Abnormal placental function has been linked with preterm birth, and although the exact mechanism is not clear, it is known that placental gene expression differs between preterm and normal term placentas. PSGs are the most highly expressed proteins in the placenta, but their exact function has yet to be determined. We hypothesize that the PSGs play a key role in placental development which determines pregnancy outcome. To test this hypothesis, I will be using CRISPR interference methodology to knockout the PSG locus, and assess this loss of function to determine their role in placental trophoblasts.