Complex sentence: Synyctin-1 mediated trophoblast fusion is essential for normal placental development and pathologies such as preeclampsia and IUGR are associated with abnormal expression of syncytin-1 in trophoblast cells.
Split into simpler sentences: Synyctin-1 mediated trophoblast fusion is essential for normal placental development and pathologies. Pre-eclampsia and IUGR are associated with abnormal expression of syncytin-1 in trophoblast cells.