Spontaneous motor behavior in fetuses and preterm neonates compared at the same postmenstrual age

The aim of this work is to extend preliminary results of a pilot study in which we compared spontaneous motor behavior of fetuses between 28 and 29 weeks with a group of preterm newborns at the same post-conceptional age. To detect and describe early behavior it was adopted a new coding scale which includes 21 complex behavioral motor patterns, based on the categories originally described in fetuses, preterm and full term newborns by de Vries (1982), Prechtl (1985), Kurjak et al. (2003), Einspieler et al. (2008) and Wolff (1987). The description of the complex behavioral motor patterns was conducted using the Facial Action Coding System (FACS) by Ekman and Friesen (Ekman & Friesen, 1978; Ekman, Friesen & Hager, 2002), with the insights and information added by Harriet Oster (Baby FACS, 2009). These methods have shown a documented reliability in the detection of facial actions in the first months of life, as well as in preterm neonates at a very low gestational age. In that study 6 fetuses and 6 preterm newborns with normal physiological characteristics were involved. Ultrasound examinations were performed by a gynecologist expert in the use of ultrasound scans in 3D and in 4D. Preterm newborns were filmed in one session, under conditions of non-stimulation, midway between two meals. During video recordings, particular attention was paid to the head position, since the camera was focused on the face for the entire length of the observation. The analysis of video recordings was performed frame by frame independently by two expert coders in behavioral micro-analysis. Data analysis were conducted on the frequency of occurrence per minute calculated for each of the 21 motor patterns. The contrasts between fetuses and preterm newborns were analyzed by using the nonparametric Mann – Whitney U – Test for independent measures. The results have shown significant differences between the two groups according to 5 behavioral motor patterns. In particular, preterm infants exhibited the facial expression of DISTRESS (M = 1.167, SD = 1,173) more frequently than fetuses, df = 1, U = 32, p = .025. Preterm infants showed also a greater number of STARTLE (M = 0.193, SD = 0.256 ), df = 1, U = 30 , p = .022 and movements related to SWALLOWING (M = 0.141, SD = 0.129), df = 1, U = 30, p = .022, than fetuses. Finally, preterm infants showed a greater number of episodes of BLINK (M = 0.370, SD = 0.410), df = 1, U = 30; p = .022 than fetuses, while fetuses showed more frequently the HAND TO FACE MOVEMENTS (M = 0.317, SD = 0.310), compared to preterm neonates, df = 1, U = 4, p = .022. Based on these promising results, our intent is to continue to collect, code and analyse new data, expanding both our samples.