Niveles de PAPP-A y fßhCG en gestantes gemelares monocoriónicas y bicoriónicas espontáneas y sus implicaciones en el cálculo del riesgo del cribado prenatal del primer trimestre

Nicolaides, 2005, Multicenter study of first-trimester screening for trisomy 21 in 75 821 pregnancies: Results and estimation of the potential impact of individual risk-orientated two-stage first-trimester screening, Ultrasound Obstet Gynecol, 25, 221, 10.1002/uog.1860 Kevin, 2007, Aneuploidy screening in the first trimester, Am J Med Genet C Semin Med Genet., 145, 18 Nicolaides, 2011, Screening for fetal aneuploidies at 11 to 13 weeks, Prenat Diagn, 31, 7, 10.1002/pd.2637 Benn, 2011, Aneuploidy screening: A position statement from a commitee on behalf of the Board of the International Society for Prenatal Diagnosis, ISPD position statement, Prenat Diagn, 31, 519, 10.1002/pd.2730 Gonce, 2005, Firt-trimester screening for trisomy 21 in twins pregnancy: Does the addition of biochemistry make an improvement?, Prenat Diagn, 25, 1156, 10.1002/pd.1304 Spencer, 2008, Screening for trisomy 21 in twin pregnancies in the first trimester: An update of impact of chorionicity on maternal serum markers, Prenat Diagn, 28, 49, 10.1002/pd.1923 Madsen, 2011, A reassessment of biochemical marker distributions in trisomy 21-affected and unaffected twin pregnancies in the first trimester, Ultrasound Obstet Gynecol, 37, 38, 10.1002/uog.8845 Linskens, 2009, Early first-trimester free fßhCG and PAPP-A serum distributions in monochorionic and dichorionic twins, Prenat Diagn, 29, 74, 10.1002/pd.2184 Prats, 2012, Early first-trimester free-ßhCG and PAPP-A serum distributions in monochorionic and dichorionic tweens, Prenat Diagn, 32, 64, 10.1002/pd.2902 Sepulveda, 1996, The lambda sign at 10-14 weeks gestation as a predictor of chorionicity in twin pregnancies, Ultrasound Obstet Gynecol, 7, 421, 10.1046/j.1469-0705.1996.07060421.x Amor, 2009, Pregnancies conceived using assisted reproductive technologies (ART) have low levels of pregnancy-associated plasma protein-A (PAPP-A) leading to a high rate of false-positive results in first trimester screening for Down syndrome, Human Reprod, 24, 1330, 10.1093/humrep/dep046