Purpose: Previous influenza pandemics have disproportionately affected pregnant women. The goal of the current investigation was to determine the epidemiologic and economic impact of an influenza pandemic on pregnant women in Allegheny County, Pennsylvania.

Methods: Using Microsoft Excel and Berkeley Madonna, a SEIR compartment model was developed simulating the effects of an influenza pandemic on the pregnant population in Allegheny County. The model used the following population assumptions: Total local population of 1,223,411; 52.4% are women; 3.3% may become pregnant in a year. We also assumed for a pandemic influenza strain an incubation period of 2 days, an infectious period of 6 days, and the Ro of 1.9. Economic impact was generated using hospital and clinic costs, productivity losses, and the costs of medications and medical equipment, all in 2007 dollars. The model also assumed absent matching between the influenza vaccine and the strain as well as random mixing among the pregnant and non-pregnant population. In addition, fetal outcomes and maternal mortality were not considered in this preliminary investigation.

Results: Among gravidas, 16,350 will contract influenza throughout the year. The peak number of actively infectious gravidas would be 2227 occurring 145 days into the epidemic. The impact of the influenza pandemic on the local pregnant population would cost society $3.128 million ($174.86 per case).

Conclusions: Pregnant women represent a vulnerable and unique patient population with specific medical and financial needs. This investigation provides preliminary projections to augment ongoing pandemic planning efforts for management of this patient population locally. This model also serves as a basis for national projections and more comprehensive analyses will be presented.