Aim: To investigate whether the same behavioral patterns were present pre- and postnatally, and whether there were any differences in the frequency of movements observed in fetal and in early neonatal life. Subjects and methods: Ten out of 37 pregnant women in the third trimester of pregnancy (median gestational age 34 weeks, range 33 to 35 weeks) in the two-month period (from November 1 st to December 31 st , 2003) were enrolled in the investigation. Ten term, appropriate for gestational age newborns (seven born vaginally, three by elective SC, six girls, six first-born) and were enrolled in the study. All 4D examinations were performed on Voluson 730 (Kretztechnik, Zipt, Austria) and Acuvix (Medison, Korea) with transabdominal 5 MHz transducer. After standard assessment in 2D B-mode ultrasound, a 4D mode was switched on and live 3D image was reconstructed by selecting the ideal representative 2D image placed in the region of interest (ROI). The recordings of neonatal behavior were made on the Sony P-612 OHMPL videotape by video camera (Sony Camcoder CC DTRV 318 Hv8) and reviewed on the videocassette recorder (Sony VHS SLV-N 900). The median of newborns' age at the moment of recording was 49 hours (range 4 to 112). During the examination, newborns were lying in the bed, separated from other infants in the nursery, dressed, and lying on their backs in a supine position with unrestrained hands. The temperature in the room was 22 to 24°C. The video recording was performed mainly while the children were actively awake or during alert inactivity. Results: There were no movements observed in fetal life that were not present in neonatal life, while the Moro reflex was present only in neonates. The most frequent fetal and neonatal movements were scowling, eye and mouth opening, and hand to face, hand to eye and hand to head movements. Isolated blinking, mouth to eyelid movement, yawning, tongue expulsion and scowling were more frequent in neonates than in fetuses, although the difference was not statistically significant. Hand to mouth movements were more frequent in neonatal than in fetal life while all other hand movements were less frequent in neonates than in fetuses, although the differences did not reach statistical significance. Spearman rank order correlation reached statistical significance in smiling (R=0.71; t=2.91; P=0.02) and in hand to ear movement (R=0.80; t=3.86; P=0.005), and was almost statistically significant in isolated eye blinking (R=0.61; t=2.17; P=0.06), while the correlations between the rest of the movements were not statistically significant. Conclusions: 4D ultrasonography is a powerful tool in the assessment of fetal behavior, and our study showed that there is a continuity from fetal to neonatal behavior, especially in terms of isolated eye blinking movements, mouth and eyelid opening, yawning, tongue expulsion, smiling, scowling and hand movements directed to other parts of the face.