SELL and preeclampsia: Mechanical disruption of the zona pellucida during ICSI sperm insertion, changes in embryonic expression of L-selectin, or cytokines at embryo implantation may lead to abnormal placentation with oxidative stress, failure or delay in cytotrophoblast differentiation, and reduced extravillous cytotrophoblast invasion and intravascular invasion, ultimately leading to fetal intrauterine growth restriction or maternal preeclampsia (41, 42).