By enabling parents to avoid unwanted female births, has prenatal sex selection accompanied reductions in patterns of excess female infant and child mortality in contexts with son preference? This study examines the relationship between prenatal and postnatal manifestations of son preference for six countries that have witnessed SRB distortions -- India, Nepal, Pakistan, Azerbaijan, Armenia and Albania. Using micro-data from birth histories of the Demographic and Health Surveys in combination with United Nations data on sex ratios at birth (SRB), I examine if differential mortality change by sex, particularly for girls at higher birth orders without brothers, can be explained by the uptake of prenatal sex selection. I find that changes in prenatal sex selection only explain mortality change in India. Across the different countries, although patterns of mortality disadvantage are concentrated among less educated mothers, prenatal sex selection is strongest among the better educated. Differential sorting into the two behaviors offers an explanation for why the effect of prenatal sex selection on mortality change is generally weak.