H1N1 Influenza in Pregnancy

Outcomes for pregnant women infected with the influenza A (H1N1) virus during the 2009 pandemic in Porto Alegre, Brazil

“…Their median age was 26 years (range, 15-41 years) and their median pregnancy duration was 29 weeks (range, 8-41 weeks). Five (8.8%) were in the first, 22 (38.6%) in the second, and 30 (52.6%) in the third trimester of pregnancy; 25 (43.9%) were in their first pregnancy (i.e., gravida 1) and 32 (56.1%) were not (i.e., gravida ≥2); and 13 (Table 1). …”

“…Considering the great benefit of starting an antiviral treatment within 48 hours of the illness onset, especially in severe cases [10][11][12], it makes no sense to delay treatment when a speedy test is not available. Although the vast majority of studies have included only patients whose infection with the A H1N1 virus was confirmed by RT-PCR [2,7,11,13], studies in Latina America also included suspected cases of H1N1 infection [14].…”

Severe 2009 A/H1N1v influenza in pregnant women in Spain*

“…178 397) 148 170) .494 b Median no. leukocytes (range): no./mm 3 7,200 (1,800-20, and receiving corticosteroids early after ICU admission had a mean duration of corticosteroid therapy of six days (interquartile range [5][6][7][8][9][10]. Pregnant patients who received early corticosteroid therapy on ICU admission had a nonsignificantly higher ICU mortality than those who did not (15.4% vs. 13.5%, p value: 0.86).…”

“…days until beginning treatment (range) 5 (1-10) 4 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) .081 a Treatment within 48 hr of symptom onset: no./total (%) 5 of 36 (14) 28 of 118 (24 response. In consequence, the proinflammatory conditions induced by influenza virus infection in pregnant women, who show in addition altered levels of cytokines and chemokines due to pregnancy itself, could impair the development of the specific host response against the virus (30).…”

Maternal immunization

“…7,8 Twentieth century influenza pandemics, including the 2009 H1N1 pandemic, demonstrated that pregnant women are at increased risk for influenza-related morbidity and mortality. [9][10][11][12][13][14] Seasonal influenza also imparts disproportionate morbidity and mortality to pregnant women, 15,16 partly due to the altered immunologic and physiologic parameters of pregnancy. 17,18 Numerous studies have documented increased respiratory, febrile, and cardiopulmonary morbidity among pregnant women during seasonal influenza epidemics.…”