Health Column: H1N1 2009 & Pregnancy: Where are we now?

By Christian S. Pope, DO, FACOG
Diplomate, American Board of Obstetrics and Gynecology
HealthCare for Women Inc., New Bedford and Mattapoisett

Dr. Pope practices at St. Luke's Hospital, the New Bedford site of Southcoast Hospitals Group. He can be reached at 508-999-6245.

Dr. Pope is a featured columnist for The Standard-Times on women's health topics. Check out Dr. Pope's column the first Tuesday of every month at www.southcoasttoday.com.

H1N1 2009 & Pregnancy: Where are we now?

In the spring of 1918, the most lethal pandemic in history accounted for nearly 100 million deaths worldwide with 600,000 deaths in the United States alone. Remarkably, instead of deaths limited to the extremes of age, and chronically ill as is typical for seasonal influenza, this pandemic hit even the healthiest population segment. Strikingly, there was a high mortality rate among pregnant women.

There is no question that medical treatment and prevention is more sophisticated than in 1918, however it's successor, H5N1 or "bird flu" from Southeast Asia was responsible for a high mortality rate of 64 percent in birds and humans, with six pregnant women infected, four of which died.

What do pregnant women need to know?

Since the virus was initially acquired in Mexico, the U.S. Centers for Disease Control and Prevention (CDC) have reported 34 cases of H1N1 swine influenza in pregnant women in thirteen states. Given the increased morbidity and mortality that pregnant women face with influenza infection, it may not be surprising that the second mortality reported in the U.S. occurred in a woman 35 weeks pregnant this past April. In general, it is estimated that there is approximately one reported case per 100,000 of H1N1 in pregnant women; and pregnant women with confirmed cases of H1N1 are four times more likely to be admitted to the hospital than the general population.

Symptoms in the confirmed cases of H1N1 include fever and cough in more than 95 percent of cases. Also a runny nose, sore throat, headache, shortness of breath and muscle aches were reported in about half the cases, with vomiting and diarrhea reported less frequently. In general, symptoms reported are similar in both pregnant and non-pregnant women; however, pregnant women were more likely to report shortness of breath.

Little is known about the effects of H1N1 on the fetus, as most of the pregnant women who tested positive have not given birth yet. Similar to seasonal influenza, much is still unknown, but it is considered infrequent for the virus to pass through the placenta.

The CDC expects a vaccine to protect against H1N1 influenza to be available this fall.In the meantime, the CDC has recommended that pregnant women with symptoms suggestive of influenza be treated with an antiviral medication, Tamiflu (oseltamivir), and those with significant exposure should receive a prophylactic course of the medicine.

Vaccination is key

Once available, vaccination will be a vital element of the public health response to this influenza.

At present, the morbidity and mortality related to the current H1N1 influenza is relatively low. However, public health officials have concerns that the virus could mutate during these summer months and produce a second phase of illness in the fall, with more severe morbidity and possibly mortality.

Pregnant women are considered a high-priority group for receipt of pandemic influenza vaccine. Getting vaccinated during pregnancy for both the seasonal influenza and the H1N1 virus is the best way to protect against the flu.

Unfortunately, studies have shown that pregnant women have one of the lowest inoculation rates of all adult population groups recommended to receive the vaccine.* Information about the safety of influenza vaccine during pregnancy is scarce, but available data suggests no evidence of harm to either mother or infant.

Whether you are pregnant or not, it is important to take preventive steps against the flu. Wash your hands frequently or use an alcohol based antibacterial. Try to avoid contact with sick people. Avoid touching your face, mouth, eyes or nose. This is how germs are transmitted. If you are pregnant and have been in close contact with someone who has a confirmed case of H1N1, consult your physician immediately.

Southcoast Hospitals has compiled an H1N1 facts page including the latest guidelines from the CDC for pregnant women: http://www.southcoast.org/health/h1n1flu.html.

* Recommendation by the US Advisory Committee on Immunization Practices and the American Academy of Obstetricians and Gynecologists.