Pregnancy and Swine Influenza A (H1N1)

Swine flu cases reached 1,085 worldwide, spreading to every major region of the U.S., Bloomberg reports. So, if you're pregnant, here are a few things about pregnancy and swine flu you should know (adapted from Pregnant women and swine influenza):

Swine flu in pregnancy, what should you expect?

- Pregnant women with swine influenza would be expected to present with typical acute respiratory illness (e.g., cough, sore throat, runny nose) and fever or feverishness.

- Many pregnant women will go on to have a typical course of uncomplicated influenza.

- For some pregnant women, illness might progress rapidly, and might be complicated by secondary bacterial infections including pneumonia.

- Fetal distress associated with severe maternal illness can occur.

- Pregnant women who have suspected swine influenza A (H1N1) virus infection should be tested [specimens from women who have unsubtypeable influenza A virus infections should be sent to the state public health laboratory for additional testing to identify swine influenza A (H1N1)].

Who should receive treatment?

- Pregnant women with confirmed, probable or suspected swine influenza A (H1N1).

- Pregnant women who are close contacts with persons with suspected, probable or confirmed cases of swine influenza A (H1N1).

Note: Pregnancy should not be considered a contraindication to oseltamivir or zanamivir use*.

* Oseltamivir (Tamiflu) and zanamivir (Relenza) are "Pregnancy Category C" medications (no clinical studies have been conducted to assess the safety of these medications for pregnant women. However, no adverse effects have been reported among women who received oseltamivir or zanamivir during pregnancy or among infants born to women who have received oseltamivir or zanamivir.).

What's the treatment for swine flu in pregnancy?

- Oseltamivir (Tamiflu) is preferred for treatment of pregnant women (because of its systemic activity).

- Antiviral treatment should be initiated as soon as possible after the onset of influenza symptoms, with benefits expected to be greatest if started within 48 hours of onset based on date from studies of seasonal influenza.

- Some data from studies on seasonal influenza indicate benefit for hospitalized patients even if treatment is started more than 48 hours after onset.

- Recommended duration of treatment is five days.

- Fever in pregnant women should be treated with acetaminophen (Tylenol).

What's the prophylaxis for swine flu in pregnancy?

- The drug of choice for prophylaxis is less clear.

- Zanamivir (Relenza) may be preferable because of its limited systemic absorption; however, respiratory complications and medication delivery system challenges that may be associated with zanamivir because of its inhaled route of administration need to be considered, especially in women at risk for respiratory problems.

- Recommended duration of treatment for chemoprophylaxis is 10 days.

Note: Oseltamivir and zanamivir treatment and chemoprophylaxis regimens recommended for pregnant women are the same as those recommended for adults who have seasonal influenza.

Breastfeeding

- The risk for swine influenza transmission through breast milk is unknown. However, reports of viremia with seasonal influenza infection are rare.

- Women who are breastfeeding can continue while receiving antivirals. However, women who are ill with swine influenza A (H1N1) should take steps to reduce the risk to their infants, such as frequent hand washing and possibly wearing a mask (see below).

What are some other ways to reduce the risk for pregnant women?

- There is no vaccine available yet to prevent swine influenza A (H1N1).

- The risk for swine influenza A (H1N1) might be reduced by taking steps to reduce the chance of being exposed to respiratory infections, like frequent handwashing, covering coughs and sneezes, and having ill persons stay home, except to seek medical care, and minimize contact with others in the household who may be ill with swine flu.

- Additional measures that can limit transmission of a new influenza strain include voluntary home quarantine of members of households with confirmed or probable swine influenza cases, reduction of unnecessary social contacts, and avoidance whenever possible of crowded settings.

- If used correctly, facemasks and respirators may help reduce the risk of getting influenza, but they should be used along with other preventive measures, such as avoiding close contact and maintaining good hand hygiene. A respirator that fits snugly on the face can filter out small particles that can be inhaled around the edges of a facemask, but compared with a facemask it is harder to breathe through a respirator for long periods of time.

Bottom line: Best thing to do is to avoiding close contact and maintaining good hygiene. If you do get the disease, most likely the course will be mild and self-limiting. And even if it's not, don't panic; effective treatment is available.