Josep Figueras

Customised birthweight standards accurately predict perinatal morbidity

Objective: Fetal growth restriction is associated with adverse perinatal outcome but is often not recognised antenatally, and low birthweight centiles based on population norms are used as a proxy instead. This study compared the association between neonatal morbidity and fetal growth status at birth as determined by customised birthweight centiles and currently used centiles based on population standards. Design: Retrospective cohort study. Setting: Referral hospital, Barcelona, Spain. Patients: A cohort of 13 661 non-malformed singleton deliveries. Interventions: Both population-based and customised standards for birth weight were applied to the study cohort. Customised weight centiles were calculated by adjusting for maternal height, booking weight, parity, ethnic origin, gestational age at delivery and fetal sex. Main outcome measures: Newborn morbidity and perinatal death. Results: The association between smallness for gestational age (SGA) and perinatal morbidity was stronger when birthweight limits were customised, and resulted in an additional 4.1% (n = 565) neonates being classified as SGA. Compared with non-SGA neonates, this newly identified group had an increased risk of perinatal mortality (OR 3.2; 95% CI 1.6 to 6.2), neurological morbidity (OR 3.2; 95% CI 1.7 to 6.1) and non-neurological morbidity (OR 8; 95% CI 4.8 to 13.6). Conclusion: Customised standards improve the prediction of adverse neonatal outcome. The association between SGA and adverse outcome is independent of the gestational age at delivery.

Influence on fetal growth of exposure to tobacco smoke during pregnancy

We analysed the effect of exposure to tobacco smoke during pregnancy on fetal growth parameters in 129 term newborns. Children were classified into four depending on exposure on the basis of a questionnaire completed by the mother. The results confirmed that tobacco smoking reduced weight, length, cranial and thoracic perimeters at birth when exposure was due to either active or passive smoking. Weight deficits of infants whose mothers smoked heavily (458 g) were higher than those whose mothers were exposed to passive smoking (192 g). We conclude that passive smoking is a very important variable and should be taken into account in any study of neonatal growth parameters.

Differential vulnerability of gray matter and white matter to intrauterine growth restriction in preterm infants at 12 months corrected age.

Intrauterine growth restriction (IUGR) is associated with a high risk of abnormal neurodevelopment. Underlying neuroanatomical substrates are partially documented. We hypothesized that at 12 months preterm infants would evidence specific white-matter microstructure alterations and gray-matter differences induced by severe IUGR. Twenty preterm infants with IUGR (26-34 weeks of gestation) were compared with 20 term-born infants and 20 appropriate for gestational age preterm infants of similar gestational age. Preterm groups showed no evidence of brain abnormalities. At 12 months, infants were scanned sleeping naturally. Gray-matter volumes were studied with voxel-based morphometry. White-matter microstructure was examined using tract-based spatial statistics. The relationship between diffusivity indices in white matter, gray matter volumes, and perinatal data was also investigated. Gray-matter decrements attributable to IUGR comprised amygdala, basal ganglia, thalamus and insula bilaterally, left occipital and parietal lobes, and right perirolandic area. Gray-matter volumes positively correlated with birth weight exclusively. Preterm infants had reduced FA in the corpus callosum, and increased FA in the anterior corona radiata. Additionally, IUGR infants had increased FA in the forceps minor, internal and external capsules, uncinate and fronto-occipital white matter tracts. Increased axial diffusivity was observed in several white matter tracts. Fractional anisotropy positively correlated with birth weight and gestational age at birth. These data suggest that IUGR differentially affects gray and white matter development preferentially affecting gray matter. At 12 months IUGR is associated with a specific set of structural gray-matter decrements. White matter follows an unusual developmental pattern, and is apparently affected by IUGR and prematurity combined.

Prediction of hyperbilirubinaemia in the healthy term newborn

The aim is to establish the correlation between transcutaneous bilirubin (TCB) and serum bilirubin (TSB) and its predictive value for significant hyperbilirubinaemia ≫290 mcmol/L (17mg/dL). We studied a total of 2004 healthy full‐term newborns, weight 3.230g ± 491g; 90% received breast milk. The study was performed in two phases. In the first phase (610 newborns), the following tests were carried out: hematocrit and bilirubin in umbilical cord blood; TCB at 24 h, 48 h and between 60 h and 96 h at the forehead and over the sternum; TSB was measured along with this last test. In the second phase (1394 newborns), the predictive value of TCB and TSB was validated. The incidence of bilirubin >290 mcmol/L was 2.95% and 3.2%. The correlation between TSB and TCB is high (n= 996; r = 0.92; y = 5.916 + 0.804x; p < 0.000). There was a better correlation between TCB and TSB with sternal compared to forehead determination (< 24 h: 0.81 vs 0.77; 24–48 h: 0.887 vs 0.83; and >48 h: 0.94 vs 0.83). The study showed the scant sensitivity of umbilical cord blood bilirubin and good predictive value at 24 h of TSB > 102 mcmol/L (6mg/dL) and at 48 h of TSB > 154 mcmol/L (9mg/dL) and TCB > 13 (equivalent to 154 mcmol/L).

Energy intake, metabolic balance and growth in preterm infants fed formulas with different nonprotein energy supplements

Objective: To study metabolic and energy balances, growth and composition of increased body mass in healthy preterm infants fed control formula or control formula with three different nonprotein energy supplements. Patients and Methods: Growing preterm infants (birth weight < 1,500 g and gestational age < 31 weeks) were fed standard preterm formula (control group) or the same formula enriched with three different nonprotein energy supplements. An energy supplement of 23 kcal/kg/day was achieved by adding medium-chain triglyceride and dextrinomaltose in three different caloric ratios: 33:66 in group A, 66:33 in group B, and 85:15 in group C. Energy balance was determined by open-circuit continuous (5–6 hours) measurements of energy expenditure, with simultaneous measurement of 24-hour urinary nitrogen excretion. Metabolic balance was determined by measurements of energy intake, energy oxidation, and energy output in urine and stool. The composition of body mass accretion was determined as the accretion of fat and protein in the total weight gain. Results: The fat accretion (4.9, 5.9, 6.2, and 3.8 g/kg/day in groups A, B, C and D, respectively) correlated directly with fat intake. Infants receiving standard energy intake had a fat percentage of weight gain significantly lower (28%) than that of the high-energy intake groups (31%, 40%, and 38% in groups A, B, and C, respectively). This difference corresponded to the results obtained from skinfold thickness measurements. Conclusions: Excess nonprotein energy is stored as fat regardless of its source (fat or carbohydrate). High caloric and medium-chain triglyceride intake in otherwise healthy growing preterm infants does not promote nitrogen retention.

Influence of breastfeeding and postnatal nutrition on cardiovascular remodeling induced by fetal growth restriction

Background:Our aim was to determine the influence of breastfeeding and postnatal nutrition on cardiovascular remodeling induced by fetal growth restriction (FGR).Methods:A cohort study including 81 children with birthweight <10th centile (FGR) and 121 with adequate fetal growth for gestational age (AGA) was conducted. Cardiovascular endpoints were left ventricular sphericity index (LVSI), carotid intima-media thickness (cIMT), and blood pressure (BP) at 4–5 y of age. The combined effect of FGR and postnatal variables—including breastfeeding, fat dietary intake, and BMI—on cardiovascular endpoints was assessed by linear and robust regressions.Results:FGR was the strongest predictor of cardiovascular remodeling in childhood, leading to lower LVSI and increased cIMT and BP as compared with AGA. Breastfeeding >6 mo (coefficient: 0.0982) and healthy-fat dietary intake (coefficient: −0.0128) showed an independent beneficial effect on LVSI and cIMT, respectively. Overweight/obesity induced an additional increment of 1 SD on cIMT in FGR children (interaction coefficient: 0.0307) when compared with its effect in AGA. BMI increased systolic BP (coefficient: 0.7830) while weight catch-up increased diastolic BP (coefficient: 4.8929).Conclusions:Postnatal nutrition ameliorates cardiovascular remodeling induced by FGR. Breastfeeding and healthy-fat dietary intake improved while increased BMI worsened cardiovascular endpoints, which opens opportunities for targeted postnatal interventions from early life.

Changes in TcPCO2 regarding pulmonary mechanics due to pneumotachometer dead space in ventilated newborns

The aim of this study was to analyze the effect of added dead space on PaCO2 after application of a pneumotachometer during the measurement of pulmonary mechanics. The study was based on 24 observations of TcPCO2 changes during the measurement of pulmonary function in 9 newborns subjected to mechanical ventilation. All newborns remained stable during the 23 minutes of the test. The introduction of a low dead space pneumotachometer (1.7 mL) for 10 minutes led to an increase in TcPCO2 of 5.40 +/- 2.66 mm Hg, from 39.76 +/- 8.69 to 45.17 +/- 9.22. Pulmonary mechanics indexes that correlated with the percentage of CO2 increase were peak inspiratory flow and expiratory time/time constant. When the pneumotachometer was removed, TcPCO2 fell but remained 0.99 +/- 2.13 mm Hg above basal TcPCO2. Final TcPCO2 tended to relate negatively with the minute volume. We conclude that this transient increase in PaCO2 should be born in mind in neonates with a high basal level and can be prevented by maintaining a long expiratory time and a high minute volume.

The impact of clinical maternal chorioamnionitis on neurological and psychological sequelae in very-low-birth weight infants: a case-control study

Abstract Aims: To assess the relationship between clinically maternal chorioamnionitis and outcome in preterm very-low-birth weight (VLBW) infants. Methods: An observational case-control study was conducted in the neonatology departments of 12 acute care teaching hospitals in Spain. Between January 2004 and December 2006, all consecutive VLBW (≤1500 g) infants who were born to a mother with clinical chorioamnionitis were enrolled. The controls included infants who were born to mothers without chorioamnionitis, matched by gestational age, and immediately born after each index case. At a corrected age of 24 months, a neurological examination and a psychological assessment of the surviving children were performed. Results: Sixty-six of the newborn infants died; therefore, 262 infants from the original sample were available for the study. Follow-up data were obtained at a corrected age of 24 months from a total of 209 children (106 cases and 103 controls, 80% of the original sample size). Seventy children (33.5%) were diagnosed with some type of sequelae. The following conditions were all more prevalent in infants born to mothers with chorioamnionitis in comparison to controls: low development quotient (98.3±12.15 vs. 95.9±15.64; P=0.497), cerebral palsy (4.9% vs. 10.4%; P=0.138), seizures (1.0% vs. 3.8%; P=0.369), and other neurological or sensorial sequelae (32.0% vs. 34.9%; P=0.611). Conclusions: After controlling for gestational age, the study population demonstrated that the neurological outcomes in infants at a corrected age of 24 months was not worsened by chorioamnionitis.

The incidence of breastfeeding in our environment

AIMS To establish the incidence of breastfeeding and its persistence after three and six months; to identify the factors which might modify attitudes towards breastfeeding. METHODS An interview, administered to mothers of term born infants of adequate weight for gestational age, after a delivery of one sole foetus, between 1st March and 31st May 1997. Mothers were asked about: previous pregnancies, children and type of feeding; during this pregnancy, their intentions regarding feeding; supervision of pregnancy, and the information received regarding breastfeeding; their work situation, and educational level. Questions regarding the neonatal period referred to the kind of lactation initiated, information received, and the use of a pacifier and supplements. A two-part poll was conducted by telephone after 3 months and after 6 months, enquiring about what kind of feeding was used, the reason for change (if any), who had provided information regarding the change, degree of satisfaction, and work situation. Three hundred and twenty-nine polls were completed, accounting for 70% of the births. RESULTS During pregnancy, 91% of mothers had intended to breastfeed, and this figure was maintained at birth. A trend towards breastfeeding was observed: 74% of those who had fed earlier children artificially started breastfeeding this time, compared with 7% of mothers who changed from breastfeeding to artificial feeding. After three months, 57% of mothers continued to breastfeed their child, and 24% after six months. High educational level exerted a positive influence on the duration of breastfeeding (OR = 1.7; p = 0.03) and the giving of supplements had a negative effect (OR = 0.4; p = 0.04). The fact that mothers work outside the home did not modify the duration of breastfeeding. CONCLUSIONS The rate of breastfeeding is high (91%). Among mothers with previous children, there is a greater trend to change from artificial feeding to breastfeeding (74% vs 7%; p < 0.002). The mothers educational level is the most important positive factor, and the early giving of supplements the most important negative factor.

Gestational Age-Specific Cutoff Levels of TDx-FLM II for the Prediction of Neonatal Respiratory Distress Syndrome

Aim: To construct a predictive model for respiratory distress syndrome (RDS) from gestational age (GA) at delivery and TDx-FLM II value. Methods: Pregnant women who underwent an amniocentesis in which TDx-FLM II was determined were included in the study. A model for the occurrence of RDS was constructed by means of a logistic regression procedure from TDx-FLM II values and GA at delivery. Results: The mean value of TDx-FLM II was 47.11 mg/g. The mean GA at delivery was 33.4 weeks. The incidence of RDS was 7.8% (18/231). The optimal cutoff of predicted risk for respiratory distress was found to be 8.8%, resulting in a sensitivity and specificity of 89 and 83%, respectively. Conclusions: The adjustment of the TDx-FLM II value for GA at delivery results in a significant improvement in the predictive capacity of the test for the occurrence of RDS. The use of GA-specific cutoff values may simplify clinical decisions.