Question: Is pregnancy an additional risk during during H1N1 infection?

Context:
H1N1 influenza in pregnancy can be associated with severe complications
This case series confirms a high number of complications in pregnant women due to pandemic H1N1/09.
Pregnant women might be at increased risk for complications from pandemic H1N1 virus infection.
Pregnant women are at increased risk for complications from pandemic influenza H1N1 virus infection. 
Vaccination of pregnant women against influenza A (H1N1) by Russian subunit formulation (MonoGrippol plus) showed reactogenicity comparable to control group by the level of influence on general metabolic and immunologic homeostasis and on the course of pregnancy, which is an evidence of its safety
Pregnancy was identified as a major risk factor for increased mortality and morbidity due to H1N1 influenza in the pandemic of 2009 to 2010
While it is not possible to ascertain retrospectively if myocarditis was caused by either infection with H1N1 virus or as a result of pregnancy (in the absence of endomyocardial biopsies), the significant association with myocardial involvement in both women demonstrates the increased risk of exposure to H1N1 influenza virus in pregnant women.
Although limited in size, the fully prospective nature of the safety follow-up of these women vaccinated during pregnancy is unique and offers an important degree of reassurance for the use of the AS03 adjuvanted H1N1 (2009) vaccine in this high risk group for H1N1 infection.
During the H1N1 2009 pandemic, pregnant women constituted one of the priority groups for vaccination in many countries, creating a need for close monitoring of the safety of the vaccine in pregnant women
Emerging data suggest that pregnancy conveys high risk for severe complications from the 2009 pandemic influenza A virus (2009 H1N1) infection
Pregnant women have been identified as a group at risk, both for respiratory complications than for the admissions to the Intensive Care Unit (ICU) during the 2009 H1N1 influenza pandemic
This report mitigates substantially the presumed severity of pandemic H1N1/09 influenza infection during pregnancy
The results of our study do not indicate a risk for the pregnant woman and the developing embryo/fetus after H1N1 vaccination
This large cohort study found no evidence of an increased risk of fetal death associated with exposure to an adjuvanted pandemic A/H1N1 2009 influenza vaccine during pregnancy
Our results suggest that second- or third-trimester H1N1 vaccination was associated with improved fetal and neonatal outcomes during the recent pandemic
Pregnant women might thus be at increased risk of complications from pandemic H1N1 virus infection, and illness may progress rapidly
Pregnant women with H1N1 infection seem to benefit from antiviral therapy.
arly identification and treatment were the most important factors in different countries and areas examined.
The vaccine and antiviral drugs that have been the most efficient means to control the novel virus appear to be safe but require more extensive study
However, there were significant differences between the two groups in relation to mean age, treatment with oseltamivir, schooling, and presence of other risk factors
To investigate whether exposure to an adjuvanted influenza A(H1N1)pdm09 vaccine during pregnancy was associated with increased risk of adverse fetal outcomes.
In this Danish cohort, exposure to an adjuvanted influenza A(H1N1)pdm09 vaccine during pregnancy was not associated with a significantly increased risk of major birth defects, preterm birth, or fetal growth restriction
Most people affected by the virus, including pregnant women, suffer a mild viral illness, and make a full recovery
Pregnant women, because of their altered immunity and physiological adaptations, are at higher risk of developing pulmonary complications, especially in the second and third trimesters
The pregnancy outcomes were also poor for women who were affected by the virus with a fivefold increase in the perinatal mortality rate and threefold increase in the preterm delivery rate
regnant women were at increased risk for serious outcomes of 2009 pandemic influenza A virus subtype H1N1 (influenza A[H1N1]pdm09) infection, but little is known about the overall impact of the pandemic on neonatal and maternal outcomes
In this large, geographically diverse population, A(H1N1)pdm09 infection increased the risk for hospitalization during pregnancy
Vaccination during pregnancy with Pandemrix(®) appeared to have no ill effects on the pregnancy. On the contrary, the rate of preterm birth and low birthweight was lower than expected, which agrees with some previous results
During the influenza A(H1N1)pmd09 pandemic, although many cases occurred in younger adults, the risk factors identified for severe infections and complications were similar to those for seasonal influenza, including chronic respiratory, renal, liver, and heart diseases.
In terms of pregnancy, the studies have shown contradictory results due to variations in methodology and medical care.
However, it seems that pregnancy, particularly during the third trimester, increases the risk of complications, and that early antiviral treatment is associated with improved outcomes.
Pregnant women with mild clinical illness secondary to 2009 H1N1 were not at a greater risk of adverse pregnancy outcomes
However, severely infected women were more likely to deliver SGA infants
Gestational age is associated with the risk of developing critical infection. The risk increases with increasing weeks of gestation.
 Following the start of winter in Liaoning province in China, the number of pregnant women infected with influenza increased significantly
regnancy, with or without additional complications, constitutes a high-risk condition for complications of influenza infection and warrants early intervention with neuraminidase inhibitors such as oseltamivir, if influenza is suspected

Answer: Pregnant women are at increased risk for complications from pandemic influenza H1N1 virus infection. Pregnant women, because of their altered immunity and physiological adaptations, are at higher risk of developing pulmonary complications, especially in the second and third trimesters. Pregnancy, particularly during the third trimester, increases the risk of complications and early antiviral treatment is associated with improved outcomes.
Exact answer: yes