Correction: Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology.

[This corrects the article DOI: 10.1371/journal.pone.0166514.].

Active sleep is associated with the face preference in the newborns who familiarized with a responsive face.

Aim of this study was to investigate the preferential looking behaviour, subsequent to a familiarization task (8-min) with a previously responsive or motionless face, before and after a sleep cycle. Moreover, the role of the active sleep in memory consolidation of the responsive or motionless faces was explored. Hypotheses were that the newborns undergoing a motionless familiarization will exhibit a novelty effect (preference for the novel face) whereas the newborns undergoing a responsive familiarization will show a familiarity effect (preference for the known face) before and after the sleep cycle; moreover, the amount of active sleep will be associated with the looking time at the known face after a sleep cycle. Forty-five healthy full-term newborns were randomly assigned to two groups (group 1: motionless-familiarization and group 2: responsive-familiarization); in both groups newborns were video-recorded during four post-familiarization face-preference tasks, two of them performed before and two after a sleep cycle. During the pre-sleep-trials, there was not a significant preference for one face in both groups. During the post-sleep trials, the newborns showed a clear preference for the novel face. This effect was more evident in group 1. Only in group 2 there was a significant positive correlation between the active sleep duration and the looking duration at the known-face during the post-sleep trials (r=0.41; p=0.040). Multiple regression confirmed that only in the group 2 the total duration of the active sleep was associated with the looking duration at the known-face during the post-sleep trials (Adjusted R2=0.13; ß=0.41; t=2.2; p=0.040). Findings showed that in newborns the face representation can be recalled after a sleep cycle. Moreover, the amount of the active sleep predicted the post-sleep looking toward the known-face only in the newborns who interactively familiarized with the face.

Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology.

OBJECTIVE: To investigate the proportion of stillbirths at term associated with abnormal growth using customized birth weight percentiles and to compare histological placental findings both in underweight stillborn fetuses and in live births. METHODS: A retrospective case-control study of 150 singleton term stillbirths. The livebirth control groups included 586 cases of low-risk pregnancies and 153 late fetal growth restriction fetuses. Stillbirths and livebirths from low-risk pregnancies were classified using customized standards for fetal weight at birth, as adequate for gestational age (AGA; 10-90th percentile), small (SGA; <10th percentile) or large for gestational age (LGA; >90th percentile). Placental characteristics in stillbirth were compared with those from livebirths using four categories: inflammation, disruptive, obstructive and adaptive lesions. RESULTS: There was a higher rate of SGA (26% vs 6%, p<0.001) and LGA fetuses (10.6% vs 5.6%, p<0.05) in the stillbirth group. Among stillbirth fetuses, almost half of the SGA were very low birthweight (≤3°percentile) (12% vs 0.3%, p<0.001). The disruptive (7.3% vs 0.17%;p<0.001), obstructive (54.6% vs 7.5%;p<0.001) and adaptive (46.6% vs 35.8%;p<0.001) findings were significantly more common in than in livebirth-low risk. Placental characteristics of AGA and SGA stillbirth were compared with those of AGA and FGR livebirth. In stillbirths-SGA we found a higher number of disruptive (12.8% vs 0%; p<0.001), obstructive (58.9% vs 23.5%;p<0.001) and adaptive lesions (56.4% vs 49%; p 0.47) than in livebirth-FGR. CONCLUSION: The assessment of fetal weight with customized curves can identify fetuses which have not reached their genetically determined growth potential and are therefore at risk for adverse outcomes. Placental evaluation in stillbirths can reveal chronic histological signs that might be useful to clinical assessment, especially in underweight fetuses.

Effects of different types of contingent tactile stimulation on crying, smiling, and sleep in newborns: an observational study.

Sleep, the brain and the ability to interact with the environment change a great deal over the first year of life; however, there are no studies on the possible influence of different environmental stimulations on the organization of subsequent sleep-wake cycles in infants. The hypothesis of this study was that greater continuity of contingent tactile stimulation decreases crying behavior, subsequent active sleep (AS) and its fragmentation, and increases smiling behavior and subsequent quiet sleep in newborns. Forty out of the 82 newborns (15- to 30-hr old) of the initial sample satisfied the inclusion criteria and completed the first cycle of sleep during the period between two feedings. The 40 newborns were randomly assigned to four groups after 2' of baseline observation: continuous stimulation (CS, n = 10); discontinuous nonperiodic stimulation (DnPS, n = 10); discontinuous periodic stimulation (DPS, n = 10); absent stimulation (AbS, n = 10). During baseline measurements, there were no significant differences in crying and smiling behaviors between the four groups, while during the subsequent stimulated wake, the CS group compared to the DnPS group showed more smiling (p < .05) and less crying (p < .05), longer poststimulation wake before sleep (p < .01) as well as AS with a lower percentage of grouped-rapid eye movements [grouped REM (GREM); p < .001]. The number of GREM during AS was negatively correlated to the number of smiles (p < .05) and positively to the number of cries (p < .05) of the previous stimulated wake. These findings suggest that, after birth, different continuity levels of contingent tactile stimulations may affect crying and smiling behaviors and the organization of behavioral states. AS could have an important role in processing affective states.

Newborn preference for a new face vs. a previously seen communicative or motionless face.

Newborn infants prefer to look at a new face compared to a known face (still-face). This effect does not happen with the mother-face. The newborns could be attracted by the mother-face because, unlike the still-face, it confirms an expectation of communication. Fifty newborns were video-recorded. Sixteen of them were recruited in the final sample: nine were exposed to a communicative face and seven to a still-face. All the 16 newborns were successively exposed to two preference-tasks where a new face was compared with the known face. Only newborns previously exposed to a still-face preferred to look at a new face instead of the known face. The results suggest that the newborns are able to build a dynamic representation of faces.

Smiling in newborns during communicative wake and active sleep.

Many studies have investigated infant smiling behaviour during wake and active sleep. In the majority of studies authors agreed that two month-old infants exhibit social smiles. However it is not clear if newborns exhibit different kinds of smiles during wake and active sleep to two month-old infants and if the communicative context can affect the quantity and quality of these smiles. The aim of this study was to test if different kinds of communication affects the amount and the quality of smiles during different behavioural states. Smiling behaviour was analyzed during interactive wake (IW) and active sleep (AS), in 40 newborns randomly assigned to 4 groups of 10 newborns each: continuous tactile communication group, discontinuous non periodic tactile communication group, discontinuous periodic tactile communication group, absent communication group. In the total sample the open/closed mouth (social/non social) smiles ratio was 38/5 during IW and 1/28 during AS (p < .001). Moreover these ratios were different between the four groups. Different kinds of tactile communication affect amount and quality of the smiles of newborns during IW and AS. Moreover the morphological difference of the smiles during IW and AS suggested that for newborns the smiling behaviour during IW could have a social meaning, as it does for two month-old infants.