Prenatal and early postnatal survival in the mouse as affected by infection of the mother with swine influenza virus during gestation.

Pregnant mice were given swine influenza virus intranasally approximately 5, 10 and 15 days after conception to determine what effect the maternal infection would have on the developing young. Effect on fetuses 10 to 15 days along at time of inoculation was negligible. Significantly fewer fetuses developed in mice inoculated approximately five days after conception. Viability of pups whelped was high and no effect on subsequent litters was manifested.