REFERENCES
- Moghadam S, Engel W, Bougoussa M, et at. Maternal serum placental hormone and insulinlike growth factor binding proteins 1 and 3 in pregnancies affected by fetal aneuploidy and other abnormalities: implications for prenatal diagnosis of trisomy 21. Fetal Diagn Ther 1998;13:291–7
- Royston P, Thompson SG. Model-based screening by risk with application to Down's syndrome. Stat Med 1992;11:257–68
- Cuckle HS. Improved parameters for risk estimation in Down's syndrome screening. Prenat Diagn 1995;15:1057–65