Translucencia nucal y ductus venoso: valores de referencia en el primer trimestre de la gestación / Nuchal translucency and ductus venosus. Reference intervals in the first trimester of pregnancy

Objetivo: Establecer los intervalos de referencia en nuestra población de la translucencia nucal (TN) y del índice de pulsatilidad para venas (PIV) del ductus venoso (DV). Métodos: Durante 4 años, se estudiaron gestaciones consecutivas con ecografía realizada entre las 11,1-14,0 semanas procedentes de la población general. Se construyeron intervalos de referencia siguiendo la metodología descrita por las National Committee for Clinical and Laboratory Standards. De acuerdo con la conclusión del test de partición, se estimaron intervalos de referencia específicos para la edad gestacional mediante modelos de regresión lineal, para la TN. La desviación de los modelos estimados respecto a la linealidad se evaluó mediante polinomios fraccionales de grado 1 o 2. Resultados: Se incluyeron un total de 2.612 gestaciones. No se observaron diferencias significativas en los intervalos calculados para PIV del DV para los grupos de edad gestacional. Se observó una diferencia significativa de los valores de TN entre los grupos de edad (p < 0,001), y la estimación de los intervalos de referencia específicos para la edad gestacional mostró un incremento no lineal. Conclusión: Se observó un incremento de la TN con la edad gestacional, mientras que el PIV del DV se mantuvo constante

Objective: To establish the reference ranges for nuchal translucency (NT) and ductus venosus (DV) pulsatility index for veins (PIV) in our population. Methods: During a 4-year period, pregnancies originated from the general population undergoing 11.1-14.0 weeks ultrasound examination were studied. Reference intervals were constructed following the methodology described by the National Committee for Clinical and Laboratory Standards. According to the conclusion of the partition test, gestational age-related reference intervals were estimated using linear regression models for the NT. Deviances from linearity in the estimated models were evaluated using fractional polynomials of 1st or 2nd degree. Results: 2,612 pregnancies were studied. No significant differences were found for DV PIV between gestational age groups. There was a significant difference of the NT values between age groups (p < 0.001) and the gestational age-related estimation of reference intervals showed a no-linear increase. Conclusion: A significant increase was found for NT with gestational age, whereas the DV PIV remained constant

First-trimester screening for trisomy 21 combining biochemistry and ultrasound at individually optimal gestational ages. An interventional study.

OBJECTIVE: To assess the effectiveness of the Combined Test in the prenatal detection of trisomy 21 in the general pregnant population using a new timing for the screening approach. METHODS: First-trimester maternal serum biochemical markers (pregnancy-associated plasma protein-A and free-beta hCG) were determined in maternal serum at 7 to 12 weeks. Fetal nuchal translucency and gestational age were assessed at the 10- to 14-week ultrasound scan. A combined risk was estimated and delivered to the women the same day. When the risk was 1:250 or above, chorionic villus sampling was offered. RESULTS: Mean gestational age at biochemistry was 9.4 weeks, being 12.3 at ultrasound. In the 2780 studied pregnancies with a complete follow-up, observed detection rates were 88% (7/8) for trisomy 21 and 75% (3/4) for trisomy 18, with a 3.3% (92/2765) false-positive rate. CONCLUSION: The Combined Test, assessing biochemistry and ultrasound at individually optimal ages in the first trimester, showed an 88% detection rate for trisomy 21 with a remarkably reduced false-positive rate (3.3%).