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C Bower

Publications and source records attributed to C Bower.

At least 37 records · Page 2Linked to original sources
PubMed2000

Ascertainment of birth defects: the effect on completeness of adding a new source of data.

BACKGROUND: The Western Australian (WA) Birth Defects Registry aims for complete ascertainment of birth defects in WA, but the proportions of birth defects in rural areas and in Aboriginal children are lower than in metropolitan and non-Aboriginal children. The effect on ascertainment of adding data from the Rural Paediatric Service (RPS) was investigated. METHOD: A file of all cases of birth defects for children born 1980-1997 and recorded on the RPS database was linked to the Registry. RESULTS: The addition of this new data source had little effect on the overall prevalence of birth defects (an increase from 5.38 to 5.41%). There was a slightly greater effect on the prevalence of birth defects in rural residents (4.67%-4.76%) and Aboriginal children (4.55-4.78%), although the prevalence for each of these groups is still less than for metropolitan residents and non-Aboriginal infants, respectively. All major categories of birth defects were represented in the new cases and, in general, their addition made little difference to the prevalence of each category. The exception was fetal alcohol syndrome, which increased from 0.13 per 1000 to 0.18 per 1000 once the 21 new cases from the RPS were added. CONCLUSION: Complete ascertainment of birth defects is important in developing and evaluating preventive programs, and in investigating clusters of birth defects.

Congenital Abnormalities↗
PubMed1999

Craniosynostosis in Western Australia, 1980-1994: a population-based study.

A craniomaxillofacial unit was established recently in Western Australia, and a study was carried out to provide some baseline characteristics of primary craniosynostosis in Western Australia and to investigate whether there has been any significant temporal change in birth prevalence. A case control study was conducted, using cases identified from a population-based register of birth defects, and a random sample of all births without a birth defect formed the control group. All subjects were born in Western Australia over the period 1980-1994 inclusive. The prevalence of craniosynostosis over the period 1980-1994 in Western Australia was 5.06 per 10,000 births. There was a significant linear increase in lambdoid synostosis over this period of 15.7% per year. Craniosynostosis was significantly more common among male infants, infants born preterm (<37 weeks gestation), breech presentation or presentations other than vertex, and infants born to fathers 40 years of age or older, even after accounting for known autosomal dominant syndromes. Other major birth defects were found in 11.2% of children with nonsyndromic craniosynostosis. Only 43 children (25.3%) with craniosynostosis were reported to have been seen by a geneticist. Thus, the prevalence of craniosynostosis in Western Australia is among the lowest reported. There is no current explanation for the increase in lambdoid synostosis. The increased risk of so-called nonsyndromic craniosynostosis with paternal age raises the possibility of undiagnosed new dominant mutations. This, along with the excess of other birth defects in children with craniosynostosis emphasises the need to ensure that these families are offered genetic counseling.

Adult↗
PubMed1999

Metacarpophalangeal pattern profile and bone age in Rett syndrome: further radiological clues to the diagnosis.

Hand radiographs of 100 girls representing 73% of the known Australian population of girls with Rett syndrome, age 20 years or less, were available for this study. Control radiographs were matched for age, sex, and laterality. Bone age was assessed against standard radiographs in Greulich and Pyle [1959: Radiographic Atlas of Skeletal Development of the Hands and Wrist, 2nd ed.]. A metacarpophalangeal pattern (MCPP) profile comparing the relative lengths of the hand bones with mean population norms by age was produced by converting the length of each of the 19 metacarpal and phalangeal bones into a Z score. In girls less than 15 years old, bone age was more advanced in Rett syndrome than in age-matched control girls (left hand P = 0.03, right hand 0.004), but was most advanced in the younger group and normalized with age. In Rett syndrome, the mean Z score for the 19 metacarpal and phalangeal bones was 1.0 in children under 5 years, -0.27 in those aged 5-11 years, and -1.7 in those aged 12 years and over. This variation between age groups was much greater than in the controls. The dips in the MCPP profile occurred at MC2 and D1, and the peaks at M5, P5, and M4. An MCPP profile may provide an additional aid to diagnosis in cases of Rett syndrome where all the criteria are not met, but in children under age 5 years, advanced bone age may be more helpful as a marker.

Adolescent↗
PubMed1999

Application of skull base techniques to pediatric neurosurgery.

Techniques for skull base surgery have become well established over the last 10 years. Most of these techniques are used in adult patients for skull base tumors and neurovascular diseases. There are very few large series of pediatric patients in whom skull base approaches have been used, because of the rarity of these conditions. The authors would like to present a relatively large series of 26 pediatric patients who underwent skull base approaches for tumor resection. These tumors involved the anterior cranial base in 5 patients, the medial cranial skull base in 4 patients, and the posterior cranial base in 12 cases. Five patients had tumors that involved two or more fossae. The overall complication rate was 57%, which included temporary cranial nerve palsies, CSF leak and infection. Patients with permanent complications were 8 in number (37%). There was 1 postoperative death from pneumonia approximately 6 weeks after surgery. Complete tumor removal was achieved in 24 of the 26 patients. Skull base tumors in children are often extensive and present significant surgical challenges. Although complete tumor extirpation is the goal in most pediatric patients, this is often achieved only with some morbidity. This paper demonstrates the effectiveness of skull base approaches for these tumors and underscores the high stakes involved.

Adolescent↗
PubMed1999

A population-based approach to the investigation of osteopenia in Rett syndrome.

This study compares bone mass in a national sample of girls with Rett syndrome (RS) with a sample of control children. The Australian RS Database was the source of cases for this population-based study. Hand radiographs were available from 101 of 137 subjects (74% of the known Australian population of girls with RS aged < or = 20 years). Control radiographs matched for age, sex, and laterality were obtained from hospital radiology departments. A measure of cortical thickness was made from the difference between the outer diameter and the medullary space in the second metacarpal bone. A mean z-score value for cortical thickness and percentage cortical area for each individual was calculated. The mean cortical thickness (z score) for girls with RS was -1.94 compared with -0.38 for control children (P<0.001). In girls with RS, the mean cortical thickness decreased with age (P<0.001). In girls who were taking epilepsy medication it was -2.21 compared with -1.23 in those not taking epilepsy medication (P<0.001). There was no evidence of a beneficial effect of increased calcium intake on cortical thickness. A similar pattern was obtained when percentage cortical area was estimated. In multivariate analysis, increasing age and use of anticonvulsant medication were associated with decreased cortical thickness and only use of anticonvulsant medication with decreased percentage cortical area. Fractures had occurred in one-third of cases and it was estimated that just over 40% of girls would sustain a fracture by the age of 15 years. Girls with RS may be at increased risk of fractures and their bone quality compromised as determined by cortical thickness and percentage cortical area measurements from the second metacarpal.

Aging↗
PubMed1999

Medical aspects of school-aged children with Down syndrome.

Current and comprehensive information about the medical issues affecting children with Down syndrome (DS) is of value in counselling parents who are considering prenatal diagnosis and in planning services for people with DS as they age, especially given the continued improvements in their survival. Parents of school-aged children (mean age 11.37 years, 57.3% male, 42.7% female) with DS were identified by linking registers from the Disability Services Commission and the Birth Defects Registry. Less than half the children had cardiac and bowel conditions. More than half had ear conditions and more than three quarters had eye conditions. Ear, nose, and throat professionals were the specialists seen most often and the rate of tympanostomy tube insertion was nearly 17 times that of the general childhood population. Children with DS were over five times more likely to wear glasses than other children. These findings suggest that chronic, non life-threatening conditions impose a burden on families but do not threaten quality of life.

Child↗
PubMed1999

Listeria awareness among new mothers in Western Australia.

OBJECTIVE: To assess awareness, knowledge and behaviour relating to Listeria among recent mothers (12 weeks post-partum) in Western Australia and determine the usefulness of a Listeria information pamphlet. METHOD: A postal survey of a random 10% sample of Western Australian mothers whose babies were born between 1 January and 13 April 1997. RESULTS: Of the 680 women surveyed, 509 (75%) responded and 451 (89%) respondents had heard of Listeria. The 11% who had not heard of Listeria had higher odds of living in a rural area, speaking a foreign language at home, having less formal education, being younger, having had an unplanned pregnancy, and having not taken folic acid supplements. Respondents who had seen the Listeria pamphlet had greater odds of correctly identifying foods at risk of Listeria. Of the women who had heard of Listeria, 90% had avoided certain foods during their pregnancy. Risk factors for not changing eating behaviour were similar to those for not having heard of Listeria. CONCLUSIONS: Factors associated with not having heard of Listeria, not having seen the pamphlet and not having changed behaviour were similar, suggesting that there may be a group of women who are less likely to be aware of Listeria or other health issues and/or may be resistant to health-related behaviour changes. IMPLICATIONS: The Listeria pamphlet is an effective medium for educating pregnant women about Listeria. Rural, young, single and non-English speaking background women may require a different or supplementary approach.

Adult↗
PubMed1998

A population-based study of abdominal wall defects in South Australia and Western Australia.

The purpose of this study was to determine the prevalence, clinical characteristics, prenatal diagnosis and occurrence of other birth defects with abdominal wall defects in births and terminations of pregnancy in South Australia (SA) and Western Australia (WA) over the period 1980-90. Cases of gastroschisis, exomphalos, bladder exstrophy, cloacal exstrophy and body stalk anomaly were ascertained from the WA Birth Defects Registry (1980-90) and the SA Birth Defects Register (1986-90). The registers are comparable population-based data collections with information on livebirths and stillbirths of at least 400 g birthweight or 20 weeks' gestation, and terminations of pregnancy for fetal abnormality. The prevalence of gastroschisis was 1.65/10,000 births (59 cases) and of exomphalos 2.90/10,000 births (104 cases). There was no significant difference in prevalence of exomphalos or gastroschisis between SA and WA for the years 1986-90. However, if data from WA for the years 1980-85 were included, SA had a significantly higher prevalence of exomphalos (prevalence ratio 1.71, confidence interval [CI] 1.16-2.55), although not of gastroschisis (prevalence ratio 1.35, CI 0.79-2.32). Exomphalos was significantly more common in mothers < 20 years (odds ratio [OR] 2.45, CI 1.22-4.86) and in mothers of 40 years or older (OR 5.65, CI 1.69-16.77). Gastroschisis was more common in younger mothers (OR 8.76, CI 4.02-19.32). Both exomphalos and gastroschisis were associated with low birthweight, prematurity, intrauterine growth retardation and caesarean section. The reason for the higher prevalence of exomphalos in SA than WA was not clear, but may be related to differences in prenatal diagnosis. The association between maternal age < 20 years and exomphalos raises the possibility of common factors in the aetiology of gastroschisis and exomphalos.

Abdominal Muscles↗
PubMed1998

22q11 deletions in patients with conotruncal heart defects.

OBJECTIVE: To ascertain the frequency of 22q11 deletions in a representative population of conotruncal heart defects (CTD) and determine which children are at risk of having a deletion. METHODOLOGY: A clinical and laboratory evaluation of 90 children with CTD, including isolated and syndromic cases. RESULTS: Fifteen children (17%) were shown to have 22q11 deletions by fluorescence in situ hybridization (FISH) studies with the Oncor probe N25. Varying degrees of developmental delay/learning disabilities and facial dysmorphism were common in these children. None of the isolated cases without dysmorphism had a deletion. CONCLUSION: 22q11 deletions are a significant cause of a specific form of congenital heart disease, CTD. It is important to have a high index of suspicion of the 22q11 deletion disorders in children with CTD and other extracardiac manifestations so that the diagnosis can be made early and appropriate interventions implemented.

Abnormalities, Multiple↗
PubMed1998

Measuring the impact of conjugate vaccines on invasive Haemophilus influenzae type b infection in Western Australia.

Haemophilus influenzae type b (Hib) causes serious infections in 26-59 per 100,000 non-Aboriginal Australian children under five years of age. Aboriginal children suffer much higher rates of infection (> or = 150 per 100,000), and at an earlier age, and have a greater risk of death and disability due to Hib infection. In 1992 and 1993, four conjugate Hib vaccines were introduced in Australia, and a nationally funded program of infant vaccination was begun in July 1993. This study aimed at evaluating the effectiveness of Hib vaccination in Aboriginal and non-Aboriginal children in Western Australia using a population-based active surveillance system for non-Aboriginal children and a case control study for Aboriginal children. The incidence of invasive Hib disease in non-Aboriginal children fell from 30.9 per 100,000 before vaccination was available to 6.3 per 100,000 in the second year after its introduction. The vaccine efficacy was estimated to be 80 per cent for Aboriginal children (odds ratio 0.20, 95 per cent CI 0.01-2.76) and, after adjustment for confounders, 75 per cent (odds ratio 0.25, CI 0.02-3.66). Based on the adjusted value (75 per cent), and using a Bayesian approach, we estimate that the posterior probability was 0.55 that the true vaccine efficacy is greater than 70 per cent, and 0.69 that the efficacy is greater than 50 per cent. We conclude that Hib vaccination is effective in preventing invasive Hib disease in Aboriginal and non-Aboriginal children in Australia.

Bacteremia↗
PubMed1998

Diagnosis of Rett syndrome: can a radiograph help?

Rett syndrome (RS), a neurodevelopmental disorder almost exclusively affecting girls, is associated with severe intellectual and motor disability. In the absence of biological markers, diagnosis is determined by a set of clinical criteria. In a previous study in Scotland, shortening of the fourth metatarsal was reported clinically in 20% of classical RS cases aged 5 years or older. The Australian Rett Syndrome Study database has facilitated a population-based radiological study of the hands and feet of girls with RS. Straight radiographs of hands and feet were available from 94 cases, representing 70.1% of the known RS population in Australia. Control radiographs were matched for age, sex, and laterality. Relative shortening of the fourth metacarpal/metatarsal was assessed using the sign method. A short ulna (negative ulna variance) was defined as the distal articular surface of the ulna being at least 5mm proximal to the distal articular surface of the radius. A positive metacarpal sign was twice as common in verified cases of RS than in controls in the right but not the left hand. A short ulna was more common in subjects with RS than in controls. A short fourth metatarsal was also more common among subjects with RS. More than half (56.6%) the girls with RS over the age of 4 years had a negative ulnar variance in either wrist or a metatarsal sign in either foot. These findings will assist with the diagnosis of RS and may help direct research towards the location of the molecular defect.

Adolescent↗
PubMed1998

Is the girl with Rett syndrome normal at birth?

The diagnosis of Rett syndrome is currently determined by a series of criteria, the first three of which are concerned with the initial period of normality. Using the Australian Rett Syndrome Database, information about this early period was obtained by questionnaires to paediatricians and families. For girls born between 37 and 42 weeks' gestation, 70.7% of girls with Rett syndrome had birthweights <3500g compared with 62.2% of singleton births of the same gestational age in Western Australia between 1980 and 1992. The mean head circumference at birth for infants with Rett syndrome was lower than the mean head circumference at birth for the reference populations after accounting for gestational age. Forty-one percent of parents reported that their daughter had some perinatal difficulty, while in 22.4% of cases clinicians reported some perinatal abnormality. In 46.5% of girls, parents reported that their daughter's development or behaviour had been unusual in the first 6 months. Our results provide further evidence that the girl with Rett syndrome may not be normal at birth.

Adolescent↗
PubMed1997

Birth defects in infants conceived by intracytoplasmic sperm injection: an alternative interpretation.

OBJECTIVE: To test the hypothesis that liveborn infants conceived by intracytoplasmic sperm injection are at an increased risk of having a major birth defect. DESIGN: Reclassification of the birth defects reported in infants born after intracytoplasmic sperm injection in Belgium and comparison with prevalence estimated in Western Australian population by means of same classification system. SETTING AND SUBJECTS: 420 liveborn infants who were conceived after intracytoplasmic sperm injection in Belgium and 100,454 liveborn infants in Western Australia delivered during the same period. MAIN OUTCOME MEASURES: Estimates of birth prevalence of birth defects and comparisons of odds ratios between cohort conceived after intracytoplasmic sperm injection and Western Australian infants. RESULTS: Infants born after intracytoplasmic sperm injection were twice as likely as Western Australian infants to have a major birth defect (odds ratio 2.03 (95% confidence interval 1.40 to 2.93); P = 0.0002) and nearly 50% more likely to have a minor defect (1.49 (0.48 to 4.66); P = 0.49). Secondary data-led analyses, to be interpreted with caution, found an excess of major cardiovascular defects (odds ratio 3.99), genitourinary defects (1.33), and gastrointestinal defects (1.84), in particular cleft palate (5.11) and diaphragmatic hernia (7.73). CONCLUSIONS: These results do not confirm the apparently reassuring results published by the Belgian researchers of intracytoplasmic sperm injection. Further research is clearly required. Meanwhile, doctors practising intracytoplasmic sperm injection should bear this alternative interpretation in mind when they counsel couples and obtain informed consent for the procedure.

Adolescent↗
PubMed1997

Surgical correction of obstructive sleep apnea in the complicated pediatric patient documented by polysomnography.

OBJECTIVE: Evaluate the effectiveness of surgical treatment of obstructive sleep apnea in a diverse population of children. DESIGN: A retrospective case series of pre and post operative polysomnograms (PSG) of pediatric patients with obstructive sleep apnea (OSA). SETTING: Tertiary care children's hospital. PATIENTS: 48 patients in whom sleep studies were performed pre-operatively for either an unclear history and/or physical findings or complicated OSA. Thirteen patients had no complicating medical factors, 35 patients had various associated medical problems, including 20 with morbid obesity, five with Down syndrome, four with asthma, two with cerebral palsy, and four other. The average age was 7.5 years with a range of 1.5-20 years. INTERVENTIONS: Thirty-one patients had a tonsillectomy and adenoidectomy (T and A) only, 13 had T and A with uvulopalatopharyngoplasty (UPPP), and three had tonsillectomy and UPPP. MAIN OUTCOME MEASURES: Pre and postoperative PSG results including apnea/hypopnea index (AHI), percent of sleep with oxygen saturation below 90%, and percent sleep time with end-tidal pCO2 > 50. RESULTS: The mean pre-operative (AHI) was 27 +/- 4 (mean +/- S.E.M.) and post operatively was 6 +/- 1 (P < 0.001). Twenty six of 48 (54%) had a postoperative AHI of less than five. Pre-operative percent of sleep with oxygen saturation below 90% was 17.9 +/- 4.5%, post-operatively it was 1.4 +/- 0.1% (P < 0.001). Pre-operative percent sleep time with end-tidal pCO2 > 50 was 22.3 +/- 3.4%, post operatively it was 12.6 +/- 2.9% (P < 0.01). UPPP was performed more commonly in patients with Down syndrome. There was a trend toward more improvement in patients who had T and performed than those undergoing UPPP (post op AHI of 4.7 vs. 7.4 respectively). CONCLUSIONS: Tonsillectomy, adenoidectomy and UPPP are effective in the treatment of OSA in a diverse group of pediatric patients. Patients with asthma, cerebral palsy, Down syndrome, morbid obesity, and hereditary syndromes all improved significantly with surgical management.

Adenoidectomy↗
PubMed1997

Promotion of folate for the prevention of neural tube defects: knowledge and use of periconceptional folic acid supplements in Western Australia, 1992 to 1995.

To assess changes in knowledge and use of folic acid supplements in relation to a statewide health promotion project for the prevention of neural tube defects, we surveyed general practitioners, pharmacists, women of child-bearing age and pregnant women in Western Australia. We also collected data on wholesale sales of folic acid supplements. By the end of the project, 56.5 per cent of general practitioner respondents knew that the recommended dose of folic acid was 0.5 mg and 70 per cent offered folic acid supplements to women planning pregnancy, 82.5 per cent of responding pharmacists knew the recommended dose, and 87.5 per cent reported an increase in sales of 0.5 mg folic acid. Wholesale sales of 0.5 mg folic acid increased markedly in Western Australia compared with other states. From shopping centre surveys of women of child-bearing age we estimated that their knowledge of the association between folate and spina bifida increased from 8.2 per cent before the project to 67.5 per cent 2.5 years later, and doctors were a major source of information for women. In a 1995 survey of a sample of pregnant women, 43.1 per cent with planned pregnancies had taken folic acid supplements periconceptionally, compared with 19.1 per cent in a similar survey in 1993.

Adult↗
PubMed1997

Changes in folate supplementation, and in serum and red cell folate levels in antenatal patients over the course of a health promotion project for the prevention of neural tube defects.

We assessed the use of folic acid supplements and changes in serum and red cell folate levels in pregnancy over the course of a health promotion project in Western Australia by 4 cross-sectional studies of women attending a public antenatal outpatient clinic in 1992 (before the launch of the health promotion project), 1993, 1994, and 1995. A short questionnaire was completed and blood taken for estimation of serum and red cell folate. There was an increase in the proportion of women taking folic acid supplements in the first trimester (51.9% in the final phase) and before pregnancy (15% in the final phase of the study), and no change in the proportion taking other vitamin supplements. Serum and red cell folate levels increased significantly over the study period in both women taking and not taking folic acid supplements. The proportion of women who had seen the pamphlet used in the health promotion project rose to 35.4% in the third phase, and fell to 27.8% in the final phase. Coincident with the health promotion project, there was an increase in folate status in early pregnancy. However, most women were not taking folic acid supplements before they became pregnant and, hence may not have had sufficient folate at the time of normal neural tube closure.

Erythrocytes↗