Non-nutritive sucking by infants exposed to pethidine in utero

Obstetric analgesia in the form of pethidine (meperidine) to mothers during delivery has adverse effects on some aspects of the behaviour of their newborn infants. The non-nutritive sucking (NNS) pattern of nine healthy full-term infants exposed to pethidine in utero was compared to that of a control group of infants. The pattern was analysed and quantified using an automatic computer-based method. The results are discussed in the context of endogenous and exogenous opiates and their effect on brain-stem rhythm generators. Conclusions: The typical NNS pattern with alternating sucking activity (bursts) and pauses is preserved in the exposed infants. There is a significantly lower sucking frequency (md 1.74 vs 1.90 Hz, p = 0.030*) and a tendency to a less stable rhythm in pethidine-exposed infants.     

Development of sucking rhythm in preterm infants

We studied the ontogeny and temporal organization of non-nutritive sucking during active sleep in 6 healthy preterm infants (mean birthweight 1.1 kg (range 0.8-1.3 kg) gestational age 28.6 weeks (range 26-30 w] from 30 to 35 weeks of post-menstrual (PM) age. Recognizable rhythmical sucking bursts were recorded at 28 weeks in one infant and by 31-33 weeks in the others. Results were analyzed for the periods 30-31, 32-33 and 34-35 PM weeks. The number of bursts/min increased with age, while the duration of each burst was stable (mean 4.1 s). The pause between bursts decreased. Sucking pace within bursts increased with age which resulted in an increase in the overall rate of sucking. The coefficient of variation (CV) for intersuck time within bursts and for interburst time was computed to examine the stability of the sucking rhythm. For intersuck time the CV was relatively low and constant across ages. However, for interburst time CV was relatively large across ages. Thus, there appears to be a stability of the intraburst sucking rhythm from 30 weeks of gestation, whereas the interburst rhythm is less regular. This documentation of temporal organization in sucking from 30 weeks is one of the earliest indications of an intrinsic rhythm in human behavior.     

Early oral behaviour in preterm infants during breastfeeding: an electromyographic study

The objectives were to increase the understanding of the characteristics of oral behaviour during breastfeeding in preterm infants and to validate direct observations of infant sucking. Twenty-six infants were investigated once by simultaneous observation and surface electromyography (EMG) at 32.1-37.1 postmenstrual weeks. The orbicularis oris muscle was used for data analysis, as it provided the most distinct registrations. High correlation coefficients were observed with respect to classifications of EMG data by two raters on the number of sucks per burst (r = 0.97) and duration of sucking bursts (r = 0.99). The agreement between direct observations of sucking and EMG data was high. The median for mean number of sucks per burst was 8 (range 2-33) and for longest burst 28 (5-96) sucks. Sucks with low and very high intensity constituted a median of 14 (1-94)% and 25 (0-87)% of all sucks. The range in mean sucking frequency was 1.0-1.8 sucks s(-1). Suck duration ranged from 0.6 to 1.1 s. There was a considerable variation between infants in the extent of mouthing. No association with maturational level appeared for any of the components in oral behaviour. Conclusion: EMG data provided evidence of early sucking competence in preterm infants during breastfeeding, with wide individual variations. Surface EMG and direct observation are recommended as valid methods in the evaluation of breastfeeding behaviour in preterm infants.     

Neurological assessment of preterm infants at term conceptional age in comparison with normal full-term infants

In a long-term prospective study 46 unselected infants born before 35 weeks of gestational age were followed up, which included repeated neurological and psychological examination. 40 of them were neurologically evaluated at term conceptional age and compared with 26 full-term newborns, all the infants being considered healthy. There was no difference in mean weight or length between the two groups, but mean head circumference was greater in the preterm group. The preterm infants had lower muscle tone as judged by spontaneous posture of arms and legs, and poor resistance to passive movements and slow arm recoil. In the traction test they had more head lag. The withdrawal and Moro reflexes were weaker, while asymmetric tonic neck reflex (ATNR) was easier to elicit. Head control in the sitting position was better. All infants were evaluated with a prenatal and perinatal optimality score, which was not however significantly correlated with the neurological findings. The preterm infants with only slightly reduced optimality score (low risk group) had approximately the same birth weight and gestational age as the other preterms. They more resembled the full-term infants with good resistance to passive movements, fast arm recoil and good responses concerning the withdrawal and Moro reflexes. However, they had a semiflexed position in supine and thus in this respect were more like the other preterms.     

Patterns of breath intervals during non-nutritive sucking in full-term and ‘at risk’ preterm infants with normal neurological examinations

The interaction between respiration and non-nutritive sucking rhythms was investigated in 12 sleeping, normal, full-term, newborn infants and in 14 preterm infants who were examined repeatedly at 34, 40 and 46 wk of conceptional age. Full-term infants showed a shortening of breath intervals in the middle of sucking bursts and a lengthening of the breath interval spanning the end of sucking bursts. The differences were more marked in females than males.A rhythm interaction between sucking and respiration was also observed in preterm infants as young as 34 wk of conceptional age. Clinical neurological examinations did not discriminate between pretern infants above and below a median score for optimal obstetric conditions, but the interaction between breathing and sucking rhythms made such a discrimination, most clearly in females. Preterm infants with lower optimal obstetric scores showed less change of breath durations during sucking than preterms with higher scores. It was concluded that interaction of concurrent motor rhythms may be a sensitive index of central nervous system integrity in newborn infants, even when there are no clinical neurological signs of nervous system dysfunction.     

Assessment of behaviour on the Brazelton scale in healthy preterm infants from 32 conceptional weeks until full-term age

20 healthy preterm infants were assessed weekly by the Brazelton Neonatal Behavioural Assessment Scale from 1–2 weeks after birth until they reached their expected date of birth. The gestational age of the infants ranged from 28 to 34 weeks. Although the full scale could not be used before 36 conceptional weeks. obvious progress in development was found for most items of the scale. In particular there was improvement in orienting responses and in motor performance during the observation period. At full-term age comparisons were made with a group of normal-term infants (n = 80). All premature infants underwent standard neonatal neurological examination at full term, and tests of neurological function and psychomotor development up to the age of 18 months.     

A neurologic comparison of pre-term and full-term infants at term conceptional age.

There are currently no neurologic examinations designed for pre-term infants with sufficient data to determine neurologic deviance at various gestational or conceptional ages (gestational age plus age from birth). In this study a neurologic examination standardized for full-term newborn infants was administered to 97 full-term newborn infants was administered to 97 full-term newborn infants and 97 pre-term infants at their expected date of birth, 40 weeks' conceptional age. The pre-term infants had more weak responses than did the full-term infants despite being at a higher level of activity state throughout the examination. The pre-term infants also had more asymmetric responses. There was no correlation between gestational age and the incidence of weak responses in the pre-term infants, but the pre-term infants of lowest birth weight at all gestational ages had the greatest number of weak responses. The latter may be because pregnancy and neonatal problems contribute more to the neurologic findings than does the length of gestation.     

Non-nutritive sucking does not increase blood levels of gastrin, motilin, insulin and insulin-like growth factor 1 in premature infants receiving enteral feedings

Non-nutritive sucking in premature infants accelerates weight gain for unclear reasons. The effects of non-nutritive sucking on enteral hormone secretion may augment digestion and/or absorption of nutrients. Blood concentrations of gastrin, motilin, insulin and insulin-like growth factor-1 were measured before and 72 h after the initiation of nasogastric feedings in 21 premature infants randomly assigned to either a non-nutritive suckling or control group. Gastrin and motilin concentrations increased significantly after feedings in all infants (mean +/- SEM) (gastrin, 41 +/- 4 to 73 +/- 9 pg/ml, p < 0.01; motilin, 141 +/- 5 to 181 +/- 3 pg/ml, p < 0.01) Pre- and post-feed insulin concentrations were greater in the non-nutritive sucking group receiving bolus feeds than in control infants who were bolus-fed (P < 0.01). Non-nutritive sucking in premature infants does not appear to alter blood concentrations of motilin, gastrin, insulin or insulin-like growth factor-1 three days after initiation of feedings. If changes in the secretion of these hormones are induced by non-nutritive sucking, they may be at a local paracrine level.     

非营养性吸吮在机械通气治疗早产儿中的应用

目的：探讨非营养性吸吮在需要机械通气辅助治疗的早产儿中的作用。方法：将68例需要机械通气辅助治疗的早产儿随机分为观察组（n=35）和对照组（n=33）。观察组进行非营养性吸吮,对照组不进行非营养性吸吮。比较两组患儿达全胃肠道喂养时间、恢复至出生体重时间、体重增长速度、住院时间、喂养耐受性、机械通气并发症等。结果：与对照组比较,观察组达全胃肠道营养时间及住院时间缩短（P0.05）。结论：在需要机械通气治疗的早产儿中采用非营养性吸吮可加快其生长发育速度、缩短住院时间,并能提高喂养耐受性,而机械通气并发症发生率没有上升。     

Total energy expenditure, body composition and weight gain in moderately preterm and full-term infants at term postconceptional age

AIM: To assess total energy expenditure (TEE) and body composition, i.e. total body water (TBW) and adipose tissue volume (ATV), at term age in 8 healthy preterm infants, born between gestational weeks 30 and 33, and in 9 healthy full-term newborns. METHODS: Total and subcutaneous ATVs were assessed using magnetic resonance imaging, while TEE and TBW were estimated using doubly labelled water. RESULTS: Total ATV was 272 +/- 21 and 261 +/- 56 ml/kg body weight, while subcutaneous ATV was 88.9 +/- 1.6 and 89.7 +/- 2.0% of total ATV for preterm and full-term infants, respectively. The corresponding figures for TBW (as percentage of body weight) were 67.4 +/- 2.5 and 68.1 +/- 4.1, respectively. A significant correlation between ATV/kg body weight and body weight was found for full-term (p < 0.0001) but not for preterm infants. TEE for preterm infants was 315 +/- 20 kJ/kg body weight/24 h, which was significantly higher (p < 0.05) than TEE for full-term infants (254 +/- 45 kJ/kg body weight/24 h). At the time of investigation preterm infants weighed significantly (p < 0.05) less (540 g) than full-term infants. After the time of investigation, weight gains of preterm and full-term infants were 38 +/- 12 and 24 +/- 14 g/24 h, respectively. CONCLUSION: When compared to full-term newborns, predominantly breastfed healthy preterm infants at term postconceptional age were significantly smaller, had a similar average proportion of body fat and showed catch-up growth. Their higher TEE/kg body weight can be explained by a higher growth rate and possibly also by higher physical activity.     

Growth patterns in preterm infants born appropriate for gestational age

Aim:   This study aimed to document the growth patterns of a contemporary cohort of preterm infants born appropriate for gestational age (AGA). It was hypothesised that preterm AGA (PT-AGA) infants would display poorer growth than full-term AGA (FT-AGA) infants.
Methods:   Sixty-four PT-AGA infants and 64 FT-AGA infants were assessed at 0, 4, 8 and 12 months of corrected age (CA). Measurements of weight and length were recorded at each of the specified ages. Centers for Disease Control and Prevention growth data were used to calculate Z-scores for weight and length based on CA.
Results:   The mean length and weight Z-scores of PT-AGA infants were found to be significantly less than those of FT-AGA infants at term, 4, 8 and 12 months of CA ( P  < 0.001). The mean weight Z-score of PT-AGA infants was found to be less than their mean length Z-score at each time point, though the differences were not significant.
Conclusions:   The results of this study suggest that PT-AGA infants are likely to display poorer growth than FT-AGA infants until at least 1 year of CA. Long-term growth monitoring in this population is recommended.     

Pharmacokinetics and dosing of arbekacin in preterm and term newborn infants

BACKGROUND: The objective of the present study was to determine pharmacokinetic variables and to characterize a new initial dosing regimen of arbekacin (ABK) for preterm and term newborn infants. PATIENTS AND METHODS: Subjects were 40 infants treated with ABK in a tertiary care neonatal unit over a period of 18 months. At birth, the infants were 23 5/7-40 0/7 weeks and weighed 530-3428 g. Serum ABK concentration was measured at two points in a course of treatment. Data were analyzed by a one-compartment model to obtain volume of distribution (Vd) and clearance (CL) of ABK. These variables were correlated with the patients' demographic and laboratory data. The new initial dosing regimen was determined based on these data. RESULTS: Sixty pairs of blood samples were taken from the infants. They were divided into three groups: preterm early (PE), gestational age (GA) < 37 weeks and postnatal age (PNA) < 28 days; preterm late (PL), GA < 37 weeks and PNA >or= 28 days; and term (T), GA >or= 37 weeks and PNA < 28 days. The Vd was 0.50 +/- 0.02, 0.48 +/- 0.04, and 0.43 +/- 0.03 L/kg, and CL was 0.59 +/- 0.04, 1.12 +/- 0.10, and 0.78 +/- 0.09 mL/min per kg (mean +/- SEM) in PE, PL, and T, respectively. The new dosing regimen is 5 mg/kg every 48 h, 5 mg/kg every 24 h, and 4 mg/kg every 24 h for PE, PL, and T, respectively. CONCLUSIONS: With the new dosing regimen, more infants achieved serum ABK levels within the optimal range than the conventional one.     

Immunogenicity of hepatitis B vaccine in term and preterm infants

Some studies have suggested that decreased seroconversion rates might be found in premature infants with low birthweight (< 2000 g) following administration of hepatitis B vaccine at birth. The aim of the present investigation was to evaluate possible differences in seropositive rates between full-term and preterm infants after primary vaccination, in particular when gestational age or birthweight is very low. Two-thousand and nine neonates born to HBs Ag-negative mothers were vaccinated with 10 μg of recombinant hepatitis B virus (HBV) vaccine, from May 1991 to October 1994. Children with infections, congenital malformations or serious illnesses were excluded. HBV vaccine was administered intramuscularly, on the fourth day of life and again at 1 and 6 months of age. A 1-ml blood sample was drawn from each infant 1 month after the third vaccine dose for determination of the level of anti-HBs antibody. The response to HBV vaccination was evaluated in 241 preterm (gestational age < 38 weeks) infants and 1727 term neonates. No statistical difference was observed in the distribution of anti-HBs antibody level, either between preterm infants (< 38 weeks) and newborns of normal gestational age, or between low birthweight (< 2500 g) and normal weight infants. The results suggest that preterm and low birthweight infants (< 2500 g) respond to HBV vaccine in the same measure as normal-term infants.     

晚期早产儿和早期足月儿1岁时神经心理发育水平的随访研究

目的 探讨晚期早产儿和早期足月儿1岁时的神经心理发育水平。方法 选择矫正年龄为1岁的1 257名儿童为研究对象。根据其出生时胎龄分为4组：早期早产儿（胎龄28~33⁺⁶周）、晚期早产儿（胎龄34~36⁺⁶周）、早期足月儿（胎龄37~38⁺⁶周）及完全足月儿（胎龄39~41⁺⁶周）。采用Gesell发展量表评估其神经心理发育水平,比较各组儿童在1岁时神经心理发育状况。结果 4组儿童1岁时5大能区（适应性、大运动、精细动作、语言、个人社交）发育商的差异均有统计学意义（P < 0.05）,且均表现为完全足月儿 > 早期足月儿 > 晚期早产儿 > 早期早产儿的趋势（P < 0.05）;各能区发育迟缓率也均表现为完全足月儿最低,早期早产儿最高（P < 0.05）。与完全足月儿相比,早期足月儿适应能力发育落后的风险增加（OR=1.796,P < 0.05）;晚期早产儿适应能力和精细动作发育落后的风险较高,OR值分别为2.651、2.679（P < 0.05）;早期早产儿适应能力、精细动作和个人社交能力发育落后的风险较高,OR值分别为4.069、3.710、3.515（P < 0.05）。结论 儿童1岁时神经心理发育落后的风险随出生胎龄的增加而降低,呈现剂量反应效应。早期足月儿和晚期早产儿仍然存在不同程度的发育落后,应重视早期足月儿和晚期早产儿的保健随访。     

Short‐term effects of fresh mother's own milk in very preterm infants

Fresh mother''s own milk (MOM) can protect preterm infants from many complications. Often MOM is pasteurized for safety, which can deactivate cellular and bioactive components with protective benefits. Questions remain regarding whether pasteurized MOM provides the same benefits as fresh MOM. The aim of this study was to evaluate the association and feasibility of feeding very preterm infants with fresh MOM. This prospective cohort study included 157 very preterm infants born before 32 weeks'' gestational age and with a birthweight below 1500 g. Of these, 82 infants were included in the fresh MOM without any processing group and 75 infants were included in the pasteurized never‐frozen MOM (PNFMOM) group. The mortality rate, survival rate without severe complication, incidence of complications, feeding indexes and growth velocities were compared to assess the association and feasibility of feeding fresh MOM. Compared with the PNFMOM group, the fresh MOM group had a higher survival rate without severe complications (p = 0.014) and a lower incidence of bronchopulmonary dysplasia (p = 0.010) after adjustment for confounders. The fresh MOM group regained birthweight earlier (p = 0.021), reached total enteral feeding earlier (p = 0.024), and received total parenteral nutrition for less time (p = 0.045). No adverse events associated with fresh MOM feeding were recorded. Feeding fresh MOM may reduce the incidence of complications in very premature infants. Fresh MOM was shown to be a feasible feeding strategy to improve preterm infants'' outcomes.     

晚期早产儿与足月小于胎龄儿生长发育状况比较

目的比较均为低出生体质量的晚期早产与足月小于胎龄(SGA)儿童的生长和发育状况。方法随机选取100例出生体质量<2 500 g的3岁儿童,其中50例为晚期早产儿童,50例为足月SGA儿童,对其进行体格测量及盖赛尔(Gesell)发育量表评估。结果晚期早产和足月SGA儿童的出生体质量、出生身长相近,但3岁时晚期早产儿童的身高、体质量、头围明显优于足月SGA儿童,差异有统计学意义(P<0.05);Gesell发育评估显示,晚期早产儿童的动作能、应物能、语言能、应人能均高于足月SGA儿童,差异有统计学意义(P<0.05)。结论同为低出生体质量,晚期早产儿童的长期生长和发育状况优于足月SGA儿童。