Allergic diseases among very preterm infants according to nutrition after hospital discharge

To cite this article: Zachariassen G, Faerk J, Esberg BH, Fenger‐Gron J, Mortensen S, Christesen HT, Halken S. Allergic diseases among very preterm infants according to nutrition after hospital discharge. Pediatr Allergy Immunol 2011; 22 : 515–520. To determine whether a cow’s milk‐based human milk fortifier (HMF) added to mother’s milk while breastfeeding or a cow’s milk‐based preterm formula compared to exclusively mother’s milk after hospital discharge, increases the incidence of developing allergic diseases among very preterm infants (VPI) during the first year of life. Of a cohort of 324 VPI (gestational age 24–32 wk), the exclusively breastfed VPI were shortly before discharge randomized to breastfeeding without fortification or supplementing with a fortifier. Those not breastfed were fed a preterm formula. The intervention period was from discharge until 4 months corrected age (CA). Follow‐up was performed at 4 and 12 months CA including specific IgE to a panel of allergens at 4 months CA. The incidence during and prevalence at 12 months CA of recurrent wheezing (RW) was 39.2% and 32.7%, while atopic dermatitis (AD) was 18.0% and 12.1%, respectively. Predisposition to allergic disease increased the risk of developing AD (p = 0.04) [OR 2.6 (95% CI 1.0–6.4)] and the risk of developing RW (p = 0.02) [OR 2.7 (95% CI 1.2–6.3)]. Boys had an increased risk of developing RW (p = 0.003) [OR 3.1 (95% CI 1.5–6.5)]. No difference was found between nutrition groups. None developed food allergy. Compared to exclusively breastfed, VPI supplemented with HMF or fed exclusively a preterm formula for 4 months did not have an increased risk of developing allergic diseases during the first year of life.     

Higher urinary excretion of essential amino acids in preterm infants fed protein hydrolysates

Aim: Protein hydrolysates have been introduced in preterm formulae, but it is not clear whether they are needed for the feeding of preterm infants. We designed a randomized, controlled trial to test the effects of a preterm formula with hydrolysed cow's milk proteins on short-term growth and urinary and plasma amino acids levels. Methods: Infants with a birthweight ≤1750 g and gestational age ≤34 wk fed a conventional preterm infant formula (formula B) or a hydrolysed formula (formula A). Weight was measured daily; length, head circumference, mid-arm circumference and total skinfold thickness were measured weekly. Blood and urine were analysed for amino acid concentrations at start, 14 and 28 d. Results: Twenty-one infants met the criteria for randomization. The daily feeding volumes were: formula A 172.8±5.6 vs formula B 170.1±2.8 ml/kg/d. Infants fed with formula A showed slower weight gain (17.4±3.4 vs 20.5±3.3 g/kg/d; p=0.045) and lower mean change in Z-scores for weight (-0.18±0.16 vs 0.00±0.09; p=0.009) and for head circumference (-0.06±0.13 vs 0.06±0.13; p=0.049). After 14 d, infants receiving formula A had statistically significant higher urinary levels of essential amino acids compared to infants receiving formula B.

Conclusion: Our results support the hypothesis of less nutritional value of hydrolysed versus conventional preterm formulae. Higher renal excretion of essential amino acids may be one of the mechanisms involved. These findings must be confirmed by further studies with larger sample sizes and protein hydrolysates with different degrees of hydrolysis.     

Considerations and approaches in determining the protein and energy composition of preterm infant formulas

Optimal early nutritional support is considered a crucial issue in the care of the preterm infant, particularly of those with very low- or extremely low-brithweight. Unfortunately, this goal is seldom satisfactorily attained.
Several conditions such as hypoxia, acidosis, patent ductus arteriosus, drug therapy, reduced intestinal motility may interfere with an adequate nutritional delivery in the early neonatal period. Moreover, there is still concern about metabolic and intestinal tolerance of the currently suggested intakes and a lack of uniformity in the nutritional program among different NICUs. Finally, the vast majority of the available preterm formulas are not fully adequate to the real nutritional needs of these infants. Inadequate protein content and inappropriate protein energy ratio of most preterm formulas represent a matter of major concern, since there is a strict relationship between formula composition and the quantity and quality of weight gain. As a consequence there is a need of at least two milk formulas for different preterm infants: one for LBW and VLBW infants, the other for preterm infants weighing >1500 g.     

Extensively and partially hydrolysed infant formulas for allergy prophylaxis

The allergy preventive effect of extensively (N) and partially (PH) hydrolysed cows' milk formulas compared with a regular formula (RM) was assessed in 155 infants with a family history of allergy. No cows' milk was given during the first nine months of life and no egg and fish up to 12 months of age. Breast feeding mothers avoided the same foods. At weaning the infants were randomised to one of the formula groups. The cumulative incidence of atopic symptoms at 18 months was 51, 64, and 84% in the N, PH, and RM groups, respectively. From 6 to 18 months there were significantly less cumulative atopic symptoms in the N group compared with the RM group, and significantly less than the PH group up to 6 (N = 25%; PH = 46%) and 9 months (N = 34%, PH = 58%). At 9 months significantly fewer infants in the N group (10%) than in the PH group (33%) had a positive skin prick test to eggs. The findings support an allergy preventive effect of an extensively hydrolysed formula, but not of a partially hydrolysed formula, during the first 18 months of life of high risk infants.     

Extensively and partially hydrolysed infant formulas for allergy prophylaxis

Accepted 17 March 1997The allergy preventive effect of extensively (N) and partially (PH) hydrolysed cows'' milk formulas compared with a regular formula (RM) was assessed in 155 infants with a family history of allergy. No cows'' milk was given during the first nine months of life and no egg and fish up to 12 months of age. Breast feeding mothers avoided the same foods. At weaning the infants were randomised to one of the formula groups. The cumulative incidence of atopic symptoms at 18 months was 51, 64, and 84% in the N, PH, and RM groups, respectively. From 6 to 18 months there were significantly less cumulative atopic symptoms in the N group compared with the RM group, and significantly less than the PH group up to 6 (N= 25%; PH = 46%) and 9 months (N = 34%, PH = 58%). At 9 months significantly fewer infants in the N group (10%) than in the PH group (33%) had a positive skin prick test to eggs. The findings support an allergy preventive effect of an extensively hydrolysed formula, but not of a partially hydrolysed formula, during the first 18 months of life of high risk infants.     

Z-score of weight for age of infants with atopic dermatitis and cow's milk allergy fed with a rice-hydrolysate formula during the first two years of life

BACKGROUND: Recently, rice-based formulas have been widely used in hypoallergenic diets, but data on nutritional values are scarce. Aim: To evaluate the growth of infants fed with a rice-based hydrolysate formula, compared to those infants fed with a soy formula or an extensively hydrolysed casein formula, in the first 2 y of life. METHODS: A total of 88 infants were enrolled between March 2002 and March 2004. Fifty-eight infants with atopic dermatitis (AD) and cow's milk allergy (CMA), confirmed by open challenge, were enrolled as study group: 15 were fed with a rice-based hydrolysate formula (RHF), 17 with a soy-based formula (SF) and 26 with an extensively hydrolysed casein formula (eHCF). Thirty infants with AD without cow's milk allergy were recruited as a control group (CG) and fed with a free diet. Weight was recorded on enrolment and at 3-monthly intervals in the first year of life, and at 6-monthly intervals in the second year. Infants were weighed naked, before feeding, by means of an electronic integrating scale. The z-scores of weight for age were calculated. Statistics: One-way analysis of variance and Student's t-test were used for statistical comparison. Significance was set at p<0.05. RESULTS: No significant differences between the RHF, SF and eHCF groups were observed for the z-score of weight for age during the first 2 y of life, but a significantly lower difference was seen in the RHF group compared to the control group in the intervals 9 mo-1 y (p=0.025) and 1-1.5 y (p=0.020) of age. In contrast, the SF and eHCF groups were comparable to the control group, but the eHCF group was significantly lower (p=0) in the first trimester of life. CONCLUSION: Even if our findings show no significant difference between RHF and control, low weight observed in infants fed with RHF raises doubts about the nutritional adequacy of rice-hydrolysate formulas.     

Conductive hearing loss in preterm infants with bronchopulmonary dysplasia

OBJECTIVE: To determine the risk of conductive hearing loss in preterm infants with bronchopulmonary dysplasia (BPD) and preterm controls. METHODOLOGY: The study population consisted of 78 infants with BPD of 26-33 weeks gestation and 78 controls of similar gestational age matched for broad-based birthweight categories. An auditory brainstem response (ABR) audiology was performed shortly before hospital discharge. Visual reinforcement orientation audiometry (VROA) and impedance audiometry were performed at 8-12 months corrected for prematurity. Infants with persistent audiological abnormalities were referred for evaluation to paediatric ENT surgeons. RESULTS: Infants with BPD had a significantly higher rate of ABR abnormalities (BPD: 22%, controls: 9%; P = 0.028). On VROA and impedance audiometry, the infants with BPD also had a higher rate of persistent abnormalities. Following ENT assessment, 22.1% of infants with BPD and 7.7% of controls had persistent conductive dysfunction requiring myringotomy and grommet tube insertion (P = 0.03). Most of these infants had normal ABR audiometry at hospital discharge. CONCLUSIONS: Preterm infants with BPD are at high risk of persistent conductive hearing loss late in the first year of life compared to controls. An ABR audiology conducted at the time of hospital discharge does not predict accurately later conductive hearing problems. Infants with BPD should have routine audiological evaluation toward the end of the first year of life.     

Correlation between early neonatal diet and atopic symptoms up to 5-7 years of age in very low birth weight infants: follow-up of randomized, double-blind study

The influence of early feeding on the risk of atopic diseases has been studied in full-term newborns, not in very low birth weight infants (VLBW). The study evaluated effect of early feeding of VLBW infants with either cow's milk-based formula (CMF) or extensively hydrolyzed milk formula (HF) on incidence of atopic diseases and markers of atopy at 5-7 years of age. This was a follow-up of the randomized, double-blind study evaluating the influence of different enteral feeding protocols on the early morbidity of VLBW infants. In the original study 80 children were randomly allocated into 2 groups receiving during first month of life HF (experimental group) or CMF (control group). At the age of 5-7 years, 62 children among 74 available (84%) with mean birthweight 1124g were evaluated according to standardized ISAAC (International Study of Asthma and Allergies in Childhood) protocol. Total IgE level, specific IgE, lymphocyte CD4+CCR4+/CD4+CXCR3+ ratio and skin prick tests (SPT) were done. Prevalence of obvious allergic diseases was not significantly different between the studied groups (HF: 12/33; CMF: 6/29; RR [relative risk] HF vs CMF: 1.76; 95%CI [confidence interval]: 0.76–4.09). Comparison of atopic status across groups revealed similar rate of positive markers of atopy: IgE (RR: 2.57 95%CI: 0.91–8,08), SPT (RR: 5.13; 95%CI: 0.93–31.6), lymphocyte CD4+CCR4+/CD4+CXCR3+ ratio (OR: 2.32; 95%CI: 0.78–7.53) in the both studied groups. Based on the carried out follow-up study we were unable to confirm the usefulness of hydrolyzed formula in prevention of allergy in an unselected cohort of very low birth weight infants.     

Use of hypoallergenic formula in the prevention of atopic disease among Asian children

OBJECTIVE: To determine the effect of a partially hydrolysed formula on genetically predisposed children, with respect to the development of atopic clinical manifestations and in vitro testing of serum IgE levels (total and milk-specific). METHODS: One hundred and ten infants were randomly assigned to receive either partially hydrolysed formula or standard infant formula, and were prospectively monitored from birth for clinical atopic symptoms and serum IgE levels. RESULTS: Eczema occurred less frequently in infants receiving partially hydrolysed formula. This was significant (P < 0.05) at 3, 6, 9, 12, 18 and 24 months. However, the significance decreased with time, although it almost reached statistical significance at 30 months by the Kaplan-Meier survival function (log-rank statistic, 3.46; P = 0.063). Although wheezing occurred less frequently in infants receiving partially hydrolysed formula, compared to those receiving standard infant formula, the difference did not reach statistical significance (P > 0.05). CONCLUSIONS: Exclusive feeding of hypoallergenic milk formula in the first 4 months of life has a protective effect in terms of the development of atopic dermatitis in the first 2 years of life, compared to feeding with cow's milk formula.     

水解蛋白婴儿配方研究进展

牛奶过敏足婴幼儿最主要的食物过敏类型,1岁以内婴幼儿大约有2.5%的人群表现牛奶过敏.以天然牛奶蛋白为基础的水解蛋白配方,其变应原性降低,其中部分水解蛋白配方(pHF)可诱导口服免疫耐受,主要用于预防婴儿食物过敏和特应性皮炎;深度水解配方主要用于治疗婴儿牛奶过敏;严重牛奶过敏导致生长发育障碍的患儿,应用氨基酸配方治疗.     

Z-score of weight for age of infants with atopic dermatitis and cow's milk allergy fed with a rice-hydrolysate formula during the first two years of life

Background: Recently, rice-based formulas have been widely used in hypoallergenic diets, but data on nutritional values are scarce. Aim: To evaluate the growth of infants fed with a rice-based hydrolysate formula, compared to those infants fed with a soy formula or an extensively hydrolysed casein formula, in the first 2 y of life. Methods: A total of 88 infants were enrolled between March 2002 and March 2004. Fifty-eight infants with atopic dermatitis (AD) and cow's milk allergy (CMA), confirmed by open challenge, were enrolled as study group: 15 were fed with a rice-based hydrolysate formula (RHF), 17 with a soy-based formula (SF) and 26 with an extensively hydrolysed casein formula (eHCF). Thirty infants with AD without cow's milk allergy were recruited as a control group (CG) and fed with a free diet. Weight was recorded on enrolment and at 3-monthly intervals in the first year of life, and at 6-monthly intervals in the second year. Infants were weighed naked, before feeding, by means of an electronic integrating scale. The z-scores of weight for age were calculated. Statistics: One-way analysis of variance and Student's t -test were used for statistical comparison. Significance was set at p <0.05. Results: No significant differences between the RHF, SF and eHCF groups were observed for the z-score of weight for age during the first 2 y of life, but a significantly lower difference was seen in the RHF group compared to the control group in the intervals 9 mo–1 y ( p =0.025) and 1–1.5 y ( p =0.020) of age. In contrast, the SF and eHCF groups were comparable to the control group, but the eHCF group was significantly lower ( p =0) in the first trimester of life.
Conclusion: Even if our findings show no significant difference between RHF and control, low weight observed in infants fed with RHF raises doubts about the nutritional adequacy of rice-hydrolysate formulas.     

Formula-fed preterm neonates

In very immature babies, nutrition often begined with human milk, but a lot of mothers have a difficulty in lactating and banked human milk is not always available. Therefore, preterm formulas have been specifically designed for very low birth weight (VLBW) infants during hospitalisation stay. They differ significantly from standard term formulas and their derivatives, such as extensively hydrolyzed protein formulas, which are not nutritionally adapted for these infants. Partially hydrolyzed protein formulas have been tried, but infants fed these formulas have a decreased nitrogen intestinal absorption rate. As a result the nitrogen content needs to be increased each time a partially hydrolyzed protein source is used in preterm formulas instead of an entire protein source. Although mineral retention in VLBW infants fed a formula is lower than in utero it might be sufficient. We recently observed an early catch up of bone mineralisation at theoretical term in VLBW infants fed a preterm formula containing highly soluble calcium salts. Probiotics and prebiotics are not yet well evaluated in preterm infants but might help in improving the development of physiologic intestinal flora and enteral feeding tolerance. There is still debate about optimal posthospital nutrition in preterm infants who are not breastfed. Feeding a nutrient-enriched formula provides a growth benefit when compared to infants fed a term formula, mainly during the first 2 to 3 months after discharge. Data about the harmful effects of using such formulas for a longer period are scarce. Therefore, the use of nutrient-enriched formula might be suggested for the first 2 months after discharge, as it is a crucial period in the development of these VLBW infants.     

北京地区25家医院晚期早产儿住院期间母乳喂养对感染相关性疾病发生的影响

目的 了解北京地区晚期早产儿住院期间感染性疾病的发生率,分析感染性疾病发生的危险因素,探讨母乳喂养对感染性疾病发生的影响。方法 收集北京地区25家医院新生儿病房在2015年10月23日至2017年10月30日住院的晚期早产儿资料。根据喂养方式分为母乳喂养组和配方奶喂养组,比较两组一般情况、感染性疾病的发生率,并应用多因素logistic回归分析感染性疾病发生的危险因素。结果 纳入1 576例晚期早产儿,其中母乳喂养组153例,配方奶喂养组1 423例。发生感染性疾病共计484例（30.71%）,其中母乳喂养组感染性疾病发生率显著低于配方奶喂养组（22.88% vs 31.55%,P=0.033）。多因素logistic回归分析显示,母乳喂养是感染性疾病发生的独立保护性因素（OR=0.534,P=0.004）,而男婴、胎膜早破、妊娠糖尿病、窒息是发生感染性疾病的危险因素（分别OR=1.328、5.386、1.535、2.353,均P < 0.05）。结论 母乳喂养可降低晚期早产儿住院期间感染性疾病的发生,是晚期早产儿感染性疾病的保护因素,应积极提倡晚期早产儿住院期间实施母乳喂养。     

Comparison of a partially hydrolyzed infant formula with two extensively hydrolyzed formulas for allergy prevention:A prospective, randomized study

The aim of this study was to compare the allergy‐preventive effect of a partially hydrolyzed formula with two extensively hydrolyzed formulas, in infants with a high risk for development of allergic disease. High‐risk infants from four Danish centres were included in the period from June 1994 to July 1995. Five‐hundred and ninety‐five high‐risk infants were identified. High‐risk infants were defined as having bi‐parental atopy, or a single atopic first‐degree relative combined with cord blood immunoglobulin E (IgE) ≥ 0.3 kU/l. At birth all infants were randomized to one of three different blinded formulas. All mothers had unrestricted diets during pregnancy and lactation and were encouraged to breast‐feed exclusively. If breast‐feeding was insufficient, one of the three formulas, according to randomization, was given during the first 4 months. It was recommended not to introduce cow's milk, cow's milk products, and solid foods until the age of 4 months. After the age of 4 months a normal unrestricted diet and conventional cow's milk‐based formula were given when needed. All infants were followed‐up prospectively with interview and physical examination at the age of 6, 12, and 18 months, and if any possible atopic symptoms were reported. If food allergy was suspected, controlled elimination/challenge procedures were performed in a hospital setting. Of 550 infants included in the study, 514 were seen at all visits and 36 were excluded owing to non‐compliance. Of 478 infants who completed the study, 232 were exclusively breast‐fed, 79 received an extensively hydrolyzed casein formula (Nutramigen), 82 an extensively hydrolyzed whey formula (Profylac), and 85 a partially hydrolyzed whey formula (Nan HA), during the first 4 months of life. These four groups were identical in regard to atopic predisposition, cord blood IgE, birthplace, and gender. Exclusively breast‐fed children were exposed less to tobacco smoke and pets at home and belonged to higher social classes, whereas the three formula groups were identical concerning environmental factors. The frequency of breast‐feeding was high; only eight (2%) children were not breast‐fed at all. The three formula groups were identical in regard to duration of breast‐feeding and age at introduction of formula and solid foods. No significant differences were found in the three groups of infants receiving formula milk regarding the cumulative incidence of atopic dermatitis or respiratory symptoms. The cumulative incidence of parental‐reported cow's milk allergy was significantly higher in children fed partially hydrolyzed formula (Nan HA) compared with extensively hydrolyzed formula (Nutramigen or Profylac) at 12 and 18 months (NanHA, 7.1%; Nutramigen, 2.5%; Profylac, 0%; p = 0.033). The cumulative incidence of confirmed cow's milk allergy was 1.3% (three of 232) in exclusively breast‐fed infants, 0.6% (one of 161) in infants fed extensively hydrolyzed formula (Nutramigen or Profylac), and 4.7% (four of 85) in infants fed partially hydrolyzed formula (Nan HA). Partially hydrolyzed formula was found to be less effective than extensively hydrolyzed formula in preventing cow's milk allergy, 0.6% vs. 4.7% (p = 0.05), but because of the small number of cases the results should be interpreted with caution. Compared with other similar studies the frequency of atopic symptoms was low, even though the dietetic intervention did not include either maternal diet during lactation or dietary restrictions to the children after the age of 4 months.     

Hypocarbia in the ventilated preterm infant and its effect on intraventricular haemorrhage and bronchopulmonary dysplasia

OBJECTIVE: To examine the relationship between PaCO2 levels in ventilated very preterm infants and (i) the incidence of severe intraventricular haemorrhage (IVH) and periventricular leukomalacia (PVL); and (ii) bronchopulmonary dysplasia (BPD). METHODS: A retrospective cohort analysis of preterm infants comparing PaCO2 levels with the incidence of severe IVH/PVL and BPD was carried out on patients born at less than 29 weeks gestation from 1992 to 1994 and admitted to the tertiary neonatal intensive care unit at the King Edward Memorial Hospital (314 infants). During the first 96 h, PaCO2 levels were examined including lowest and highest PaCO2 levels, mean PaCO2 levels and duration of hypocarbia both pre- and post-surfactant administration. RESULTS: Of the 314 infants, there were 40 early neonatal deaths (less than 48 h) who were not included in the analysis. Of the 274 surviving infants, 72 (26%) infants had severe IVH. Infants whose PaCO2 fell below 30 mmHg at any stage in the first 48 h of life had an increased risk of severe IVH or PVL (odds ratio 2.38; 95% CI 1.27-4.49; P = 0.007). Of the 265 survivors to 36 weeks corrected gestational age, 134 (51%) had BPD. Infants with at least three PaCO2 values less than 30 mmHg in the first 24 h of life had an increased risk of BPD (odds ratio 2.21; 95% CI 1.05-4.57; P = 0.036). CONCLUSIONS: The risk of severe IVH/PVL was significantly increased by hypocarbia. There was also an association between hypocarbia and BPD, particularly when hypocarbia was prolonged. These findings suggest that avoidance of hypocarbia may reduce the incidence of severe IVH/PVL and BPD in preterm infants.     

Clinical experience with preterm formulas in very low birthweight infants

Infants below 1500 g at birth were randomly assigned to receive one of two preterm infant formulars: S26 Low Birthweight (S26-LBW, 25 infants) or Enfalac Premature (EPF, 24 infants). They were either exclusively formula-fed (13 infants) or the formula was used to supplement their own mother's fresh breast milk (36 infants). The mean age when milk feeds were commenced was 7 days and the mean age when birthweight was regained was 12 days. The mean age when 2000 g was reached was 45 days at which time 10 (20%) infants were below the tenth centile on the intrauterine growth chart. None of the above variables were significantly different between the S26-LBW and EPF groups. However, the S26-LBW group established full enteral feeding significantly earlier compared to the EPF group (42 versus 64 d) and the number with adverse gastrointestinal effects was lower (4 versus 10 infants). Both preterm infant formulas supported a growth rate in excess of that in utero without stressing the infants' metabolic system. The growth rate of infants fed preterm breast milk supplemented with preterm infant formula was quantitatively similar to those exclusively fed preterm infant formula.     

Food allergy in preterm infants fed human milk

In 80 preterms aged 9-24 months (mean age: 15.9) and in 80 sex- and age-matched full-terms the frequency of atopic diseases and of positive skin tests to 8 food and 6 inhalant allergens was determined. The two groups did not differ as to overall percentages of cutipositive subjects and patients with atopic diseases. In particular, frequencies of positive skin tests to foods and of atopic dermatitis (the peak prevalence of which occurs early in infancy) were similar in preterm (16.2 and 7.5%, respectively) and full-term (13.7 and 5.0%, respectively) infants. We suggest that preterm infants fed human milk are not at increased risk of developing food allergy and related diseases and that the absorption of antigens through the immature intestine does not seem to favor the development of an IgE sensitization to foods.     

Effects of weaning cereals with different phytate content on growth, development and morbidity: a randomized intervention trial in infants from 6 to 12 months of age

BACKGROUND: Phytate decreases iron and zinc bioavailability and contributes to deficiencies of iron and zinc, potentially causing anaemia, poor psychomotor development, impaired growth and increased risk of diarrhoea and respiratory infections. AIM: To investigate whether a reduced dietary intake of phytate, either via extensively phytate-reduced infant cereals [milk cereal drinks (MCDs) and porridge] or a milk-based infant formula, would improve growth and development and reduce morbidity in infants. DESIGN: Infants (n = 300) were, in a double-blind design, randomized to three diet intervention groups from 6 to 12 mo of age-commercial MCD and porridge (CC group), phytate-reduced MCD and phytate-reduced porridge (PR group), or milkbased infant formula and porridge with regular phytate content (IF group)-then followed until 18 mo. Dietary intake, anthropometry, development (Bayley Scales of Infant Development) and episodes of infectious diseases were registered. Results: There were no significant differences between study groups in growth, development or morbidity until 12 mo of age. The IF group had a 77% higher risk (95% CI: 1.05-2.97) of diarrhoea compared to the PR group during the 12-17-mo period. Infants with haemoglobin concentration (Hb) < 110 g/l at 12 mo had lower attained weight at 18 mo (11.14 kg vs 11.73 kg, p = 0.012). Infants with serum zinc (S-Zn) <10.7 pmol/l at 12 mo had higher risk of respiratory infections (RR = 1.74, 95% CI: 1.19-2.56) compared to controls. CONCLUSION: Phytate reduction had no effect on growth, development or incidence of diarrhoeal or respiratory infections. Infants with low Hb or low S-Zn may be at higher risk of poor growth and respiratory infections, even in this high-income population.     

Inguinal hernia in extremely preterm infants

The prevalence of inguinal hernia during primary hospitalization was determined in 250 infants with gestational age 24–29 weeks. Fourteen per cent developed hernia, with prevalence significantly higher in boys than girls. Infants with respiratory distress syndrome and those requiring prolonged mechanical ventilation were significantly predisposed to the development of hernia. Male infants, especially those who required prolonged ventilatory assistance, were at greatest risk. This information may be used when counselling parents regarding complications of very preterm infants.     

晚期早产儿呼吸系统疾病患病临床特点

目的：探讨晚期早产儿呼吸系统疾病患病的临床特点。方法：选取2009年1月至2010年12月在我院产科出生的新生儿,其中晚期早产儿 (胎龄34~36+6周)630例,足月儿4401例,早期早产儿（胎龄≤33+6周）328例。其中患呼吸系统疾病者包括晚期早产儿84例,足月儿135例,早期早产儿182例。比较3组新生儿呼吸系统疾病发病情况、临床特点及危重程度。结果：（1）晚期早产儿组呼吸系统疾病发生率、病死率及危重症比例均高于足月儿组,而低于早期早产儿组(P<0.01)。（2）晚期早产儿组呼吸困难起病时间早于足月儿组,晚于早期早产儿组（P<0.01）;呼吸增快百分比较其他两组高,而三凹征百分比较低(P<0.05); 晚期早产儿组需氧疗及机械通气的比例均明显高于足月儿组,而低于早期早产儿组(P<0.05)。（3）多元线性回归分析发现血氧分压降低、红细胞压积减低、血pH值减低、呼吸减慢、动脉血氧饱和度减低、动脉收缩压减低、5 min Apgar评分减低、胎龄较小、血尿素氮增高、心率增快、呼吸增快是新生儿呼吸系统疾病危重症的影响因素。结论：晚期早产儿比足月儿更容易出现呼吸系统疾病,危重程度较重,需加强呼吸支持。晚期早产儿呼吸困难多表现为呼吸增快,起病时间早于足月儿而晚于早期早产儿。对于晚期早产儿,如发现呼吸困难、心率、血压异常及多系统受累表现,常提示其病情危重,应积极治疗。