BIRC5 and placental insufficiency: They commented upon the conflicting results of other studies that confused IUGR with fetuses that were small for their gestational age, because all participants in their study were assessed with Doppler velocimetry, which ensured that placental insufficiency was present, upregulating both pro-and anti-apoptotic genes (and thus can cause an increase in the survivin level) as a response to hypoxia [18].