Placental findings in malnourished term neonates

Background:  The aim of the present study was to investigate placental pathologies in malnourished term neonates.
Methods:  A group of term newborns was evaluated at birth for fetal malnutrition (FM) using the Clinical Assessment of Nutritional Status (CANS) score. The study group consisted of 37 malnourished neonates and 13 well-nourished newborns, including their placentas. Infants with FM were subdivided into two groups: appropriate for gestational age (AGA) and small for gestational age (SGA).
Results:  The proportion of subjects having antepartum complications was 18.9% in the FM group, whereas none was found in the control group. Similarly, a significant portion, 83.8% of the study group, had gross placental abnormalities, while the control group had none. The placental microscopic findings in the study group included perivillous fibrin deposition, calcification, necrosis, retroplacental hematoma, and infarction. In contrast, the control group had only perivillous fibrin deposition and calcification. Placental histopathological findings between FM term AGA and SGA neonates were also compared, and no statistically significant differences were found ( P  < 0.05).
Conclusions:  Placental findings in malnourished term AGA neonates are not different from findings documented in malnourished SGA cases, but they are different from those in well-nourished term AGA newborns.     

Range of echocardiographic findings in term neonates with high oxygen requirements

AIMS—To examine the hypothesis that right to left shunting occurs mainly in the lungs rather than through the fetal channels in neonates.METHODS—Thirty two term babies requiring over 70% oxygen had daily colour Doppler echocardiograms until recovery. Measurements included left ventricular fractional shortening, right and left ventricular outputs, colour and pulsed Doppler ductal and atrial shunting and systolic pulmonary artery pressure (SPAP) derived from ductal shunt or tricuspid incompetence velocities.RESULTS—The babies were retrospectively classified into a respiratory group (n=19) and a persistent pulmonary hypertension (PPHN) group (n=13) on the basis of clinical history and radiology. At the initial echocardiogram, just 50% of babies had suprasystemic SPAP. Despite better oxygenation, more of the PPHN group had suprasystemic PAP (85% vs 26%). A correlation between SPAP and Oxygen index (OI) was present only in the respiratory group (r=0.7). Low ventricular outputs (<150 ml/kg/min) were common in both groups (53% and 79%). The respiratory group had more closed ducts (47% vs 0%) and those ducts which were patent were more constricted (1.75mm vs 2.6 mm). Pure right to left ductal shunts were seen in just 15% and pure right to left atrial shunts in just 6% of all babies. The serial echocardiograms showed that SPAP fell and ducts closed well before oxygenation improved. Ventricular outputs increased with age in both groups.CONCLUSIONS—Apart from early on in the sickest babies with a primarily respiratory diagnosis and the babies with primary PPHN, most right to left shunting occurred at an intrapulmonary level.     

Gentamicin dosage in preterm and term neonates.

Pre-dose and peak serum levels of gentamicin were measured in 82 neonates (25-42 weeks'' gestational age), and for comparison in 10 infants and 9 children. Dosage was 2-2.5 mg/kg twice daily for the neonates, and three times daily for infants and children. Neonates were subdivided according to gestational age and weight. Serum levels of gentamicin were very variable in all groups. Preterm neonates of low gestational age (25-30 weeks) showed a 66% incidence of pre-dose levels exceeding 1 microgram/ml, indicating possible accumulation. In the less premature neonates this incidence was still 20-29%. The level of 4 microgram/ml, the minimum concentration required to inhibit most of the bacteria sensitive to gentamicin, was reached in increasing numbers of neonates as their gestational age rose (from 30% in the 31- to 35-week gestational age group, to 60% at term); those small-for-gestational age had consistently lower levels. It is concluded that term neonates require dosage to be individualized and serum levels of the drug to be monitored.     

Peripheral oxygenation in term neonates

The aim of this study was to analyse changes in peripheral oxygenation in healthy term neonates within the first week of life with near-infrared spectroscopy and venous occlusion. Oxygen delivery did not change with increasing age. Oxygen consumption and fractional oxygen extraction increased, whereas tissue oxygenation index decreased with increasing age.     

Intraosseous lines in preterm and full term neonates.

AIM: To evaluate the use of intraosseous lines for rapid vascular access in primary resuscitation of preterm and full term neonates. METHODS: Thirty intraosseous lines were placed in 27 newborns, in whom conventional venous access had failed. RESULTS: All the neonates survived the resuscitation procedure, with no long term side effects. CONCLUSION: Intraosseous infusion is quick, safe, and effective in compromised neonates.     

Respiratory mechanics in spontaneously breathing term and preterm neonates.

The compliance (Crs), resistance (Rrs) and passive time constant (tau rs) of the respiratory system were determined by the single-breath method (sb) in 24 healthy term and preterm newborns. In 22 of them, Crssb was compared to the slope of the pressure-volume curve determined by the multiple occlusion technique (mo), which is not dependent on the assumption of a linear flow-volume relationship. Crssb and Rrs correlated significantly with body weight (kg): Crssb = 0.56 x kg + 1.22 (r = 0.67); Rrs = -20.1 x kg + 134.6 (r = -0.68). No difference in Crs and Rrs between prone and supine positions was found. tau rs was not significantly different between premature (0.21 +/- 0.06 s) and full-term infants (0.21 +/- 0.05 s). Crssb was significantly higher than Crsmo in premature babies (2.27 +/- 0.41 ml.cm H2O-1 vs. 1.98 +/- 0.47 ml.cm H2O-1. This difference may be explained by a continuous braking of expiratory airflow after release of the occlusion, or more likely, by a difference in the lung volume at which Crssb and Crsmo are measured. However, the difference between Crssb and Crsmo (approximately 15%) is in the same range as the intrasubject variability, and is meaningless compared to the alterations of respiratory mechanics observed during neonatal ventilatory disorders. Therefore, the single-breath method appears to be a suitable and noninvasive method to measure respiratory mechanics in nonintubated prematures.     

Birth asphyxia alters neonatal intestinal motility in term neonates.

As an extension of an earlier study showing that manometry can identify preterm newborns at risk for feeding intolerance, the authors investigated whether abnormalities of intestinal motor activity underlie the feeding intolerance seen in asphyxiated newborns. Low-compliance perfusion manometry was recorded within the first postnatal week in 25 term neonates admitted consecutively for respiratory diseases. Eleven of these neonates were identified to have experienced birth asphyxia because three concurrent features were present: 1-minute Apgar score of less than 2; 5-minute Apgar score of less than 4; and recurrent seizures within the first 48 postnatal hours. The remaining 14 neonates, who did not have any of these three characteristics, were considered to be nonasphyxiated control neonates. Motor activity differed in nonasphyxiated and asphyxiated neonates during fasting and feeding. During fasting, asphyxiated neonates had less migrating activity than nonasphyxiated neonates. In addition, episodes of motor quiescence and clustered phasic activity were less well organized in asphyxiated neonates. Both groups of neonates displayed a change in motor activity in response to a feeding infusion; however, the response was initiated significantly sooner in asphyxiated than in control neonates. All of the 11 asphyxiated neonates were intolerant of enteral feedings during the first poststudy week, but no control neonate was feeding intolerant. Six of the asphyxiated neonates were reevaluated 1 to 2 weeks later. During this latter study, motor activity in these asphyxiated neonates was similar to that of nonasphyxiated neonates; 5 of 6 of these neonates subsequently tolerated enteral feedings. It is speculated that changes in motor activity underlie the feeding intolerance that asphyxiated neonates typically exhibit.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cerebral infarcts in full term neonates

Cerebral infarcts are an important cause of neonatal convulsions. We report the etiologic factors, and clinical and neuroradiologic findings of four full term neonates who presented with neonatal convulsions and had cerebral infarct. In our patients the risk factors for the cerebral infarct were perinatal asphyxia, sepsis, dehydration and catheter application. All had convulsions as the initial sign of infarct and had cranial imaging which revealed the definitive diagnosis. The patients underwent an extensive evaluation for hereditary causes of cerebral infarct that included anticoagulant factors (Proteins C and S, antithrombin III, antiphospholipid antibodies), factor V Leiden and prothrombin gene mutations, blood and urine amino acid and urine organic acid levels. The results were found to be within normal limits. In conclusion, neonatal convulsions can be the first sign of cerebral infarct. For this reason it seems preferable to include cranial imaging by computed tomography or magnetic resonance imaging (MRI) in the work-up of cases with unexplained neonatal convulsions.     

Anthropometric standards for term neonates

32 anthropometric measurements have been carried out (within 48 h of birth) on 106 full-term normal neonates. Trunk and limb parameters are considered and the results presented as mean values with standard deviations. Comparison with previously published standards, where available, showed good agreement. Both sides of the body were measured but no significant difference was found overall between values for left and right sides of the body. The effect of gender on each measurement was also considered with females having significantly smaller head circumferences and head lengths and larger upper leg lengths.     

Sodium homeostasis in term and preterm neonates. II. Gastrointestinal aspects.

Eighty five 24 hour balance studies were performed on 70 healthy newborn infants of gestational age 27-40 weeks; dietary intake and stool losses of sodium were measured. There was a relation between gastrointestinal sodium absorption and conceptional age (the sum of gestational and postnatal age), whether expressed as absolute stool sodium losses or as the ratio of stool sodium to dietary sodium intake. The stool K:Na ratio rose appreciably with maturation, although stool content of potassium was not greatly increased. These findings suggest that intestinal sodium absorption is inefficient in immature babies and that the degree of malabsorption is inversely related to conceptional age.     

Sodium homeostasis in term and preterm neonates. I. Renal aspects.

Eighty five 24 hour sodium balance studies and creatinine clearance measurements were performed in 70 infants of gestational age 27-40 weeks and postnatal age 3-68 days. The kidney''s capacity to regulate sodium excretion was a function of conceptional age (the sum of gestational age and postnatal age) and an independent effect of postnatal age was also observed--extrauterine existence increased the maturation of this function. The sodium balance was negative in 100% of infants of less than 30 weeks'' gestation, in 70% at 30-32 weeks, in 46% at 33-35 weeks, and in 0% of greater than 36 weeks, and the incidence of hyponatraemia closely paralleled that of negative sodium balance. Despite a low glomerular filtration rate (GFR) urinary sodium losses were highest in the most immature babies but fractional sodium excretion (FENa) was exponentially related to gestational age. An independent effect of postnatal age could be identified on FENa but not in GFR. These findings indicate that in infants of greater than 33 weeks'' gestation sodium conservation is possible because of a favourable balance between the GFR and tubular sodium reabsorption, but that below this age GFR exceeds the limited tubular sodium reabsorption capacity. The rapid increase in sodium reabsorption in the first few postnatal days seems to be due to maturation of distal tubular function, probably mediated by aldosterone. We suggest that the glomerulotubular imbalance for sodium is a consequence of the immaturity of the tubuloglomerular feedback mechanism, and we estimate that the minimum sodium requirement during the first 2 weeks of extrauterine life is 5 mmol (mEq)/kg/day for infants of less than 30 weeks'' gestation and 4 mmol (mEq)/kg/day for those born between 30 and 35 weeks.     

Arterial oxygen saturation in healthy term neonates

Our objective was to determine arterial oxygen saturation as measured by pulse oximetry (SpO₂) in healthy term neonates during their first 4 weeks of life. Overnight recordings of SpO₂ (Nellcor N200), photoplethysmographic (pulse) wave-forms from the oximeter and breathing movements were performed in 60 term infants. They were studied initially during their 1st week of life (median age 4 days, range 1–7) and then again during their 2nd–4th week (median age 17 days, range 8–27). Median baseline SpO₂, measured during regular breathing, was 97.6% (range 92–100) during week 1 versus 98.0% (86.6–100) during week 2–4 (P>0.05). Episodes of desaturation, defined as a fall in SpO₂ to 80% for 4 s, were found in 35% of recordings obtained in week 1 compared to 60% of those obtained in week 2–4 (P<0.01). Their frequency increased from a median of 0 (0–41) per 12 h of recording at the initial recording to 1 (0–165) at follow up (P<0.01). Analysis of the data by week of life showed a peak in desaturation frequency in the 2nd week of life. The infants with extreme values at follow-up (e.g. a baseline SpO₂ of 86.6%, 5th percentile 91.9%, or a desaturation frequency of 165 per 12 h of recording, 95th percentile 32) had had values well within the normal range during their initial recording (a baseline SpO₂ of 94.4%, or a desaturation frequency of 4). Most of the desaturations in the infants with extreme values were associated with periodic apnoea. These results demonstrate only relatively minor developmental changes in oxygenation in term neonates during the first 4 weeks of life. The clinical significance of outlying values, i.e. a low baseline SpO₂ or a high number of episodic desaturations, remains to be determined.Conclusion These healthy term neonates had values for baseline oxygen saturation and desaturation frequency that were not substantially different from those observed in older infants.     

Vasomotor reactivity in premature neonates at term

In order to assess the specific sympathetic reactivity in premature infants at term, we designed a study to evaluate the peripheral vasomotor response of such infants when exposed to auditory challenges. Testing was performed in 29 premature neonates at term in both quiet and active sleep during a morning session. Two types of noises were used (click and continuous tones) at three frequencies (250, 1,000 and 6,000 Hz) and at three intensities (60, 85 and 110 dBA). Vasomotor response was studied by analyzing with Mathlab software the variability of the plethysmographic wave of the oxymetric pulse. No behavioral awakening was observed in response to any stimulation. When a tachycardia or a bradycardia reaction to the stimuli was observed, all neonates responded with a vasoconstriction. The global mean of the vasoconstrictive response was 18.45%. The overall ANOVA on the vasomotor response revealed significant effects for sleep stages (t: 1.98; p < 0.05), for frequency (t: 3.3; p < 0.001) and for intensity of noise (t: 3.01; p < 0.03) but no significant response with heart rate variability. From these results, we could conclude that the assessment of the vasomotor response is a very sensitive procedure to determine the reactivity of the autonomic nervous system in neonates, and could be used to study such vegetative responses in other stressful situations with good accuracy.     

Temperature measurement in term and preterm neonates

Body temperatures of 99 term and 44 preterm infants were measured at four sites: core (5 cm beyond the anus, with an electronic telethermometer), rectum (2 cm, with a mercury-in-glass thermometer), axilla, and between the skin and mattress. Temperatures measured at the four sites agreed closely in this group of largely normothermic infants. However, five of seven term infants with abnormal core temperature (greater than 1.5 SD below or above the mean) would have been judged to be normothermic by each of the three other measurements. The temperatures in preterm infants were lower and varied less with the site of measurement, indicating a smaller core-surface temperature gradient because of their relative lack of thermal insulation by body fat. Axillary temperature was as reliable as rectal temperature measured in the usual way with a mercury-in-glass thermometer. Measurement of the temperature between the skin and mattress was nearly as accurate as the other more frequently used methods. Ninety percent of temperatures were within 0.1 degree C of their final stabilization readings by 5 minutes for each type of thermometer and measurement site.     

Hindmilk for procedural pain in term neonates

The aim of this study was to investigate whether repeated doses of hindmilk were effective for pain relief during routine heel stick in term neonates. Infants enrolled in this double-blind placebo-controlled study were randomly assigned to hindmilk, 12.5% sucrose and distilled water groups. Infants were given 1 ml of the test solution 1 minute prior to, immediately before and 1 minute after the heel stick. Pain responses were assessed by physiologic and behavioral parameters and also according to the Neonatal Facial Coding System (NFCS). There were significant reductions in crying time, duration of the first cry and tachycardia, time needed for return to baseline heart rate, and the average and 1- and 5-minute NFCS scores in the hindmilk group when compared with the distilled water group. When the hindmilk group was compared to the sucrose group, only the NFCS scores at 1 and 2 minutes reached statistical significance in favor of the sucrose group. Repeated dose hindmilk administration is an effective analgesic intervention in term newborns during heel stick. Although the analgesic effect of 12.5% sucrose is slightly superior, hindmilk may be considered as a physiologically suitable alternative to sucrose.