, the time when they are infective is before the rash appears, which is often before the diagnosis has been made, unless there is another case (within a group of children)," Bostwick says. This is different than for many other rash illnesses, such as measles, for which the child is contagious while he has the rash.

There is hope on the horizon for treatments for pregnant women and their unborn babies. According to the March of Dimes, researchers are creating diagnostic tools and treatments for fetal infection, including tests that can detect parvovirus B19 in a sample of amniotic fluid (obtained by amniocentesis) or fetal blood (obtained through the umbilical cord). One potential treatment may involve performing an intrauterine blood transfusion directly into an umbilical-cord blood vessel. These tests and treatments are not yet widely available, but your doctor can tell you if they are available in your area.

The best approach is to be proactive, McGregor says. "If you're pregnant, keep washing your hands and be aware of infections like human parvovirus B19, as well as other bacterial and viral infections."

Organizations & Resources:

  • Children's Hospital Boston - Offers a comprehensive checklist about fifth disease and warnings regarding the use of certain medications.

  • Children's Hospital Los Angeles - Offers a plethora of information on syndromes, diseases and conditions.

  • C.S. Mott Children's Hospital, University of Michigan Presents information about recent studies and advances in the treatment of numerous childhood diseases.

  • March of Dimes - A leader in helping to prevent birth defects, this organization offers information on a number of common complications and infections for pregnant women to keep on their radar.

  • Mayo Clinic - Offers in-depth health information for the prevention and treatment of conditions that affect all ages.

  • Nemours Foundation - Offers "doctor-approved" health and well-being information for infants through teens on fifth disease and other conditions.

  • New York State Department of Health - Offers a complete breakdown on the cause, prevention and treatment of fifth disease, as well as links to other resources.

  • U.S. Centers for Disease Control and Prevention - You'll find an array of information on infectious and chronic diseases, as well as facts on environmental health threats.

Kathy Sena is a freelance writer specializing in health and parenting issues. Angela Scott, a special sections editor for United Parenting Publications, also contributed to this piece.