First trimester risk assessment for trisomy 21 in twin pregnancies combining nuchal translucency and first trimester biochemical markers[J] . Pilar Prats,Ignacio Rodríguez,Carmina Comas,Bienvenido Puerto.Prenat Diagn . 2012 (10)Prats, P.; Rodriguez, I.; Comas, C.; Puerto, B. First trimester ...
first trimester is 12 weeks after ___ of last menstrual period first day gestational age is synonymous with ___ age and is used to date age of pregnancy menstrual ___is the first day of pregnancy conception first day of last menstrual period is beginning of ___ gestation we us ___ fo...