Bacterial endocarditis in neonatal intensive care.

OBJECTIVES: To ascertain the incidence of bacterial endocarditis in a level III neonatal nursery. To document the clinical features, assess survival, and evaluate the role of central venous catheters in neonates with bacterial endocarditis. METHODOLOGY: Index cases were identified by retrospective review of the echocardiographic records of infants admitted to the neonatal nursery from 1983 to 1995. Data obtained by review of the clinical records of these infants, and case-matched controls. RESULTS: From January 1983 to December 1995, 12,249 infants were admitted to the Special Care Nursery. Eight infants with endocarditis were identified, an incidence of 0.07%. Presenting symptoms and signs were often vague and nonspecific. Gestation less than 32 weeks, birthweight less than 1500 g, thrombocytopenia and neutropenia or neutrophilia were common features. Infants with endocarditis had a significantly higher Clinical Risk Index for Babies score than those without endocarditis. The tricuspid valve was involved in seven infants, six of whom had a percutaneous central venous catheter in situ before diagnosis. Mitral valve involvement occurred in two infants, neither of whom had central lines inserted. However, compared to infants without endocarditis, the placement of a central venous line was not of statistical significance. Seven of the eight infants survived following prolonged antibiotic therapy. CONCLUSIONS: Bacterial endocarditis is a rare but serious condition which is usually not fatal. In the premature newborn infant, presenting signs and symptoms are often nonspecific. Endocarditis should therefore be considered in the unwell very low birthweight infant.

Neonatal whole blood hyperviscosity: the important factor influencing later neurologic function is the viscosity and not the polycythemia.

The neurologic outcome of 23 seven-year old children who had cord blood hyperviscosity was compared with that of children with normal cord blood viscosity in a randomised, controlled and blinded study. Viscosity was measured using a coaxial narrow-gap couette viscometer. Sixteen (69.6%) of the children with hyperviscous cord blood had a disability; this incidence being three times greater (22.7%) than in children whose cord blood was not hyperviscous (P < 0.01). In three children with cord-blood hyperviscosity, the disability was severe. No child had a severe disability with normal cord blood viscosity. Of the eight children whose cord blood was hyperviscous, but not polycythemic, six (75.0%) had a disability and in one child the disability was severe. These results demonstrate an association between cord blood hyperviscosity and later neurologic development. Cord studies are non-invasive and result in the rapid diagnosis of the neonatal hyperviscosity syndrome, so allowing earlier treatment. This may be crucial in altering the effects of hyperviscosity on the developing brain in the early neonatal period. Because the neurologic outcome of children was similar whether polycythemia was present or not, the prime factor was the viscosity and not the hematocrit level. We suggest it may be necessary to perform cord blood viscosity studies routinely.

False negative cytogenetic results following amniocentesis.

We report 2 cases where prenatal cytogenetic studies following amniocentesis yielded false negative results. Both mothers requested termination of pregnancy but were reassured by the normal chromosome analysis and therefore continued their pregnancies. When cytogenetic studies were repeated in the neonatal period, they demonstrated chromosomal abnormalities, which were confirmed when the initial specimens from amniocentesis were reviewed. Because of our findings, we suggest that if prenatal chromosome analysis is reported as normal, where there is a high index of suspicion of a chromosome abnormality, the result should be questioned and neonatal chromosome analysis undertaken.

Auditory steady-state evoked potential in newborns.

Steady-state evoked potential responses were recorded from 337 normal full-term sleeping newborns to combined amplitude and frequency modulated tones. Responses were automatically detected by statistical analysis of the response phase. Responses were most easily and consistently recorded at carrier frequencies of 500 Hz, 1500 Hz and 4000 Hz when the modulation frequency was between 60 Hz and 100 Hz. In this modulation frequency range, the response latencies were found to be between 11 ms and 15 ms, depending on carrier frequency, and the mean response thresholds for the three carrier frequencies were found to be 41.36 dB HL, 24.41 dB HL and 34.51 dB HL respectively. The results of this study suggest that steady-state evoked potentials at modulation rates in excess of 60 Hz may be useful for frequency specific, automated hearing screening in newborns.

Hydrocephalus ex vacuo and clasp thumb deformity due to congenital cytomegalovirus infection.

A case of congenital hydrocephalus in a male infant with flexion deformity of the thumbs and great toes is reported. A maternal uncle had undefined intellectual impairment and X-linked hydrocephalus was considered among the differential diagnoses. However, this diagnosis was considered unlikely as the pyramids were preserved at autopsy. In addition, postmortem histopathology and viral culture established cytomegalovirus (CMV) infection as the underlying cause of the hydrocephalus. Although CMV infection is a well recognized cause of congenital hydrocephalus, the associated flexion deformities of the thumbs and great toes have not been previously described and may reflect injury to the corticospinal tracts.

Perhaps vigintiphobia should only apply to infants with Rhesus erythroblastosis.

Forty-two children who sustained a serum bilirubin (SBR) level above 339 mumol/L as newborn infants were assessed at our Growth and Development Clinic to determine presence of sequelae. Only one child (2.3%) had mild sensorineural deafness and one child (2.3%) performed below age-matched standards on psychological testing. As the SBR level rose the psychological scores were lower. Three infants had sepsis associated with the hyperbilirubinaemia. Two (maximum SBR levels of 371 and 366 mumol/L) children were normal (General Cognitive Index (GCI) 117 and 119, respectively) and one child (maximum SBR level 556 mumol/L) was borderline abnormal (GCI 74) on psychological testing; he also suffered from Rhesus erythroblastosis. Premature infants recorded a mean GCI of 109.9 (+/- 33.4) and for term infants mean GCI was 110.3 (+/- 17.3; NS); however, the youngest premature infant was 32 weeks' gestation. When maximum SBR level was correlated with GCI and Motor Index (MI) the only significant correlation (r = -0.7445; P = 0.03) occurred in infants with Rhesus erythroblastosis and GCI. Since exchange transfusion has a mortality of between 0.3 and 5.3% and an associated morbidity incidence of 5.2% we suggest that the standard indication for its use (SBR level of 342 mumol/L) should only apply to infants with Rhesus erythroblastosis. The actual SBR level which places a newborn infant at significant risk of bilirubin encephalopathy, where the cause of jaundice is other than Rhesus erythroblastosis, cannot be determined by this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Jaundice: clinical practice in 88,000 liveborn infants.

We reviewed jaundiced infants born between 1971 and 1989. Jaundice was diagnosed in infants whose serum bilirubin level was found to be 154 umol/l or greater. Of 88,137 livebirths, 10,944 (12.4%) were jaundiced. The most common aetiological factor was prematurity (20.3%), followed by ABO erythroblastosis (5.5%), sepsis (1.8%), Rh erythroblastosis (1.8%), bruising (1.3%), multifactorial (1.0%) and glucose-6-phosphate dehydrogenase deficiency (0.5%). In the remainder (67.8%) no cause was found or inadequate investigations were performed to determine a cause. During the period under review there was a significant increase (r = 0.91) in the proportion of newborn infants with jaundice of prematurity, in those not investigated (r = 0.92) and a decrease in the proportion with bruising (r = -0.90) as the cause. Phototherapy was used on 4,126 (37.7%) infants and exchange transfusion performed on 248 (2.3%). Causes of jaundice in infants requiring exchange transfusion were Rh erythroblastosis (108, 43.6%), ABO erythroblastosis (58, 23.4%), jaundice of prematurity (44, 17.7%) and a variety of causes in the remaining 38 (15.3%). Death occurred in 164 (1.5%) infants. In only 7 (4.3%), however, was the death possibly related to hyperbilirubinaemia or its treatment (Rh erythroblastosis (4), necrotizing enterocolitis following exchange transfusion (2) and pulmonary haemorrhage following exchange transfusion (1)). Phototherapy proved safe with no deaths attributable to its use.

Prospective study of the quality of survival of infants with critical fetal reserve detected by antenatal cardiotocography.

From 1981 to 1986 antenatal cardiotocographic monitoring was performed on 9,992 high-risk pregnancies selected from a total obstetrical population of 31,518 patients (31.7%). A critical fetal reserve pattern was detected in 89 patients (0.9%) whose pregnancies resulted in 68 surviving infants, 19 perinatal deaths and 2 sudden infant deaths. Since 47.4% of the infants who died in the perinatal period did so because of a related congenital malformation, such a defect should be excluded in the fetus with critical fetal reserve, by ultrasonography, before delivery (there is usually insufficient time for fetal karyotyping). Sixty-three (92.6%) of the surviving children were assessed at our Growth and Developmental Clinic and disabilities were detected in 16 (25.4%); however, the disability was major in only 5, including 2 children with Down syndrome. The quality of survival of infants born from pregnancies complicated by critical fetal reserve was satisfactory as 60 of 63 children (95.2%) had neither a major disability related to intrauterine hypoxia identified by the cardiotocographic pattern, or had one likely to significantly interfere with their quality of life. Our results suggest that pregnancies can be continued until the cardiotocographic pattern becomes critical in order to gain fetal maturity, without compromise to the fetal brain.

Cord whole blood hyperviscosity: measurement, definition, incidence and clinical features.

Cord whole blood viscosity and haematocrit values (PCV) were determined in 2461 live birth infants. Viscosity measurements were performed on an Australian-designed coaxial narrow-gap viscometer. Normal viscosity values were determined for each week of gestation above 34 weeks. Hyperviscosity was defined as a viscosity value above 2 s.d. from the mean for each week of gestation and it occurred in 164 (6.7%) newborn infants. Although a close relationship existed between cord whole blood viscosity and PCV (r = 0.6597, P less than 0.0001), only 47.4% of polycythaemic infants (PCV greater than 65) were also hyperviscous and only 23.9% of hyperviscous infants were also polycythaemic. Hence, using the haematocrit to select which infants require viscosity studies fails to detect many hyperviscous newborn infants. Hyperviscosity was less common (3.6%, P less than 0.001) in infants who were born by Caesarean section and more common (16.5%, P less than 0.001) in those who were growth retarded. Of the hyperviscous infants, 84.5% were not growth retarded, most (87.8%) were term and most (86.6%) were delivered vaginally. Most hyperviscous newborn infants may thus remain undetected unless routine whole blood viscosity studies are performed.

Second twin: quality of survival if born by breech extraction following internal podalic version.

The intrapartum management of the vertex-breech and vertex-transverse twin gestation is controversial. The fall in perinatal mortality rate to a low level has resulted in this parameter failing to be an adequate gauge of the safety of breech extraction and the answer lies in the quality of survival of the infants. Fifty-one twin pairs, collected over 12 years at the Mercy Hospital for Women, Melbourne, occurred where twin 2 was born by breech extraction following internal inversion and the control (twin 1) did not have this procedure performed. In 8 pairs either a stillbirth or neonatal death occurred; in one pair childhood death due to an accident (fire) occurred; in 4 pairs the parents refused entrance to the study as they perceived both twins to be similar; in 2 sets the assessment was incomplete; 11 sets were untraceable leaving 25 sets fully assessed as children ranging in age from 2 to 12 years. Growth, and psychological scores were not significantly different between twins 1 and 2 but 2 children had cerebral palsy and both were born by breech extraction following internal version at 29.2 and 30.1 weeks' gestation, respectively. Because of small numbers the results failed to achieve statistical significance and this study was unable to answer the question regarding the safety of breech extraction following internal version but did show that the majority of infants so born do well.

Methods of delivery and resuscitation of very-low-birthweight infants in Victoria: 1982-1985.

This article describes the patterns of delivery and resuscitation for very-low-birthweight infants who were born in Victoria from 1982 to 1985. Caesarean delivery rates increased from 15% to 30% for infants of birthweights of 500-999 g, and from 39% to 52% for infants of birthweights of 1000-1499 g. In level-III hospitals, the proportion of live-born infants who did not receive active resuscitation fell from 32% to 18% for those who weighed 500-999 g, and from 28% to 15% for those who weighed 1000-1499 g. Time trends over the four years showed the management of very-low-birthweight infants to be in a state of rapid transition in all birth settings. At the same time there was a fall in the still-birth rate of infants of birthweights of 500-999 g. Still-births rates for infants of birthweights of 1000-1499 g remained unchanged, as did neonatal mortality rates in both weight groups.

Outcomes following the use of rational guidelines in the management of jaundiced newborn infants.

In 1975, rational guidelines for management of the jaundiced newborn infant were introduced to the Mercy Maternity Hospital, Melbourne. The guidelines were produced as four charts, each chart covering a particular birthweight range. The charts have been used widely. The effect of introduction of the charts has been examined by comparing the years 1971-74 with 1975-77. An overall decrease occurred in the use of phototherapy, without an increase in the use of exchange transfusion or in those with a serum bilirubin level above 339 mumol/L. The difference was not explained by an alteration in the spectrum of causes of jaundice. Long-term follow-up of jaundiced infants managed according to these guidelines revealed a satisfactory outcome despite a significant reduction in active treatment. The associated avoidance of potential side effects of treatment of the jaundiced newborn infant warrants consideration of the use of these charts by other neonatal units.

Non-immune hydrops fetalis: rapidity of onset and usefulness of prenatal ultrasonography.

Non-immune hydrops fetalis (NIHF) has become more common than immune hydrops fetalis as a cause of fetal hydrops and its contribution to the total perinatal mortality rate has increased from 0.1% to 3.0% for the 10 years to 1979. A case is reported where an antenatal ultrasonograph performed within 24 hours of delivery showed hydrops was not present, however, at birth the infant was grossly hydropic and died despite intensive management. This case shows the rapidity of onset of NIHF and the devastating effect of this disorder. A review of two large series of NIHF revealed that in only 11.4% and 16.3% respectively, a significant uncorrectible associated major malformation may have been missed by antenatal ultrasonography. Hence, if prenatal ultrasonography fails to reveal a major malformation a viable fetus with NIHF should be regarded as salvageable. Pulmonary hypoplasia occurred in over 90% and is probably due to compression from serous cavity effusions. Thus to improve survival the ultrasonographer needs to watch for the development of serous cavity effusions so that a pregnancy complicated by NIHF can be terminated before the fetus develops pulmonary hypoplasia.

Incidence of prematurity and low birth-weight in an immigrant Chinese population.

This paper analyses the incidences of prematurity (gestation less than 37 weeks) and low birth-weight (birth-weight between 500 and 2,500g) in liveborn singleton infants born in Australia to mothers of the Chinese race. The incidence of prematurity was lower in infants born to mothers from Hong Kong (4.6%), to those from an almost exclusive Chinese population (5.5%) and to those that comprised a predominantly Chinese population (6.1%) when compared to that in a mainly non-Chinese population (7.7%). The incidence of low birth-weight was lower in infants born to mothers from Hong Kong (3.5%) and to those born to an almost exclusive Chinese population (4.1%) but not to those born to a predominantly Chinese population (5.9%) when compared to that in those born to a mainly non-Chinese population (5.9%). The incidence of major fetal malformations was similar in these Chinese and non-Chinese populations. This study confirms that Chinese have a significantly low incidence of prematurity and that this finding remains true when they live in Australia. Detailed prospective studies are required in immigrant Chinese to determine why they have such a low incidence of prematurity and to determine the incidence of fetal malformations which is said to be different than in Caucasian populations.

The survival of extremely-low-birthweight infants in Victoria: 1982-1985.

A population-based survey of mortality in extremely-low-birthweight (500- to 999-g) infants was carried out in Victoria for the years 1982 to 1985. No increase in the number of extremely-preterm births occurred during that time. The still-birth rate fell from 498 still births per 1000 births in 1982-1983 to 403 still births per 1000 births in 1984-1985. The neonatal mortality in 1982-1985 was 638 deaths per 1000 live births, with no significant decline from that of the 1978-1981 cohort. The small increase in neonatal survivors was not associated with any change in the postneonatal death rate. Delivery in a level-3 unit was associated with a significantly better outcome. Multiple births made a major contribution to the extremely-low-birthweight group of infants.

Contribution of prematurity and low birth-weight to neonatal death in Chinese and Western populations.

This paper analyses the contribution of low birth-weight (birth-weight between 500 and 2,500 g) and prematurity (gestation less than 37 weeks) to neonatal death in Chinese and Western populations. The incidences of low birth-weight in the Tsan Yuk Hospital, Hong Kong, the State of Victoria, and the Mercy Maternity Hospital, Melbourne, were 4.63%, 4.29% and 5.66% respectively and the incidences of prematurity were 2.08%, 4.89% and 7.42% respectively. The neonatal mortality rate (per 1,000 livebirths) for premature infants born in Victoria was 64, 89 for those born at the Mercy Maternity Hospital and 119 for the Tsan Yuk Hospital. This paper has demonstrated that a striking differences exists in prematurity rates between Chinese and Western populations, and also that the mortality rate of premature infants is lower in Western populations. If the reason for the lower incidence of prematurity in the Chinese population could be determined and the mortality of premature infants maintained in the Western population, a significant lowering of perinatal mortality would result. Studies to determine causes for premature births in Chinese and Western populations should therefore be undertaken.

Cephalhaematoma: a 10-year review.

The incidence of cephalhaematoma at the Mercy Maternity Hospital over a 10-year period was 2.5%; of the 1,030 infants 68.4% were born to primiparas, 65.6% were males, the majority (91.1%) were between 37 and 42 weeks' gestation and 3,000 and 4,000 g birth-weight (71.6%). Forceps delivery and vacuum extraction were associated with increased incidences of cephalhaematoma (5.1% and 22.9% respectively), and the incidence was slightly increased (3.8%) when a scalp electrode had been applied. Hyperbilirubinaemia was more prevalent (12.9%) in infants with a cephalhaematoma as was exchange transfusion (0.8%) and the need for phototherapy (4.9%).

Infant development following the use of intravenous nutrition to women with persistently low urinary oestriol excretion.

During the 6-year period 1971 to 1976, 10,545 patients had urinary oestriol determinations during pregnancy and 333 (3.2%) had persistently low values. Of the 335 resultant infants 206 were from patients treated with intravenous dextrose and/or amino-acids (treated group) and 129 from nontreated patients (nontreated group). The stillbirth rate was 2.4% in the treated group and 11.6% in the untreated group (p greater than 0.001), and the neonatal death rates were 2.9% and 4.7% respectively (p = NS). Assessment of the surviving infants to 7 years of age revealed no significant differences in growth between treated and nontreated groups. There was no increase in the incidence of major neurological abnormalities in the treated infants (2.9%) when compared to those from nontreated pregnancies (1.3%) (p = NS), nor was there a significant difference in the incidence of minor neurological abnormality or findings on psychological assessments. We conclude that dextrose and/or amino-acid infusions given to pregnant women with low oestriol excretion reduced the perinatal mortality rate without significant compromise to subsequent development of surviving infants.