Participants
A sample of 27 LGA mother-neonate pairs were recruited from the SJD
Barcelona Children’s Hospital (Catalonia, Spain) between April 2019 and
January 2020. Two cases were excluded because the FFR signal could not
be identified (i.e., the FFR’s signal-to-noise ration computed in the
consonant transition and/or vowel regions <0; see below).
Thus, the final sample included 25 LGA neonates and 25 neonates born
AGA, all paired by sex and gestational age (GA) at birth (Table 1). AGA
neonates were drawn from a larger cohort assessed in a previous
study39. In case that a LGA case could be paired with
more than one AGA neonate, the AGA pair was selected randomly using
Matlab (R2019b, Mathworks) .
AGA and LGA neonates were defined as those with a birth weight between
>10th and ≤90thpercentiles and >90th percentile,
respectively55.
Exclusion criteria were multiple
gestations, preterm delivery, preeclampsia, chromosomal or major
structural abnormalities or risk factors associated with hearing
impairment56. Also, since pre-gestational and
gestational diabetes mellitus have been associated with increased risk
of maternal and perinatal adverse outcomes57,58, cases
affected by these clinical conditions were also excluded. To monitor and
detect a possible late gestational diabetes debut, in addition to the
O’Sullivan test and the subsequent oral glucose tolerance test (OGTT)
implemented for positive O’Sullivan cases, a further OGTT was carried
out in those pregnant women with a fetus diagnosed of LGA. This further
OGTT was implemented after the LGA diagnosis following the hospital LGA
care guide, resulting in a negative result in all our cases. The
specific protocol of this study was approved by the institutional Ethics
Committee of Clinical Research (CEIC) of the Sant Joan de Déu Foundation
(Approval ID: PIC-53-17) and all parents gave the informed consent in
compliance with the Declaration of Helsinki.