Changing outcome of extremely premature infants (less than or equal to 26 weeks' gestation and less than or equal to 750 gm): survival and follow-up at a tertiary center

Mortality and morbidity in extremely low birth weight (ELBW) infants in a neonatal intensive care unit

OBJECTIVE

To determine the morbidity and mortality in ELBW babies till discharge from a Neonatal Intensive Care Unit (NICU).

METHODS

This study was a prospective observational study conducted in a 40 bed well equipped level III care NICU between 01.12.2006 and 30.04.2008. All ELBW babies admitted during this period were assessed for morbidities and interventions required during NICU stay and for their outcome like survival or death.

RESULTS

The survival rate of 87 ELBW babies admitted during this period was 56.1 %. Pulmonary hemorrhage was the commonest cause of death (25 %) followed by respiratory distress syndrome (22.5 %), intraventricular hemorrhage (22.5 %) and sepsis (20 %). Significantly higher number of non-survivors were <750 g at birth (p = 0.0001) and <28 wk gestation (p = 0.0001). Small for gestational babies had better chances of survival compared to those appropriate for gestational age (p = 0.005). RDS (67.8 %), probable sepsis (62.1 %) and hyperbilirubinemia (59.8 %) were the most frequent morbidities. Conventional ventilation (72.4 %) and nasal CPAP(48.3 %) were the commonest respiratory interventions. Surfactant replacement therapy was required in 47.1 % babies.

CONCLUSIONS

ELBW babies have a major contribution to mortality in a NICU. Babies with birth weight <750 g and gestation <28 wk have poor survival. RDS, pulmonary hemorrhage, IVH and sepsis are the common causes of death while RDS, sepsis and hyperbilirubinemia are the most common morbidities.

Survival and long-term neurodevelopmental outcome of extremely premature infants born at 23-26 weeks' gestational age at a tertiary center

OBJECTIVE

Long-term outcome, including school-age function, has been infrequently reported in infants born at ages as young as 23-26 weeks' gestation. The objective of this study is to report outcome on a large cohort of these infants to understand better the risks and factors that affect survival and long-term prognosis.

METHODS

Records from 1036 infants who were born between January 1, 1986, and December 31, 2000, were analyzed retrospectively by logistic regression to correlate multiple factors with both survival and long-term outcome. A total of 675 surviving infants were analyzed at a mean age of 47.5 months for developmental outcome. A subset of 147 surviving infants who were born before 1991 were followed through school-age years using the University of Vermont Achenbach Child Behavioral Checklist and Teachers Report Form. Longitudinal follow-up was performed comparing 1-year outcome with school-age performance.

RESULTS

Gestational age and recent year of birth correlated highly with survival. Maternal nonwhite race, female sex, inborn status, surfactant therapy, single gestation, and secondary sepsis also correlated positively with survival. Normal cranial ultrasound results, absence of chronic lung disease, female sex, cesarean delivery, and increased birth weight correlated favorably with long-term outcome. Infants who were born at 23 weeks were more likely to have severe impairments compared with those who were born at 24-26 weeks. Early follow-up identified most subsequent physical impairments but correlated poorly with school-age function.

CONCLUSIONS

Survival continues to improve for infants who are born at extremely early gestational ages, but long-term developmental concerns continue to be prevalent. Early outcomes do not reliably predict school-age performance. Strategies that reduce severe intraventricular hemorrhage and chronic lung disease will likely yield the best chances to improve long-term outlook.

Study of a group of extremely preterm infants (25-27 weeks): how do they function at 1 year of age?

The functional outcome of 49 extremely preterm infants (gestational age: 25-27 weeks) was studied at the corrected age of 12 months. Apart from pediatric follow-up, a full neurologic assessment and the Bayley Motor and Mental Scales of Infant Development was done. Emphasis was placed on postural control, spontaneous motility, hand function, and elicited infantile reactions. Special attention was given to symmetric development. The infants were then categorized as having optimal or nonoptimal or asymmetric outcome. Overall, an optimal outcome was found in 19 infants (39%) and nonoptimal outcome in 30 infants (61%), 7 of whom failed on all domains of function. Postural control had a significant influence on the different domains of development such as motility (P < or = .001) and persistent infantile reactions (P < or = .001) and slightly less on hand function (P = .08) and asymmetry (P = .06). The outcome on spontaneous motility was significantly related to the results on infantile reactions (P < or = 005) and hand function (P = .05). Also, the score on the motor scale of the Bayley Developmental test was clearly related to outcome on spontaneous motility (P < or = .001) and reactions (P< or = .02). Abnormal brain ultrasonograms were related to the asymmetry of the infantile reactions (P < or = .05). Poor coordination of gross motor function will have consequences for appropriate visuomotor and sensorimotor integration, thereby hampering motor learning and later cognitive function, as is often described in preterm infants. It is suggested that the poor postural control found in many infants born preterm is the result of both myogenic and neurogenic deviations caused by the preterm birth and its nursing consequences.

A critical birth weight and other determinants of survival for infants with severe intrauterine growth restriction

Our objective was to assess the perinatal management and neonatal outcomes of premature, severely intrauterine growth-restricted (IUGR) neonates. A cohort of neonates <1000 grams, < or = first percentile for weight, and <37 weeks' gestation was identified and matched 2:1 to two control sets of premature, appropriate-for-gestational age (AGA) infants-one with similar gestational age (AGA-GA group) and the other with similar birth weight (AGA-BW group) to determine the effect of IUGR on the outcome of the premature infant. The IUGR group was then examined in detail for descriptive statistics. Data were analyzed by t-tests and Chi-square analyses where appropriate. The IUGR infants had worse outcomes than AGA-GA controls but had somewhat better results than the AGA-BW controls. In the IUGR group, a birth weight less than 550 grams was significantly associated with neonatal death (p < 0.001). However, increasing gestational age was not associated with neonatal survival (p = 0.661) if birthweight remained below 550 grams. Classical cesarean delivery was associated with neonatal death (p = 0.003). Neonatal variables associated with poor outcome included patent ductus arteriosus (p = 0.034), feeding intolerance (p = 0.046), and failure to thrive (p = 0.05). Overall, neonatal survival was 73%. Of the surviving neonates, 69% had evidence of neurodevelopmental delay when tested at 6 and 12 months. Premature, growth-restricted neonates with birth weights of <550 grams versus those of >550 grams have dismal outcomes despite a gestational age that is compatible with survival.

A simulated reality scenario compared with the computerized Wisconsin card sorting test: an analysis of preliminary results

Neuropsychologists and other clinicians often comment on the minimal relationship that frequently exists between formal assessments of executive functions, analysis of findings, recommendations, and the person's real-life functioning. The authors' believe that current assessments of executive functions do not transfer easily to real-world behavior. There are limitations in the current examinations and in the settings in which they are given. The tests are artificial and the test settings lack the usual stresses, distractions, and multiple demands common to real life. The interactions are unlike what they experience in everyday life. The examiner often, but unintentionally orients the participant to relevant information that in turn can help the person compensate for the difficulties with executive control processes and bias the findings. We believe that virtual reality (VR) more closely approximates real life settings, the distractions, and the common interchanges (VR) provides a "life-like," three-dimensional (3-D) highly interactive environment, and safety from potential dangers that could arise in actual situations. VR can increase motivation because of its gaming, interactive, and immersive qualities and features are easily modified and allow for multiple applications. Our goal is to develop VR assessments that can be administered under controlled and safe conditions, but which are more sensitive to difficulties with executive control processes critical to safe, independent living. This initial study compares several functions assessed by the Wisconsin Card Sorting Test (WCST) with our three-dimensional, stereographic scenario, Look for a Match (LFAM) Study participants completed questionnaires, alternately began with either the WCST or LFAM, and then took the second test. All participants completed motion sickness and follow-up questionnaires. The results demonstrated that the study participants found LFAM to be more enjoyable and interesting, but found the WCST to be easier. While there is an effect of order with participants doing relatively better on the assessment tool administered second, overall the LFAM performance was inferior to that on the WCST. However, even considering the order effect, LFAM seemed to be more difficult than the WCST.

Population-based study of infants born at less than 28 weeks' gestation in New South Wales, Australia, in 1992-3. New South Wales Neonatal Intensive Care Unit Study Group

The aims of the study were to use the population base of New South Wales (NSW) to study all births from 20 to 27 weeks' gestation in 1992-3 and to compare two data sources for perinatal deaths. The prospective population-based statewide audit (NICUS) of infants admitted to tertiary neonatal intensive care units (NICUs) in NSW was used to collect data on infants less than 28 weeks' gestation registered in 1992-3. This audit also surveyed the 160 obstetric hospitals in NSW to ascertain information on stillbirths and early neonatal deaths in the study period. The NSW midwives data collection (MDC) was the other source of information on stillbirths and labour ward deaths. Data were analysed using SAS. In 1992-3 in NSW 1170 infants were born at 20-27 weeks' gestation. There were 556 stillbirths and 614 live births, of whom 180 (29.3%) died in the labour ward and 434 (70.7%) were admitted to a tertiary NICU. Sixty-six per cent of stillbirths were identified by both data collections, 16.5% by the MDC only and 17% by NICUS only. There was a high major congenital anomaly rate (18.5%) among the stillbirths. Two-thirds of the infants admitted to NICUs survived to 1 year. Information was available on at least one follow-up parameter for 89% (255/288) of the survivors to 12 months (corrected age). Of the 244 infants who had a neurological assessment by a paediatrician, 17% were diagnosed to have cerebral palsy. Eleven per cent of the 239 who had a formal Griffiths developmental assessment had a major intellectual disability. Five (2% of 255) of the 1-year-olds were blind, and 12 (4.7% of 255) had bilateral hearing aids. Seventy-one per cent of the infants examined at 1 year did not have a major disability. For accurate perinatal death data, collection from more than one source is recommended. Infants born at 20-27 weeks' gestation contribute 40% of all stillbirths in NSW, most of the costs of neonatal intensive care as well as the costs of long-term morbidity. In Australia in the early 1990s, the survival of infants born at less than 28 weeks' gestation was best from 26 weeks gestational age onwards. Long-term morbidity did not change from that of earlier cohorts. The most common major disability was cerebral palsy.

Survival and follow-up of infants born at 23 to 26 weeks of gestational age: effects of surfactant therapy

Little information is available regarding the effect of surfactant on outcome for infants born at or before 26 weeks of gestation. We addressed this issue by reviewing records of 310 infants born at gestational ages of 23 through 26 weeks who were admitted to our nursery from 1986, when surfactant was introduced, through 1990. Surfactant was administered to 154 infants (5 during a single-dose prevention study, 25 during a multiple-dose prevention study, 124 while receiving a Food and Drug Administration treatment investigational new drug); 156 infants were not treated with surfactant. Seventy-three percent of the treated infants survived, compared with 55% of the nontreated infants. Increased survival occurred at all gestational ages between 23 and 26 weeks but were greatest in infants born at 23 and 24 weeks. At follow-up, no differences in neurologic outcome were detected between surfactant-treated and nontreated infants. We conclude that surfactant use in extremely premature infants improves survival rates without increasing the proportion of impaired survivors.

Developmental outcome in extremely premature infants. Impact of surfactant

Advances in neonatology, particularly surfactant, have enabled us to significantly improve mortality in the extremely low-birth-weight prematurely born infant. The impact on morbidity remains less clear but decidedly optimistic as the preponderance of the data currently available suggests that although we have not improved outcome in this high-risk group of infants, neither have we increased the percentage of infants with significant impairments. But overall morbidity remains high, especially for the smallest and earliest survivors. There is a growing body of research that supports the idea that with modification of the stressful impact of the NICU environment on the physiologically unstable and vulnerable premature infant, we may be able to improve developmental outcome. We are already seeing even very small infants extubated at a younger age and ready for discharge home well before their originally anticipated "due date." Within this setting we have unequalled opportunity to positively impact development by caring for the infants in a supportive environment that integrates parents as primary caretakers who are comfortable and competent at the time of the infant's discharge home. Further research endeavors should be enlightening in this regard.

Long-term outcome of infants born preterm

This chapter outlines some of the many long-term health problems to be expected in surviving preterm children. They have higher rates of sensorineural impairments (such as cerebral palsy, and visual, auditory and intellectual impairments) and sensorineural disabilities from these impairments, than children born at term. In addition, they grow poorly and have higher rates of other health problems, including poorer respiratory health in early childhood. There is little doubt that preterm children contribute disproportionately to the prevalence of health problems in childhood. However, there are still many gaps in our knowledge of the outcome for preterm survivors, particularly regarding outcome in adulthood. Obstetricians and neonatologists working in intensive care, as well as parents, want to know the long-term outcome for preterm children born today, not that of children born a generation ago when fewer preterm children (particularly those of extremely low birthweight) survived. Despite the many problems, the conclusion is that most preterm children are as healthy as term children, suffering only usual childhood illnesses; we feel confident that the majority make, and will continue to make, useful contributions to their families and the societies in which they live.

Evaluation of care for the preterm infant: review of literature on follow-up of preterm and low birthweight infants. Report from the collaborative Project on Preterm and Small for Gestational Age Infants (POPS) in The Netherlands

Since the introduction of neonatal intensive care in the 1960s, mortality in very preterm and very low birthweight infants has been decreasing steadily. Consequently, interest in the outcome of surviving infants is growing. Restriction of health care resources has stressed the need for information concerning the effect of individual treatment components on mortality and morbidity. Concern about the quality in apparently normal survivors has been increasing as well. The current flood of papers on these subjects illustrates the interest in these issues. The first part of this paper reviews the methodology used in follow-up studies in the past decades. It aims at methodological problems that hamper comparison between studies and preclude unequivocal conclusions. New treatment techniques seldom were but should be evaluated by randomised trials. To monitor the combined effects of changing obstetric and neonatal techniques on perinatal outcome, studies in geographically defined populations are recommended using data from early pregnancy until at least preschool age. Comparability of outcomes could be enhanced by international agreement on standardisation of assessment methods and outcome measures. In the second part the results concerning gestational age- and birthweight-specific mortality, impairments and disabilities and the risk factors for such disorders are discussed. Increased survival of even the tiniest infants is clearly established. This increase in survival has not yet been accompanied by an apparent increase in major morbidity. However, many minor impairments are reported, occurring often in combination and predisposing these children to deviations of normal development. Important changes in the manifestation of brain damage appear to occur during development. These findings stress the importance of long-term follow-up studies.

Case report: survival of an infant with a birthweight of 345 grams

Infant survival with ever-decreasing birthweights is attainable with recent advances in maternal-fetal medicine and enhanced neonatal intensive care. We report a gestation complicated by severe chronic hypertension and fetal distress necessitating delivery at 26 1/7 weeks. The growth-retarded newborn weighted 345 g (12 oz) and survived with minimal sequelae despite a protracted and complicated neonatal course.

Light and the neonatal eye

The lighting environment where the baby born prematurely is placed is different from that experienced in utero. As early exposure to light may affect the immature visual system we have attempted to quantify the neonatal ocular light dose. Lighting surveys performed in 7 neonatal units (NNUs) suggested that mean unit illuminance was 470 lux (range 192-890 lux) and intensive care areas within the NNU were significantly brighter than their corresponding low dependency nurseries. The spectral power distribution of fluorescent lights in NNUs was weighted towards the blue end of the spectrum. Datalogging studies demonstrated that between about 30% and 98% of environmental light was incident on the eyelid, which acts as a predominantly red-pass filter, permitting 21% transmission at 700 nm with less than or equal to 5% transmission at 580 nm. Eye-lid opening frequency was quantified: 45% less than or equal to 26 weeks gestational age and decreasing to 7% at 28 weeks gestational age. The onset of the pupillary reflex to light was between 30 and 34 weeks postmenstrual age, the mean diameter was 3.46 mm before this event and 3.02 mm afterwards. Retinal irradiance values calculated from these data show that it is a function of postmenstrual age. Further studies are required to determine its effect on the immature visual system.