This issue of Clinics in Laboratory Medicine, Guest Edited by Anthony Odibo and David Krantz, will feature article topics such as: Screening for Chromosomal abnormalities; Cystic fibrosis screening; The role of second-trimester screening, in the post-first trimester screening era; Modifying risk for Aneuploidy with second-trimester ultrasound after a positive serum screen; Cost-effectiveness of Down syndrome screening paradigms; Biochemical and biophysical screening for the risk of Preterm delivery; Pre-implantation genetic diagnosis; Prenatal testing for infectious disease, Thrombophilias, Preeclampsia, Neural Tube Defects; Management of Multiple Pregnancy; Genetic Counseling Issues in Down syndrome Screening; First Trimester Ultrasound Markers; Quality Control of Nuchal Translucency; Clinical Implications of First Trimester Screening; Adverse Pregnancy Outcomes after Positive Screening; First Trimester Combined Screening: Instant Risks Approach.