Parenting stress in mothers of preterm infants during early infancy

Objective

Mothers of preterm infants during the first year of life may experience stresses greater that those found in mothers of term infants. The aim of the study was to determine the levels of parenting stress and psychological well-being in mothers of very preterm babies in comparison to a control group of term mothers.

Methods

One hundred and five mothers who delivered 124 babies at ≤ 30 weeks gestation were recruited together with 105 mothers who delivered 120 babies at term. At 4 months of age (corrected for prematurity for the preterm babies), the mothers completed the Parenting Stress Index Short Form, the Edinburgh Postnatal Depression Scale (EPDS), the Dyadic Adjustment Scale (DAS) and the Short Temperament Scale for Infants (STSI). The preterm and term groups were compared.

Results

Questionnaires were returned from 86 of the preterm mothers and 97 of the term mothers. The mean Total Stress score for the preterm and term groups was 67.0 and 63.79 respectively (P = 0.32) with 17% of the preterm and 9% of the term group having high scores (P = 0.135). There were no differences of the EPDS and the DAS between the groups. The temperament of the preterm infants was similar to the term infants. For both groups, scores on the EPDS, DAS and the STSI were independent predictors of Total Stress scores on multiple regression analysis.

Conclusion

Parenting stress in mothers of preterm infants during early infancy does not appear to be greater than that in mothers of infants born at term. For both groups of mothers, depression symptoms, marital satisfaction and infant temperament were independent risk factors for high levels of parenting stress.     

Antimeasles antibodies in preterm infants during early infancy in Turkey

AIM: To measure maternally derived measles antibodies in sera of premature infants at birth and seropositivity rates in early infancy in a rural area of central Turkey. METHODS: 65 premature and 24 full-term infants born in Erciyes University Hospital and their mothers were recruited to a longitudinal, prospective study. The infants were divided into three groups by gestational age: group A, <33 weeks; group B, 33-37 weeks; group C, >37 weeks. For specific analyses, the groups were subdivided into groups Al, B1 and C1 (infants of naturally immunised mothers) and A2, B2 and C2 (infants of vaccinated mothers). Blood samples were obtained from mothers and infants after delivery. The infants were re-evaluated at 2, 4 and 6 months of age. RESULTS: Of 25 mothers, 20.3% were seronegative for measles antibodies. Twenty of the mothers had not been vaccinated. The percentages of seronegative infants at birth were 24.2% (n=8), 12.5% (n=4) and 0% (n=0) in groups A, B and C, respectively. No infants were seronegative at birth in Al, B1 or C1. Mean levels of antimeasles antibodies in all naturally immunised mothers were significantly higher than in vaccinated mothers. Antibody levels in all infants decreased rapidly with increasing age. Gestational age at birth [beta=0.179, t=3.359, 95% confidence interval (CI) 0.0001-0.0001, p<0.05], birthweight (beta=0.637, t=9.691, 95% CI 0.057-0.086, p<0.05) and maternal naturally immunised status (beta=0.168, t=2.825, 95% CI 0.002-0.014, p<0.05) were significantly associated with antibody levels after birth. In all groups of naturally immunised mothers, the percentages of seronegative infants were significantly lower than in vaccinated mothers at birth and at 2, 4 and 6 months of age. CONCLUSION: The current recommendation to immunise all infants at 9 months of age might require revision for premature infants, especially those whose mothers have vaccination-induced immunity.     

支气管肺发育不良早产儿婴儿期预后研究

目的 探讨支气管肺发育不良（BPD）患儿婴儿期体格发育、呼吸系统常见疾病发生情况以及运动发育情况。方法 回顾性分析2012年1月至2015年12月入住新生儿重症监护室的BPD早产儿的临床特征和婴儿期结局，并与同期住院胎龄及出生体重相近但未发生BPD的早产儿进行比较，比较两组早产儿婴儿期生长发育和运动发育情况、住院次数以及肺炎、喘息等疾病的发生情况。结果 与非BPD组患儿相比，BPD组患儿出院时更容易发生宫外发育迟缓（48% vs 41%），且生后更容易发生肺炎、喘息、湿疹、鼻炎，因呼吸道感染再次住院次数增加，差异均具有统计学意义（P < 0.05）。矫正3月龄、6月龄及12月龄时BPD组患儿头围小于非BPD组（P < 0.05）。矫正6月龄及9月龄时BPD组患儿粗大运动、精细运动以及总发育商均落后于非BPD组患儿（P < 0.05）。结论 BPD患儿出院时容易发生宫外发育迟缓，头围增长相对缓慢，婴儿期易发生肺炎及喘息，而且矫正6月龄及9月龄运动发育落后于非BPD早产儿。     

Diet and body composition of preterm infants

There have been few systematic studies of the effects of energy and protein intake on the body composition of preterm infants. Analysis of published studies suggests a roughly inverse relation between energy stored per gram of weight gain (a measure of the fatness of new tissues) and the ratio of protein to energy in the preterm infant's diet. At least within a certain range of energy and protein intakes, a higher protein diet promotes leaner body composition. Studies of the effects of varying the dietary ratio of carbohydrate to fat in preterm infants have shown reduced rates of carbon dioxide production with high-fat diets, fed by either the parenteral or enteral route. The little information available suggests no clear effect of varying the carbohydrate-to-fat ratio on body composition. The mineral content of the body can be influenced by diet. Insufficient intakes of calcium and phosphorus reduce the bone mineral content and thus the whole-body content of these minerals.     

Body water content of extremely preterm infants at birth

BACKGROUND: Preterm birth is often associated with impaired growth. Small for gestational age status confers additional risk. AIM: To determine the body water content of appropriately grown (AGA) and small for gestational age (SGA) preterm infants in order to provide a baseline for longitudinal studies of growth after preterm birth. METHODS: All infants born at the Hammersmith and Queen Charlotte's Hospitals between 25 and 30 weeks gestational age were eligible for entry into the study. Informed parental consent was obtained as soon after delivery as possible, after which the extracellular fluid content was determined by bromide dilution and total body water by H(2)(18)O dilution. RESULTS: Forty two preterm infants were studied. SGA infants had a significantly higher body water content than AGA infants (906 (833-954) and 844 (637-958) ml/kg respectively; median (range); p = 0.019). There were no differences in extracellular and intracellular fluid volumes, nor in the ratio of extracellular to intracellular fluid. Estimates of relative adiposity suggest a body fat content of about 7% in AGA infants, assuming negligible fat content in SGA infants and lean body tissue hydration to be equivalent in the two groups. CONCLUSIONS: Novel values for the body water composition of the SGA preterm infant at 25-30 weeks gestation are presented. The data do not support the view that SGA infants have extracellular dehydration, nor is their regulation of body water impaired.     

Body composition of preterm infants measured during the first months of life: bioelectrical impedance provides insignificant additional information compared to anthropometry alone

Detailed knowledge of body composition in preterm neonates during their later postnatal period may be important for the treatment process. However, little consideration has been given to test whether bioelectrical impedance analysis (BIA) is a useful bedside method to predict fat-free mass (FFM). The aim of the study is to assess whether BIA is a bedside method to measure FFM in preterm neonates. FFM of 118 white subjects (51 males, 67 females), mean gestational age of 30.1±3.1 weeks and birth weight of 1.26±0.47 kg, was measured at a gestational age of 38.6±3.8 weeks and actual body weight of 2.6±0.54 kg using dual energy X-ray absorptiometry (FFM_DXA). Weight (W), height (Ht), and bioelectric impedance (I) measurements were collected. Multiple regression analysis was performed to develop prediction equations to estimate FFM with impedance index (Ht²/I, cm²/Ω) and W (kg) as predictor variables. Bootstrap analysis was performed for validating the derived prediction equations. Correlations between FFM_DXA and weight were 0.96, 0.98, and 0.97 in boys, girls, and both sexes, respectively. Those between FFM_DXA and Ht²/I were: 0.73, 0.81, and 0.79. Equations used to predict FFM (kg) were for boys: and for girls: . Conclusions. In preterm neonates, weight is a more effective predictor of FFM than impedance index. The study provides a bedside procedure for estimating FFM, mainly based on anthropometric parameters rather than BIA.     

Inflation times during resuscitation of preterm infants

Data on the effects of a prolonged inflation time during the resuscitation of very prematurely born infants are limited; one study showed no effect, and in another, although lower bronchopulmonary dysplasia (BPD) rates were seen, that effect could have been due to the prolonged inflation time, the positive end expiratory pressure applied or the combination of the two. The aims of our study were to assess the length of inflation times used during face mask and t-piece resuscitation of prematurely born infants in the labour suite and determine whether prolonged inflations led to longer inflation flow times. A respiration monitor (NM3 respiratory profile monitor) was used to record flow, airway pressure and tidal volume changes. The first five inflations for each baby were analysed. Forty prematurely born infants (median gestational age 30, range 26–32 weeks) were examined. Their median inflation pressure was 17.6 (range 12.2–27.4) cm H₂O, inflation time 0.89 (range 0.33–2.92) s, expiratory tidal volume 1.01 (range 0.02–11.41) ml/kg and inflation flow time 0.11 (range 0.04–0.54) s. There was no significant relationship between the inflation time and the inflation flow time, but there was a significant relationship between the inflation pressure and the inflation flow time (p = 0.024). Conclusion: These results suggest that prolonging inflation times during face mask resuscitation of prematurely born infants would not improve ventilation as prolonged inflation did not lead to longer inflation flow times.     

Altered body composition in preterm infants at hospital discharge

Aim:  To test the hypotheses that body size is reduced and body composition altered in preterm infants at hospital discharge.
Methods:  Preterm infants (≤34 weeks gestation, ≤1750 g at birth) were enrolled. Body weight, length and head circumference were converted to standard deviation or z- scores. Body composition was measured using dual emission X-ray absorptiometry. The results were analysed using standard statistics.
Results:  One hundred and forty-nine infants (birth weight = 1406 ± 248 g, gestation = 31 ± 1.7 weeks) were studied. Postmenstrual age at discharge was 37 ± 1.2 weeks. Z -scores for head circumference, weight and length differed (−0.1 ± 0.6 > −1.4 ± 0.6 > −1.9 ± 0.6; p < 0.0001). Global fat-free mass was less in study infants than the reference infant at the same weight (2062 < 2252 g; p < 0.0001) or gestation (2062 < 2667 g; p < 0.0001). Global fat mass was greater in study infants than the reference infant at the same weight (307 > 198 g, 13 > 8%) or gestation (307 > 273 g; 13 > 9%; p < 0.0001). Changes in central fat mass closely paralleled those in global fat mass (r² = 0.76, p < 0.0001).
Conclusion:  Reduced linear growth and a reduced fat-free mass suggest that dietary protein needs were not met before discharge. A reduced fat-free mass coupled with an increased global and central fat mass echoes concerns about the development of insulin resistance and metabolic syndrome X in these high-risk infants.     

Neurobehavioral and developmental profile of very low birthweight preterm infants in early infancy

AIM: To describe the neurobehavioral and developmental profile of very low birthweight (VLBW) preterm infants in early infancy. METHODS: Twenty VLBW infants and 10 term control infants were assessed at term, 3 and 6 mo of age. Neurobehavioral assessments included the Neonatal Behavioral Assessment Scale (NBAS) at term; the Infant Behavioral Assessment at term, 3 and 6 mo of age and the Behavioral Rating Scale of the Bayley Scales of Infant Development-II (BSID-II) at 3 and 6 mo of age. Development was evaluated with the Bayley Motor and Mental Scale at 3 and 6 mo. RESULTS: At term age VLBW infants differed from term infants on all the clusters and supplementary items of the NBAS. VLBW infants also showed more stress and less approach behavior at term and 6 mo of age and more problems with self-regulation in all subsystems at 6 mo of age. Moreover, VLBW infants performed lower on the Bayley Motor, Mental and Behavioral Rating Scale: 12 VLBW infants scored questionable or non-optimal on the Psychomotor Development Index and 18 questionable or non-optimal on the Behavioral Rating Scale. These results support the need for neurobehavioral intervention of VLBW infants in the first 6 mo of life. CONCLUSION: Almost all VLBW infants showed non-optimal motor quality behavior at 6 mo and encountered far more problems with self-regulation compared with term infants.     

Cardiorespiratory stability during echocardiography in preterm infants

Blood pressure, heart rate, and oxygen saturation were monitored prospectively during 40 echocardiography recordings on 17 preterm infants (25-29 weeks; 510-1430 g), to examine whether echocardiography can be performed without disturbing cardiorespiratory status in preterm infants. There was no impact on absolute blood pressure. Heart rate increased by a mean of 4 beats per minute, and oxygen saturation decreased by a mean of 1% during echocardiography. While these changes reached statistical significance they are not of clinical significance as they remained well within ranges seen during control rest periods. All readings had greater minute-to-minute variability during echocardiography but differences were small and again remained within physiological ranges.     

Cerebral hemodynamics during arousals in preterm infants

The aim of the study was to evaluate potential changes of cerebral blood volume (CBV) related to arousals in preterm infants. As arousals are known to change different physiological parameters, it was postulated that this could also hold true for CBV. Polygraphic recordings were performed in 38 preterm infants (18 female, 20 male). The infants' gestational age at birth was 32.0+/-2.3 weeks, postconceptional age was 35.1+/-1.2 weeks and postnatal age at study entry was 24.3+/-2.9 days, birth weight was 1793+/-527 g and actual weight at study entry was 2011+/-324 g [mean (+/- standard deviation)]. CBV was measured using near infrared spectroscopy. Arousals were scored due to the guidelines of the "International Paediatric Work Group on Arousals" and categorized as either cortical (CA) or subcortical arousals (SCA). Altogether, 122 arousals (66 CA, 56 SCA) were scored. According to sleep stage, 77 arousals were analyzed in active sleep, 23 in quiet sleep and 22 in intermediate sleep. Mean duration of arousals was 8.8+/-0.3 s. CBV, cerebral vascular oxygenation and the balance between oxygen delivery and oxygen consumption remained constant during arousals in preterm infants. This was demonstrated for both CA and SCA and was independent of sleep stage, suggesting that the impact of arousals in stable preterm infants is too small to alter cerebral vascular autoregulation.     

Growth and body composition in preterm infants with bronchopulmonary dysplasia

OBJECTIVE: To compare growth and body composition in preterm infants with bronchopulmonary dysplasia (BPD) with normal healthy term infants during the first year of life. DESIGN: Twenty nine preterm infants with BPD (mean (SD) gestational age 27.1 (1.6) weeks; birth weight 852 (173) g) were followed prospectively. Anthropometry and body composition determined by total body electrical conductivity were measured and compared with those of healthy term infants at the same post-term age. RESULTS: In infants with BPD, the mean weight standard deviation scores (SD scores) 6 weeks after term were significantly lower (-1.44 and -2.68, boys and girls respectively) than in healthy term infants of the same age and did not improve during the first year. The mean length SD score was significantly lower in infants with BPD 6 weeks after term than in healthy term infants of the same age, and, although it improved significantly during the first year, the mean length SD score in girls with BPD was significantly below 0 12 months after term. In infants with BPD, the mean free fat mass (FFM) SD score and the mean total body fat (TBF) SD score at 6 weeks post-term age were significantly below 0. The mean FFM SD scores (-1.01 and -2.56, boys and girls respectively) and the mean TBF SD scores (-1.14 and -2.40, boys and girls respectively) 12 months after term were significantly lower than in healthy term infants of the same age. CONCLUSIONS: Preterm infants with BPD have impaired growth, with a deficit in TBF and FFM already 6 weeks after term; FFM and TBF remain low compared with healthy term infants during the first year of life. Nutritional intervention studies in infants with BPD are needed to evaluate if nutrition is the major determinant of growth and body composition or if this pattern of growth in preterm infants with BPD is the result of disturbed endocrine control.     

Fatty acid composition of plasma and erythrocyte phospholipids in preterm infants

Erythrocyte and plasma phospholipid fatty acids were determined in preterm babies at 0, 6 and 10 weeks. There were highly significant changes in fatty acid composition between birth and 6 weeks in both plasma and erythrocyte phospholipids, the changes being more numerous and quantitatively greater in phosphatidyl choline. There was little further change by 10 weeks. Linoleic acid increased by approximately 100% at 6 weeks in plasma phosphatidyl ethanolamine and 200% in phosphatidyl choline. In erythrocyte phosphatidyl ethanolamine, linoleic acid increased by approximately 150% at 6 weeks and in phosphatidyl choline increased 170%. Arachidonic acid decreased by 54%. The essential fatty acid status of the preterm babies studied using contemporary feeding regimes was satisfactory and by 6 weeks phospholipid fatty acid profiles were comparable with published data for normal healthy breast-fed infants.     

Evaluation of air-displacement plethysmography for body composition assessment in preterm infants

Background:Adiposity may contribute to the future risk of disease. The aim of this study was to evaluate the accuracy and reliability of an air-displacement plethysmography (ADP) system to estimate percentage fat mass (%FM) in preterm infants and to evaluate interdevice reliability in infants.Methods:A total of 70 preterm and 9 full-term infants were assessed. The accuracy of ADP measurements was assessed by determining reference %FM values using H(2)(18)O dilution measurement.Results:Mean %FM by ADP was 5.67 ± 1.84 and mean %FM by H(2)(18)O dilution was 5.99 ± 2.56. Regression analysis showed that %FM by ADP was associated with %FM by H(2)(18)O dilution (R(2) = 0.63, SE of estimate (SEE) = 1.65, P = 0.006). Bland-Altman analysis showed no bias (r = -0.48, P = 0.16) and 95% limits of agreement were -3.40 to 2.76 %FM. There was no difference in mean interdevice reliability %FM values (8.97 vs. 8.55 %FM) between ADP 1 and 2. Regression analysis indicated a low SEE (1.14% FM) and high R(2) (0.91); 95% limits of agreement were -1.87 to 2.71 %FM. The regression line did not differ significantly from the line of identity.Conclusion:ADP is a noninvasive, reliable, and accurate technique to measure preterm infants' body composition in both research and clinical settings.     

Decreased ventilation in preterm infants during oral feeding

As respiratory difficulty may accompany nipple feeding in preterm neonates, we studied the effect of oral feeding on ventilation in 23 preterm infants. The infants composed two groups based on their postconceptional age at the time of study: Group A comprised 12 infants 34 to 35.9 weeks of age, and group B, 11 infants 36 to 38 weeks. Ventilation was measured via a nasal mask pneumotachometer, and sucking pressure via a nipple that also permitted milk delivery; transcutaneous PO2 and PCO2 were continuously monitored. The feeding pattern comprised an initial period of continuous sucking of at least 30 seconds, followed by intermittent sucking bursts for the remainder of the feed. When compared with an initial semi-upright control period, minute ventilation (V1) during continuous sucking fell by 52 +/- 6% (P less than 0.001) and 40 +/- 2% (P less than 0.001) in groups A and B, respectively. This was the result of a decrease in respiratory frequency and tidal volume and was associated with a fall in TcPO2 of 13 +/- 4 mm Hg (P less than 0.01) in group A and 10 +/- 2 mm Hg (P less than 0.01) in group B. During intermittent sucking, V1 and TcPO2 recovered partially only in the more mature infants (group B). At the end of the feed, TcPCO2 have risen by 3 +/- 1 mm Hg (P less than 0.001) in group A and by 2 +/- 2 mm Hg (P less than 0.05) in group B. Thus oral feeding results in an impairment of ventilation during continuous sucking and the subsequent recovery during intermittent sucking is dependent on postconceptional age.     

Cardiorespiratory stability during echocardiography in preterm infants.

Blood pressure, heart rate, and oxygen saturation were monitored prospectively during 40 echocardiography recordings on 17 preterm infants (25-29 weeks; 510-1430 g), to examine whether echocardiography can be performed without disturbing cardiorespiratory status in preterm infants. There was no impact on absolute blood pressure. Heart rate increased by a mean of 4 beats per minute, and oxygen saturation decreased by a mean of 1% during echocardiography. While these changes reached statistical significance they are not of clinical significance as they remained well within ranges seen during control rest periods. All readings had greater minute-to-minute variability during echocardiography but differences were small and again remained within physiological ranges.     

Patterns of oxygenation during periodic breathing in preterm infants

The characteristics of the arterial oxygen saturation (SaO2) signal during episodes of hypoxaemia (SaO2 less than or equal to 80% for greater than or equal to 4 s) associated with periodic and non-periodic apnoeic pauses were studied in 16 preterm infants with cyanotic episodes (patients). and 15 asymptomatic preterm infants (controls), matched on birthweight and gestational age. The patients showed a significantly higher percentage of apnoeic pauses followed by a hypoxaemic episode (25 vs. 6%, P less than 0.01), and a two-fold increase in the slope of the desaturation curve (8.4 vs. 4.3% per s, P less than 0.005) in periodic compared with non-periodic breathing. All other characteristic of oxygenation (baseline SaO2 before episodes of hypoxaemia, delay between onset of apnoeic pause and onset of desaturation, lowest SaO2 during episodes of hypoxaemia) were similar for periodic and non-periodic breathing patterns. Similar, but not significant, differences between isolated and periodic apnoeic pauses were also present in the controls. An analysis of episodes of bradycardia (less than or equal to 100 beats per minute (bpm] showed that out of 121 episodes in the patients 118 were accompanied by a fall in SaO2 to less than or equal to 80%, and in the remaining three SaO2 fell to 82%, 85% and 86%, respectively. Thus all episodes of bradycardia (less than or equal to 100 bpm) were associated with a fall in SaO2 detected by beat-to-beat pulse oximetry. Examination of hypoxaemic episodes and their relationship with bradycardia and with apnoeic pauses, periodic and non-periodic, may help the further understanding of the control of arterial oxygenation in preterm infants with cyanotic episodes.     

Physiological stability of preterm infants during magnetic resonance imaging

Aim: This study looked for evidence of physiological disturbance in preterm infants undergoing magnetic resonance imaging (MRI). Methods: Intensive care was continued, as appropriate, throughout scanning in each infant. The heart rate, oxygen saturation (SaO₂), temperature and mean arterial blood pressure (BP) was monitored during MRI in preterm infants, median gestational age at birth 27 (range 23–32) weeks and median postnatal age at initial MRI, 3 days (range 1–42). The acoustic noise level during imaging was also measured. Results: 2087 min of data were obtained from 39 examinations in 23 infants. The median heart rate was 159 and no bradycardia <100 or tachycardia >200 bpm occurred. Although 42 episodes of desaturation <90% were detected only three were <80, and these occurred in one infant due to endotracheal tube blockage. The median axillary temperature was 36.9°C (range 35.7–37.8) and median BP (n=6) was 37 mmHg (24–48). The ambient noise level in the MR system during scanning was 67–72 dBA. Conclusion: In preterm infants who required intensive care during scanning, MRI could be performed without major physiological instability.