Increased inspiratory effort in infants with a history of apparent life-threatening event

The objective of this study was to compare the results of polysomnography between infants with a history of apparent life-threatening event (ALTE) and controls. In this case-control study, 40 full-term ALTE infants, aged 2-36 wk at the time of the event, were compared with 40 age- and sex-matched randomly selected controls. SaO2, tcpO2, tcpCO2, heart rate (HR), vector of rib cage and abdominal respiratory movements (phase angle, as an index of inspiratory effort) were recorded during natural nocturnal active and quiet sleep (AS, QS). SaO2, tcpO2, tcpCO2 were similar in ALTE and controls in both sleep states. Phase angle was increased in ALTE infants in both AS (59+/-46 vs 26+/-17 degrees) and QS (53+/-46 vs 18+/-14, p < 0.001). Eleven ALTE infants (27.5%) experienced SaO2 < 90%, with a mean decrease in SaO2 to 86+/-1.6% (mean +/- SD), compared with 10% for controls (p=0.003). In eight ALTE infants, SaO2 values <90% were linked to thoracoabdominal asynchrony. SaO2 < 90% in conjunction with HR <100 bpm were detected in three ALTE infants and one control. Periodic breathing was observed in 45% of ALTE infants and 40% of controls. CONCLUSION: The mean values of oxygen saturation, tcpO2 and carbon dioxide levels in ALTE infants are comparable with those of healthy controls but the ALTE infants exhibit more hypoxaemic episodes and increased inspiratory effort during sleep.     

Bed sharing patterns in a cohort of Australian infants during the first six months after birth

OBJECTIVE: To measure bed sharing (BS) activity in healthy term infants. METHODOLOGY: The sleep-wake behaviour and place of infant sleep were recorded for infants aged between 2 and 24 weeks. Infants were then identified as BS or non bed sharing (NBS) according to each of four different definitions of bed sharing. RESULTS: The mean proportion of infants who spent any time BS during a 24-h period was significantly greater (P < 0.05) between 2 and 12 weeks (40.9 +/- 1. 4%) than between 13 and 24 weeks (36.5 +/- 1.5%). A significantly greater proportion (P < 0.005) of infants bed shared for more than 2 h (25 +/- 1%) than for either 1-2 h (10.5 +/- 1.1%) or for less than 1 h/24 h (3.2 +/- 0.5%) during the whole study period. Each of the definitions of BS used in the study separated infants on the basis of the amount and frequency of BS activity. CONCLUSION:: Bed sharing activity was common and varied in this cohort. It was possible, using quantitative definitions, to identify those infants who routinely bed share.     

Sleep patterns of New Zealand infants during the first 12 months of life

The sleeping patterns of 874 infants aged 1-12 months were recorded by parents over a 6 day period. The most striking feature of the results was the wide range in total hours slept by infants of the same age, for example, the average total sleeping time per 24 h period for 4 month old infants was 14.8 h with a range of 11.0-19.3 h. Furthermore, over the 6 day period, individual infants showed wide variations in their sleeping times with a range as great as 12 h. Despite these wide variations, several clear trends emerged: from 1 to 8 months, a decrease with age of the average number of hours slept per 24 h period; and from 8 to 12 months, and a continuing shift towards a dominance of night over day sleep. The frequency of night wakings was, on average, 77%, a finding that contrasted sharply with parental perception of frequency of night waking; the transition from bassinet/carrycot to cot was most common between 3 and 4 months of age; 25% of babies slept with the light on, 9% used a dummy, and 37% sucked their fingers; first-born infants woke significantly less often at night than those with one or more sibling. These results provide an important comparative data set on the sleep patterns of infants.     

Sleep and arousal, synchrony and independence, among mothers and infants sleeping apart and together (same bed): an experiment in evolutionary medicine

Although solitary sleeping in infancy is a very recent custom, limited to Western industrialized societies, and most contemporary people practice parent-infant co-sleeping, virtually all laboratory research on sleep in human infants assumes that solitary infant sleep is the normal and desirable environment. We have used evolutionary and developmental data to challenge this view. We suggest that co-sleeping provides a sensory-rich environment which is the more appropriate environment in which to study infant sleep. In addition, two preliminary, in-laboratory, polygraphic investigations of mother-infant co-sleeping are reported in normal infants, within the peak age range for sudden infant death syndrome (SIDS). Five mother-infant pairs co-slept one night in the first study; in the second, three additional pairs slept separately for two nights and co-slept the third consecutive night. The results suggest that co-sleeping is associated with enhanced infant arousals and striking temporal overlap (synchronicity) in infant and maternal arousals, and that, possibly as a result, co-sleeping mothers and infants spend more time in the same sleep stage or awake condition. The implications of the hypothesis and preliminary results for research on the normal development of infant sleep and on SIDS are discussed.     

Growth and development in preterm infants during the first 18 months

In a long-term prospective study 46 unselected infants born before 35 completed weeks of gestational age were followed up, and compared to 26 fullterm infants. At 9 and 18 months of chronological age their height and weight were still lower than that of fullterms, but the difference disappeared when age was corrected for gestational age at birth. The motor and neurological maturity and language development was delayed in the preterms still at 18 months, which could possibly also be explained by their lower biological age.

Ten of the preterm infants showed, at one or several occasions during follow up, definite neurological abnormality. At 18 months of age two of them were handicapped, one with retrolental fibroplasia, nearly blind, and another with cerebral palsy (slight spastic diplegia). Five of them had late psychomotor development, while two were borderline and one normal.

We defined pre- and perinatal risk groups, but found that development at 18 months was not correlated to degree of risk. Neither was there any correlation between neurological examination at term and later handicap or psychomotor retardation.

We found more illness, mostly due to common infections, during the first 18 months in the preterm group, as measured by the number of visits to a doctor and days spent in hospital.     

General movements in healthy full term infants during the first week after birth

Background

The quality of general movements (GMs) is a widely used criterion to assess neurological dysfunction in young infants. It is unknown, however, whether the birth process influences the motor repertoire of healthy full term infants during the first week after birth.

Aims

To assess the quality of GMs and to determine the motor optimality score (OS) in healthy full term infants during the first week after birth and to evaluate the influence of the mode of delivery on GM quality.

Study design

Thirty-three healthy full term infants born either vaginally or after caesarean section (CS) under spinal anaesthesia were video recorded in the first week after birth in order to assess GM quality and to determine OS with Prechtl's method.

Results

Abnormal GMs were observed mainly on the early recordings: 86% on the day of birth (day 0), 94% on day 1, and 68% on day 2. On days 5 to 7 (day 5–7) all GMs were normal (P < .001). The OSs increased significantly from median 12 on day 0 to 18 on day 5–7 (P < .001). Monotonously slow movements were frequently seen during the first days but not on day 5–7 (P < .001). GM quality and OS did not differ between infants born by vaginal delivery or after CS under spinal anaesthesia.

Conclusions

Healthy full term infants often showed abnormal GM quality and lower OSs during the first week after birth, irrespective of the mode of delivery. GM quality normalised during subsequent days and was normal on day 5–7.     

Glycerol carbon contributes to hepatic glucose production during the first eight hours in healthy term infants

The newborn infant must mobilize endogenous substrate stores to meet the requirements of glucose-dependent organs. High concentrations of free fatty acids and glycerol, and a rapid decrease in the respiratory quotient, indicate that lipids are an important fuel soon after birth. The purpose of the present study was to determine the onset of lipolysis and gluconeogenesis from glycerol in healthy, term, unfed infants. Eight infants were studied from a postnatal age of 3.5 ± 0.5 h to 7.4±0.2h using [6,6-²H₂]glucose and [2-¹³C]glycerol analysed by gas chromatography/mass spectrometry. Plasma concentrations of glucose, glycerol and insulin averaged 2.9±0.4mM, 369±89μM and 9.4 ±3.7 μU·ml^-1, respectively. The hepatic glucose production rate averaged 25.0±3.5 μmol·kg^-1 min^-1 (4.5 ±0.6mgkg^-1·min^-1) and the endogenous plasma appearance rate of glycerol 8.7±1.2/μmol·kg^-1min^-1. On average, 57.9±8.4% of the glycerol was converted to glucose, representing 11.1 ± 2.3% of hepatic glucose output. Thus, lipolysis and gluconeogenesis from glycerol are established within the first 8 h of life in term infants.     

健康足月新生儿生后10分钟内血氧饱和度及心率研究

目的探讨健康足月新生儿在出生后10 min内血氧饱和度(SpO2)及心率(HR)的变化及参考值。方法采用脉压氧饱和度仪测定203例正常足月新生儿(阴道产97例,剖宫产106例)在正常呼吸时的血SpO2及HR,描绘SpO2及HR在生后1~10分钟的第10~95百分位图表。结果生后第1分钟,健康新生儿血SpO2的P10、P50和P95分别为62%、71%和85%;HR的P10、P50和P95分别为66次/min、98次/min和126次/min。SpO2上升至90%的中位数时间为5 min。健康新生儿在出生后1~5 min HR随时间上升趋势明显,之后趋于平稳。结论可参考SpO2及HR,并结合临床表现综合评估新生儿,谨慎用氧,避免高氧或低氧血症对新生儿造成的损伤。     

Interactions among peripheral perfusion, cardiac activity, oxygen saturation, thermal profile and body position in growing low birth weight infants

Aims: To investigate the correlation between the ‘perfusion index’ (PI) and other commonly used estimates of cutaneous blood flow [heart rate (HR), surface temperatures (ST) and central‐to‐peripheral thermal gradients (C‐P grad)] and to use this new non‐invasive tool to compare differences between prone and supine sleep position in low birth weight (LBW) infants. Methods: Six‐hour continuous recordings of pulse oximetry, cardiac activity and absolute ST from three sites (flank, forearm and leg), along with minute‐to‐minute assessment of behavioural states were performed in 31 LBW infants. Infants were randomly assigned to the prone or supine position for the first 3 h and then reversed for the second 3 h. PI data were correlated with HR and C‐P grad, and compared across sleep positions during quiet sleep (QS) and active sleep (AS). Results: Perfusion index correlated significantly with HR (r² = 0.40) and flank‐to‐forearm thermal gradient (r² = 0.28). In the prone position during QS, infants exhibited higher PI (3.7 ± 0.9 vs. 3.1 ± 0.7), HR (158.4 ± 8.9 vs. 154.1 ± 8.8 bpm), SpO₂ (95.8 ± 2.6 vs. 95.2 ± 2.6%), flank (36.7 ± 0.4 vs. 36.5 ± 0.4°C), forearm (36.1 ± 0.6 vs. 35.5 ± 0.4°C) and leg (35.4 ± 0.7 vs. 34.7 ± 0.7°C) temperatures and narrower flank‐to‐forearm (0.6 ± 0.4 vs. 0.9 ± 0.3°C) and flank‐to‐leg (1.3 ± 0.6 vs. 1.8 ± 0.7°C) gradients, compared to those of the supine position. Similar differences were observed during AS. Conclusion: Perfusion index is a good non‐invasive estimate of tissue perfusion. Prone sleeping position is associated with a higher PI, possibly reflecting thermoregulatory adjustments in cardiovascular control. The effects of these position‐related changes may have important implications for the increased risk for sudden infant death syndrome in prone position.     

Sudden infant death syndrome and sleeping position in pre-term and low birth weight infants: an opportunity for targeted intervention

Aims

To determine the combined effects of sudden infant death syndrome (SIDS) risk factors in the sleeping environment for infants who were “small at birth” (pre‐term (<37 weeks), low birth weight (<2500 g), or both).

Methods

A three year population based, case‐control study in five former health regions in England (population 17.7 million) with 325 cases and 1300 controls. Parental interviews were carried out after each death and reference sleep of age matched controls.

Results

Of the SIDS infants, 26% were “small at birth” compared to 8% of the controls. The most common sleeping position was supine, for both controls (69%) and those SIDS infants (48%) born at term or ⩾2500 g, but for “small at birth” SIDS infants the commonest sleeping position was side (48%). The combined effect of the risk associated with being “small at birth” and factors in the infant sleeping environment remained multiplicative despite controlling for possible confounding in the multivariate model. This effect was more than multiplicative for those infants placed to sleep on their side or who shared the bed with parents who habitually smoked, while for those “small at birth” SIDS who slept in a room separate from the parents, the large combined effect showed evidence of a significant interaction. No excess risk was identified from bed sharing with non‐smoking parents for infants born at term or birth weight ⩾2500 g.

Conclusion

The combined effects of SIDS risk factors in the sleeping environment and being pre‐term or low birth weight generate high risks for these infants. Their longer postnatal stay allows an opportunity to target parents and staff with risk reduction messages.     

高原地区健康足月新生儿生后30分钟内 血氧饱和度、心率变化研究

目的探讨高原地区健康足月新生儿在出生后1～30分钟内血氧饱和度(SpO_2)及心率(HR)的变化情况。方法采用脉氧饱和度仪持续测定不同海拔地区194例正常足月新生儿在生后1～30分钟的SpO_2及HR,描绘生后1～30分钟的SpO_2及HR的P_5～P_(95)图表,并比较不同分娩方式、性别及不同海拔地区新生儿的差异。结果生后1分钟,新生儿平均SpO_2为(59±4)%,平均HR为(135±13)次/min,之后SpO_2逐渐上升,5分钟时达80%,10分钟时上升至89%,15分钟后稳定在95%左右。HR在生后2分钟后稳定在175次/min左右。出生1～15分钟,不同海拔地区新生儿的SpO_2差异均有统计学意义(P0.001);随海拔升高SpO_2降低,这种差异在生后20分钟及以后消失。生后1～30分钟,不同海拔地区新生儿的HR差异均有统计学意义(P0.001),海拔越高HR越高。不同分娩方式新生儿出生1～30分钟SpO_2和HR随时间变化的趋势有所不同(F=2.45、2.09,P均0.05),但不同性别之间SpO_2和HR随时间变化的趋势类似(P0.05)。结论随着海拔增高,新生儿出生后1～10分钟的SpO_2可略低于窒息复苏指南推荐的SpO_2,且上升至90%所需时间延长;海拔越高,新生儿HR越高。在高原地区进行窒息复苏时应结合临床表现,谨慎用氧,避免高氧损害。     

Use of a behavioural programme in the first 3 months to prevent infant crying and sleeping problems

OBJECTIVE: To assess the effectiveness of a behavioural programme introduced in the first 3 months of age in preventing infant crying and sleeping problems. Two issues were addressed: (i) which elements of the behavioural programme would parents implement; and (ii) whether the behavioural programme was more effective in reducing infant crying and encouraging night-time sleeping than an educational intervention or the routine services. METHODOLOGY: Mothers and newborns were assigned at random to the behavioural programme (n = 205), educational intervention (n = 202), or control (n = 203) group. Behaviour diaries kept before randomization and at 3, 6, 9 and 12 weeks of age were used to measure implementation of the interventions and infant behaviour, including crying and sleeping. Crying and sleeping problems were followed up using questionnaire measures at 9 months of age. RESULTS: The educational intervention did not change parental care behaviour. One element of the behavioural programme, a focal feed between 10 PM and midnight, was not implemented. A second element, stretching of interfeed intervals after 3 weeks of age, was implemented initially, but not maintained at older ages. The third element, which asked parents to emphasise day and night differences in the environment, and to settle their babies in the cot and minimise interaction at night, was carried out by more parents in the behavioural group than in the other groups. This led to an increase of around 10% in the number of babies who slept for 5 or more hours at night (a definition of sleeping through the night) at 12 weeks of age. Fewer behavioural programme parents sought help for crying and sleeping problems between 3 and 9 months of age. CONCLUSION: The behavioural programme produced a modest increase in the number of infants who slept through the night by 12 weeks of age. The results are discussed in relation to other findings, which bear on the programme's adoption for routine health-care policy and practice.     

出院后喂养方式对早产低出生体重儿生后3个月生长指标增长率的影响

目的：通过研究早产儿出院后配方奶（PDF）与母乳（BM）、足月儿配方奶（TF）等不同喂养方式对早产低出生体重儿（LBWI）出院至生后3个月时的体重、身长、头围等生长指标增长率的影响,为早产LBWI出院后喂养方式的选择提供参考。方法：广东省广州市、佛山市10家医院新生儿科出院的407例早产LBWI按照出院后喂养方式的不同,分为PDF组（n=258）、BM组（n=58）、TF组（n=91）,观察各组在生后3个月时的体重、身长、头围等生长指标值,并计算和比较各生长指标较出生时的增长率。结果：PDF组在生后3个月时的体重、身长和头围分别大于BM组和TF组（P＜0.05）;体重和身长增长率分别大于BM组和TF组（P＜0.05）。结论：出院后予PDF喂养能使早产LBWI在生后3个月时的体重、身长增长率较BM、TF喂养者更大,从而具有较大的体重、身长值,但远期效果有待进一步研究。     

出生3个月内婴儿的碘营养状态及其对早期生长发育的影响

目的了解出生3个月内婴儿的碘营养状态及其对早期生长发育的影响。方法在非碘缺乏地区的上海随机选取122名出生3个月内的婴儿(母乳喂养儿68名,配方乳喂养儿54名)进行观察性研究。分别于婴儿日龄42d和90d时测定其母乳或配方乳及婴儿尿中的碘浓度,并对婴儿进行身长、体重和头围测量,婴儿90d时行Gesell智力发育评估。结果①42d和90d时婴儿尿碘浓度(中位数)分别为161.0μg/L和184.1μg/L;②母乳和配方乳喂养婴儿在42d和90d日龄时的尿碘浓度(中位数)分别为197.9μg/L、115.4μg/L和219.2μg/L、140.1μg/L;尿碘浓度低于100μg/L的比例分别为12.0%、42.4%和4.4%、33.6%;③母乳和配方乳的乳碘浓度(中位数)分别为109.1μg/L和88.9μg/L,均与婴儿尿碘浓度呈正相关(r=0.523,0.696);④出生3个月内不同碘营养状态的婴儿在体格和智能发育方面差异均无统计学意义。结论①部分婴儿存在碘营养不足或过多,应加强对婴儿碘营养状态的监测;②母乳喂养婴儿的碘营养状态优于配方乳喂养的婴儿,积极鼓励母乳喂养;③出生3个月内不同碘营养状态婴儿间的体格和智能发育尚未见明显差异,有待进一步随访观察。     

Transcutaneous oxygen and carbon dioxide during the first half year of life in premature and normal term infants.

Repetitive polysomnograms were recorded from a total of 33 infants, 19 healthy preterm infants, and 14 term controls between 40 wk postconceptional age and 6 mo of age. These nighttime recordings lasted 2-4 h, except at 52 wk in preterm infants and at 3 mo of age in term infants when an overnight 12-h recording was performed. Minute by minute values of transcutaneous PO2 (PtCO2) and transcutaneous PCO2 (PtcCO2) levels and variability during the awake state, active sleep, and quiet sleep were obtained through computer analyses of the polygraphic data. The results from preterm infants at corrected postconceptional age could not be differentiated from those of control infants. PtCO2 levels rose between 40 wk and 3 mo, and PtcCO2 levels declined. Sleep states modulated only the variability of PtcO2, not the level; in contrast, state modulation was seen in both variability and level of PtcCO2 throughout the age span studied. During sleep the number of transient declines in PtCO2 greater than 2.03 kPa (15 mm Hg) decreased with advancing age. Hypercapnic PtcCO2 values decreased with age as well, but their prevalence in healthy, young infants suggests the need for reevaluation of criteria for hypercapnia based on transcutaneous measurements. The data demonstrate that ventilatory regulation continues to undergo changes between 1 and 3 mo, the age of highest risk for sudden infant death syndrome.