Lullabies and pre-term infants: A contribution to the study of infant-directed singing in the NICU.

Background: The presence of lullabies has been observed around the world, in all cultures and historical periods. However, nowadays it seems that there has been a decrease in the knowledge and practice of lullabies in several contexts (Esteve-Faubel, Esteve-Faubel, Cavia-Naya, & Benlloch, 2014; Doja, 2014). It has been reported that in Portugal a small number of mothers and educators know and use this repertoire in order to lull their babies (Canez, 2008; Castro, 2013). We studied the case of a Portuguese Neonatal Intensive Care Unit (NICU) in order to observe this specific context. Aims: This study aims to produce more scientific data in the context of Infant Directed Singing in the case of pre-term infants in Portuguese NICU, as a complement to the limited existing literature. Our purpose was to understand what and how these mothers sing to lull their babies, focusing on lullabies as a specific behavior of mother-infant interaction. Method: We used a quantitative method, with a study case, where 36 mothers sang without words to their hospitalized preterm infants born between 32 and 37 weeks of gestation, in Kangaroo Supported Diagonal Flexion Positioning (Buil, Carchon, Apter, Laborne, Gratier, & Devouche, 2016). We parametrize the repertoire and analyze its characteristics, namely the melodic contours, range pitch, melodic intervals, rhythm, tempo and form. The participants also responded to a questionnaire regarding the habits of singing to their baby. Results: The repertoire sung by the participants was mainly based on pre-existing, highly mediated melodies such as Brahm’s Lullaby, Twinkle Twinkle Little Star or Happy Birthday. Few mothers chose to sing Portuguese play songs or lullabies. The improvised singing was highly repetitive and mostly by whole tones. Older and more educated mothers sang more pre-existing melodies and younger mothers tended to improvise. Conclusions: This study showed that these mothers tend to sing more adult songs and children’s mediated songs to their hospitalized babies than traditional Portuguese play songs or lullabies suggesting that, as shown in other studies (Grasina, 2017) mothers are not familiar with the Portuguese repertoire. It is possible that the sociological changes of a family in Portugal (Leandro, 2006), as well as the development of automatic reproduction devices that replace mother’s voice, led to this fact (Baker & Mackinlay, 2006). The characteristics in the improvised repertoire, which may be related to an attempt to please and calm the baby, were also common to a comfortable chant for a female voice. Further studies should tell us the vocal and physiological response of preterm infants to these songs.