RHD and alloimmunization: Although the largest decline in Rh alloimmunization occurred in the 10 years following the approval of RhoGAM, the first anti-RhD prophylactic agent, in 1968,22 we observed a decline in the mean live birth prevalence of Rh-induced HDFN from 99 per 100,000 newborns in the period from 1996 to 2000 to 76 per 100,000 newborns from 2001 to 2005 and 44 per 100,000 newborns from 2006 to 2010.