Table 4.

Grading of evidence based on JBI grading

Number	Author	Recommendations	Grade
1	Lang A et al. (2020)  [23]	Prenatal experience or “fetal programming” may have an effect on behavioral (sleep/wake states) and physiological (heartrate) reactions just weeks after birth as evident in less waking periods and HR habituation to stimuli heard already in the last trimester before birth. Parents and societies should be aware of such effects and may consider this in their parenting methods even before birth. This is not to say that we are in favor of overambitious stimulation of the fetus in order to maximize learning even before birth. Rather we call into attention that much of what a fetus is exposed to before birth—whether it is parental movements, touch, music, or speech—may shape the infants’ physiology and later perception of the world	A
2	Lang et al. (2020) [24]	Our results indicate that newborns show distinct reactions to the maternal voice already at birth (two and five weeks) even on a physiological level and identifiable with ECG and EEG. Furthermore, it appears that basic memory traces are formed in utero and shape the newborn’s autonomic and neuronal reactions to speech and voice stimuli, namely, in such a way that newborns familiarized to nursery rhymes prenatally show distinctly different reactions than newborns being naïve in this respect. This again emphasizes the importance of the prenatal environment and calls into attention that already at these times the brain is tuned or “programmed” for the postnatal environment predicted and most likely experienced	A
3	Partanen E et al.(2013) [17]	These results indicate that auditory experiences during the fetal period can induce changes in neural processing and therefore have several important practical implications. First, these results indicate that the shaping of the central auditory system begins before birth. Repeated exposure to certain types of sounds leads to the development of neural memory traces for these sounds, as suggested by the strengthening of the activation in the MMR time range to changes in the learned material in the learning group. Thus, it appears likely that hearing a great deal of speech before birth may have positive effects, preparing the neural apparatus for the accurate analysis and discrimination of the fine acoustic features of speech. These early experiences may, then, affect the individual’s later abilities of speech perception and language acquisition	B
4	Partanen E et al.(2013) [25]	Our results show that prenatal exposure to music can have long-term plastic effects on the developing brain and enhance neural responsiveness to the sounds used in the prenatal training. Furthermore, we found that these plastic changes are long lasting. These findings have several practical implications. First, since the prenatal auditory environment modulates the neural responsiveness of fetuses, it seems plausible that the adverse prenatal sound environment may also have long-lasting detrimental effects. Such environments may be, for example, noisy workplaces and, in case of preterm infants, neonatal intensive care units. Furthermore, as prenatal exposure still affected the ERP responses months after birth, additional fetal exposure to structured sound environments might be beneficial for supporting the auditory processing of, for example, infants at risk for dyslexia in whom basic auditory processing was shown to be impaired	B
5	Arya R et al.(2012) [26]	In conclusion, this study provides preliminary evidence that maternal music exposure beneficially affects neonatal behaviour. A trained clinician can utilize the behavioural organization of the newborn infant to gain insights into the intrauterine experience and the perinatal events which may have influenced the neonate’s CNS organization	A
6	Granier-Deferre C et al.(2011) [27]	3-weeks of prenatal exposure to a specific melodic contour affects infants ‘auditory processing’ or perception, i.e., impacts the autonomic nervous system at least six weeks later, when infants are 1-month old. The long-term memory for the descending melody is interpreted in terms of enduring neurophysiological tuning and its significance for the developmental psychobiology of attention and perception, including early speech perception, is discussed	B
7	James D et al.(2002) [28]	The first prospective randomized controlled study to demonstrate that fetal exposure to a complex sound stimulus results in the development of altered behavior in the fetus and the occurrence of altered behavior in the newborn period compared to unexposed controls. We have not examined whether this effect is specific to this stimulus or sound exposure in general. Furthermore, there is no information that such effects are either long lasting or beneficial	A
8	Decasper A et al. (1986) [29]	The study provides the first direct evidence that prenatal auditory experience with a particular maternally generated speech stimulus influences the reinforcing value of that stimulus after birth. The present study suggests noninvasive, ethically acceptable methods to further study the effects of prenatal auditory stimulation on postnatal auditory function and development, especially the development of speech perception	B