MATERIALS AND METHODS. We examined 56 fetuses from weeks 15–39 of gestation. Each fetus was examined throughout four distinct periods of gestation: weeks 15–18, 22–25, 30–34, and 37–39. During the examination, seven gray-scale sonography or color Doppler sonography patterns and their prevalence were considered.

RESULTS. Mandibular and/or labial movements (² = 56.4, p < 0.0001) and their rhythmic activity (² = 41.4, p < 0.0001) were seen on gray-scale sonography in an increasing percentage of fetuses as gestational age increased. Doppler findings showed an increase for nose–mouth flow signals (² = 57.6, p < 0.0001), larynx–esophagus flow signals (² = 13.2, p = 0.0003), and effective swallowing (² = 36.0, p < 0.0001) as gestational age increased.

CONCLUSION. There is a trend in the fetus toward development of increased coordinated movement and more functional nose–mouth flow with increasing gestational age: 32.1% of the 56 fetuses in our series achieved effective swallowing at 37–39 weeks, on the basis of gray-scale and Doppler evaluations. Knowledge of the physiologic mechanism involving swallowing development may allow identification of altered swallow-related movements in fetuses with malformations of the digestive tract or with neurologic disorders.

MATERIALS AND METHODS. Fetuses with genitourinary abnormalities underwent blinded retrospective calculation of TLV. Distribution of the TLV–gestational age ratios for survivors and nonsurvivors were compared using the Wilcoxon's rank sum test. Lung volume calculation was compared with the presence or absence of oligohydramnios.

RESULTS. There were 21 survivor and 24 nonsurvivor outcomes based on neonatal discharge. TLV–gestational age ratios were significantly different between the survivor and nonsurvivor groups (p = 0.0001). No apparent difference was seen until after 26 weeks of gestation. TLV–gestational age ratios were equal to the presence or absence of oligohydramnios in predicting outcome after 26 weeks of gestation.

CONCLUSION. After 26 weeks' gestation, the prediction of outcome in fetal genitourinary abnormalities using the MRI TLV–gestational age ratio is comparable to the presence or absence of oligohydramnios.