Pregnant women who experience flu symptoms should get medical advice and treatment. (CBC)

Pregnant women are at greater risk of complications from swine flu and should consider avoiding crowded events, federal health authorities advised Friday.

Pregnant women should continue going about their daily lives during the pandemic, such as going to work or church.

"Caution should be taken, however, when entering situations where there are many people in close quarters with little control over personal contact," the Public Health Agency of Canada said in new guidelines and fact sheets posted on its website.

Events such as musical festivals expose people to many strangers who may be coughing or sneezing without the opportunity to practise "social distancing" or stepping away from the infectious person.

The advice also applies to people with chronic health conditions such as diabetes, Dr. David Butler-Jones, Canada's chief public health officer, said in a teleconference with reporters.

The risk of serious illness may be higher for pregnant women given the stress that fever and coughing from influenza places on a pregnant woman's body, when her immune system may not be able to respond as it would at other times.

The guidelines for pregnant women also recommend they be more vigilant about hand washing and carrying a hand sanitizer.

Research shows that pregnant women are not at greater risk of contracting the H1N1 virus itself, but are at greater risk of complications including delivering early or miscarrying.

In one province, of six cases in intensive care, three are pregnant women, said Dr. Danielle Grondin, assistant deputy minister of PHAC's infectious disease and emergency preparedness branch.

Antivirals recommended

The risk of complications is greater in the second and third trimesters of pregnancy and within four weeks postpartum, the agency noted in its guide for health care professionals.

The Public Health Agency of Canada also recommended treating pregnant women who develop influenza-like symptoms with the antiviral medication oseltamivir (Tamiflu), citing a study published last month in the Canadian Medical Association Journal.

The antiviral zanamivir (Relenza) may be preferred when nausea and vomiting are present in pregnant women, the agency said.

Both oseltamivir and zanamivir are considered to be compatible with breastfeeding, and the agency recommended women continue to breastfeed while taking the antiviral medications.

The supply of ventilators and surge capacity of health care workers continue to be key issues for health authorities.

The federal government is purchasing another 370 ventilators for the national stockpile for provinces and territories to use, Butler-Jones said.

These basic infection control practices continue to apply to all Canadians:

• Wash hands thoroughly with soap and warm water, or use hand sanitizer ( i.e. an alcohol-based hand-rub).
• Cough and sneeze in your arm or sleeve, not your hand.
• Keep common surfaces and items clean and disinfected.
• Keep doing what you normally do, but stay home if sick.
• Seek medical care if symptoms get worse.

Symptoms of the H1N1 pandemic flu virus include rapid onset of fever, cough, sore throat, wheezing and fatigue. Nausea, vomiting and diarrhea may also occur. Fever may not be prominent.