Pandemic influenza A H1N1 2009 is a benign disease when infecting healthy adults, but it can lead to severe consequences in pregnant woman, for the fetus or its mother. The incidence of the disease is increasing strongly, and health authorities estimate that one third of the world population might be infected before the end of the winter. Diagnosis of infection with influenza virus H1N1 is suspected when a patient presents with the association of symptoms of the respiratory tract like sore throat, cough, or dyspnea, with general signs like fever, myalgias, or exhaustion. Diagnosis confirmation is obtained with nasopharyngeal swab and virus detection with molecular biology. This flu can lead to severe consequences for the pregnant woman and fetus. For this reason, it is advisable to treat pregnant women systematically by oseltamivir or zanamivir, and to treat preventively the pregnant woman in case of close contact with a suspected or confirmed infected person. Even if the management of influenza A H1N1 2009 infection during pregnancy relies on family physicians and gynecologists, every physician having in charge such cases should regularly update his knowledge regarding the evolution of the recommendations for the pandemic.