Perinatal mortality disparities between public care and private obstetrician-led care: a propensity score analysis.

OBJECTIVE: To examine whether disparities in stillbirth, and neonatal and perinatal mortality rates, between public and private hospitals are the result of differences in population characteristics and/or clinical practices. DESIGN: Retrospective cohort study. SETTING: A metropolitan tertiary centre encompassing public and private hospitals. Women accessed care from either a private obstetrician or from public models of care - predominantly midwife-led care or care shared between midwives, general practitioners, and obstetricians. POPULATION: A total of 131 436 births during 1998-2013: 69 037 public and 62 399 private. METHODS: Propensity score matching was used to select equal-sized public and private cohorts with similar characteristics. Logistic regression analysis was then used to explore the impact of public-private differences in the use of assisted reproductive technologies, plurality, major congenital anomalies, birth method, and gestational age. MAIN OUTCOME MEASURES: Stillbirth, and neonatal and perinatal mortality rates. RESULTS: After controlling for maternal and pregnancy factors, perinatal mortality rates were higher in the public than in the private cohort (adjusted odds ratio, aOR 1.53; 95% confidence interval, 95% CI 1.29-1.80; stillbirth aOR 1.56, 95% CI 1.26-1.94; neonatal death aOR 1.48, 95% CI 1.15-1.89). These disparities reduced by 15.7, 20.5, and 19.6%, respectively, after adjusting for major congenital anomalies, birth method, and gestational age. CONCLUSIONS: Perinatal mortality occurred more often among public than private births, and this disparity was not explained by population differences. Differences in clinical practices seem to be partly responsible. The impact of differences in clinical practices on maternal and neonatal morbidity was not examined. Further research is required. TWEETABLE ABSTRACT: Private obstetrician-led care: more obstetric intervention and earlier births reduce perinatal mortality. PLAIN LANGUAGE SUMMARY: Background Babies born in Australian public hospitals tend to die more often than those born in private hospitals. Our aim was to determine whether this pattern is a result of public-private differences in care or merely linked with differences in the characteristics of the two groups. In Australian private hospitals, a private obstetrician almost always provides continuing care to each woman during pregnancy and birth. Public hospitals provide a number of care options, which usually involve midwives and/or a family doctor. Method The study population included 131 436 births (52.5% public; 47.5% private) from 1998-2013 at a single metropolitan centre with co-located public and private facilities. To isolate the effect of differences in care, we used a statistical technique called propensity score matching to select a public group and a private group with similar characteristics and equal size. This enabled us to compare 'apples with apples' when comparing public versus private perinatal death rates. Perinatal deaths include stillbirths and babies that die within 28 days of birth. Main findings After matching and after accounting for different patterns in the use of fertility treatments and multiple-birth pregnancies (such as twins), babies born in the public sector were approximately 1.5 times more likely to die than babies born in the private sector. This difference was reduced to 1.3 times more likely to die than babies born in the private sector after taking into account other factors that could skew the data, such as major congenital anomalies, birth method, and duration of pregnancy. Limitations This was a single-centre study, so the results may not apply to all settings. Despite our efforts to create highly similar public and private cohorts, some differences between the groups are likely to have remained and this may have affected the results. Implications Our findings suggest that private obstetrician-led care has a beneficial impact on perinatal deaths, despite, or possibly because of, higher obstetric intervention rates and earlier births in the private hospital. Further research is required.

Hematologic scoring system in early diagnosis of sepsis in neutropenic newborns.

The hematologic profiles of 1000 newborns were prospectively examined to identify infants with neutropenia (N = 170) according to the system of Manroe et al. (J Pediatr 1979;95:89-98) and to evaluate a hematologic scoring system (Rodwell et al. J Pediatr 1988;112:761-7) as a screening test for sepsis. Neutropenia was more commonly of noninfectious than infectious origin (83.5% vs. 16.5%; P < 0.001). On the initial test a positive screen (scores > or = 3) identified 26 of 28 infants with sepsis or probable infection (sensitivity 93%; specificity 82%; positive and negative predictive values 50 and 98%, respectively). Corresponding values for an elevated immature:total neutrophil ratio were 100, 75, 43 and 100%. Overall mortality with neutropenia was 15% and was higher with an infectious than a noninfectious etiology (39% vs. 11%, P < 0.001) despite early antibiotic therapy. The combination of a neutrophil count < or = 500/mm3 and scores > or = 3 or an elevated immature:total neutrophil ratio identified a poor prognostic group: 67% (8 of 12) and 70% (7 of 10) infants, respectively, with these findings died, 6 in the infected group. The hematologic scoring system or immature:total neutrophil ratio in combination with the degree of neutropenia provides valuable diagnostic and prognostic information which could be applied to identification of possible candidates for granulocyte transfusions or other experimental treatments.

A longitudinal study of Streptococcus mutans colonization in infants after tooth eruption.

We previously reported that, before tooth eruption, over one-half of infants aged 6 mos were already infected with Streptococcus mutans. The aim of this investigation was to determine the colonization of S. mutans after tooth eruption in the same cohort of 111 infants (35 pre-term, 76 full-term). Our results showed that S. mutans colonization increased with increasing age, so that by 24 mos of age, 84% harbored the bacteria (p < 0.01). The mean and median ages of S. mutans colonization in dentate infants were 15.7 mos and 16.0 mos, respectively. Factors associated with S. mutans colonization were sweetened fluids taken to bed (p < 0.01), frequent sugar exposure (p < 0.03) and snacking (p < 0.03), sharing of foods with adults (p < 0.03), and maternal S. mutans levels of > 10(5) CFU/mL (p < 0.02). In contrast, non-colonization of S. mutans was associated with toothbrushing (p < 0.03) and multiple courses of antibiotics (p < 0.001). Analysis of our data establishes the timing of S. mutans colonization in children from birth to 24 mos of age.

Oral colonization of Streptococcus mutans in six-month-old predentate infants.

We hypothesize that S. mutans colonization occurs more frequently in pre-term children due to their relative immaturity. In this study of 172 predentate, six-month-old infants, we found that 50% of pre-term and 60% of full-term children harbored S. mutans. The colonization was confirmed by repeat sampling. Although there were minor differences, factors associated with S. mutans infection in pre-term and full-term infants were generally similar. In both groups, increased frequency of sugar was ranked the most important factor (p < 0.001), followed by breast-feeding (p < 0.001), and habits which allowed saliva transfer from mother to infant (p < 0.01). By contrast, non-colonization of S. mutans was associated with multiple courses of antibiotics (p < 0.001). Compared with pre-term children, there were higher percentages of full-term who had night feedings and consumed sugar during sleep times. Mothers with infected infants had S. mutans levels > 5 x 10(5) CFU/mL saliva (p < 0.001), poorer oral hygiene, more periodontal disease, and lower socio-economic status (p < 0.02) and snacked frequently (p < 0.001), compared with mothers with non-infected infants.

Association of Streptococcus mutans infection and oral developmental nodules in pre-dentate infants.

Since dental caries may present soon after tooth eruption, we hypothesized that colonization of Streptococcus mutans can occur in the predentate stages. In this study, we examined S. mutans colonization and its association with oral developmental nodules (Bohn's nodules) in 60 pre-term and 128 full-term, three-month-old infants. Overall, S. mutans was cultured from 30% (56/188) of the infants, and oral developmental nodules were noted in 55% (103/188). Compared with the pre-term, full-term infants showed a higher prevalence of S. mutans (34% vs. 20%, p < 0.02) as well as developmental nodules (61% vs. 42%, p < 0.05). In both groups, S. mutans was positively associated with numbers of developmental nodules in a dose-response relationship (p < 0.001), and with maternal salivary levels of the bacteria (p = 0.03). The permanence of S. mutans infection was confirmed by repeat saliva sampling at 6 months of age. Our results thus showed that many infants have already acquired S. mutans at 3 months of age, prior to tooth eruption.

The prevalence and origins of left hand preference in high risk infants, and its implications for intellectual, motor and behavioural performance at four and six years.

This study investigates the origins of hand preference at 4 years in a cohort of 115 high risk and premature infants; the relationship between patterns of hand preference and intellectual, motor, temperament and behavioural status at 4 and 6 years; and evidence for brain injury in mediating the relationship between hand preference and development disorder. Increased left hand preference was independently associated with extreme prematurity, high neonatal risk, increased numbers of minor physical anomalies, lowered intellectual and motor abilities, and more difficult temperament. These findings supported the presence of intrauterine and neonatal pathological mechanisms leading to left hand preference in a small number of children. Neither poor function of the non dominant hand nor absence of a family history of left handedness could further define this pathological subgroup. Support for pathological mechanisms producing left handedness was found predominatly in the infants of high birth weight, whereas prevalence of left handedness was increased mainly among the extremely low birth weight infants. In this latter group the prevalence of left handedness was also increased among children of normal intelligence, suggesting that mechanisms other than brain damage lead to left hand preference in very premature infants.

Handedness in extremely low birth weight infants: aetiology and relationship to intellectual abilities, motor performance and behaviour at four and six years.

Hand preference was measured in a total group of 71 ELBW children to determine patterns of hand preference at 4 and 6 years, possible aetiological factors leading to handedness, and whether left or non right hand preference were markers for intellectual, motor, temperament or behavioural differences. At both 4 and 6 years the prevalence of left handedness was increased, though this prevalence changed over the period of the study. Results supported brain injury as one mechanism leading to increased left hand preference, though this process did not adequately explain this increase. Possible reasons for this and the apparent change in prevalence with time are examined. Mixed handedness at 4 years was associated with lower intellectual abilities though otherwise children were similar in motor skills, temperament and behaviour independent of hand preference category.

Neurodevelopmental outcome of preterm infants with bronchopulmonary dysplasia.

The neurodevelopmental outcome of 78 infants with bronchopulmonary dysplasia (BPD) was compared with that of 78 control infants matched for birthweight. To determine the effect of the severity of BPD, 62 infants requiring oxygen at 36 weeks' postmenstrual age (sBPD) were compared with their matched controls. Infants were followed up to 2 years of age, corrected for prematurity, and were classified for neurological impairment, developmental delay, and neurodevelopmental disability. Seventy six (98%) BPD infants and 71 (91%) controls had follow up data available to two years. Neurological impairment, developmental delay, and neurodevelopmental disability occurred more frequently in infants with BPD than in controls but this was not significant. For infants with sBPD, the increased incidence of neurological impairment and definite developmental delay was not significant when compared with the controls, though neurodevelopmental disability occurred more frequently (odds ratio (OR) 3.6: 95% confidence intervals (CI) 1.1-11.8). Predictors of disability in infants with sBPD included periventricular haemorrhage (OR 19.4: 95% CI 4.3-86.6), ventricular dilatation (OR 12.8: 95% CI 2.9-57.3), and sepsis (OR 5.0: 95% CI 1.3-19.4). Adjusting for the presence of these factors, the association between BPD and disability was no longer apparent (OR 0.9: 95% CI 0.2-3.6). The findings suggest that BPD is not independently associated with adverse neurodevelopmental outcome.

Extremely low birth weight and control infants at 2 years corrected age: a comparison of intellectual abilities, motor performance, growth and health.

A 2-year cohort of 63 surviving extremely low birth weight (ELBW) infants was prospectively studied and 60 of these infants, together with 44 normal birth weight control infants, were assessed at 2 years of age for intellectual abilities, motor skills, growth and health. The total ELBW group differed significantly from controls on overall Griffiths developmental quotient (99.3 vs. 103.8 P = 0.02) and in the personal/social subscale (100.7 vs. 106.7 P = 0.01). A subset of 43 of the ELBW infants was identified as low risk at discharge. No statistically significant differences were present between the low risk ELBW subset and controls in intellectual abilities though both the total ELBW group and the low risk ELBW subset differed from controls in fine and gross motor abilities, and in weight at 2 years. The total ELBW group also experienced more frequent ill health and hospital readmission.

Non-anaemic iron deficiency identified by ZPP test in extremely premature infants: prevalence, dietary risk factors, and association with neurodevelopmental problems.

INTRODUCTION: The aims of this study were to determine, in a cohort of extremely premature infants, the prevalence of iron deficiency identified by zinc protoporphyrin/heme ratio (ZPP) testing, and its association with neurodevelopmental problems and dietary risk factors for iron deficiency. METHODS: Infants of less than 29 weeks' gestation or less than 1000 g birth weight were studied prospectively at a multidisciplinary follow-up clinic. Assessments were made at a corrected age of either 12 months (n=72) or 2 years (n=69). Physical examination, Griffiths Developmental Scale, and neurosensory-motor assessment were administered, information on diet and behaviour was obtained by questionnaire, and a fingerprick ZPP ratio was performed to identify iron deficiency. RESULTS: 18.4% of infants had positive ZPP tests. There was no significant association between a positive ZPP test result and dietary risk factors, or symptoms of lethargy, irritability or poor attention. In children without cerebral palsy, there was no difference on Griffiths scores or neurosensory-motor assessment between ZPP-positive and ZPP-negative groups. The diagnosis of cerebral palsy (n=12) was significantly associated with both a positive ZPP test and a lower Griffiths general quotient (GQ) score. CONCLUSIONS: Iron deficiency occurs commonly in extremely low birth weight (ELBW) children in early childhood, and is not predicted by dietary risk factors. The prevalence of iron deficiency is increased in ELBW children with cerebral palsy. Non-anaemic iron deficiency (NAID) does not impair development or significantly affect behaviour of ELBW subjects who do not have cerebral palsy.

Characteristics at four months follow-up of infants born small for gestational age: a controlled study.

This prospective study compared 65 small-for-gestational-age (SGA) (birth weight < 3rd centile) and 71 control infants at a corrected age of 4 months. It was hypothesised that differences would exist in growth, development, temperament and minor neurological signs and that these would be predicted by type (proportional/disproportional) of growth restriction at birth and maternal mood disturbance at birth or at 4 months. Infants had a Griffith's developmental test and neuromotor assessment. Maternal mood and infant temperament were surveyed. Few differences were found between SGA and control infants. SGA infants showed catch-up growth with 63% being above the third percentile and 43% being above the tenth percentile for weight. SGA infants had lower Griffith's GQ scores (97 vs. 102, P = 0.02) and they were rated in temperament as more manageable than controls. There were no differences in subtle neuromotor signs. Neither type of SGA nor maternal mood disturbance at birth had prognostic significance for infant catch up growth, neuromotor scores, or temperament though level of maternal stress and anxiety at 4 months were related to lower GQ scores in SGA infants.

Enteral antibiotics for preventing necrotising enterocolitis in low birthweight or preterm infants.

BACKGROUND: Necrotising enterocolitis continues to be a problem, particularly in preterm neonates. There have been reports published suggesting that the use of enteral antibiotics may be effective as prophylaxis. This systematic review was undertaken to clarify the issue. OBJECTIVES: To evaluate the benefits and harms of enteral antibiotic prophylaxis for necrotising enterocolitis in low birth weight and preterm infants. SEARCH STRATEGY: Searches were made of the Oxford Database of Perinatal trials, MEDLINE (search terms: necrotizing enterocolitis, antibiotics; LIMITS: newborn infant), previous reviews with cross references, abstracts, conference and symposia proceedings, expert informants and journal handsearching in the fields of Neonatal Pediatrics and Microbiology. SELECTION CRITERIA: All randomized or quasi-randomized controlled trials where enteral antibiotics were used as prophylaxis against NEC in LBW (<2500g) and/or preterm (<37 weeks gestation) infants. DATA COLLECTION AND ANALYSIS: The standard method of the Cochrane Collaboration and its Neonatal Review Group was used. The methodological quality of each trial was reviewed by the second author who was blinded to the trial authors and institutions. Each author extracted data separately before comparison and resolution of differences. Relative risk (RR), risk difference (RD), and number needed to treat were used in the analysis. MAIN RESULTS: The administration of prophylactic enteral antibiotics resulted in a statistically significant reduction in NEC [RR 0.47 (0.23, 0.98); RD -0.072 (-0.136, -0.008); NNT 13.9 (7.4, 125)]. There was a reduction in NEC-related deaths which was of borderline statistical significance [RR 0.16 (0.02, 1.26); RD -0.097 (-0.183, -0.010); NNT 10.3 (5.46, 100)]. There were no significant differences in all deaths (one trial only) or in NEC-like enteropathies (one trial only). There was a statistically significant increase in the incidence of colonisation with resistant bacteria [RR 1.73 (1.00, 2. 97); RD 0.123 (0.008, 0.238); NNT 8.1 (4.2, 125)]. REVIEWER'S CONCLUSIONS: There is insufficient evidence to support the use of enteral antibiotic prophylaxis for NEC in clinical practice. To address this question further, a large trial would be required with a sample size sufficient to examine all the important benefits and harms. Adverse outcomes associated with infection, particularly with resistant bacteria, should be evaluated.

Enteral antibiotics for preventing necrotizing enterocolitis in low birthweight or preterm infants.

BACKGROUND: Necrotizing enterocolitis continues to be a problem, particularly in preterm neonates. There have been reports published suggesting that the use of enteral antibiotics may be effective as prophylaxis. This systematic review was undertaken to clarify the issue. OBJECTIVES: To evaluate the benefits and harms of enteral antibiotic prophylaxis for necrotizing enterocolitis in low birth weight and preterm infants. SEARCH STRATEGY: Searches were made of the Oxford Database of Perinatal trials, MEDLINE (1966 - June 2000; search terms: necrotizing enterocolitis, antibiotics; limits: newborn infant), previous reviews with cross references, abstracts, conference and symposia proceedings, expert informants and journal hand searching in the fields of neonatal pediatrics and microbiology. SELECTION CRITERIA: All randomized or quasi-randomized controlled trials where enteral antibiotics were used as prophylaxis against NEC in LBW (<2500g) and/or preterm (<37 weeks gestation) infants. DATA COLLECTION AND ANALYSIS: The standard method of the Cochrane Collaboration and its Neonatal Review Group was used. The methodological quality of each trial was reviewed by the second author who was blinded to the trial authors and institutions. Each author extracted data separately before comparison and resolution of differences. Relative risk (RR), risk difference (RD), and number needed to treat were used in the analysis. MAIN RESULTS: Five eligible trials involving 456 infants were included. The administration of prophylactic enteral antibiotics resulted in a statistically significant reduction in NEC [RR 0.47 (0.28, 0.78); RD -0.10 (-0.16, -0.04); NNT 10 (6, 25)]. There was a statistically significant reduction in NEC-related deaths [RR 0.32 (0.10, 0.96); RD -0.07 (-0.13, 0.01); NNT 14 (8, 100)]. There was a trend towards a reduction in all deaths which was not significant [RR 0.67(0.34, 1.32)]. There were no significant differences in NEC-like enteropathies (one trial only). One study found a statistically significant increase in the incidence of colonization with resistant bacteria and the summary analysis of three trials gave an increase which was just significant [RR 1.73 (1.00, 2.97); RD 0.07 (0.00, 0.13)]. REVIEWER'S CONCLUSIONS: Evidence suggests that oral antibiotics reduce the incidence of NEC in low birth weight infants. However concerns about adverse outcomes persist, particularly related to the development of resistant bacteria. To address this question further, a large trial would be required with a sample size sufficient to examine all the important benefits and harms. Adverse outcomes associated with infection should be evaluated, and microbiological studies looking for the development of resistant bacteria should be undertaken

Fibreoptic phototherapy for neonatal jaundice.

BACKGROUND: Phototherapy is used to treat newborn infants with hyperbilirubinaemia. Fibreoptic phototherapy is a new mode of phototherapy which is reported to lower serum bilirubin (SBR) while minimising disruption of normal infant care. OBJECTIVES: To evaluate the efficacy of fibreoptic phototherapy. SEARCH STRATEGY: The standard search strategy of the Cochrane Collaboration was used including searches of the Cochrane Controlled Trials Register, MEDLINE, EMBASE and discussion with experts in the field. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating the efficacy of fibreoptic phototherapy in the management of newborn infants with hyperbilirubinaemia. DATA COLLECTION AND ANALYSIS: Thirty-one studies were identified of which 24 met inclusion criteria. They evaluated the efficacy of fibreoptic phototherapy in a number of different clinical situations and patient populations. MAIN RESULTS: Fibreoptic phototherapy was more effective at lowering SBR than no treatment but less effective than conventional phototherapy (percentage change in SBR after 24 hours of treatment: WMD -10.7%, 95%CI -18.14, -3.26 and WMD 3.59%, 95%CI 1.27, 5.92 respectively). Fibreoptic phototherapy was equally as effective as conventional phototherapy in preterm infants and when two fibreoptic devices were used simultaneously (change in SBR after 24 hours of treatment: WMD 1.7%, 95%CI -2.65, 6.05 and change in SBR per day over whole treatment period: WMD 2.82%, 95%CI -1.84, 7.48 respectively). A combination of fibreoptic and conventional phototherapy was more effective than conventional phototherapy alone (duration of phototherapy: WMD -12.51 hr, 95%CI -16.00, -9.02, meta-analysis affected by heterogeneity). No conclusion can be made on the superiority of one fibreoptic device over another as the two studies comparing them (one favouring BiliBlanket, the other finding no difference) did not contain a common outcome measure. REVIEWER'S CONCLUSIONS: Fibreoptic phototherapy has a place in the management of neonatal hyperbilirubinaemia. It is probably a safe alternative to conventional phototherapy in term infants with physiological jaundice. No trials have been identified which support the widely-held view that fibreoptic devices interfere less with infant care or impact less on parent-child bonding.

Varicella-zoster virus infection in Australia.

OBJECTIVE: To determine the epidemiology of varicella-zoster virus (VZV) infection in Australia using currently available data sources. DESIGN: Analysis of national death data (23 years), congenital and neonatal cases (one year) and attendances at sentinel general practices (two years); hospital admissions in NSW and SA (six years); serological studies in 1995 involving antenatal clinics in Sydney and Brisbane and child-care centre staff and refugees in Sydney; and case-ascertainment in 1995 in South Western Sydney among public hospital staff, child-care centre staff and the community. RESULTS: In Australia, there have been an average of 3.5 deaths from chickenpox (mostly children) and 11 from herpes zoster (mostly older people) each year since 1980. The crude death rate for chickenpox has declined (p > 0.05). In 1995, there were 14 cases of neonatal and two of congenital varicella. Average annual admission rates for NSW and SA showed 1,200 hospital bed-days used for chickenpox, more than 20% with complications, and more than 7,300 bed days for zoster; annually more than 880 in-patient admissions were complicated by VZV. Most people encounter the virus in their first 15 years, but some remain susceptible into their 20s; 25% of cases and 37% of hospital admissions for chickenpox occur in people > or = 15 years of age. CONCLUSION: VZV infection involves people of all ages. It causes substantial morbidity and mortality, particularly at the extremes of life. The death rate from chickenpox but not zoster has fallen since the introduction of acyclovir in the 1980s. Surveillance of VZV infection must be given priority once vaccines become available, to monitor changes in morbidity and mortality.

Auditory brainstem evoked response inter-peak latencies in very low birthweight infants.

A population of very low birthweight (VLBW) infants consisting of 41 infants (24 female) less than 1000 g birthweight and 108 infants (63 female) 1000-1499 g together with a normative group of 36 full-term infants (18 female) 2400-4500 g birthweight were used to acquire auditory brainstem evoked response data. Inter-peak latency intervals were derived from the response and the data acquired were analysed across a range of related variables. The Wave V-III peak to peak latency interval was found to have significant age-related attributes together with an interactive birthweight effect, however no significant difference was established between the VLBW and normative groups when an age correction factor was applied.

The utility of the auditory brainstem response as a screening procedure.

A population of very low birthweight infants consisting of 41 infants (24 female) less than 1000 g birthweight and 108 infants (63 female) 1000-1499 g birthweight received auditory brainstem response audiometry (ABR) before initial discharge from hospital and were subsequently monitored via behavioural audiometry and tympanometry as part of their pediatric medical team follow-up assessment at age 7 months. Results support the use of ABR but indicate that its diagnostic yield was enhanced by the use of multiple ABR parameters in combination with basic audiological techniques. The commonly used single-value ABR pass/fail criterion was not found to be clinically practical.

Otoacoustic emission criteria for neonatal hearing screening.

Transient evoked otoacoustic emission measures are gaining acceptance as a technique in new-born hearing screening. At present a wide variety of pass-fail screening criteria are used in otoacoustic emission screening programs. In a study of 100 special care neonates and 35 well, full term babies, a number of screening criteria were examined for sensitivity and specificity characteristics when compared to a standard auditory brainstem response protocol. Results indicate that, for normal and special care neonates with a gestational age at test of 38-41 weeks, high sensitivity ( > 80%) could be obtained when a pass-fail criterion involving analysis of emission reproducibility, or emission reproducibility and emission response level, was set. Sensitivity was reduced for special care neonates who fell outside this age range. Specificity was found to be relatively low overall (always < 65%) and may relate to clinical factors in special care neonates not investigated in this study.

Enamel hypoplasia and dental caries in very-low birthweight children: a case-controlled, longitudinal study.

This longitudinal study investigated the sequelae of enamel defects in a group of 25 white, very-low birthweight (VLBW), preterm children (mean birthweight 969 +/- 218 g, mean gestational age 27 +/- 1.9 weeks). Twenty-five race-, age-, and sex-matched, full-term normal birthweight (NBW) control children born at the same hospital, were selected randomly from hospital records. The children were examined at approximate ages of 30, 44, and 52 months. At all examinations, VLBW children had significantly higher prevalence of enamel hypoplasia than did the NBW children. At the last recall examination, 96% of VLBW group, and 45% of the NBW group had at least one tooth with enamel defect, with a mean of 7.6 +/- 4.9 affected teeth per VLBW child, and only 1.0 +/- 1.3 affected teeth per control child (P < 0.001). A significant association of enamel defects with dental caries was observed only in the VLBW group on the second and third examinations (P < 0.001). The defect identified to be most significantly associated with dental caries was a variant showing both enamel hypoplasia and opacity. In spite of a high prevalence of enamel defects, the overall prevalence of dental caries in the VLBW children was not significantly different from that of NBW controls at all three examinations (P < 0.1). Other caries risk factors such as levels of Streptococcus mutans infection, fluoride supplementation, plaque scores, toothbrushing frequency, and daily sugar exposures were examined but none was found to be related significantly to development of dental caries.

Mineral deficiency in the pathogenesis of enamel hypoplasia in prematurely born, very low birthweight children.

Although it is well known that enamel hypoplasia commonly is observed in prematurely born, very low birthweight (VLBW) children, its pathogenesis is not understood clearly. One likely mechanism may be related to mineral deficiency, which may be diagnosed as radiological demineralization of the long bones. In this study, we compared the cortical area of the humerus as measured from neonatal radiographs in 31 VLBW children with enamel hypoplasia and 14 VLBW children without enamel hypoplasia. The results showed that children with enamel hypoplasia had a lower mean cortical area of 10.1 +/- 1.9 mm2 compared with 13.9 +/- 1.4 mm2 in children without enamel hypoplasia (P less than 0.001). It was also found that intubated children with a lower cortical mass may be more predisposed to develop localized enamel hypoplasia caused by the laryngoscope (P less than 0.001).