title: Fetal auditory responses to external sounds and mother's heart beat: detection improved by Independent Component Analysis.
abstract: In this paper, we present a magnetoencephalographic study of the fetal auditory response to external stimuli and to the sound of the mother's heartbeat. We describe how an ad hoc functional selection procedure allowed us to isolate the sources in the fetal brain responding to sounds only, after the application to the recorded data of a standard Independent Component Analysis algorithm. In our experiment, acoustic stimuli were delivered to twelve healthy women with uncomplicated pregnancies at a time between 36 and 40 weeks gestational age, with their fetuses in breech presentation. Ultrasound images allowed determination of the region over the women's abdomen nearest to the fetal head, over which both the acoustic stimulator and the MEG sensors were subsequently placed. In 8 out of the 12 cases, our analysis provided consistent evidence of a fetal response both to the mother's heartbeat and to the external auditory stimulation; both were characterized by a clear prominent component at around 200 ms latency, which is widely accepted as the marker of the fetal response to auditory stimuli.
authors.affiliation: AFaR, Center of Medical Statistics and Information Technology, Department of Neuroscience, Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy. camillo.porcaro@afar.it
authors.forename: Camillo
authors.initials: C
authors.lastname: Porcaro
authors.forename: Filippo
authors.initials: F
authors.lastname: Zappasodi
authors.forename: Giulia
authors.initials: G
authors.lastname: Barbati
authors.forename: Carlo
authors.initials: C
authors.lastname: Salustri
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pizzella
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
authors.forename: Franca
authors.initials: F
authors.lastname: Tecchio
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D005072:Evoked Potentials, Auditory / Q000528:radiation effects*; D005260:Female; D005333:Fetus / Q000502:physiology / Q000528:radiation effects*; D005865:Gestational Age; D006339:Heart Rate; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D033261:Maternal-Fetal Relations; D011247:Pregnancy; D011930:Reaction Time; D013016:Sound; D018709:Statistics, Nonparametric; D014732:Vibration