The predictive significance of biologic risk factors for deficits in children of a high-risk population

Reduced fetal movements and maternal medication - new pregnancy risk factors for neurodevelopmental disability in childhood

A case-control study was undertaken of 471 children on the Nottingham Special Needs Register (SNR) who were born in one of the two maternity units in the city between 1987 and 1993 (inclusive). Controls were selected as the next infant born at the same hospital following each index case. The aim of the study was to identify risk factors on the Nottingham Obstetric Database for a baby subsequently appearing on the SNR. Disability was analysed by both ICD-9 coding and functional assessment. Factors which independently and significantly predicted a child's likelihood of being on the SNR were breech presentation (adjusted odds ratio (OR) = 4.0), congenital abnormality (OR=4.9), intrapartum fetal distress (OR=1.7), fetal growth restriction (OR=2.0), socioeconomic deprivation (OR=1.8), prematurity (OR=2.2), reduced fetal movements (OR=2.5) and medication in pregnancy (OR=10.4). To our knowledge the last two factors have not previously been reported as risk predictors for neurodevelopmental disability.

Outcome of very-low-birth-weight (< 1,500 grams) infants born to mothers with diabetes

Premature delivery is common in pregnancies complicated by maternal diabetes. However, the outcome of very-low-birth-weight infants (VLBWI) born to mothers with diabetes is not known. Employing a matched double-cohort design, we investigated the influence of maternal diabetes on the outcome of VLBWI born in Winnipeg from 1988 to 1994. We compared mortality rates and early and late morbidity rates in VLBWI born to mothers with diabetes mellitus (DM) (cases, n = 43, 23 with gestational DM and 20 with pregestational DM) and without DM (controls, n = 539). Controls were matched for gestational age (GA), sex, and the year of birth. All subjects were enrolled in the Newborn Follow-Up Program. Relative risks and 95% confidence limits were calculated for each variable and Chi 2 analysis, Student t-test, and Mann-Whitney test were used as appropriate for analysis. Diabetes mellitus control was assessed by conventional criteria. There were no differences between cases and controls in mode of delivery, birth weight (mean +/- SD, 1,160 +/- 25 g vs 1,110 +/- 26 g), GA (29 +/- 2.8 wk vs 29 +/- 2.4 wk), smallness for gestational age (35% vs 30%), head circumference (26.5 +/- 1.9 vs 26.2 +/- 2.2 cm), length (38.8 +/- 2.8 vs 37.5 +/- 3.7 cm), Apgar score < 4 at 1 min (42% vs 40%) and < 7 at 5 min (37% vs 42%). Incidence of hyaline membrane disease (60% vs 71%), bronchopulmonary dysplasia (33% vs 31%), patent ductus arteriosus (30% vs 43%), necrotizing enterocolitis (12% vs 12%), sepsis (23% vs 25%), acute renal failure (9% vs 10%), intraventricular hemorrhage--all grades (74% vs 64%), retinopathy of prematurity--all stages (30% vs 26%), median days on ventilator (4 vs 4 days), and median days on supplemental oxygen (46 vs 42 days) were similar in both groups (p = NS, 95% confidence limits included 1 for all of these variables). There was no significant difference in mortality (21% vs 15%) or the incidence of major congenital anomalies. Weight, head circumference, and length at 6, 12, and 18 months were similar in both groups. There were no group differences in developmental quotients, prevalence of neurodevelopmental impairments, respiratory morbidity, or number of hospitalizations up to the last follow-up (18 months). Our data suggest that with contemporary perinatal care there is no significant increase in mortality rates or early and late morbidity rates between VLBWI born to mothers with DM and VLBWI of nondiabetic mothers. It seems that with reasonable diabetic control, prematurity rather than the diabetic state determines the neonatal outcome, and this knowledge can be useful in parental counselling.

Neurometabolic testing in developmental delay

The goal of this study was to examine the usefulness of neurometabolic testing in patients with unexplained developmental delay. We included 118 patients from ages 3 months to 13 years. The evaluation was conducted according to a protocol that called for stepwise investigations with the intention to minimize unnecessary tests. Clinical and neuroradiologic abnormalities were used as guidelines for the type and extent of the neurometabolic work-up. Based on our results, a diagnosis for a neurometabolic disorder was established in 16 patients (13.6%). Findings regarding abnormal metabolites (amino acids, ammonia, lactate, pyruvate, urine organic acids) did not lead to a diagnosis but to further investigations. Abnormalities in lysosomal enzymes, very-long-chain fatty acids, and urine mucopolysaccharides were definitive in establishing a diagnosis. In conclusion, in children with slowly progressing development with no apparent cause, there is a need for guidelines regarding the type of patients who need to be tested and the kind and extent of neurometabolic diagnostic work-up.

Identifying at-risk children for early intervention services: lessons from the Infant Health and Development Program

A U.S. law mandates early intervention services for infants and young children who have, or are at risk for, developmental problems. Participating states must develop definitions for identifying infants and young children at risk for developmental problems. To assess the sensitivity, specificity, and positive predictive value of some commonly identified risk factors, we examined the definitions proposed by five states. Data on risk factors and 36-month developmental outcomes were obtained from follow-up participants in the Infant Health and Development Program, a multisite, collaborative prospective intervention program involving 985 low birth weight preterm infants. Few individual risk factors proposed by these states were associated with poor developmental outcomes. Characteristics with positive predictive values greater than 30% were highly specific but tended to involve few cases. Risk factors with positive predictive values greater than 50%, such as hypothyroidism, occurred infrequently (< 6%) in this sample. When state definitions for at-risk children were examined in composite, each definition yielded a positive predictive value of 25% to 35%, with poor specificities ranging from 12% to 40%. These data on low birth weight infants have implications for the design and funding of population-based early intervention programs, and suggest that more careful clinical and longitudinal research is necessary before appropriate definitions can be promulgated for identifying children in need of early intervention services.

Neonatal intensive care: is it worth it? Developmental sequelae of very low birthweight

A significant portion of the health care dollar has been spent on neonatal intensive care since the early 1970s when technologic developments permitted salvage of very small premature infants. The wisdom of allocating so much for so few has been challenged, especially if the result is an increase in the number of severely mentally and motorically disabled children. Studies from around the world of the secular trends in mortality and morbidity for very and extremely low-birthweight babies uniformly indicate that there have been dramatic decreases in mortality and morbidity in the past 20 years. The relative proportion of moderate to severe disability has remained stable during this period of increasing survival potential. Thus, although the absolute numbers of children with disabilities caused by complications of very low birthweight may have increased slightly, they constitute a small minority of the overall number of children with disabilities requiring special educational and other services. Most surviving children with birthweights less than 1500 g remain free of significant functional impairments. It is often difficult for the clinician to identify early or even midway through the neonatal course which infants will have severe, life-long disabilities. By the time identification is feasible, heroic decisions about life supports are no longer called for. Thus, the ethical issues discussed earlier regarding decision-making based on anticipated quality of life become less relevant as the child's condition stabilizes. Given the generally favorable prognosis for even the smallest premature infant, the clinician is probably best advised to give the individual patient the benefit of the doubt. Undoubtedly, there will be exceptions. The more subtle effects of very low birthweight on learning and behavior are just becoming clear as long-term follow-up studies appear in the literature. Very low-birthweight infants who do not manifest severe disability do seem to be at risk for learning problems, although overall cognitive function is in the normal range. There are other effects of preterm birth. On average, stature appears to remain lower, although there may be catch-up growth later in childhood. Having a very low-birthweight infant places considerable stress on the family, but it is unclear whether this has a long-term impact. Studies have failed to show a consistent influence of preterm birth on long-term behavior. Behavior is likely affected more by the social-emotional milieu in which the child is reared than prematurity itself. The environment seems to take over in importance in affecting cognitive functioning after the first several years of life.(ABSTRACT TRUNCATED AT 400 WORDS)

The relationship between perinatal hypoxia and newborn encephalopathy

Newborn encephalopathy was observed in 30% of 303 selected high-risk preterm and term newborn infants. The newborn encephalopathy was mild or moderate in 65 children and severe in 27. The predictive significance of newborn encephalopathy to motor and cognitive deficits at 1 year was evident from the incidence of deficits in the children with no encephalopathy (17%), in children with mild or moderate encephalopathy (25%), and in children with severe encephalopathy (55%). The biologic risk factors with a significant association with newborn encephalopathy included severe intrapartum fetal hypoxia, moderate and severe newborn respiratory complications, and major infections. Perinatal hypoxia was associated with, and may have contributed to, 26% of the cases of mild and moderate newborn encephalopathy and 66% of the cases of severe newborn encephalopathy. Fetal and newborn hypoxia occurred with equal frequencies in cases of mild and moderate encephalopathy; however, newborn hypoxia was twice as frequent as fetal hypoxia in cases of severe newborn encephalopathy.