Search

In this article I evaluate recent attempts to illuminate the human infant cry from an evolutionary perspective. Infants are born into an uncertain parenting environment, which can range from indulgent care of offspring to infanticide. Infant cries are in large part adaptations that maintain proximity to and elicit care from caregivers. Although there is not strong evidence for acoustically distinct cry types, infant cries may function as a graded signal. During pain-induced autonomic nervous system arousal, for example, neural input to the vocal cords increases cry pitch. Caregivers may use this acoustic information, together with other cues, to guide caregiving behavior. Serious pathology, on the other hand, results in chronically and severely abnormal cry acoustics. Such abnormal crying may be a proximate cause of adaptive infant maltreatment, in circumstances in which parents cut their losses and reduce or withdraw investment from infants with low survival chances. An increase in the amount of crying during the first few months of life is a human universal, and excessive crying, or colic, represents the upper end of this normal increase. Potential signal functions of excessive crying include manipulation of parents to acquire additional resources, honest signaling of need, and honest signaling of vigor. Current evidence does not strongly support any one of these hypotheses, but the evidence is most consistent with the hypothesis that excessive early infant crying is a signal of vigor that evolved to reduce the risk of a reduction or withdrawal of parental care. Keywords: colic; crying; early infant crying; honest signaling; infanticide; parental care; parent-offspring conflict., separation call; vocalization

Objective. The risk of becoming a victim of sudden infant death syndrome is increased in infants who sleep with their face under bedding items. The present study was designed to evaluate auditory arousal thresholds of infants who sleep with their face covered by bedclothes. Methods. Twenty healthy infants with a median age of 11.5 weeks (range: 4-22 weeks) were recorded polygraphically for 1 night. Although they slept in their usual supine position, a bed sheet was placed over their face for 60 minutes. Fifteen of the 20 infants were chosen at random and were exposed to white noises of increasing intensities to determine their auditory arousal thresholds. All infants were challenged with the face covered and with the face free during both rapid eye movement (REM) and non-REM (NREM) sleep. Seven infants were first challenged with the face covered, and 8 were challenged with the face free. The following variables were recorded simultaneously: electroencephalogram, breathing and heart rates, and rectal and pericephalic temperatures. In 5 infants who were not exposed to the auditory challenges, end tidal C[O.sub.2] was recorded for 30 minutes while sleeping with the face covered. Results. During REM sleep, arousals occurred for significantly more intense auditory stimuli when the infant's face was covered than when free. No significant difference was seen in NREM sleep. Compared with the face-free periods, the face-covered sleep periods were characterized by greater rectal and pericephalic temperatures, a greater density of body movements, and a decrease in NREM sleep. Respiratory frequency was increased during the face-covered periods in both REM and NREM sleep. No differences were seen in the frequency or duration of apnea. There was a tendency for heart rate to increase during both sleep stages when the face was covered, compared with the face-free periods, but the changes were not statistically significant. A positive correlation was found between pericephalic temperatures and arousal thresholds (r = 0.60) during REM sleep. End tidal C[O.sub.2] values increased when the face was covered, reaching a maximum value during the first 5 minutes of the experiment. No fall in oxygen saturation was seen. Conclusions. Covering the infant's face with a bed sheet was associated with a significant increase in auditory arousal threshold. The finding could be related to an elevation in temperatures within the infant's microenvironment. Pediatrics 2002;109:1112-1117; arousal, bedding, infant, temperature, sleep, sudden infant death syndrome. ABBREVIATIONS. SIDS, sudden infant death syndrome; REM, rapid eye movement; NREM, non-rapid eye movement., The risk of dying from sudden infant death syndrome (SIDS) is increased when an infant sleeps with the face covered by bed sheets, blankets, quilts, or duvets. (1-4) Under such [...]

Objective. The introduction of the "Back to Sleep" campaign for the prevention of sudden infant death syndrome (SIDS) brought with it concern that there might be an increase in the incidence of aspiration-related deaths. The objective of this analysis was to describe the trends in postneonatal mortality and proportionate mortality ratios for the United States for the years 1991 to 1996 for aspiration-related deaths and other causes to which a SIDS death could conceivably be reclassified. Methods. Linked birth and infant death vital statistic files for the United States were used for the years 1991, 1995, and 1996. US Vital Statistic Mortality files for the years 1992, 1993, and 1994 were used because of the absence of linked files for those years. Results. The overall postneonatal mortality rate between 1991 and 1996 declined 21.9%, whereas the SIDS rate declined 38.9%. The proportion of the postneonatal mortality (PNPMR) contributed by SIDS declined from 37.1% in 1991 to 28.8% in 1996. There was no significant increase in the PNPMR for aspiration, asphyxia, or respiratory failure. There was, however, a significant increase in the PNPMR for suffocation in bed or cradle from 0.9 to 1.3. Conclusions. These data show no evidence of an increased risk of death from aspiration as a result of the "Back to Sleep" program. Although there has been an increase in the proportion of postneonatal mortality attributable to suffocation, this represents a very small proportion of postneonatal mortality and thus potentially a very small number of SIDS deaths reclassified as suffocation. Pediatrics 2002;109:661-665; sudden infant death syndrome, aspiration, suffocation., ABBREVIATIONS. SIDS, sudden infant death syndrome. The American Academy of Pediatrics Task Force on Infant Positioning and SIDS issued its first recommendation on the nonprone positioning of infants in June [...]

Objective. In an attempt to foster self-soothing during the night, a novel sleep aid infused with maternal odor was introduced to 4 groups of infants ranging in age from 3 to 12 months. Infants' use of parent-provided sleep aids also was examined. Methodology. Nighttime sleep and waking behaviors were videotaped for 2 consecutive nights on 3 occasions over a 3-month interval. Using all-night video recording, the study examined the infant's use of a novel sleep aid and parent-provided sleep aids during sleep onset and after nighttime awakenings. Results. Results indicated that infants of different ages differed in the types of sleep aids used when falling asleep either at the beginning of the night or after awakenings in the middle of the night. More 3-month-olds used their thumbs/fingers/hands, whereas more 6-month-olds used soft objects. The 6-month-olds were most likely to use the novel sleep aid. Almost all of the infants at all 4 ages used some type of object during the night. Intra-individual analyses showed that infants tended to change their pattern of sleep aid use over the 3-month study period. Conclusions. The data provide evidence that infants during the first year of life use sleep aids frequently and interchangeably rather than a specific favorite object. Pediatrics 2002;109:594-601; sleep aids, infants, self-soothing., Parents of infants and young children regularly consult their pediatricians about how to get their child to fall asleep at the beginning of the night or how to get their [...]

Objectives. The Back to Sleep campaign has been credited with recent declines in the incidence of sudden infant death syndrome. Using survey data for the 1996-1998 birth cohorts, this epidemiologic study examines infant sleep position in a large, population-based sample. Data and Methods. Data concerning infant sleep position are drawn from the 1996-1998 Pregnancy Risk Assessment Monitoring System for 15 states. Weighted multiple logistic regression analysis is used to examine correlates of infant sleep position. Results. The prevalence of prone infant sleeping significantly declined between 1996 and 1998 (adjusted odds ratio [AOR] = 0.70; 95% confidence interval [CI] = [0.63, 0.78]). African Americans were more likely than non-Hispanic whites to sleep prone, (AOR = 1.45; 95% CI = 1.33,1.59), and were less likely to sleep supine (AOR = 0.52; 95% CI = 0.48, 0.57). Hispanic/Latinos were less likely overall than non-Hispanic whites to sleep prone (AOR = 0.81; 95% CI = 0.69, 0.95), but were also less likely to sleep supine (AOR = 0.78; 95% CI = 0.69, 0.87). Adherence to sleep position recommended by the American Academy of Pediatrics increased sharply among Hispanic/Latino infants. Very low birth weight infants and infants in larger families were less likely to sleep in the recommended supine position. Infants born between 1001 and 1500 g (AOR = 0.67; 95% CI = 0.57, 0.79), and extremely low birth weight infants between 500 and 1000 g (AOR = 0.57; 95% CI = 0.45, 0.72) were especially unlikely to sleep supine. Infants in households with more than 3 other children (AOR = 1.72; 95% CI = 1.08, 2.74) were more likely to sleep prone. Conclusions. The prevalence of supine infant sleep increased between 1996 and 1998. Low adherence to sleep position recommendations of the American Academy of Pediatrics among African Americans, very low birth weight infants, and infants in large families remain public health concerns. Pediatrics 2002;109:608-614; sudden infant death syndrome, sleep position, low birth weight, racial disparities, PRAMS, Back to Sleep. ABBREVIATIONS. SIDS, sudden infant death syndrome; AAP, American Academy of Pediatrics; LBW, low birth weight; VLBW, very low birth weight; ELBW, extremely low birth weight; PRAMS, Pregnancy Risk Assessment Monitoring System; AOR, adjusted odds ratio., Sudden infant death syndrome (SIDS) is the most common cause of postneonatal infant death in the United States. In 1992, the American Academy of Pediatrics (AAP) issued a recommendation that [...]

Hypothesis. Laying supine with the head in midline position improves cerebral venous return by preventing functional occlusion of the vessels of the neck. Objectives. To assess changes in cerebral blood volume ([DELTA]CBV) and cerebral blood flow (CBF) with the position of the head in ventilated patients using a noninvasive method. The influence of the type of ventilation and birth weight was evaluated. Methods. Thirteen conventionally ventilated and 8 high-frequency oscillatory ventilated infants, with mean gestational ages and birth weights of 31 [+ or -] 5 weeks (24-38) and 1575 [+ or -] 803 g (560-3000), respectively, were studied 5.8 [+ or -] 7.8 days (1-33) after birth. [DELTA]CBV (mL/100 g) and CBF (mL/100 g/min) were measured by near-infrared spectroscopy with the head in supine midline position ([DELTA]CBVs, CBFs) and rotated 90 [degrees] to one side ([DELTA]CBVlat, CBFlat). Heart rate, peripheral saturation, transcutaneous PC[O.sub.2], and blood pressure were monitored continuously. Ventilatory settings remained constant throughout the study period. Results. Mean [DELTA]CBVs was lower than mean [DELTA]CBVlat, although no changes in blood pressure, transcutaneous PC[O.sub.2], oxygenation, or heart rate occurred. This change in [DELTA]CBV was not associated with the type of ventilation or birth weight, but the differences tended to be greater (d[DELTA]CBV = [DELTA]CBVlat-[DELTA]CBVs) in the smallest infants ( Conclusion. The supine midline position of the head favors cerebral venous drainage and helps to prevent elevation of CBV. Speculation. This finding may be important in the first days of life, particularly in tiny preterm infants recovering from lung disease with improving lung compliance, in which functional obstruction of cerebral venous drainage should be avoided. Pediatrics 2002;109: 434-440; neonate, cerebral blood volume, cerebral blood flow, head position, mechanical ventilation, near-infrared spectroscopy., ABBREVIATIONS. CBF, cerebral blood flow; CBV, cerebral blood volume; [DELTA]CBV, changes in cerebral blood volume; Sa[O.sub.2], arterial oxygen saturation; NIRS, near-infrared spectroscopy; [O.sub.2]Hb, oxyhemoglobin; HHb, deoxyhemoglobin; [DELTA]THb, changes in total [...]

CASE Jaquette, a 4-month-old African-American infant, is brought to the pediatrician for a health supervision visit. She was born full term after a healthy gestation, labor, and delivery. She nurses [...]