tailieunhanh - Molar pregnancy and other gestational trophoblastic

The spectrum of GTD includes: Choriocarcinoma, placental site trophoblastic Risk factors for GTD are: tumor PSTT) and epithelioid trophoblastic; teenage pregnancies tumor (ETT) which are all malignant degenera; pregnancies in women above the age of 35 years tions of placental tissue. Very rarely no antecedent; history of molar pregnancy: the risk of recur-pregnancy can be identified. PSTT and ETT are rence is 1% after one molar pregnancy and rare and are not discussed further in this book. | 27 Molar Pregnancy and other Gestational Trophoblastic Diseases Heleen van Beekhuizen INTRODUCTION Gestational trophoblastic disease GTD is a placental disease it arises from abnormal proliferation of trophoblastic cells in the placenta. When GTD persists or recurs it is often called gestational trophoblastic neoplasm GTN . The spectrum of GTD includes Complete and partial hydatidiform molar pregnancies the most common form of GTD invasive mole GTN . Choriocarcinoma placental site trophoblastic tumor PSTT and epithelioid trophoblastic tumor ETT which are all malignant degenerations of placental tissue. Very rarely no antecedent pregnancy can be identified. PSTT and ETT are rare and are not discussed further in this book. Most but not all GTD produce P-human chorionic gonadotropin hCG which is also produced in normal pregnancies and can be detected with a urine pregnancy test UPT . Complete mole This is the most frequent form 80 of GTD . Its chromosomal pattern is mostly 46XX and all chromosomes are paternal often an empty ovum is fertilized by a single sperm that duplicates but sometimes two sperm cells fertilize an empty ovum. No fetus is present in a complete molar pregnancy. In 15-20 of the complete hydatidiform moles the trophoblastic tissue persists and causes persistent invasive mole or choriocarcinoma. Partial mole In partial mole two sperm cells fertilize a normal ovum resulting in a 69XYY XXX or XXY chromosome pattern. Often a fetus or fetal tissue is present. Only of partial moles develop into invasive moles1. INCIDENCE Molar pregnancies are rare approximately 1 in every 400-800 pregnancies is a complete or partial molar pregnancy. Choriocarcinoma and persistent trophoblastic neoplasm are even rarer with an incidence of approximately 1 50 000 pregnancies. Risk factors for GTD are Teenage pregnancies Pregnancies in women above the age of 35 years History of molar pregnancy the risk of recurrence is 1 after one molar pregnancy and 15-20 after two .