NLRP3 and infection: To determine if hemolysis and/or activation of the NLRP3 inflammasome is important for fetal injury and preterm birth caused by hyperhemolytic GBS strains, we utilized pregnant homozygous NLRP3 knockout (NLRP3KO) mice (Brydges et al, 2009; Kovarova et al, 2012) in the in utero model of infection described above.