Cardiac output decreases and systemic vascular resistance increases in newborns placed in the left-lateral position.

OBJECTIVE: The objective of the study was to study the effect of short-term left-lateral position on cardiovascular parameters in hemodynamically stable newborns. STUDY DESIGN: Cardiac output (CO), stroke volume (SV), systemic vascular resistance index (SVRI) and heart rate (HR) were measured by electric velocimetry in hemodynamically stable newborns without respiratory support in the supine, left-lateral and back-to-supine positions, each kept for 10 min. RESULTS: Thirty-two newborns were enrolled, birth weight 2134 (1818 to 2460) g, gestational age 34.5±2.4 weeks. CO and SV decreased significantly from supine to left-lateral position (CO supine: 193.4 (168.0 to 229.6) ml kg-1min-1; CO left-lateral: 172.0 (154.9 to 201.6) ml kg-1min-1, P<0.0001; SV supine: 3.0 (2.7 to 4.0) ml; SV left-lateral: 2.7 (2.4 to 3.2) ml, P<0.0004). Conversely, SVRI increased in left-lateral position: SVRI supine: 18865±9244 dyns cm-5 m-2; SVRI left-lateral: 21203±10059 dyns cm-5 m-2, P<0.0001). All variables returned to the initial value when infants were back in the supine position. HR and blood pressure did not change. CONCLUSION: In stable infants, CO and SV decrease and SVRI increases, in left-lateral position.

Thoracic fluid content by electric bioimpedance correlates with respiratory distress in newborns.

OBJECTIVE: The objective of the study was to compare thoracic fluid content (TFC) between newborn infants with and without respiratory distress. We tested the hypothesis that TFC would be higher in infants with respiratory distress. STUDY DESIGN: A total of 96 newborn infants, gestational age 37.9 (2.6) weeks, were enrolled at birth. TFC by electrical bioimpedance was recorded within 3 h after birth (TFC1) and at 24 h of life (TFC2). RESULTS: TFC1 was higher in infants with respiratory distress at birth (76.8 (24.9) versus 61.6 (16.1) 1 KOhm-1, P<0.0005). The association was independent from gestational age and mode of delivery. TFC2 was independently associated with respiratory distress at 24 h of life (adjusted coefficient b=0.5 (s.d. 0.02), P=0.02). CONCLUSION: TFC by electric bioimpedance independently correlated with the presence of respiratory distress at birth and at 24 h of life in late preterm and term newborn infants.

Impact of metabolic control of diabetes during pregnancy on neonatal hypocalcemia: a randomized study.

OBJECTIVE: To test the hypothesis that strict control of diabetes during pregnancy can reduce the risk for neonatal hypocalcemia in infants of diabetic mothers. METHODS: One hundred thirty-seven pregnant women with insulin-dependent diabetes enrolled before 9 weeks' gestation were randomized to one of two treatment groups. In 68 subjects, the goals were fasting blood glucose level less than 4.44 mmol/L (80 mg/dL) and 1.5-hour postprandial blood glucose level less than 6.66 mmol/L (120 mg/dL) (strict control), whereas in 69 the goals were fasting blood glucose level less than 5.55 mmol/L (100 mg/dL) and 1.5-hour post-prandial glucose level less than 7.77 mmol/L (140 mg/dL) (customary control). RESULTS: Infants in the strict control group had a significantly lower rate of hypocalcemia (mean calcium less than 8.0 mg/dL in term infants and less than 7.0 mg/dL in preterm infants) than infants in the customary control group (17.6 versus 31.9%; P < .05). Using logistic regression analysis and after adjusting for the effects of gestational age, asphyxia, and White class on hypocalcemia, the difference between groups remained significant. The lowest infant serum calcium concentration correlated significantly with maternal glycohemoglobin A1 concentration at delivery (P = .03), gestational age (P = .0001), and the lowest serum magnesium concentration (P = .0001). CONCLUSION: Strict management of diabetes in pregnancy is associated with a reduction in the rate of neonatal hypocalcemia.

Fetal weight and progression of diabetic retinopathy.

OBJECTIVE: To test the hypothesis that progression of diabetic retinopathy in pregnancy is associated with reduced fetal growth and related neonatal morbidity. METHODS: Women with type 1 diabetes (n = 205) were enrolled before 14 weeks' gestation in a prospective study of diabetes in pregnancy and treated with intensive insulin therapy. They had serial ophthalmologic evaluations before 20 weeks' gestation and in late gestation or postpartum. Subjects were divided into two groups based on whether retinopathy progressed (progression group) or remained unchanged (no progression group). RESULTS: Retinopathy progressed in 59 of 205 women (29%) and was associated with advanced White classification (P =.001): three (5%) were class B, 14 (23%) class C, 24 (41%) class D, and 18 (30%) class F-RF. Reduced fetal growth was associated with progression of retinopathy. Mean birth weight was lower (P =.02), and more infants were small for gestational age (P =.02) and had low birth weights (P =.02) in the progression group. More large-for-gestational-age infants were noted in the no-progression group (P =.04). Birth weight percentile distributions showed a shift of the curve to the left in the progression group (P =.03). There were no differences in gestational age at delivery, macrosomia, preterm delivery, respiratory distress syndrome, neonatal hypoglycemia, or neonatal death. Small for gestational age was associated with chronic hypertension (odds ratio [OR] 6.4; 95% confidence interval [CI] 1.5, 27.9) and retinopathy progression (OR 4.7; 95% CI 1.2, 23.8). CONCLUSION: Development and progression of diabetic retinopathy during pregnancy were associated with reduced fetal growth manifested as increased rate of small-for-gestational-age and low-birth-weight infants.

Effects of antenatal corticosteroids on blood pressure in very low birth weight infants during the first 24 hours of life.

OBJECTIVE: We tested the hypothesis that prenatal glucocorticoids significantly increase mean arterial blood pressure in very low birth weight preterm infants during the first 24 hours after birth. STUDY DESIGN: Prospectively collected data from 178 inborn infants with birth weights between 500 and 1499 gm were examined. A total of 80 infants were born to mothers treated with corticosteroids (birth weight: 1057 +/- 271 gm, gestational age: 28.0 +/- 2.6 weeks), and 98 infants were untreated controls (birth weight: 1030 +/- 280 gm, gestational age: 28.0 +/- 2.8 weeks). The study setting was a university-based tertiary care center for newborn intensive care. RESULTS: Mean blood pressures on admission and at 3, 6, 12, 18, and 24 hours were significantly higher in steroid-treated infants. Steroid-treated infants received significantly less volume expansion (3.8 +/- 8.5 ml/kg versus 14.4 +/- 20.7 ml/kg; p < 0.001) than controls. Vasopressor support was also reduced in the steroid group (2.5% versus 11.5%; p < 0.05). CONCLUSION: Antenatal steroids are associated with both a higher mean systemic blood pressure and a decreased use of vasopressors and plasma expanders in very low birth weight infants during the first 24 hours after birth. This effect is not limited to infants of < 1000 gm; it is also significant in infants with a birth weight between 1000 and 1499 gm, and is already detectable in the first hours of life. We speculate that this finding may contribute to the mechanism of steroid protection against conditions such as intraventricular hemorrhage.

Techniques of enteral feeding in the newborn.

Among techniques of enteral feeding, gastric bolus feeding still appears to be the method of choice for most newborn babies because it is both practical and inexpensive. Unstable preterm infants and those with severe respiratory diseases or with delayed gastric emptying time may not tolerate intermittent gastric feedings and may benefit from continuous gastric feedings. Transpyloric feedings do not seem to offer any advantage over continuous gastric feedings and should be reserved for infants at risk of aspiration, such as those with gastroesophageal reflux or delayed gastric emptying. Early low-volume feedings appear beneficial and are not associated with increased morbidity. Once enteral feedings are established, daily increments of 10-20 ml/kg appear to be safe and not associated with an increased risk of necrotizing enterocolitis.

Neonatal aspiration: not just meconium.

Aspiration of uncontaminated amniotic fluid as a cause of neonatal respiratory distress is scarcely documented. A term neonate who presented with early onset respiratory distress with a radiographic appearance of an aspiration syndrome is therefore reported. Differential diagnosis and implication of this diagnosis in the management of neonatal respiratory distress are discussed. This case highlights amniotic fluid aspiration as a possible cause of severe respiratory distress even in the absence of meconium stained fluid.

Bilistick: a low-cost point-of-care system to measure total plasma bilirubin.

BACKGROUND: Severe neonatal hyperbilirubinemia, with consequent encephalopathy, remains a common cause of morbidity and death in many regions of the world. Poor access to clinical laboratory resources and screening programs to measure plasma bilirubin levels is a major contributor to delayed treatment in developing countries, and the cost of existing point-of-care screening instruments precludes their dissemination. OBJECTIVES: We are evaluating the accuracy of a low-cost, minimally invasive point-of-care system (Bilistick) requiring a 25-µl blood sample that could be used in low-resource environments to evaluate patients with neonatal jaundice. METHODS: We compared plasma bilirubin levels in divided blood samples by clinical laboratories and by Bilistick at two medical centers serving term and near-term newborns from ethnically different populations. RESULTS: 118 neonates with bilirubin levels ranging from 24.8 to 501.0 µmol/l were analyzed. The mean bilirubin concentration (±SD) was 215.6 ± 85.5 µmol/l for Bilistick and 226.1 ± 86.4 µmol/l by laboratory determination. Pearson's correlation coefficient between all paired results was 0.961, and the Bland-Altman analysis showed a mean difference of 10.3 µmol/l with a 95% interval of agreement of -38.0 to 58.7 µmol/l. CONCLUSION: Bilistick is a minimally invasive method for measuring total bilirubin concentration over a wide range of values and should provide an affordable and accurate system for pre-discharge and follow-up screening of jaundiced infants, particularly in low-resource environments.

Premature birth with complicated perinatal course delaying diagnosis of prader-willi syndrome.

Prader-Willi syndrome in the newborn is essentially characterized by marked hypotonia, feeding difficulties, hypogonadism, and possible characteristic facial features. However, diagnosis at this age may be particularly difficult, and dysmorphic features may be subtle or absent. Prematurity can furthermore delay clinical features recognition and typical complications due to preterm birth may contribute to divert the diagnosis. We describe a preterm baby with a complicated perinatal course later diagnosed as PWS.

Near-infrared interactance (NIR): a new non-invasive technique to estimate subcutaneous body fat in newborns.

Body fat (BF) is rarely determined routinely in infants due to the lack of a simple measuring device. A portable NIR instrument, successfully applied in adults, takes 5 seconds for a measurement and involves no skin manipulation. We designed this study 1) to compare BF estimates by NIR to skinfold thickness (ST) and 2) to assess the relationship of NIR and ST values with standard measures reflecting BF, such as Weight/Length Ratio, Body Mass Index and Ponderal Index. We studied BF in 40 healthy term infants within 12 hours of birth by NIR and ST at 3 standard sites: triceps (TRI), subscapular (SUB) and abdominal (ABD). RESULTS. Significant correlations were found between NIR and ST (R=0.70, 0.58 and 0.64 for SUB, TRI and ABD, respectively); between the sums of the 3 measurements (R= 0.69), and between birthweight and ST (R=0.57) or NIR (0.51), and between Weight/Length Ratio and ST (R=0.55) or NIR (R=0.51). We conclude that NIR measurements correlate well with skinfold measurements and NIR can be measured faster than skinfolds (5 vs 60 seconds). We speculate that NIR could be cost-effective for routine clinical measure of body fat and growth in infants.

Changes in static and dynamic skin fold measurements in the first 60 hours of life: higher values following cesarean delivery.

Infants born by cesarean section (CS) have been reported to have increased intracellular and total body water and have a slower postnatal decline in cell water content compared to vaginally delivered infants. These findings support the hypothesis that delivery-related changes in water compartmentalization will result in postnatal differences in tissue compressibility. In order to test this hypothesis, static and dynamic skin fold thicknesses (SFTs) were obtained in 60 healthy, term, appropriate for gestational age infants between 1 and 60 h of life. Thirty infants were delivered vaginally and 30 by CS. Midtriceps, subscapular and abdominal skin folds were measured twice daily during the first 3 days of life. There were no differences between groups in birth weight, length, head circumference, gestational age, sex or ponderal index. Our results showed that static SFTs were significantly greater in CS than in vaginally delivered infants at birth and remained so throughout the study period. In both groups, static SFTs increased while weight decreased over time. At birth, dynamic SFTs were significantly greater in infants delivered by CS. We speculate that skin fold differences between CS and vaginal deliveries may reflect a different dynamic of perinatal body water distribution. The mechanism underlying the paradoxical increase in static SFTs in both groups is unknown.

Maturation of thermal capabilities in preterm infants.

Very low-birth-weight infants (VLBW) may initially require environmental temperatures higher than skin temperature. We examined the correlation between gestational age, birth weight, and the time to reach skin-air temperature equilibration (TTE) in VLBW infants. We also examined the effect of antenatal steroids on TTE in infants with birth weight < 1000 g. There is a significant exponential correlation between TTE and birth weight or gestational age (p < 0.05). There was no significant change in TTE in infants who were treated antenatally with steroids, as compared with infants who were not treated. Multiple regression analysis with TTE as the dependent variable and birth weight or gestational age, race, betamethasone treatment, and gender as the independent variables showed a significant correlation between gestational age and TTE (p = 0.04). We conclude that thermal capabilities are exponentially correlated with gestational age or birth weight.

Evidence of increased intrauterine bone resorption in term infants of mothers with insulin-dependent diabetes.

Infants of diabetic mothers (IDMs) have lower bone mineral content than control subjects at birth. We measured cord blood propeptide of type I procollagen (PICP), a marker of bone formation, and telopeptide of type I collagen (ICTP), a marker of bone resorption, in 25 term IDMs and 20 term control subjects. Concentrations of ICTP were higher in IDMs than in control subjects; there was no difference in PICP concentrations. We conclude that osteoclastic activity appears to be higher in IDMs than in control subjects in utero.