Irwin J. Light

A SIMPLIFIED ASSESSMENT OF GESTATIONAL AGE

Accurate gestational assessment is important for the appropriate management of every newborn infant. There is still a need for a simple yet reliable method which could be used by ancillary personnel as well as physicians. A score was developed by condensing the methods of Dubowitz and others. The new score consists of 6 neurologic and 6 physical criteria (see Klaus and Fanaroff: CARE OF THE HIGH RISK NEONATE p. 47, W.B.Saunders,1973). To obtain this, multiple physical criteria were combined into single observations and neurologic signs using active muscle tone (which are misleading in sick infants) were eliminated. To test the accuracy of the simplified system, the Dubowitz method was used as a standard, and 284 babies were examined by both methods by unbiased observers. Ages ranged from 12 to 96 hrs with weights ranging from 760 to 5460 gms. Correlation between the two examinations was 0.975, p<.001). Individual criteria of the simplified score on a second group of 86 infants were then weighted for predictive value according to their correlation with known dates. The gestational age tended to be more closely related to the individual components of the physical assessment (r=0.614-0.784) than to the neurologic criteria (r-0.437-0.756). The correlation for the score obtained for the total assessment (r=0.952) was greater than that for any of the individual components. The average time required for Dubowitz exam was 10-15 min, the simplified method 3-4 min. This simplified scoring system provides a rapid and accurate assessment of gestational age.

Hypocalcemia in infants of diabetic mothers: Studies in calcium, phosphorus, and magnesium metabolism and parathormone responsiveness

Since infants of diabetic mothers are often delivered prematurely, it has been uncertain whether the hypocalcemia reported in them is related to maternal diabetes or to prematurity. In this study of 28 infants of diabetic mothers and 28 prospectively matched infants born to nondiabetic mothers, the incidence of hypocalcemia was significantly increased in the infants of diabetic mothers, even when gestational age and perinatal complications were taken into consideration. Renal studies demonstrated no differences in excretion of calcium, magnesium, and phosphorus between infants of diabetic mothers and control infants. Serum calcium levels were higher in diabetic mothers than in nondiabetic control subjects. Lower serum calcium levels and higher serum phosphate levels were present in infants of diabetic mothers postnatally. End organ responsiveness was shown by a calcemic and phosphaturic response to exogenous parathormone. It is speculated that relative maternal hyperparathyroidism leading to fetal hypoparathyroidism may be a factor in the pathogenesis of neonatal hypocalcemia in infants of diabetic mothers.

Maternal intravenous glucose administration as a cause of hypoglycemia in the infant of the diabetic mother

Abstract The effect of the cord blood glucose level on early neonatal glucose homeostasis was studied in 18 infants of diabetic mothers. The higher the cord blood glucose, the more rapid the disappearance of glucose, the lower the level to which the glucose concentration falls, and the greater the prevalence of hypoglycemia during the first 4 hours of life. The data also indicate that the umbilical cord blood glucose is directly related to the rate of glucose administration to the diabetic mother, immediately prior to delivery. The more rapid the glucose infusion to the mother, the higher the cord blood glucose level. The cord blood glucose level may also be related to the maternal blood glucose level, the route of delivery, and the severity of the maternal diabetes. It is recommended that restriction of glucose administration to the diabetic mother during labor and delivery decreases the likelihood that the infant will develop early neonatal hypoglycemia.

Impaired Epinephrine Release in Hypoglycemic Infants of Diabetic Mothers

CARBOHYDRATE homeostasis represents a complex interaction between multiple humoral agents. In the normal person a fall in blood sugar initiates physiologic responses that reduce the blood sugar to ...

The reponse to parathyroid extract (PTE) in infants of diabetic mothers (IDM)

Neonatal hypoclacemia (NHC) in infants of diabetic mothers (IDM) has been thought to be related to transient hypoparathyroidism or lack of responsiveness to parathyroid hormone. Previous reports of NHC in IDM have not documented its existence when compared to gestation matched infants. A previous study of low birth weight infants demonstrated the importance of early gestation on the incidence of NHC. In the present study 28 IDM were matched with infants of similar age, sex, gestation and perinatal complications. Seven IDM developed NHC compared with one in controls (p < 0.025). In IDM mean calcium levels were lower at 12, 24, 48, 60 and 72 hours of age. One IDM (maternal class D) developed temporary hypomagnesemia with NHC. During the first 3 days of life, in all infants tubular reabsorption of P (TRP) fell (93% to 87%), urinary P excretion rose (5 to 40 mg/24 hour) and urinary Ca and Mg remained low (<1 and <0.5 mg/24 hr respectively). In 6 IDM who were given PTE (5 units/kg) at 24 hours and 48 hours of age, 5 responded with temporary elevations of Ca at 12 hours post-injection compared with untreated IDM (p < 0.05). There was no significant difference in serum Mg and P levels, TRP and urinary P, Ca and Mg between treated and untreated IDM and between IDM and controls. This report demonstrates that IDM are prone to NHC, are capable of conserving Ca and Mg, and have a positive calcemic response to PTE.

152 CARDIOVASCULAR EFFECTS OF HYPOTHERMIA AND REWARMING IN NEWBORN DOGS

The cardiovascular effects of acute hypothermia and rapid rewarming were studied in 11 newborn dogs, 2-5 days of age, anesthetized lightly with penthothal, 20 mg/kg. Cardiac output and organ blood flows were measured by the radioactive microsphere reference organ technique. Animals were made hypothermic by placing them in an incubator without heat, resulting in rectal and skin temperatures of 33.0±.25° C and 33.7±.28° C, respectively (mean±SE). Animals were rapidly rewarmed by setting the incubator heater to maximum, resulting in a rise of rectal and skin temperatures to 35.1±.49° C and 35.5±.40° C, respectively, within 60 minutes. Rapid rewarming resulted in a slight rise in BP from 45.0 to 49.4 mmHg (p<.025), a slight rise in renal blood flow from 2.17 to 2.81 ml/min/g (p<.05) and a large (65%) increase in cerebral blood flow (CBF) from .31 to .51 ml/min/g (p<.05). There were no significant changes in cardiac output or blood flow to the GI tract. Measurements of the effects of cooling were made in 4 animals and revealed a marked drop in CBF from .51 to .20 (p<.025). During the rewarming procedure, 4 animals became apneic and bradycardic, responding to tactile stimulation. These studies demonstrate that acute changes in body temperature result in altered function of the cardiovascular system, particularly flow to the brain, and such changes may contribute to the clinical disorders found in infants under similar thermal conditions.

MIDDLE EAR FUNCTION OF NEONATES

Results of impedance audiometry can determine middle ear pressure, eustachian tube function, tympanic membrane mobility, and presence of fluid in the middle ear cavity. The present study utilized an impedance audiometer to measure middle ear function of neonates.Subjects included 20 infants with a mean age of 7.4 hrs. Their average weight was 3120 grams. All were healthy with no obvious congenital defects. Both ears were tested on every baby. The vernix caseosa was removed from the external auditory meatus prior to taking impedance measurements.Results indicated that all of the infants had normal tympanic membrane mobility and normal middle ear pressure. The data show 33 ears with Type Ad tympanograms and 7 Type W tympanograms. The average middle ear pressure was 6.75 mm. (H2O). The average compliance at the tympanic membrane was 1.113 cu. cm.Many pediatric textbooks state that the middle ear of neonates is filled with a mucoid material which is present for the first few days of life and is a factor in the ability of newborns to respond to sound. The finding of normal middle ear function in neonates would suggest that mucous is not commonly present and therefore not a factor in infants response to sound.

SERUM CALCIUM IN INTRAUTERINE GROWTH RETARDATION (IUGR)

Infants with intrauterine growth retardation (IUGR) often exhibit signs of neuromuscular irritability, even without associated hypoglycemia. Little is known about serum Ca in such infants. In this study 47 IUGR infants and 70 infants with birth weights appropriate for gestational age (AGA) were studied serially in the first 3 days of life. Serum Ca in AGA infants was correlated with gestational age; serum Ca in IUGR infants was within the 95% confidence limits for AGA infants of comparable gestation. Forty IUGR infants were matched with 40 AGA infants for birth weight and birth asphyxia (1 minute Apgar Score≤6, or necessity for resuscitation): neonatal serum Ca was not significantly different between the 2 groups. Among IUGR infants postnatal serum Ca was not correlated with birth weight, but correlated significantly with Apgar Scores(r=0.471, p<0.01) and initial acidosis(r=0.34, p<0.05). The lowest serum Ca In IUGR infants with birth asphyxia was 7.52±SE 0.23 mg% compared to 8.41±0.21 In IUGR Infants without birth asphyxia. Lower serum Ca was associated with higher serum P at 24 hours of age (r=0.332,p<0.05). Serum Ca was not related to neuromuscular symptomatology. Thus neonatal serum Ca is affected by gestational age and not by birth weight; intrauterine growth retardation is not associated with lower serum Ca, except in the presence of birth asphyxia.

The Neonate With Congenital Heart Disease, vol 5, Major Problems in Clinical Pediatrics.

Any book must be evaluated in the context of its goals. The authors indicate it is not their aim to present an encyclopedia containing all possible presentations of congenital heart disease in newborn infants. Rather, with unnecessary apologies to their colleagues in pediatric cardiology, the book is directed to pediatricians and general practitioners who constitute the newborn infants first line of defense. Such a noncardiologist pediatrician is not likely to be primarily interested in the detailed anatomy of various malformations of the heart and great vessels. Rather, he is searching for a better understanding of the infant with disturbed cardiac function, ie, the systemic effects of cardiac disease, or the cardiac effects of systemic diseases. The pediatric generalist may then better be able to recognize the early signs of heart disease in the newborn infant and to approach the primary diagnosis in a logical manner; and, having consulted the cardiologist,