High prevalence of moderately severe vitamin D deficiency in preterm infants

Background: The recommended dose of vitamin D supplementation of preterm infants is based on data from populations in which severe vitamin D deficiency is uncommon and may be inadequate for infants in high risk population. However, data on vitamin D status of preterm infants in high‐risk populations, such as Middle Eastern countries is scarce. Methods: This study investigates the vitamin D status of Arab mothers and their preterm infants. Maternal serum and cord blood 25(OH)D, calcium (Ca), phosphorus (P) and alkaline phosphate (ALP) were measured at delivery. Serum 25(OH)D was measured by HPLC while the other biochemical parameters were measured by standard autoanalyzer. Results: Thirty‐four preterm infants were studied. The mean gestational age was 31.4 weeks and birth weight was 1667 g. The median serum 25(OH)D of 17.0 nmol/L in 28 mothers and 14.5 nmol/L in 34 cord blood samples were low. The median maternal and cord blood Ca, P and ALP levels were within normal range. Fifteen (44%) of the infants had moderately severe vitamin D deficiency (serum 25 (OH)D levels <12.5 nmol/L). The median serum 25(OH)D levels of mothers who had reportedly taken prenatal vitamin D supplementation and those who had not were similar (17.3 vs 16.3) nmol/L. The mean serum 25(OH)D levels among preterm infants in this study were low when compared to levels in Caucasians preterm infants on which the current vitamin D recommendations are based. Conclusion: The high prevalence of moderately severe vitamin D deficiency in Arab preterm infants provides a justification to investigate vitamin D requirement of preterm infants in this and other high‐risk populations.     

Cord blood red cell osmotic fragility: a comparison between preterm and full-term newborn infants

BACKGROUND: The osmotic fragility of red blood cells reflects their membrane ability to maintain structural integrity. The osmolality at which the cells lyse is related to their shape, deformability, surface area/volume ratio and intrinsic membrane properties. In cord blood, there may be differences between premature and term infants, and be influenced by maternal medication and other factors. There have been no definitive findings on possible differences between preterm and full-term infant osmotic fragility. AIMS: To determine if cord blood erythrocyte osmotic fragility differs between premature and full-term newborn infants, using two parallel techniques. PATIENTS AND METHODS: Cord blood samples were obtained from preterm singletons (N=11), preterm multiple births (N=10), full-term infants (N=24), as well as adults (N=22), for comparison. An osmotic fragility test was used to determine the NaCl concentration at which 20%, 50% and 80% of hemolysis occurred using individual logistic curves. A glycerol lysis test determined the time needed to lyse 50% of red blood cells. RESULTS: Cord blood red cells of multiple birth premature infants were more hemolysis-resistant than erythrocytes from full-term infants or adults. Another index of osmotic fragility, the difference in NaCl concentration for 80% and 20% red cell hemolysis showed that premature infants had greater differences than full-term infants or adults. Glycerol lysis time revealed that both preterm and full-term infants had an erythrocyte subpopulation that took longer than adult blood to attain 50% hemolysis. Correlation between both tests was very significant (r=-0.603, P<0.0001, N=67). CONCLUSIONS: This study shows that erythrocytes of premature infants, although, in average, less osmotically fragile than those of healthy full-term infants, contain a more hemolysis-susceptible cell subpopulation.     

The thrombopoietin level in the cord blood in premature infants born to mothers with pregnancy-induced hypertension

OBJECTIVE: To investigate the level of thrombopoietin in the cord blood of preterm infants, and its relationship with neonatal platelet count and pregnancy-induced hypertension. STUDY METHOD: Thrombopoietin levels in the cord blood of preterm neonates, with or without maternal pregnancy-induced hypertension, were measured by enzmye-linked immunosorbent assay. RESULTS: The platelet count was significantly lower in very low birth weight infants, infants with maternal pregnancy-induced hypertension, and infants with maternal thrombocytopenia. Neonatal thrombocytopenia was associated with maternal pregnancy-induced hypertension and very low birth weight. The neonatal platelet count was correlated significantly with the birth weight and the maternal platelet count. There was no difference in the cord blood level of thrombopoietin between infants born to mothers with pregnancy-induced hypertension and those without. No correlation was found between the thrombopoietin level and the neonatal platelet count. A positive correlation between the cord blood thrombopoietin and the maternal platelet count was identified. CONCLUSIONS: Maternal pregnancy-induced hypertension and very low birth weight were significantly associated with thrombocytopenia in premature infants, which cannot be explained by decreased thrombopoietin level.     

The spectrum of ABO hemolytic disease of the newborn infant.

A series of 1,704 infants of blood group O mothers have been studied to determine the relation between the degree of red cell sensitization and the cord hemoglobin and bilirubin concentrations. The infants with blood group A or B had significantly higher cord bilirubin and lower cord hemoglobin concentrations than the group O babies. Those infants whose red cells had the greatest evidence of sensitization had the highest bilirubin and lowest hemoglobin levels. The infants in whom no antibody was demonstrable on the red cells or in the red cell eluate also had significantly higher cord bilirubin and lower cord hemoglobin levels than the ABO compatible group; it is suggested that these infants had sufficient erythrocyte sensitization to produce mild hemolysis. ABO incompatibility represents a spectrum of hemolytic disease extending from those in which there is little laboratory evidence of erythrocyte sensitization, but evidence of hemolysis, to severe hemolytic disease in which erythrocyte sensitization is usually easily demonstrable.     

SELENIUM AND VITAMIN E IN CORD BLOOD FROM PRETERM AND FULL TERM INFANTS

ABSTRACT. Selenium was determined in erythrocytes and serum, and vitamin E and β-lipoprotein in serum from cord blood samples of 31 full term and 20 preterm infants. Venous samples from 21 mothers at birth and 15 normal adult women were also analyzed. No difference for either selenium or vitamin E was found between the preterm and full term infants. The selenium concentration in red blood cells was the same for newborn, mothers at birth, and normal adult women. The serum concentration of selenium was, however, significantly lower in the newborn, the mean level in the children being 64% of that in the mothers. The level in the mothers did not differ from that in non-pregnant women. The vitamin E concentration was found to correlate very well with the β-lipoprotein concentration. This indicates that differences in the transport capacity account for the large difference in the serum tocopherol levels of mothers at birth and newborn.     

早产儿脐血维生素K依赖因子水平及产前补充维生素K1对其影响的研究

目的了解早产儿是否存在维生素(Vit)K依赖因子水平低下及其与早产儿脑室周围-脑室内出血的关系,探讨产前补充维生素(Vit)K1对早产儿血浆VitK依赖因子水平的影响及对脑室周围-脑室内出血的预防作用.方法将有早产可能且至分娩时孕周不足35周的孕妇分为两组对照组133例,在产前给予地塞米松注射;对照组44例,产前给予地塞米松+VitK1.两组早产儿各30例留取脐动脉血离心零下20℃以下保存用凝固法检测Ⅱ、Ⅶ、Ⅸ、Ⅹ等凝血因子活性水平,同时留取同期出生的健康足月新生儿30例脐血标本作对照.两组早产儿生后1周内常规作头颅超声检查以明确有无脑室周围-脑室内出血及其程度.结果早产儿与足月新生儿脐血VitK依赖因子活性水平分别为Ⅱ(25.6±9.5)%对(36.7±4.9)%,Ⅶ(59.0±17.7)%对(64.5±10.6)%,Ⅸ(24.7±8.9)%对(30.2±5.7)%,Ⅹ(30.2±5.0)%对(34.3±12.6)(P<0.05).母亲产前补充VitK1后其婴儿脐血VitK依赖因子水平分别为Ⅱ(36.4±6.9)%,Ⅶ(69.6±16.6)%,Ⅸ(25.7±10.9)%和Ⅹ(39.3±8.0)%,除Ⅸ因子外,Ⅱ、Ⅶ和Ⅹ因子活性均显著升高(P<0.05).脑室周围-脑室内出血发生率在对照组为52.6%,观察组为31.8%(χ2=5.744,P=0.017);重度出血对照组为12.0%,观察组为2.3%(χ2=3.626,P=0.057).结论早产儿存在VitK依赖因子水平低下,可能为其易于发生脑室周围-脑室内出血的原因之一.分娩前母亲补充VitK1可显著提高其血浆Ⅱ、Ⅶ和Ⅹ因子水平,并对脑室周围-脑室内出血有一定的预防作用.     

Selenium and vitamin E in cord blood from preterm and full term infants.

Selenium was determined in erythrocytes and serum, and vitamin E and beta-lipoprotein in serum from cord blood samples of 31 full term and 20 preterm infants. Venous samples from 21 mothers at birth and 15 normal adult women were also analyzed. No difference for either selenium or vitamin E was found between the preterm and full term infants. The selenium concentration in red blood cells was the same for newborn, mothers at birth, and normal adult women. The serum concentration of selenium was, however, significantly lower in the newborn, the mean level in the children being 64% of that in the mothers. The level in the mothers did not differ from that in non-pregnant women. The vitamin E concentration was found to correlate very well with the beta-lipoprotein concentration. This indicates that differences in the transport capacity account for the large difference in the serum tocopherol levels of mothers at birth and newborn.     

The vitamin status of low birth weight infants and their mothers

The levels of vitamins A, E, B1, B2, folate, and B12 were measured in maternal blood, cord blood, and in 5-day neonate capillary blood samples. Twenty-six infants and their mothers served as controls and were compared with 32 low birth weight (LBW) infants. LBW infants showed significantly lower levels of vitamins A, E, B2, and folate than the controls. The folate status of mothers of LBW infants was significantly lower (7 +/- 1.8 ng/ml) than that of control mothers (21 +/- 0.8 ng/ml).     

Maternal-neonatal serum vitamin A concentrations

Prevention of neonatal vitamin A deficiency is related to the adequacy of maternal vitamin A stores. In this study we investigated maternal and cord serum vitamin A and retinol-binding protein (RBP) values in an Indian population including, for the first time, clinically vitamin A-deficient mothers. Twenty-eight maternal-neonatal pairs were selected from maternal cohorts of high socioeconomic status without clinical evidence of vitamin A deficiency (group I) and low socioeconomic status with conjunctival xerosis and Bitot's spots (group II). Maternal education, caloric and vitamin A intakes, weight, height, hemoglobin, and birth weight were significantly lower in group II. Serum vitamin A levels were significantly higher in group I mothers and newborns as were RBP levels in group I mothers. However, a significant difference between groups I and II in cord blood RBP was not observed. Upon correlation of maternal vitamin A levels with cord blood vitamin A levels, a logarithmic relationship was revealed, suggesting saturable transplacental transport of vitamin A.     

Subclinical hypovitaminosis D among exclusively breastfed young infants

OBJECTIVE: To determine Vitamin D status of mother-newborn diads at birth and of their exclusively breastfed (EBF) infants at 3 months. DESIGN: Longitudinal study. METHODS: Exclusively breastfed infants born at term with birth weight > 2.5 kg to normal, healthy mothers followed till 3 months. Serum calcium, phosphorous, heat labile alkaline phosphatase (HLAP) and 25(OH)D estimated in 42 mother / cord blood diads and in 35 (EBF) infants followed up at 3 months. Twenty five (OH)D < 15 ng/mL was considered low and 15 to 25 ng/mL low to normal. RESULTS: Ca, P, HLAP were significantly higher in cord blood (P < 0.001) but mean 25 (OH)D, 19.36 ng/mL was comparable to maternal level of 22.9 ng/mL (r = 0.82, P < 0.001). At 3 months only HLAP was significantly higher compared to cord blood. Higher 25 (OH)D at 3 months correlated with higher 25 (OH)D values in cord blood (r = +0.616, P < 0.001) as well as higher antenatal maternal levels (r = + 0.552, P < 0.001). Serum 25 (OH)D values < 25 ng/mL was observed in 50 % mothers, 62 % cord blood specimens and 80 % infants at 3 months. CONCLUSIONS: Subnormal maternal vitamin D status is associated with vitamin D deficiency in newborns and persists in exclusively breastfed infants.     

25-Hydroxycholecalciferol serum levels in breast-fed infants.

Serum 25-hydroxycholecalciferol levels were measured longitudinally in a series of breast-feeding mothers and their healthy, term infants for up to 6 months after birth. Although levels both in mothers and infants were lower at 6 weeks'' postpartum than at delivery and in cord blood, there was little change thereafter with unsupplemented breast feeding. These findings do not support recommendations for routine supplementation of breast-fed term infants with vitamin D.     

Ghrelin and adiponectin levels in colostrum,cord blood and maternal serum

Background: Ghrelin and adiponectin, which are considered to take part in the regulation of energy metabolism, have been found in breast milk and cord blood. The aims of this study were to determine ghrelin and adiponectin levels in colostrum, cord blood and maternal serum and to investigate the correlations between colostrum and cord blood levels of these peptides and the anthropometry of newborn infants and their mothers. Methods: Total ghrelin (TGHR), free ghrelin (FGHR) and adiponectin levels were studied in colostrum and the serum samples of 25 healthy lactating women and the cord blood of their healthy full‐term infants. Results: No significant differences could be found among TGHR and adiponectin levels in colostrum, cord blood and maternal serum. The median FGHR level in colostrum was significantly higher than that of maternal serum and cord blood. The colostrum TGHR was negatively correlated with body mass index (BMI) and weight of the infants at birth. TGHR and FGHR levels in colostrum were found to be positively correlated with those of maternal TGHR and FGHR concentrations, respectively. Adiponectin levels in colostrum were not correlated with BMI or birthweight of the infants or BMI of the mothers. Conclusion: These findings suggest that the source of ghrelin in breast milk is probably both breast tissue itself and the serum of the mother. Ghrelin in colostrum seems to be related to the anthropometry of infants even at birth, unlike adiponectin.     

早产儿长链多价不饱和脂肪酸水平及相关因素研究

目的 探讨早产儿出生时长链多价不饱和脂肪酸（ＬＣＰ）水平及其相关因素。方法 用毛细管气相色谱法测定２８例早产儿脐静脉血（简称脐血）及其母亲静脉血血浆和红细胞膜ＬＣＰ水平,同时测定早产儿出生时体重、身长、头围。２０例健康足月儿作为对照组。结果（１）母血亚油酸（ＬＡ）、亚麻酸高于脐血,差异有显著意义;脐血花生四烯酸（ＡＡ）、廿二碳六烯酸（ＤＨＡ）高于母血;脐血（ＬＡ）、亚麻酸高于脐血,差异有显著意义;     

Neonatal hypoglycaemia in infants of diabetic mothers

OBJECTIVE: To determine whether umbilical cord blood glucose correlates with subsequent hypoglycaemia after birth in infants of well-controlled diabetic mothers. METHODOLOGY: Thirty-eight term infants of well-controlled diabetic mothers were enrolled. Five mothers had pre-existing diabetes. Of the 33 gestational diabetic mothers, 16 were managed on insulin and 17 on diet. Maternal blood glucose was maintained between 4 and 8 mmol/L during labour and delivery. Infants' plasma glucose levels were measured from venous cord blood and serially, at less than 30 min, 1 h and 2 h of life by glucose hexokinase method. Blood glucose levels were further monitored by bedside Dextrostix for 24 h. RESULTS: Eighteen (47%) infants developed hypoglycaemia (blood glucose level less than 2 mmol/L) during the first 2 h of life. There was no difference in the cord blood glucose levels between infants with or without hypoglycaemia (3.7 +/- 1.1 vs 4.5 +/- 1.1 mmol/L, respectively). Infants of mothers with diabetes diagnosed prior to 28 weeks gestation were at a higher risk of developing hypoglycaemia (8 of 10 vs 10 of 28, OR 7.2, 95%CI 1.3-40.7). Hypoglycaemic infants were of significantly higher birthweight, and were more likely to be born to Caucasian mothers and by Caesarean section. Raised maternal fructosamine blood level, the need for insulin treatment or the infant's haematocrit were not different between infants with or without hypoglycaemia. CONCLUSIONS: In well-controlled diabetic mothers, the incidence of early hypoglycaemia in infants is still high, particularly in those mothers who had a longer duration of diabetes. Cord blood glucose level did not identify the infants with hypoglycaemia.     

Thyroid function tests in preterm infants born to preeclamptic mothers with placental insufficiency

OBJECTIVE: Since preeclampsia causes placental insufficiency, it can be hypothesized that it decreases placental passage of thyroxine (T4) from mother to infant and thus may deepen the transient hypothyroxinemia seen in preterm infants after birth. The aim of this study was to compare thyroid function tests of preterm infants born to preeclamptic mothers with placental insufficiency with preterm infants born to mothers without placental insufficiency. METHODS: Thirty-one preterm infants born to preeclamptic mothers with placental insufficiency were included in the study (group I) and 31 preterm infants born to mothers without placental insufficiency were included as the control group (group II). Thyroid hormone levels were assayed from blood samples obtained from the women before birth and thereafter from the infants at delivery (cord) and on the 1st, 3rd, 7th, and 21st days of life. RESULTS: Cord blood triiodothyronine (T3), free T3 (FT3) and free thyroxine (FT4) levels in group I were lower than in group II, whereas thyrotropin (TSH) and thyroxine binding globulin (TBG) levels were higher. No statistical difference in hormone levels studied at postnatal 1st, 3rd, 7th, and 21st day was found between the two groups. CONCLUSION: Low levels of thyroid hormones and high level of TSH in cord blood in premature infants born to preeclamptic mothers with placental insufficiency suggest intrauterine hypothyroidism. Increase in TSH and thyroid hormone concentrations after birth reveal that the hypothalamic-pituitary-thyroid axis is intact.     

母乳喂养早产儿血清维生素E水平动态变化

目的：探讨母乳喂养健康早产儿血清维生素E水平的动态变化以及临床对于健康早产儿是否需要常规补给维生素E。方法：38例母乳喂养的健康早产儿随机分成干预组(n=20)和对照组(n=18),干预组早产儿于出生当天第1次采血后每天给予维生素E 50 mg肌肉注射,连续3 d;对照组不给予维生素E。用荧光分光光度计测定两组早产儿出生后0,10,30 d的血清维生素E水平,并作比较分析。结果：两组早产儿出生时血清维生素E水平,干预组1.64±0.68 mg/dL;对照组1.76±0.74 mg/dL差异无显著性(P>0.05);两组早产儿在生后10 d时血清维生素E均呈升高趋势,干预组2.54±1.23 mg/d l,对照组2.64±1.13 mg/dL,两组间差异无显著性,(P>0.05)。生后30 d时,干预组血清维生素E仍维持原增高水平,而对照组血清维生素E呈下降趋势,干预组2.77±1.56 mg/dL,对照组为2.37±1.07两组差异无显著性(P>0.05)。各时间点,两组早产儿血清维生素E均高于0.5 mg/dL(范围0.59~6.45 mg/dL)。结论：母乳喂养健康早产儿生后30 d内血清维生素E与用维生素E干预组比较无显著差别,且两组早产儿都无维生素E缺乏发生。故认为对于母乳喂养早产儿无需常规补给维生素E。[中国当代儿科杂志,2005,7(6):503-505]     

Serum 25 hydroxyvitamin D status in 6‐month‐old infants in Guangzhou,China: A paired longitudinal follow up study

To assess the vitamin D status in healthy 6‐month‐old infants, as well as vitamin D supplementation and feeding patterns in Guangzhou, China, serum 25‐hydroxyvitamin D (25OHD) concentrations of 202 infants were measured at birth (cord blood) and at 6 months of age in Guangzhou, China. Questionnaires acquiring demographic characteristics, maternal and infantile vitamin D supplementation during pregnancy and first 6 months after birth, and feeding patterns during the first 6 months were completed by participating mothers. Physical examinations and blood sampling were carried out among infants at 6 months of age. The majority of infants (93.6%) were supplemented with vitamin D during the first 6 months of life on a voluntary basis. The M ± SD of cord serum 25OHD concentration was 46.2 ± 16.4 nmol/L, whereas the M ± SD of 25OHD concentration at 6 months was 82.9 ± 24.9 nmol/L. Serum 25OHD concentrations <30 nmol/L were seen in 34 (16.8%) infants at birth but only one (0.5%) at 6 months. Only 11 (5.4%) infants had concentrations >75 nmol/L at birth, whereas the majority of infants (n = 131, 64.9%) had concentrations >75 nmol/L at 6 months. The main predictors of 25OHD levels at 6 months included season, vitamin D supplementation, parental education level, and feeding patterns. To conclude, serum 25OHD concentrations were low at birth in a southern Chinese population, and infantile supplementation is an effective way to improve 25OHD status. Exclusively breastfed infants might need greater vitamin D supplementation, and individualized vitamin D supplementation plans might be needed.     

Deleterious effects of smoking during pregnancy: studies on blood oxygen affinity

16 mothers smoking 1-40 cigarettes dialy during pregnancy and their infants were studied at delivery compared to 13 non-smoking controls. The infants of smoking mothers had significantly decreased weight and length at birth compared to the infants of non-smokers. In the smoker group the thiocyanate level in maternal venous and newborn cord blood sera was significantly higher than in the non-smokers. The standard blood oxygen affinity of cord blood was significantly increased in the smokers' group and was positively correlated to the thiocyanate level in cord blood. At the age of three and five days there were no differences in the newborns' capillary blood standard oxygen affinity between the two groups. The deleterious effect of maternal smoking on the fetus and newborn is discussed.     

Vitamin E and neonatal bilirubinemia.

A study was designed to determine the effect of vitamin E on bilirubinemia in the preterm infant. Twenty infants with birth weight between 1,000 and 1,500 gm and 20 infants with birth weights between 1,501 and 2,000 gm were studied. Half the infants in each birth weight group received vitamin E administered intramuscularly in a total dose of 50 mg/kg during days 1 to 3 of life; the remaining infants served as controls. The administration of vitamin E produced significantly increased plasma tocopherol concentrations and normal hydrogen peroxide hemolysis tests by the end of the first week of life. Infants with birthweights less than or equal to 1500 gm who received vitamin E demonstrated a significant decrease in serum bilirubin on day 3 of life (6.5 +/- 2.2 vs 8.8 +/- 2.2 mg/dl) as well as a significant decrease in peak serum bilirubin during the first week of life (8.3 +/- 2.2 vs 10.6 +/- 2.6 mg/dl). The duration of phototherapy also was significantly less in the vitamin E-supplemented group (48 +/- 18 vs 107 +/- 31 hours). These differences were less pronounced in infants with birth weights more than 1,500 gm.     

Oral vitamin E supplementation for the prevention of anemia in premature infants: a controlled trial

Serum vitamin E levels are reduced in newborn infants. It has been reported that this deficiency is responsible, in part, for the development of anemia in premature infants during the first 6 weeks of life. The efficacy of vitamin E supplementation for the prevention of anemia in premature infants has been studied in a randomized, controlled, and blinded trial. Premature infants whose birth weights were less than 1,500 g were given, by gavage, 25 IU of dl-alpha-tocopherol or a similar volume of the drug vehicle. Treatment was continued for the first 6 weeks of life. A total of 178 infants were studied. Vitamin E levels were significantly higher in a supplemented group by day 3 and for the remainder of the 6-week period. At 6 weeks of age, there was no significant difference between the supplemented and unsupplemented groups in hemoglobin concentration, reticulocyte and platelet counts, or erythrocyte morphology. It is concluded that there is no evidence to support a policy of administering vitamin E to premature infants to prevent the anemia of prematurity.