Assessment of nasal and oral flow of amniotic fluid in 46 non-anomalous fetuses with sonographic and echocardiographic examination.

Abstract

The aim of the paper was to assess nasal and oral amniotic fluid flows, with the use of color ultrasound and spectral Doppler, in normal fetuses. Forty-six fetuses of singleton gestations were studied prospectively. Spectrum imaging and maximal nasal fluid flow velocities were described. Episodes of regurgitation (external flow from the mouth), swallowing (internal flow at the level of oropharynx and then entrance to the esophagus) were evaluated in two groups: Fetuses < 27 weeks of gestation and 27 weeks of gestation and older. Statistical analysis was done using Fischer exact test and t-test at p = 0.05. Twenty-one fetuses were < 27 weeks of gestational age and presented mean maximal both inspiratory and expiratory nasal fluid flow velocities significantly lower than twenty-five fetuses who were ≥ 27 weeks of gestational age (p = 0.035 and p = 0.031 respectively, t-test). Episodes of regurgitation were observed more frequently in group of "younger" fetuses (p = 0.006, Fischer exact test). There was no statistically significant relationship between irregular nasal flow spectrum by color Doppler and gestational age group (p = 0.264, Fischer exact test). Episodes of regurgitation occurred in normal fetuses < 27th week of gestation. Fast amniotic nasal fluid flows without episodes of regurgitation were observed more frequently in fetuses ≥ 27 weeks and it could be interpreted as an additional sonographic feature of prenatal maturation.