First Trimester Screening for Chromosomal Aneuploidies INTRODUCTION The incidence of fetal numerical chromosomal aneuploidies such as trisomy 21 (T21; Down syndrome), trisomy 18 (T18; Edwards syndrome), and trisomy 13 (T13;…
The Detailed First Trimester Ultrasound Examination INTRODUCTION The role of the ultrasound examination in the first trimester has changed over the last 30 years with the introduction of nuchal translucency…
Technical Aspects of the First Trimester Ultrasound Examination INTRODUCTION Over the past two decades the detailed ultrasound examination of a fetus before the 16th week of gestation was made possible…
Multiple Pregnancies in the First Trimester INTRODUCTION The widespread use of assisted reproductive technologies along with increasing maternal age has resulted in a steady rise in the frequency of multiple…
Fetal Biometry and Pregnancy Dating in the First Trimester INTRODUCTION Accurate performance of an ultrasound examination in the first trimester is important given its ability to confirm an intrauterine gestation,…
Physical Principles and Bioeffects of First Trimester Ultrasound INTRODUCTION Recent advances in ultrasound technology along with a growing body of literature expanded the role of obstetric ultrasound in the first…
Guidelines to Fetal Imaging in the First Trimester INTRODUCTION In the late 1980s and early 1990s, ultrasound evaluation of the fetus at less than 16 weeks of gestation was made…
