[A H1N1 influenza infection in pregnant patients]

Despite the severity of infection with influenza virus, little has been reported about its presence in pregnant women.

To communicate our experience on influenza virus H1N1 in pregnant women.

We conducted a retrospective cohort study on 16 hospitalized patients with diagnosis of pregnancy and probable or confirmed case of infection with H1N1 influenza virus. SUSPECTED CASE: Sudden onset of respiratory infectious process, in 2009, in Mexico City. All cases underwent the fast detection test and subsequently confirmation by PCR test. Discharge criteria: clinical improvement, PaO(2) above 60 mm Hg and absence of bilateral consolidation on chest radiographs. Severity criteria: type I respiratory failure (PaO(2) < 50 mm Hg) who required mechanical ventilatory support, radiographic pattern compatible with multisegmental pneumonia and PaO(2)/FiO(2) < 200 mm Hg.

The pregnant patient mortality was 4.25%. The average age was 25.8 years, with 24.13 weeks of gestation with 5.6 days average of hospital stay. The main co-morbidity was obesity.

The fatal cases were those with longer time of evolution and late diagnosis.