Correlation between ductus venosus, gestational age and nuchal translucency at 11–14 weeks scan: preliminary study

Abstract

Background/objective: Fetal ductus venosus assessment at 11–14 weeks' gestation is one of the best tests to identify fetuses with cardiac malformation. Negative blood flow during atrial contraction has been used as qualitative sign in this cases. The aim of this study is to describe normal ranges for Doppler velocimetry of ductus venosus at 11–14 weeks' gestation and correlate it with nuchal translucency thickness.Material and methods: We performed a prospective study, 88 patients were examined at 11–14 weeks of pregnancy. Crown rump length, nuchal translucency, fetal anatomy and uterine artery Doppler velocimetry were evaluated transabdominally. Ductus venosus was identified using longitudinal plane and Doppler velocimetry index was measured using Doppler duplex ultrasound. An average of three waveforms were analyzed and pulsatility index venousus was measured. For statistical analysis mean values and 95% CI for pulsatility index of ductus venosus was established for each crown rump length, Spearman regression and normal centile distribution was performed.Results: The 77 out of 88 patients with nuchal translucency below 95th centile were used for calculating normal ranges for each gestational age. Mean maternal age was 29 ± 6.5 years old (range = 15–42), and 20% was over 35 years old. Mean pulsatility index was 1.02, 0.99, 0.95 and 0.92 at 11, 12, 13 and 14 weeks, respectively. Although ductus venosus pulsatility index was not modified according to gestational age, there was a significant positive correlation with nuchal translucency thickness (r = 0.59, P ≤ 0.001).Conclusion: Ductus venousus pulsatility index is correlated positively with nuchal translucency at 11–14 weeks' gestation.