Perinatal outcomes of a large cohort of extremely low gestational age infants (twenty-three to twenty-eight completed weeks of gestation)

Effect of biomedical complications on very and extremely preterm children's language

Introduction

Very and extremely preterm children have been found to show delays in the development of language in early years. In some investigations, however, a rigorous control of biomedical complications, such as Periventricular Leukomalacia (PVL), Intraventricular Hemorrhage (IVH) or Bronchopulmonary Dysplasia (BPD), does not always exist. For that reason, a confounding effect of low gestational age and biomedical complications may lead to erroneous conclusions about the effect of gestational age.

Methods

In this investigation we compare language development [use of words, sentence complexity and mean length of the three longest utterances (MLU3)] of three groups of Chilean children at 24 months of age (corrected age for preterm children). The first group was composed of 42 healthy full-term children (Full term group: FT), the second group of 60 preterm children born below 32 gestational weeks without medical complications (low risk preterm group: LRPT), and the third group was composed of 64 children below 32 gestational weeks who had medical complications (High risk preterm group: HRPT). The three groups were similar in terms of gender distribution, maternal education, and socio-economic environment. The instrument used to assess language was the Communicative Development Inventories (CDI). In addition, the Ages and Stages Questionnaire-3 (ASQ-3) was also used to assess other developmental dimensions.

Results

The results indicate that HRPT and LRPT children obtained significantly lower results than the FT group in the three language measures obtained through the CDI. No significant differences were observed between the HRPT and the LRPT groups, although the HRPT obtained the lowest results in the three CDI measures. The results obtained through the administration of the ASQ-3 confirm the delay of both preterm groups in communicative development when compared to the FT group. No significant differences between the FT and the PT groups were observed in gross motor, fine motor and problem solving dimensions of the ASQ-3. The LRPT group obtained results that were significantly higher than those of the FT group and the HRPT group in gross motor development.

Discussion

These results seem to indicate that the area of language development is particularly influenced by very or extremely low gestational age.

Over-reaching with causality language in neurodevelopmental infant research: A methodological literature review

BACKGROUND

A methodological review of 78 empirical articles focusing on the neurodevelopmental outcomes of at-risk infants was conducted.

AIMS

To examine ways language and terminology are used to describe methods, present results, and/or state conclusions in studies published during 1994-2005, a decade reflecting major advances in neurodevelopmental research and in medical intervention. More specifically, to investigate to what extent the design of the study and the language in the results section aligned in regard to causality.

METHODS

A process of search and selection of studies published in pediatric journals was conducted through Google Scholar. Criteria of inclusion and exclusion, following PRISMA, were used. Selected studies reported neurodevelopmental outcomes of infants and young children considered at-risk, and were further categorized accordingly to their study designs. Language use in regard to whether the presentation and interpretation of results may convey causal relationships between birth risk factors and neurodevelopmental outcomes was examined following two analytical steps.

RESULTS

Forty out of 78 studies, (51.28 %) used causality-implying language (e.g., effect, predict, influence) notwithstanding that the study design was non-causal.

CONCLUSIONS

Anticipating the next generation of neurodevelopmental-outcomes research, a framework that aims to raise awareness of the importance of language use and the impact of causality-related terms often used in longitudinal studies is proposed. The objective is to avoid ambiguities and misunderstandings around causal or non-causal connections between birth risk factors and developmental outcomes across diverse audiences, including early intervention practitioners working directly with infants and their families.

Single Center Outcome of Multiple Births in the Premature and Very Low Birth Weight Cohort in Singapore

OBJECTIVE

The aim of this study is to compare neonatal mortality and morbidity in multiple and singleton preterm/very low birthweight (PT/VLBW) multiethnic Asian infants.

STUDY DESIGN

Cohort study of 676 singleton and 299 multiple PT/VLBW infants born between 2008 and 2012 at KK Women's and Children's Hospital, the largest tertiary perinatal center in Singapore with further stratification by gestational ages 23 to 25 (Group 1), 26 to 28 (Group 2), and ≥29 (Group 3) weeks. Outcome measures included predischarge mortality and major neonatal morbidity.

RESULTS

Overall survival to discharge was comparable for singletons 611/676 (90%) and multiples 273/299 (91%). Use of assisted reproductive technologies (47 vs. 4%), antenatal steroids (80 vs. 68%), and delivery by cesarean section (84 vs. 62%) were significantly higher (p < 0.001) in multiples while pregnancy induced hypertension (8.7 vs. 31.6%, p < 0.001) and maternal chorioamnionitis (31 vs. 41%, p < 0.01) were seen less commonly compared with singleton pregnancies. Survival was comparable between singletons and multiples except for a lower survival in multiples in Group 2 (81.7 vs. 92.4%, p = 0.007). Major neonatal morbidities were comparable for multiples and singletons in the overall cohort. Presence of hemodynamically significant patent ductus arteriosus (HsPDA) requiring treatment (88.9 vs. 72.5%), air leaks (33 vs. 14.6%, p = 0.02), NEC (30 vs. 14.6%, p = 0.04), and composite morbidity (86 vs. 66%, p = 0.031) were significantly higher in multiples in Group 1. A significantly higher incidence of HsPDA (68.1 vs. 52.4%, p = 0.008) was also observed in multiples in Group 2. Multiple pregnancy was not an independent predictor of an adverse outcome on regression analysis (OR: 0.685, 95% confidence interval: 0.629-2.02) even in GA ≤25 weeks.

CONCLUSION

Neonatal mortality and morbidity were comparable in our cohort of PT/VLBW singletons and multiple births, but preterm multiple births ≤25 weeks had a higher incidence of neonatal morbidity.

KEY POINTS

· Use of assisted reproductive technologies was significantly higher in multiples as compared to singletons.. · Major neonatal morbidities and mortality were similar between singletons and multiples in our cohort.. · In gestations less than 25 weeks multiples had higher neonatal morbidities than their singleton counterparts..

Concurrence of stunting and overweight/obesity among children: Evidence from Ethiopia

Background

Nutrition transition in many low- and middle-income countries (LMICs) has led to shift in childhood nutritional outcomes from a predominance of undernutrition to a double burden of under- and overnutrition. Yet, policies that address undernutrition often times do not include overnutrition nor do policies on overweight, obesity reflect the challenges of undernutrition. It is therefore crucial to assess the prevalence and determinants of concurrence stunting and overweight/obesity to better inform nutrition programs in Ethiopia and beyond.

Methods

We analyzed anthropometric, sociodemographic and dietary data of children under five years of age from 2016 Ethiopian Demographic and Health Survey (EDHS). A total of 8,714 children were included in the current study. Concurrence of stunting and overweight/obesity (CSO) prevalence was estimated by basic, underlying and immediate factors. To identify factors associated with CSO, we conducted hierarchical logistic regression analyses.

Results

The overall prevalence of CSO was 1.99% (95% CI, 1.57–2.53). The odds of CSO was significantly higher in children in agrarian region compared to their counter parts in the pastoralist region (AOR = 1.51). Other significant factors included; not having improved toilet facility (AOR = 1.94), being younger than 12 months (AOR = 4.22), not having history of infection (AOR = 1.83) and not having taken deworming tablet within the previous six months (AOR = 1.49).

Conclusion

Our study provided evidence on the co-existence of stunting and overweight/obesity among infants and young children in Ethiopia. Therefore, identifying children at risk of growth flattering and excess weight gain provides nutrition policies and programs in Ethiopia and beyond with an opportunity of earlier interventions through improving sanitation, dietary quality by targeting children under five years of age and those living in Agrarian regions of Ethiopia.

Morbidity and mortality among very preterm singletons following fertility treatment in Australia and New Zealand, a population cohort study

BACKGROUND

Due to high rates of multiple birth and preterm birth following fertility treatment, the rates of mortality and morbidity among births following fertility treatment were higher than those conceived spontaneously. However, it is unclear whether the rates of adverse neonatal outcomes remain higher for very preterm (<32 weeks gestational age) singletons born after fertility treatment. This study aims to compare adverse neonatal outcomes among very preterm singletons born after fertility treatment including assisted reproductive technology (ART) hyper-ovulution (HO) and artificial insemination (AI) to those following spontaneous conception.

METHODS

The population cohort study included 24069 liveborn very preterm singletons who were admitted to Neonatal Intensive Care Unit (NICU) in Australia and New Zealand from 2000 to 2010. The in-hospital neonatal mortality and morbidity among 21753 liveborn very preterm singletons were compared by maternal mode of conceptions: spontaneous conception, HO, ART and AI. Univariate and multivariate binary logistic regression analysis was used to examine the association between mode of conception and various outcome factors. Odds ratio (OR) and adjusted odds ratio (AOR) and 95% confidence interval (CI) were calculated.

RESULTS

The rate of small for gestational age was significantly higher in HO group (AOR 1.52, 95% CI 1.02-2.67) and AI group (AOR 2.98, 95% CI 1.53-5.81) than spontaneous group. The rate of birth defect was significantly higher in ART group (AOR 1.71, 95% CI 1.36-2.16) and AI group (AOR 3.01, 95% CI 1.47-6.19) compared to spontaneous group. Singletons following ART had 43% increased odds of necrotizing enterocolitis (AOR 1.43, 95% CI 1.04-1.97) and 71% increased odds of major surgery (AOR 1.71, 95% CI 1.37-2.13) compared to singletons conceived spontaneously. Other birth and NICU outcomes were not different among the comparison groups.

CONCLUSIONS

Compared to the spontaneous conception group, risk of congenital abnormality significantly increases after ART and AI; the risk of morbidities increases after ART, HO and AI. Preconception planning should include comprehensive information about the benefits and risks of fertility treatment on the neonatal outcomes.

Neonatal deaths: prospective exploration of the causes and process of end-of-life decisions

OBJECTIVE

To determine the causes and process of death in neonates in Canada.

DESIGN

Prospective observational study.

SETTING

Nineteen tertiary level neonatal units in Canada.

PARTICIPANTS

942 neonatal deaths (215 full-term and 727 preterm).

EXPOSURE AND OUTCOME

Explored the causes and process of death using data on: (1) the rates of withdrawal of life-sustaining treatment (WLST); (2) the reasons for raising the issue of WLST; (3) the extent of consensus with parents; (4) the consensual decision-making process both with parents and the multidisciplinary team; (5) the elements of WLST; and (6) the age at death and time between WLST and actual death.

RESULTS

The main reasons for deaths in preterm infants were extreme immaturity, intraventricular haemorrhage and pulmonary causes; in full-term infants asphyxia, chromosomal anomalies and syndromic malformations. In 84% of deaths there was discussion regarding WLST. WLST was agreed to by parents with relative ease in the majority of cases. Physicians mainly offered WLST for the purpose of avoiding pain and suffering in imminent death or survival with a predicted poor quality of life. Consensus with multidisciplinary team members was relatively easily obtained. There was marked variation between centres in offering WLST for severe neurological injury in preterm (10%-86%) and severe hypoxic-ischaemic encephalopathy in full-term infants (5%-100%).

CONCLUSIONS AND RELEVANCE

In Canada, the majority of physicians offered WLST to avoid pain and suffering or survival with a poor quality of life. Variation between units in offering WLST for similar diagnoses requires further exploration.

Maternal and perinatal outcomes of pregnancies delivered at 23 weeks' gestation

OBJECTIVE

To evaluate the maternal and perinatal outcomes of pregnancies delivered at 23+0 to 23+6 weeks' gestation.

METHODS

This prospective cohort study included women in the Canadian Perinatal Network who were admitted to one of 16 Canadian tertiary perinatal units between August 1, 2005, and March 31, 2011, and who delivered at 23+0 to 23+6 weeks' gestation. Women were included in the network if they were admitted with spontaneous preterm labour with contractions, a short cervix without contractions, prolapsing membranes with membranes at or beyond the external os or a dilated cervix, preterm premature rupture of membranes, intrauterine growth restriction, gestational hypertension, or antepartum hemorrhage. Maternal outcomes included Caesarean section, placental abruption, and serious complication. Perinatal outcomes were mortality and serious morbidity.

RESULTS

A total of 248 women and 287 infants were included in the study. The rate of Caesarean section was 10.5% (26/248) and 40.3% of women (100/248) had a serious complication, the most common being chorioamnionitis (38.6%), followed by blood transfusion (4.5%). Of infants with known outcomes, perinatal mortality was 89.9% (223/248) (stillbirth 23.3% [67/287] and neonatal death 62.9% [156/248]). Of live born neonates with known outcomes (n = 181), 38.1% (69/181) were admitted to NICU. Of those admitted to NICU, neonatal death occurred in 63.8% (44/69). Among survivors at discharge, the rate of severe brain injury was 44.0% (11/25), of retinopathy of prematurity 58.3% (14/24), and of any serious neonatal morbidity 100% (25/25). Two subgroup analyses were performed: in one, antepartum stillbirths were excluded, and in the other only centres that indicated they offered fetal monitoring at 23 weeks' gestation were included and antepartum stillbirths were excluded. In each of these, perinatal outcomes similar to the overall group were found.

CONCLUSION

Pregnant women delivering at 23 weeks' gestation are at risk of morbidity. Their infants have high rates of serious morbidity and mortality. Further research is needed to identify strategies and forms of management that not only increase perinatal survival but also reduce morbidities in these extremely low gestational age infants and reduce maternal morbidity.

Prevalence of cerebral palsy in Quebec: alternative approaches

AIM

To provide an estimate of the period prevalence of cerebral palsy (CP) in the province of Quebec.

METHODS

Children with CP were identified from three consecutive birth cohorts (1999-2001) from the Quebec CP Registry, covering 6 of the 17 administrative health regions of the province. Two inferential approaches were applied for period prevalence estimation, frequentist and bayesian.

RESULTS

228 children were identified with CP. Using a frequentist approach, the overall prevalence of CP was 1.84 per 1,000 children aged 9-11 years living in those areas in 2010 (95% CI 1.60-2.08). Using a bayesian approach taking into account the uncertainty about the registry's sensitivity in capturing all cases, the overall prevalence is higher at 2.30 per 1,000 children with a 95% CI (1.99-2.65).

CONCLUSION

Using a bayesian approach to adjust for the registry's known high specificity and lower sensitivity, the prevalence estimate is in concordance with worldwide estimates and estimates using administrative databases in western Canadian provinces. Future studies are needed to validate the diagnosis of CP within administrative databases and to evaluate possible regional trends across Canada in both prevalence and health service utilization, which may highlight disparities in healthcare delivery.

Focused attention, heart rate deceleration, and cognitive development in preterm and full-term infants

The majority of children who are born very preterm escape major impairment, yet more subtle cognitive and attention problems are very common in this population. Previous research has linked infant focused attention during exploratory play to later cognition in children born full-term and preterm. Infant focused attention can be indexed by sustained decreases in heart rate (HR). However there are no preterm studies that have jointly examined infant behavioral attention and concurrent HR response during exploratory play in relation to developing cognition. We recruited preterm infants free from neonatal conditions associated with major adverse outcomes, and further excluded infants with developmental delay (Bayley Mental Development Index [MDI < 70]) at 8 months corrected age (CA). During infant exploratory play at 8 months CA, focused attention and concurrent HR response were compared in 83 preterm infants (born 23-32 weeks gestational age [GA]) who escaped major impairment to 46 full-term infants. Focused attention and HR response were then examined in relation to Bayley MDI, after adjusting for neonatal risk. MDI did not differ by group, yet full-term infants displayed higher global focused attention ratings. Among the extremely preterm infants born <29 weeks, fewer days on mechanical ventilation, mean longest focus, and greater HR deceleration during focused attention episodes, accounted for 49% of adjusted variance in predicting concurrent MDI. There were no significant associations for later-born gestational age (29-32 weeks) or full-term infants. Among extremely preterm infants who escape major impairment, our findings suggest unique relationships between focused attention, HR deceleration, and developing cognition.

Follow-up issues with multiples

The rate of multiple pregnancy has increased in developed countries, a finding usually attributed to more widespread use of assisted reproductive technologies. Multiple pregnancies are associated with a greater risk of pregnancy complications, including intrauterine growth restriction of one or more of the fetuses, vascular communications within a shared monochorionic placenta and premature delivery. Surviving infants are at significantly greater risk of developing cerebral palsy due to a combination of a higher proportion of them being preterm or of low birth weight, and complications associated with chorionicity. These infants are also at greater risk for abnormal cognitive development and learning disabilities for the same reasons. Parenting styles and family dynamics may also differ with multiples compared with singletons, which may affect long-term behaviour and development.Thus, infants of multiple pregnancies should receive careful neurodevelopmental follow-up. For larger, lower risk infants, this follow-up may be provided by general paediatricians within the community. However, for infants with birth weights of less than 1000 g or with a complicated antenatal or neonatal course, follow-up should be in a high-risk neonatal follow-up clinic with appropriate multidisciplinary support.

Effect of pregestational maternal, obstetric and perinatal factors on neonatal outcome in extreme prematurity

Purpose

To investigate the effect of pregestational maternal, obstetric and perinatal factors on neonatal outcome in extreme preterm deliveries.

Methods

Retrospective study of deliveries in a Norwegian tertiary teaching hospital. All women with live births at 24⁺⁰– 27⁺⁶ weeks of gestation between 2004 and 2007 were included. Major morbidity is defined as intraventricular haemorrhage grade 3–4, periventricular leukomalacia, bronchopulmonary dysplasia or necrotizing enterocolitis. Pregestational maternal, obstetric and perinatal variables were initially compared for mortality and survival with major morbidity at 24-h, 7- or 28-day postpartum/discharge in univariate analysis. Then, a multivariate analysis was conducted in order to determine independent factors associated with mortality and survival with major morbidity.

Results

A total of 109 babies were delivered alive in 92 women, representing 1.6% of total births. The survival rates were 93.6, 84.4 and 80.7%, with a prevalence of major morbidity among survivors of 40.4, 32.1 and 39.4% at 24-h, 7- and 30-day postpartum/discharge, respectively. After adjustment using multiple logistic regression, only a 5-min Apgar score ≤3 and babies with at least one major morbidity had significantly independent effects on neonatal survival. Multiple pregnancy and gestational age <26 weeks were the only two independent risk factors for survival with major morbidity.

Conclusions

Neonatal survival was significantly predicted by a 5-min Apgar score and neonatal morbidity, independent of pregestational maternal disease, obstetric complications, method of delivery, gestational age and birth weight in extreme preterm deliveries. The excess morbidity rate was confined among multiples and babies who were delivered before 26 weeks of gestation.

Effect of older maternal age on birth outcomes in twin pregnancies: a population-based study

OBJECTIVE

We compared perinatal mortality, preterm birth (<37, <33 and <28 weeks), small for gestational age (SGA), Apgar score (<4), mechanical ventilation (1 days) and prolonged neonatal intensive care unit (NICU) hospitalization (13 days) between twins of 25 to 34 and >35-year-old women. Further, we examined whether older maternal age effects were modified by parity or otherwise affected by chorionicity.

STUDY DESIGN

We carried out a population-based retrospective cohort study including all twin births in British Columbia (BC), Canada, from 1999 to 2003. The BC perinatal database registry was used to obtain clinical, behavioral and demographic data. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated using generalized estimating equation models.

RESULT

Overall, twins of older women were more likely to be born preterm (<37 weeks), but not very or extremely preterm (<33 weeks). These twins were not at increased risk of perinatal death, mechanical ventilation or were not SGA compared with twins of younger women. Twins of older primiparous women did not have an elevated risk of NICU hospitalization; twins born to older multiparous women had higher risk (OR=1.8; 95% CI: 1.2 to 2.6). Analyses restricted to opposite-sex (dichorionic) twins showed that perinatal death, mechanical ventilation and very preterm birth occur less likely among older women (OR=0.2 (95% CI: 0.0 to 0.8), OR=0.3 (95% CI: 0.1 to 0.7) and OR=0.4 (95% CI: 0.2 to 0.7), respectively). Further, the risk of late preterm birth was increased and NICU hospitalization was reduced among opposite-sex twins born to older compared with younger primiparous women (OR=1.9 (95% CI: 1.3 to 2.8) and OR=0.2 (95% CI: 0.1 to 0.5), respectively).

CONCLUSION

Twins of older mothers did not have an elevated risk for most adverse birth outcomes, except for late preterm birth. Risks of neonatal care admission may be elevated among older multiparous women.

The effect of maternal age on adverse birth outcomes: does parity matter?

OBJECTIVES

To examine the effect of parity on the association between older maternal age and adverse birth outcomes, specifically stillbirth, neonatal death, preterm birth, small for gestational age, and neonatal intensive care unit admission.

METHODS

We conducted a retrospective cohort study of singleton births in British Columbia between 1999 and 2004. In the cohort, 69 023 women were aged 20 to 29, 25 058 were aged 35 to 39, and 4816 were aged 40 and over. Perinatal risk factors, obstetric history, and birth outcomes were abstracted from the British Columbia Perinatal Database Registry. Logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals for adverse outcomes in the two older age groups compared with the young control subjects.

RESULTS

Compared with younger control subjects, women aged 35 to 39 years had an aOR of stillbirth of 1.5 (95% CI 1.2 to 1.9) and women aged >or= 40 years also had an aOR of 1.5 (95% CI 1.0 to 2.4). The aOR for NICU admission was 1.2 (95% CI 1.0 to 1.3) in women aged 35 to 39 years and 1.4 (95% CI 1.1 to 17) in women aged >or= 40 years compared with younger control subjects. The risk of preterm birth and SGA differed by parity. The aOR for preterm birth compared with younger primiparas was 1.5 (95% CI 1.4 to 1.7) for women aged 35 to 39 years and 1.6 (95% CI 1.3 to 2.0) for women aged >or= 40 years. In multiparas the aOR for preterm birth was 1.1 (95% CI 1.1 to 1.2) in women aged 35 to 39 and 1.3 (95% CI 1.1 to 1.5) in women >or= 40 years. The aOR for SGA in primiparas was 1.2 (95% CI 1.1 to 1.4) for women aged 35 to 39 and 1.4 (95% CI 1.1 to 1.7) for women aged >or= 40 years. The risk of neonatal death was not significantly different between groups.

CONCLUSION

Older women were at elevated risk of stillbirth, preterm birth, and NICU admission regardless of parity. Parity modified the effect of maternal age on preterm birth and SGA. Older primiparas were at elevated risk for SGA, but no association between age and SGA was found in multiparas. Older primiparas were at higher risk of preterm birth than older multiparas compared with younger women.

Birth outcomes among older mothers in rural versus urban areas: a residence-based approach

PURPOSE

We examined the association between rural residence and birth outcomes in older mothers, the effect of parity on this association, and the trend in adverse birth outcomes in relation to the distance to the nearest hospital with cesarean-section capacity.

METHODS

A population-based retrospective cohort study, including all singleton births to 35+ year-old women in British Columbia (Canada), 1999-2003. We compared birth outcomes in rural versus urban areas, and between 3 distance categories to a hospital (<50, 50-150, >150 km). Outcomes included labor induction, cesarean section, stillbirth, perinatal death, preterm birth (<37 weeks), small-for-gestational-age, large-for-gestational-age, and neonatal intensive care unit admission. We used multivariate regression to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

FINDINGS

Among the 29,698 subjects, 11.5% lived in rural areas; 5% lived within 50-150 km; and 1.1% lived >150 km from a hospital. Rural women were at lower risk of primary and repeat cesarean section (OR = 0.9, CI: 0.9-1.0; OR = 0.7, CI: 0.6-0.9) and small-for-gestational-age (OR = 0.8, CI: 0.7-0.9) births; they were at increased risk for perinatal death (OR = 1.5, CI: 1.1-2.1) and large-for-gestational-age (OR = 1.1, CI: 1.1-1.2) births. The association was stronger among multiparous versus primiparous women. No differences in emergency cesarean section, preterm birth, or neonatal intensive care admission were found, regardless of parity. Perinatal mortality increased with distance from hospital; OR = 1.5 (CI: 1.1-2.1) per distance category.

CONCLUSIONS

Older women in rural versus urban areas had a lower rate of cesarean section and increased risk of perinatal death. The risk of perinatal death increased with the distance to hospital. Further studies need to evaluate the contribution of underlying perinatal risks, access to care, and decision making regarding referral and transport.

Early outcome of preterm infants with birth weight of 1500 g or less and gestational age of 30 weeks or less in Isfahan city, Iran

BACKGROUND

The outcome of preterm neonates has been varied in different hospitals and regions in developing countries. This study aimed to determine the mortality, morbidity and survival of neonates weighing 1500 g or less and with gestational age of 30 weeks or less who were admitted to referral neonatal intensive care units (NICUs) of two hospitals in Isfahan city, Iran and to investigate the effect of birth weight, gestational age and Apgar score on infant mortality.

METHODS

We studied retrospectively the morbidity, mortality and survival of 194 newborns with a birth weight of </=1500 g and a gestational age of </=30 weeks who had been hospitalized during a 15-month period in NICUs of the two referral hospitals. The Kaplan-Meier method was used to estimate the survival of the neonates. The survival was defined as the discharge of live infant from the hospital within 75 days.

RESULTS

Overall, 125 (64.4%; 95%CI 58%-71%) of the 194 infants died during their hospital stay. The morbidity in this study was as follows: respiratory distress syndrome 76% (95%CI 70%-82%), septicemia 30.9% (95%CI 24%-37%), bronchopulmonary dysplasia 10.3% (95%CI 6%-15%), necrotizing enterocolitis 6.7% (95%CI 3%-10%), patent ductus arteriosus 12.4% (95%CI 8%-17%), intraventricular hemorrhage 7.2% (95%CI 4%-11%), and apnea 16.5% (95%CI 11%-22%). Packed cell transfusion was required in 43.3% (95%CI 36%-50%) of the neonates. The Kaplan Meier survival analysis revealed that 75% of the infants would live past 2 days, 50% after 14 days, and 25% after 69 days.

CONCLUSIONS

Even with modern perinatal technology and care, early deaths of very low birth weight infants are still common in our referral hospitals. The outcome of infants born at 24-28 weeks is unfavorable. The hospital level is an important factor affecting the mortality and morbidity of these infants.

Cost of racial disparity in preterm birth: evidence from Michigan

This study examined the economic costs associated with racial disparity in preterm birth and preterm fetal death in Michigan. Linked 2003 Michigan vital statistics and hospital discharge data were used for data analysis. Thirteen percent of the singleton births among non-Hispanic Blacks were before 37 completed weeks of gestation, compared with only 7.7% among non-Hispanic Whites (risk ratio = 1.66, 95% confidence interval: 1.59-1.72; p<.0001). One thousand one hundred and eighty four (1,184) non-Hispanic Black, singleton preterm births and preterm fetal deaths would have been avoided in 2003 had their preterm birth rate been the same as Michigan non-Hispanic Whites. Economic costs associated with these excess Black preterm births and preterm fetal deaths amounted to $329 million (range: $148 million-$598 million) across their lifespan over and above the costs if they were born at term, including costs associated with the initial hospitalization, productivity loss due to perinatal death, and major developmental disabilities. Hence, racial disparity in preterm birth and preterm fetal death has substantial cost implications for society. Improving pregnancy outcomes for African American women and reducing the disparity between Blacks and Whites should continue to be a focus of future research and interventions.

Age-appropriate early school age neurobehavioral outcomes of extremely preterm birth without severe intraventricular hemorrhage: a single center experience

BACKGROUND

Extremely low birth weight (ELBW) is an established risk factor for poor neurocognitive outcome, particularly when severe intraventricular hemorrhage (IVH) complicates the neonatal course. Those born <26 weeks gestational age (GA) are at greatest risk, their outcomes poorer than later born ELBW children. Outcomes of GA subgroups of ELBW uncomplicated by severe IVH have not been well described.

AIM

To compare neurocognitive and behavioral outcomes of those born < and >or=26 weeks for an ELBW cohort treated in a single center with extremely low IVH incidence.

DESIGN

Single center retrospective observational cohort study of <or=1000 g survivors born between 1998-2000, using standardized tests of cognition, academic achievement, executive function, attention, language, memory, motor/visual-motor skill, parent and teacher behavioral questionnaires.

RESULTS

ELBW participants (mean age: 6.85+/-0.79) had a mean General Cognitive Ability of 101.4+/-13.05; no significant differences found between <26 weeks (98.19+/-12.48) and >or=26 weeks (102.97+/-13.21) subgroups. No neurocognitive, achievement, or behavioral score was impaired (>or=2 SDs below the normative mean). Subgroup comparisons were nonsignificant after controlling for BW and maternal education, except for >or=26 week advantage for phoneme analysis. Poorer, but low average, performances were found for motor dexterity/coordination, spatial working memory, and selective attention.

CONCLUSIONS

Age-appropriate neurocognitive and behavioral function of ELBW survivors suggests outcome may be predicted based on IVH incidence as opposed to birth weight or GA. Factors leading to decreased IVH incidence deserve further study, via single- and cross-center methodologies, to enhance decision-making regarding resuscitation and care of these highly at-risk neonates.

An algorithm for identifying and classifying cerebral palsy in young children

OBJECTIVE

To develop an algorithm on the basis of data obtained with a reliable, standardized neurological examination and report the prevalence of cerebral palsy (CP) subtypes (diparesis, hemiparesis, and quadriparesis) in a cohort of 2-year-old children born before 28 weeks gestation.

STUDY DESIGN

We compared children with CP subtypes on extent of handicap and frequency of microcephaly, cognitive impairment, and screening positive for autism.

RESULTS

Of the 1056 children examined, 11.4% (120) were given an algorithm-based classification of CP. Of these children, 31% had diparesis, 17% had hemiparesis, and 52% had quadriparesis. Children with quadriparesis were 9 times more likely than children with diparesis (76% versus 8%) to be more highly impaired and 5 times more likely than children with diparesis to be microcephalic (43% versus 8%). They were more than twice as likely as children with diparesis to have a score <70 on the mental scale of the BSID-II (75% versus 34%) and had the highest rate of the Modified Checklist for Autism in Toddlers positivity (76%) compared with children with diparesis (30%) and children without CP (18%).

CONCLUSION

We developed an algorithm that classifies CP subtypes, which should permit comparison among studies. Extent of gross motor dysfunction and rates of co-morbidities are highest in children with quadriparesis and lowest in children with diparesis.

The risks for very low birth weight infants from multiple pregnancies

Advances in perinatal and neonatal care in recent years have resulted in dramatic improvements in the rate of intact survival of preterm infants. As a result, neonatologists have focused on the new challenge of bringing about similar advances for the tiniest infants who are born at or near the current limits of viability. Although these tiny infants comprise only a small proportion of all births, the ravages of prematurity make them by far the most challenging group of infants who require our attention in the neonatal intensive care unit.

Standards for the measurement of birth weight, length and head circumference at term in neonates of European, Chinese and South Asian ancestry

BACKGROUND

Fetal growth restriction is associated with metabolic derangements in the newborn, impaired functioning in childhood and chronic diseases in adulthood. Differences between ethnic groups with respect to fetal growth may result in the misclassification of constitutionally small or large babies as having abnormal growth for their gestational age. We have developed intrauterine growth charts based on precise measurements of newborns whose parents were both of European, Chinese or South Asian ethnicity.

METHODS

Weight, length and head circumference were measured in 2695 infants born to healthy non-smoking mothers in British Columbia at 37-41 completed weeks of gestation. Gestational age was confirmed by ultrasound before 20 weeks of gestation. Weight was measured by digital scale, length by stadiometer and head circumference by firm plastic tape measures. Means and 95% confidence intervals were compared among newborns grouped by ethnicity and sex. Smoothed graphs were constructed for visual interpretation.

RESULTS

At 40 weeks, infants of European descent ("European" infants) weighed 225.5 g more on average than infants of Chinese descent ("Chinese" infants) (p < 0.001) and 254.6 g more than infants of South Asian descent ("South Asian" infants) (p < 0.001). The mean difference in birth weight between Chinese and South Asian infants (19.1 g) was not statistically significant. The mean length of European infants at 40 weeks of gestation was 0.89 cm greater than that of Chinese infants (p < 0.001). Differences in mean length between European and South Asian babies or between Chinese and South Asian babies was not statistically significant. The mean head circumferance of European babies was 0.50 cm larger than that of Chinese babies at 40 weeks (p < 0.001) but did not differ significantly from that of South Asian babies. South Asian and Chinese babies had similar mean head circumferences at 40 weeks. When differences in mean birth weight, length and head circumference were examined within boys and girls, the observed differences according to ethnicity remained statistically significant.

CONCLUSION

Important differences in weight, length and head circumferences are reported among babies according to ethnicity. The use of sex- and ethnicity-specific growth charts may prevent the misclassification of newborns as small or large for gestational age.

Boys are more stunted than girls in sub-Saharan Africa: a meta-analysis of 16 demographic and health surveys

Background

Many studies in sub-Saharan Africa have occasionally reported a higher prevalence of stunting in male children compared to female children. This study examined whether there are systematic sex differences in stunting rates in children under-five years of age, and how the sex differences in stunting rates vary with household socio-economic status.

Methods

Data from the most recent 16 demographic and health surveys (DHS) in 10 sub-Saharan countries were analysed. Two separate variables for household socio-economic status (SES) were created for each country based on asset ownership and mothers' education. Quintiles of SES were constructed using principal component analysis. Sex differentials with stunting were assessed using Student's t-test, chi square test and binary logistic regressions.

Results

The prevalence and the mean z-scores of stunting were consistently lower amongst females than amongst males in all studies, with differences statistically significant in 11 and 12, respectively, out of the 16 studies. The pooled estimates for mean z-scores were -1.59 for boys and -1.46 for girls with the difference statistically significant (p < 0.001). The stunting prevalence was also higher in boys (40%) than in girls (36%) in pooled data analysis; crude odds ratio 1.16 (95% CI 1.12–1.20); child age and individual survey adjusted odds ratio 1.18 (95% CI 1.14–1.22). Male children in households of the poorest 40% were more likely to be stunted compared to females in the same group, but the pattern was not consistent in all studies, and evaluation of the SES/sex interaction term in relation to stunting was not significant for the surveys.

Conclusion

In sub-Saharan Africa, male children under five years of age are more likely to become stunted than females, which might suggest that boys are more vulnerable to health inequalities than their female counterparts in the same age groups. In several of the surveys, sex differences in stunting were more pronounced in the lowest SES groups.

Behavioral responses to pain are heightened after clustered care in preterm infants born between 30 and 32 weeks gestational age

OBJECTIVE

To compare biobehavioral pain responses of preterm infants born at differing gestational ages (GAs) when pain was preceded by a rest period or by a series of routine nursing interventions.

METHODS

In a randomized, within subjects, cross-over design, facial (Neonatal Facial Coding System), sleep/wake state and heart rate (HR) responses of 43 preterm infants [mean birth weight: 1303 g (range 590 g to 2345 g); mean GA at birth: 30 weeks (range 25 to 32)] were examined across 3 phases of blood collection (Baseline, Lance, and Recovery) under 2 conditions: pain after a 30-minute rest period versus pain after a series of routine nursing interventions (clustered care). Infant behavioral responses were coded from continuous bedside videotapes. HR was analyzed using custom physiologic signal processing software.

RESULTS

Infants born at earlier GA (<30 wk) had equally intense facial responses during the Lance phase regardless of condition. However, later born infants (> or =30 wk GA) showed heightened facial responses indicative of sensitized responses during blood collection when it was preceded by clustered care (P=0.05). Moreover, later born infants had significantly lower facial (P=0.05) and HR (P=0.04) reactivity during Recovery when blood collection followed clustered care.

DISCUSSION

Earlier born preterm infants showed heightened states of arousal and poor ability to modulate HR during Recovery when an invasive procedure was preceded by routine tactile nursing procedures. Alternatively, later born infants exhibited sensitized responses when clustered care preceded blood collection. Our findings support the importance of cue based individualized approaches to care.

Evaluation and development of potentially better practices for perinatal and neonatal communication and collaboration

OBJECTIVE

The obstetric and neonatal exploratory focus group of the Vermont Oxford Network Neonatal Intensive Care Quality Improvement Collaborative 2002 set out to improve collaboration, communication, and coordination between maternal and neonatal caregivers in 3 areas: the pregnancy at 22 to 26 weeks, measurement of maternal outcomes that are linked with neonatal outcomes, and team performance during high-risk delivery. Antepartum and intrapartum maternal attributes and interventions also were considered important measurements to identify practice variations and their relationship to neonatal outcomes for ongoing obstetric and neonatal collaboration.

METHODS

Potentially better practices were developed on the basis of evidence in the literature, expert opinion, and internal analysis at the participating perinatal centers. The potentially better practices include development of local guidelines at each center for the care and counseling of pregnant women who are at risk for delivering at the margin of viability; communication strategies for obstetric and neonatology providers relating to high-risk pregnancy treatment plans; team communication and performance at high-risk deliveries; design of organizational structures and processes that facilitate obstetric and neonatal collaboration; and development of perinatal data to evaluate effects of perinatal practices on maternal, fetal, and neonatal outcomes.

RESULTS

As a result of the project, participating centers developed local guidelines for pregnancies between 22 and 26 weeks, created a cross-center maternal database that currently is being linked to neonatal outcomes, and completed a pilot study on video simulation of neonatal-perinatal team communication.

CONCLUSIONS

Increased understanding of practice variation in the management of care for infants who are at the margins of viability, locally developed guidelines, and a focus on improved team communication during delivery can be accomplished with a multicenter collaborative approach.

Medical staff guidelines for periviability pregnancy counseling and medical treatment of extremely premature infants

OBJECTIVES

The goal of this report is to describe the collaborative formation of rational, practical, medical staff guidelines for the counseling and subsequent care of extremely early-gestation pregnancies and premature infants between 22 and 26 weeks. The purposes of the guidelines were to improve knowledge regarding neonatal outcomes, to provide consistency in periviability counseling, and to promote informed, supportive, responsible choices.

METHODS

To formulate the guidelines, a 5-step process was conducted; it began with a series of multidisciplinary meetings among maternal-fetal medicine specialists (MFMs), obstetricians, neonatologists, neonatal nurse practitioners, and nurses from both the labor and delivery unit and the NICU at Providence St Vincent Medical Center (Portland, OR). First, our discussions reviewed mortality rates, morbidity rates, and long-term neurodevelopmental outcomes for extremely premature infants. Second, we explored the variations in counseling that pregnant women received, based on providers' individual beliefs and disparate knowledge of neonatal outcomes. Third, we asked participants to complete a survey that focused on the theoretical impending delivery of a premature infant, presenting at each week between 22 and 26 weeks of gestation. Participants indicated their recommendations for NICU care at each gestational age by using a numeric scale. Fourth, the survey results were tabulated and used as a basis for the formation of guidelines related to the recommended obstetric and neonatal care at each week of gestation. MFMs and neonatologists were urged to use these specific guidelines as a framework for counseling pregnant women between 22 and 26 weeks of gestation. Fifth, we surveyed women approximately 3 days after they were counseled by their MFM and neonatologist, to assess comprehension, utility, consistency, and comfort with the periviability counseling.

RESULTS

Twenty pregnant women with the possibility of delivery between 22 and 26 weeks of gestation (mean: 24 weeks) received periviability counseling with our consensus medical staff guidelines. The respondents rated the counseling process as highly understandable (80%), useful (95%), consistent (89%), and performed in a comfortable manner (100%). All (100%) of the pregnant women thought they were given enough information to make critical decisions related to the potential level of care of their infant.

CONCLUSIONS

Informative, supportive, clear, medical staff guidelines developed to assist in the counseling of women delivering extremely premature infants have been designed and implemented successfully at our hospital. These guidelines form the basis of periviability counseling, which is appreciated by our at-risk pregnant patients. We recommend that all hospitals that provide high-risk obstetric and neonatal intensive care develop similar consensus guidelines based on published outcomes and local provider experience.

Actuarial survival of a large Canadian cohort of preterm infants

Background

The increased survival of preterm and very low birth weight infants in recent years has been well documented but continued surveillance is required in order to monitor the effects of new therapeutic interventions. Gestation and birth weight specific survival rates most accurately reflect the outcome of perinatal care. Our aims were to determine survival to discharge for a large Canadian cohort of preterm infants admitted to the neonatal intensive care unit (NICU), and to examine the effect of gender on survival and the effect of increasing postnatal age on predicted survival.

Methods

Outcomes for all 19,507 infants admitted to 17 NICUs throughout Canada between January 1996 and October 1997 were collected prospectively. Babies with congenital anomalies were excluded from the study population. Gestation and birth weight specific survival for all infants with birth weight <1,500 g (n = 3419) or gestation ≤30 weeks (n = 3119) were recorded. Actuarial survival curves were constructed to show changes in expected survival with increasing postnatal age.

Results

Survival to discharge at 24 weeks gestation was 54%, compared to 82% at 26 weeks and 95% at 30 weeks. In infants with birth weights 600–699, survival to discharge was 62%, compared to 79% at 700–799 g and 96% at 1,000–1,099 g. In infants born at 24 weeks gestational age, survival was higher in females but there were no significant gender differences above 24 weeks gestation. Actuarial analysis showed that risk of death was highest in the first 5 days. For infants born at 24 weeks gestation, estimated survival probability to 48 hours, 7 days and 4 weeks were 88 (CI 84,92)%, 70 (CI 64, 76)% and 60 (CI 53,66)% respectively. For smaller birth weights, female survival probabilities were higher than males for the first 40 days of life.

Conclusion

Actuarial analysis provides useful information when counseling parents and highlights the importance of frequently revising the prediction for long term survival particularly after the first few days of life.

Long-term outcomes in multiple gestations

Children born from a multiple gestation are at increased risk for cerebral palsy, learning disability, and language and neurobehavioral deficits. With the increased incidence of multiple pregnancies and use of assisted reproductive technology (ART), these issues are more commonly affecting parents. Long-term outcomes are a critical part of preconceptual and early pregnancy counseling for parents faced with a multiple gestation or considering ART, and the provider should be well versed on issues surrounding zygosity, gestational age, higher-order multiples, and the effects of options such as multifetal pregnancy reduction.

Prenatal risk factors for severe retinopathy of prematurity among very preterm infants of the Australian and New Zealand Neonatal Network

OBJECTIVE

To identify prenatal and perinatal risk factors for clinically severe (stage 3 or 4) retinopathy of prematurity (ROP).

METHODS

Data were collected prospectively as part of the ongoing Australian and New Zealand Neonatal Network audit of high-risk infants (birth weight of <1500 g or gestational age [GA] of <32 weeks) admitted to a level III neonatal unit in Australia or New Zealand. Prenatal and perinatal factors to 1 minute of age were examined for the subset of infants with GA of <29 weeks who survived to 36 weeks' postmenstrual age and were examined for ROP (n = 2105). The factors significantly associated with stage 3 or 4 ROP were entered into a multivariate logistic regression model.

RESULTS

Two-hundred three infants (9.6%) had stage 3 or more ROP. Prematurity was the dominant risk factor, with infants with GA of <25 weeks having 20 times greater odds of severe ROP than infants with GA of 28 weeks. Birth weight for GA also had a "dose-response" effect; the more growth-restricted infants had greater risk, with infants below the 3rd percentile of weight for GA having 4 times greater odds of severe ROP than those between the 25th and 75th percentiles. Male gender was also a significant risk factor (odds ratio: 1.73; 95% confidence interval: 1.25-2.40).

CONCLUSIONS

These data, for a large, essentially population-based cohort, suggest that factors related to the degree of immaturity, intrauterine growth restriction, and male gender contribute to severe ROP.

Ensuring accurate knowledge of prematurity outcomes for prenatal counseling

OBJECTIVES

To determine the accuracy of knowledge of different health care providers regarding survival and long-term morbidity rates for very premature infants and to examine whether a focused educational intervention improves the accuracy of this knowledge and influences health care decisions.

METHODS

Using hypothetical case scenarios with infants at < or =28 weeks of gestation, we surveyed a variety of caregivers involved in perinatal communication and decision-making processes at a tertiary center that provides intensive care for neonates. We asked physicians from the pediatrics and obstetrics services and nurses and nurse practitioners from the NICU and obstetrics ward for their best estimates of survival and major long-term disability rates and for their opinions regarding the appropriateness of resuscitation and life support at each week of gestation of <29 weeks. After the survey, we educated all providers about current data on survival and long-term disability rates for preterm infants and gave them pocket-sized cards summarizing this information for reference during prenatal counseling. One month after the educational intervention and complete dissemination of the cards, a questionnaire with questions identical to those in the first survey was mailed to the same individuals.

RESULTS

Fifty-one health care providers were involved in the baseline survey. The response rates for the postintervention survey were 100% for physicians (20 of 20 subjects) and nurses (20 of 20 subjects) and 91% (10 of 11 subjects) for the nurse practitioners. In the baseline survey, statistically significant underestimates of survival rates were seen for physicians and nurses at 23 to 28 weeks of gestation and for nurse practitioners at 23 to 27 weeks of gestation. Statistically significant overestimates of disability rates were seen for physicians and nurse practitioners at < or =26 weeks of gestation and for nurses at < or =28 weeks of gestation. After the intervention, respondents demonstrated significant improvements in the accuracy of survival and disability estimates at many, but not all, gestational ages. Although underestimation of survival rates and overestimation of disability rates decreased after the intervention, it persisted to some degree. After the intervention, a larger proportion of physicians (53% vs 21%) and a smaller proportion of nurses (10% vs 37%) were likely to recommend resuscitation for infants born at 23 weeks of gestation.

CONCLUSIONS

Physicians, nurses, and nurse practitioners underestimated survival rates and overestimated long-term disability rates for very premature infants. After education, their estimates of survival and long-term disability rates for these infants improved significantly. More accurate estimates of survival and disability rates affected physicians' and nurses' theoretical decision-making regarding the appropriateness of resuscitation at 23 weeks of gestation.

Neonatal morbidity of very low birth weight infants from multiple pregnancies

The epidemic of multiple births has translated into a marked rise in very low birth weight infants, who are at risk for major neonatal morbidity and mortality. Gestational age-adjusted comparisons of outcome between singletons and multiples have shown conflicting results. Comparisons that corrected for relevant confounding variables show that twins and singletons have similar risks for early morbidity and mortality. Very low birth weight triplets may have increased risk for neonatal mortality, however. Second-born very low birth weight twins seem to be at risk for increased respiratory morbidity, even in the era of routine antenatal corticosteroids and postnatal surfactant therapy.

The EPIBEL study: outcomes to discharge from hospital for extremely preterm infants in Belgium

OBJECTIVE

To determine mortality and morbidity at discharge from the hospital of a large population-based cohort of infants who were born at <or=26 weeks' gestation.

METHODS

Perinatal data were collected on extremely preterm infants who were alive at the onset of labor and born between January 1, 1999, and December 31, 2000, in all 19 Belgian perinatal centers.

RESULTS

A total of 525 infants were recorded. Life-supporting care was provided to 322 liveborn infants, 303 of whom were admitted for intensive care. The overall survival rate of liveborn infants was 54%. Of the infants who were alive at the age of 7 days, 82% survived to discharge. Vaginal delivery, shorter gestation, air leak, longer ventilator dependence, and higher initial oxygen need all were independently associated with death; gender, plurality, and surfactant therapy were not. Among the 175 survivors, 63% had 1 or more of the 3 major adverse outcome variables at the time of discharge (serious neuromorbidity, chronic lung disease at 36 weeks' postmenstrual age, or treated retinopathy of prematurity). The chance of survival free from serious neonatal morbidity at the time of hospital discharge was <15% (21 of 158) for the admitted infants with a gestation <26 weeks.

CONCLUSIONS

If for the time being prolongation of pregnancy is unsuccessful, then outcome perspectives should be discussed and treatment options including nonintervention explicitly be made available to parents of infants of <26 weeks' gestation within the limits of medical feasibility and appropriateness.

Fetal infants: the fate of 4172 infants with birth weights of 401 to 500 grams--the Vermont Oxford Network experience (1996-2000)

OBJECTIVE

Improvement in the survival of extremely low birth weight infants requires that we evaluate the limits of our care and assess the impact of treatment on a population of infants who previously rarely survived.

METHODS

A review was conducted of demographic and clinical data of infants who had birth weight 401 to 500 g and were entered in the Vermont Oxford Network Database between 1996 and 2000.

RESULTS

A total of 4172 infants who weighed 401-500 g (mean gestational age: 23.3 +/- 2.1 weeks) were born at 346 participating centers. Overall, 17% survived until discharge. A total of 2186 (52%) died in the delivery room (DR), and 1986 (48%) were admitted to a neonatal intensive care unit (NICU). Compared with infants who died in the DR, infants who survived the DR and were admitted to the NICU were more likely to be female (58% vs 49%), to be small for gestational age (56% vs 11%), to have received prenatal steroids (61% vs 12%), and to have been delivered by cesarean section (55% vs 5%). Thirty-six percent of NICU admissions survived to discharge. Mean gestational age of the 690 NICU survivors was 25.3 +/- 2.0 weeks. These survivors experienced significant morbidity in the NICU.

CONCLUSIONS

An appreciable number of these marginally viable fetal infants survive. They experienced a high rate of serious morbidities while in the NICU. There is very little information about long-term outcomes, as the medical and developmental status of few of these infants has been followed carefully. Parents should be made aware of the high incidence of serious problems, and concerted efforts should be made to follow the status of these infants.

Survival of very preterm infants: Epipage, a population based cohort study

OBJECTIVE

To evaluate the outcome for all infants born before 33 weeks gestation until discharge from hospital.

DESIGN

A prospective observational population based study.

SETTING

Nine regions of France in 1997.

PATIENTS

All births or late terminations of pregnancy for fetal or maternal reasons between 22 and 32 weeks gestation.

MAIN OUTCOME MEASURE

Life status: stillbirth, live birth, death in delivery room, death in intensive care, decision to limit intensive care, survival to discharge.

RESULTS

A total of 722 late terminations, 772 stillbirths, and 2901 live births were recorded. The incidence of very preterm births was 1.3 per 100 live births and stillbirths. The survival rate for births between 22 and 32 weeks was 67% of all births (including stillbirths), 85% of live births, and 89% of infants admitted to neonatal intensive care units. Survival increased with gestational age: 31% of all infants born alive at 24 weeks survived to discharge, 78% at 28 weeks, and 97% at 32 weeks. Survival among live births was lower for small for gestational age infants, multiple births, and boys. Overall, 50% of deaths after birth followed decisions to withhold or withdraw intensive care: 66% of deaths in the delivery room, decreasing with increasing gestational age; 44% of deaths in the neonatal intensive care unit, with little variation with gestational age.

CONCLUSION

Among very preterm babies, chances of survival varies greatly according to the length of gestation. At all gestational ages, a large proportion of deaths are associated with a decision to limit intensive care.

Ten-year trends in neonatal assisted ventilation of very low-birthweight infants

OBJECTIVES

To examine ventilatory support for the VLBW infant over the past 10 years in a single academic NICU and determine factors that predicted length of ventilation, death, and CLD.

STUDY DESIGN

A retrospective cohort review of neonatal blood gases, ventilatory support, and clinical outcomes.

RESULTS

From 1992 through October 2002, 6254 infants were admitted, of whom 2388 required intubation for mechanical ventilation. Of these, 837 were <1500 g at birth (VLBW) infants and 453 were less than 1000 g (ELBW). Total duration of ventilation decreased in all weight groups. Noninvasive ventilatory support increased from 20 to 55% of total ventilation from 1997 to 2002. During this same period, CLD decreased from 20 to 11% in ventilated VLBW infants. Duration of total ventilation was best predicted by birth weight, with each 100 g increment decreasing the duration of ventilation by 71 hours. Lower birth weight, male sex, and a longer total duration of ventilatory support were significant factors in predicting the occurrence of CLD. Death alone was best predicted by lower birth weight and maximum oxygen index (OI). Transported infants had significantly increased maximal OIs, durations of ventilation, and incidence of death. A total of 48% of infants with a single OI >10 either died or survived with CLD.

CONCLUSIONS

Birth weight is the best predictor of duration of ventilation, and CLD is best predicted by birth weight, duration of ventilation and male sex. The increasing use of noninvasive strategies has not been associated with an observable increase in respiratory morbidity. VLBW infants with a single OI>10 may benefit from inclusion in future interventional rescue studies.

Mortality and neurologic, mental, and psychomotor development at 2 years in infants born less than 27 weeks' gestation: the Leiden follow-up project on prematurity

OBJECTIVE

To determine the outcome of infants with a gestational age (GA) <27 weeks, born in the mid-1990s.

DESIGN

Regional, prospective study; part of the Leiden Follow-Up Project on Prematurity.

SETTING

Three health regions in The Netherlands.

PATIENTS

A total of 266 live born infants (1996/1997) with GA <32 weeks; 46 infants were <27 weeks.

MAIN OUTCOME MEASURES

Neurologic examination (according to Hempel) and assessment of mental and psychomotor development using the Bayley Scales of Infant Development I, at the corrected age of 2 years.

RESULTS

Mortality was 35% (16 of 46) <27 weeks, compared with 6% (14 of 220) in infants with GA 27 to 32 weeks; withdrawal of treatment in 60% and 43%, respectively. Below 27 weeks mortality was higher after extra-uterine transport and pregnancy induction. Neonatal morbidity was higher in infants <27 weeks compared with infants 27 to 32 weeks. Below 27 weeks postnatal use of dexamethasone and being hospitalized at term were associated with abnormal neurologic outcome; there was a higher incidence in (mild) mental developmental delay compared with the older infants. Adverse outcome (dead or abnormal neurologic, psychomotor, or mental development) in infants 23 to 24, 25, 26, and 27 to 32 weeks GA was, respectively, 92% (11 of 12), 64% (7 of 11), 35% (8 of 23), and 18% (40 of 220).

CONCLUSIONS

Mortality and neonatal morbidity were higher in infants with GA <27 weeks compared with infants born between 27 and 32 weeks. The high adverse outcome of infants <25 weeks suggests that one should carefully weigh whether or not to aggressively resuscitate and treat these extremely premature infants.

Measuring functional outcomes after prematurity: developmental impact of very low birth weight and extremely low birth weight status on childhood disability

Our purpose was to describe functional outcomes in essential activities in preschool, school-age, and adolescent children who were born very (<32 weeks gestation) and extremely (<28 weeks gestation) prematurely. Very low birth weight (VLBW; 1000-1499 g), or extremely low birth weight (ELBW;<1000 g) populations are the focus of our analysis. We describe models of disablement and enablement for specifying the complexity of childhood outcomes using a framework of pathophysiology, impairment, functional limitation and functional strengths, disability in social roles and social participation, societal limitations and environmental facilitators. Representative early childhood, preschool, school-age, and adolescent studies were examined in terms of describing children's functional strengths and challenges after VLBW and ELBW survival. In early childhood, disability was assessed by diagnosing neurosensory impairments and delays on developmental testing. Instruments for measuring functional status in essential activities of self-care, mobility, communication and learning are described. Rates of neurosensory disability in the first three years among recent ELBW survivors ranged from 9-26% for cerebral palsy, 1-15% for blindness, 0-9% for deafness, and 6-42% for evolving cognitive disability (MDI <70). Rates of preschool functional limitation were 5-27% motor, 5-30% self-care, and 5-22% communicative. Rates of school-age functional educational disabilities exceeded 50%. Rates of adolescent activity limitation were 13-32% and vocational limitations were 27-71%. By examining the functional strengths and challenges of children with major neurodevelopmental impairments after very or extremely preterm birth, we can examine causal pathways that lessen the risk of severe functional disability. Among children with mild to moderate disability, we can enhance functional outcomes, optimize community participation, and provide quality family supports. In order to assess the changing outcomes of this vulnerable population of survivors, combinations of clinical and survey based methodologies are required.

Posthemorrhagic ventricular dilation in the neonate: development and characterization of a rat model

Intraventricular hemorrhage is a common complication of prematurity. Posthemorrhagic ventricular dilation (PHVD) has a high rate of disability and no safe and effective treatment. Its pathogenesis is poorly understood, largely because of the lack of a satisfactory animal model. We have developed a model of neonatal PHVD in the rat. Seven-day-old (P7) Wistar rat pups were given 80-microl injections of citrated rat blood or artificial cerebrospinal fluid (CSF) into alternate lateral ventricles on P7 and P8. Intracranial pressure was monitored and increased briefly by over 8-fold. Some rats received further 10-microl intraventricular injections of India ink on P21. Animals were weighed daily and simple neurologic tests performed. On P21 (or P22 if India ink had been injected), the rats were perfusion-fixed and blocks processed for paraffin histology. Sixty-five percent of pups injected with blood and 50% injected with artificial CSF developed dilated lateral ventricles, with patchy loss of ependyma, marked astrocytic gliosis, and rarefaction of periventricular white matter. India ink injection revealed slow transit of CSF from the dilated lateral ventricles but eventual passage into the subarachnoid space. Pups that had received intraventricular injections but did not develop ventricular dilation nonetheless had lighter brains than littermate controls (p < 0.001). Body weights were not significantly different from controls. Hydrocephalic animals had reduced motor performance as assessed by a grip traction test (p = 0.0002). This model is well suited to studying the pathogenesis of PHVD.

A population-based study of prognostic factors related to major disability in very preterm survivors

OBJECTIVE

This study was conducted to determine the rates and risk factors for major disability in very preterm survivors born to residents of Nova Scotia, Canada between 1992 and 1996.

STUDY DESIGN

A cohort study was conducted of all 355 infants born to Nova Scotia residents between 22 and 30 weeks gestation. Major disability was defined by mental development index <70, moderate or severe cerebral palsy, bilateral visual acuity <20/200, or deafness requiring bilateral hearing aids. Logistic regression analysis was used to determine which factors were significantly associated with major disability.

RESULTS

Of the infants who survived 1 year and had follow-up data, 21 (8.3%) developed a major disability. Cystic periventricular leukomalacia (PVL), hypernatremia and surgery requiring general anesthesia were independently associated with the development of a major disability.

CONCLUSION

This study confirms the association between cystic PVL and major disability observed in other studies. Surgery and hypernatremia will be important to verify in future studies since preventive measures may be possible.

Excess risk of mortality in very low birthweight triplets: a national, population based study

BACKGROUND

Neonatal morbidity and mortality differ between singletons, twins, and triplets.

OBJECTIVE

To evaluate whether plurality is associated with excess risk of neonatal morbidity and poor outcome (death, chronic lung disease, or adverse neurological findings) in very low birthweight (VLBW) infants from a national, population based cohort.

METHODS

The Israel national VLBW infant database has prospectively collected extensive perinatal and neonatal data on all liveborn VLBW infants since 1995. The study sample (n = 5594) consisted of all singletons (n = 3717) and all complete sets of twins (n = 1394) and triplets (n = 483) born during 1995-1999. To account for differences in case-mix, both univariate and multivariate comparisons that included confounding variables such as antenatal steroid treatment and mode of delivery were performed for each of the outcome variables.

RESULTS

There was a small inverse correlation between gestational age (GA) and birth weight (BW) and the number of fetuses (singletons: GA 28.9 (2.6) weeks, BW 1096 (269) g; twins: GA 28.4 (2.3) weeks, BW 1062 (271) g; triplets: GA 28.5 (2.4) weeks, BW 1049 (259) g). Triplets were significantly more likely to have been conceived following fertility treatments, to have received antenatal steroids, and to be delivered by caesarean section. Respiratory distress syndrome was significantly more common in twins and triplets in spite of the increased exposure to antenatal steroids. Multivariate logistic regression analysis using all significant perinatal covariates showed that triplets were at increased risk of death (odds ratio (OR) 1.54, 95% confidence interval (CI) 1.13 to 2.11), but not of adverse neurological outcome (OR 1.29, 95% CI 0.91 to 1.85) or chronic lung disease (OR 0.69, 95% CI 0.46 to 1.02).

CONCLUSION

Despite considerable differences in the incidence of confounding variables between the groups, VLBW triplets are at increased risk of death compared with twins and singletons. In addition, VLBW twins and triplets more often have respiratory distress syndrome but not chronic lung disease or adverse neurological findings.

Perinatal factors affecting survival and survival without disability of extreme premature infants at two years of age

OBJECTIVE

To study obstetrical factors leading to very preterm delivery (between 24 and 28 weeks) and to relate these factors to neonatal outcome and psychomotor development at two years.

STUDY DESIGN

Among 144 infants born alive before 28 weeks of gestation at a single perinatal center between January 1993 and December 1996, we analyzed the influence on neonatal outcome and on psychomotor development at 24 months of a variety of perinatal and neonatal factors. Psychomotor development at two years was classified as: normal, borderline, or moderately or severely handicapped.

RESULTS

During the study period, 114 women delivered live infants before 28 weeks' gestation: 87 singletons, 25 sets of twins, 1 set of triplets and 1 set of quadruplets. All 144 live-born infants received neonatal resuscitation: 50 died before discharge. At two years of age, 6 of the 94 survivors were lost to follow-up. Assessments of the psychomotor development of the other 88 was normal for 52%; borderline for 20%, moderately handicapped for 20%, and severely handicapped for 8%. Multivariate analysis found that two factors affected survival: birthweight and fetal heart rate. (The 42% of infants with a birthweight below 700 g survived versus 83% above 900 g, P<0.001, OR=5.2, 95% CI (confidence interval) [2.4-11.2].)

CONCLUSION

These data show the influence of perinatal factors on the outcome of very preterm infants; birthweight and fetal heart rate are strongly correlated with survival. Gestational age is a good predictor of psychomotor development at two years.

Fetal heart rate and survival of the very premature newborn

OBJECTIVE

Our purpose was to study the likelihood of survival of infants who are born before 28 weeks of gestation and to examine the influence of fetal heart rate findings on neonatal death.

STUDY DESIGN

In this retrospective study, we analyzed the mortality rate of infants at 2 months of age as a function of various obstetric and prenatal indicators.

RESULTS

At 2 months, 207 of 325 children were still alive. The survival rate was also a function of gestational age, birth weight, the administration of corticosteroids, multiple pregnancies, and fetal heart rate. Fetal heart rate had the greatest effect on the mortality rate. Children with a reactive rate were 4 times more likely to survive than children with a flat tracing (P =.003; odd ratio, 4; 95% CI, 12.1; 39.8).

CONCLUSION

The results in our study lead us to think that recording the fetal heart rate before and during labor may be useful in the prediction of perinatal death and may help obstetric decision-making.

Neonatal survival rates in 860 singleton live births at 24 and 25 weeks gestational age. A Canadian multicentre study

OBJECTIVE

To determine the current survival rate of singleton living newborns born at gestational age of 24 and 25 weeks, using obstetric factors available to the physician before birth.

DESIGN

Retrospective study of all live births in 13 of 17 Canadian tertiary centres. Population All singleton live births without congenital abnormalities.

METHODS

During the years 1991-1996, data were abstracted from clinical databases and charts of 860 live births, in 13 of the 17 tertiary centres in Canada, all with major neonatal intensive care units. Newborn survival was defined as alive at discharge from neonatal intensive care unit. Abstracted elements included gestational age, maternal antenatal corticosteroid treatment, birthweight, gender, fetal presentation and mode of delivery.

RESULTS

Average survival rates increased from 56.1% at 24 weeks (n = 406) to 68.0% at 25 weeks (n = 454). Survival rates ranged from 53.1% at day 168 to 81.6% at day 181 (r = 0.802, P < 0.05). Steroid administration improved the survival rates at 24 and 25 weeks compared with that of unexposed fetuses, respectively (58.9% vs 41.8%; OR 1.70; 95% CI 1.03-2.08 and 74.2% vs 56.8%; OR 2.19; 95% CI 1.41-3.38). Caesarean delivery for breech presentation improved survival compared with vaginal delivery, both at 24 and 25 weeks (56.1% vs 36.0%; OR 2.19; 95% CI 1.10-4.34, and 68.7% vs 55.2% OR 1.78; 95% CI 0.093-3.43). Female neonates displayed better survival rates (59.6% vs 52.1% OR 1.36; 95% CI 0.92-2.01, and 72.6% vs 63.1% OR 1.51; 95% CI 1.02-2.25) at 24 and 25 weeks, respectively. Explanatory regression model confirmed these factors as prognostic variables associated with survival.

CONCLUSIONS

This extensive collaborative study confirms that several prognostic factors, known before birth, including gestational age in days, steroid treatment, mode of presentation and fetal sex may help obstetricians, neonatologists and parents in their decision-making process at 24 and 25 weeks of pregnancy.

Neonatal and long-term outcomes of very low birth weight infants from single and multiple pregnancies

The revolution in artificial reproductive technologies has resulted in a dramatic rise in the incidence of multiple pregnancies. Many of these infants are born prematurely, often extremely so. Consequently, perinatal morbidity and mortality are highly correlated with plurality. The primary mechanism for this increased risk is prematurity. Studies of the relationship between plurality and outcome are frequently hampered by major differences in case mix between singletons, twins and high multiples. For example, high multiples tend to receive earlier prenatal care, receive more antenatal steroids, are more often delivered by Caesarean section and more often suffer from respiratory distress syndrome. However, recent studies that appropriately account for relevant confounding variables have suggested that very low birth weight infants from high multiple pregnancies are at excess risk for mortality when compared with twins and singletons. This article reviews the current available evidence.

Risk factors for early death among extremely low-birth-weight infants

OBJECTIVE

The purposes of this study were to compare the clinical characteristics of extremely low birth-weight infants (501-1000 g birth weight) who die early (<12 hours of age) with those of infants who die >12 hours after birth and infants who survive to neonatal intensive care unit discharge and to develop a model of risk for early death.

STUDY DESIGN

Perinatal data were prospectively collected on 5986 infants in the 12 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network from March 1993 through December 1997. Maternal and neonatal characteristics of infants who died early were compared with infants who survived and infants who died beyond 12 hours of age. A model for risk for early death was developed by logistic regression analysis, with results expressed as odds ratio with 95% CI.

RESULTS

Mothers of infants who died early were more likely to be delivered in an inborn setting and experience labor and were less likely to have hypertension or preeclampsia, to receive antenatal corticosteroids, or to be delivered by cesarean birth than mothers of infants who died >12 hours after birth or infants who survived. Infants who died early were more likely to have lower Apgar scores and lower gestational age/birth weight and were less likely to be intubated at birth and to receive mechanical ventilation and surfactant therapy than infants who died >12 hours after birth or infants who survived. Greater risk for early death versus survival to neonatal intensive care unit discharge was associated with the lack of surfactant administration (odds ratio, 8.6; 95% CI, 6.3-11.9), lack of delivery room intubation (odds ratio, 5.3; 95% CI, 3.5-8.1), lack of antenatal corticosteroid use (odds ratio, 2.3; 95% CI, 1.6-3.2), lower 1-minute Apgar score (odds ratio, 2.0; 95% CI, 1.8-2.2), male sex (odds ratio, 1.7; 95% CI, 1.3-2.3), multiple gestation (odds ratio, 1.7; 95% CI, 1.2-2.5), no tocolytics (odds ratio, 1.7; 95% CI, 1.2-2.3), lower gestational age per week (odds ratio, 1.4; 95% CI, 1.3-1.6), and lower birth weight per 50 g (95% CI, 1.2-1.4).

CONCLUSION

Early death (<12 hours of age) among extremely low-birth-weight infants may reflect an assessment of non-viability by obstetricians and neonatologists.

Birth weight by gestational age for Albertan liveborn infants, 1985 through 1998

OBJECTIVES

(1) To provide percentile tables and graphs of birth weight by gestational age and by gender, for singleton and twin liveborn neonates. (2) To determine changes in birth weight relative to gestational age over the study period.

METHODS

Data on 556,775 singletons and 12,125 twins, born alive in Alberta from 1985 through 1998, were obtained from Alberta Registries - Vital Statistics. Mean birth weights for individual and grouped years were compared by independent two-tailed t-tests. Linear trends in birth weight over the 14-year period were obtained using one-way analyses of variance.

RESULTS

Four tables and corresponding graphs showing birth weight for gestational age by gender for 21 through 44 completed weeks gestation provide data for the 1st to 99th percentile. Changes in birth weight for the combined gestational ages included an increase for singletons (male, F 17.6, p < 0.001; female, F 53.3, p < 0.001), and a decrease for female twins (F 5.8, 0.004). The increase for singletons was seen at 38 through 42 weeks gestation for both genders. No change occurred under 38 weeks except in singleton females of 33 to 35 weeks with a decrease in birth weight observed from 2636 +/- 539 g, 1985 to 2576 +/- 479 g, 1998; t 2.5, p = 0.002.

CONCLUSIONS

The graphs and tables established in this study represent a specific geographic area and population. They may be relevant as a reference for other geographic regions and populations. The clinical significance of the observed increased birth weight among term, but not preterm newborns, requires critical evaluation.

Developmental coordination disorder in extremely low birth weight children at nine years

Developmental coordination disorder (DCD) is defined as an impairment in the development of motor coordination that interferes with academic achievement or activities of daily living (DSM-IV). DCD has been reported to affect 5% to 9% of children in the normal population. This study describes the prevalence of DCD in a cohort of extremely low birth weight children (ELBW, < or = l800 g) at 8.9 years of age, from which were excluded children with major impairments. Seventy-three children were included in the study group, along with 18 term-born, socially matched controls. Of the 73 ELBW children, 37 (51%) were classified as having DCD. ELBW children with DCD also had significantly lower Performance IQ (PIQ) scores and were more likely (43%) to have a learning difficulty in arithmetic than ELBW children who did not have DCD. This study found that DCD is a common problem in school-aged ELBW children.

Comparison of the prediction of extremely low birth weight neonatal mortality by regression analysis and by neural networks

AIMS

To compare the prediction of mortality in individual extremely low birth weight (ELBW) neonates by regression analysis and by artificial neural networks.

STUDY DESIGN

A database of 23 variables on 810 ELBW neonates admitted to a tertiary care center was divided into training, validation, and test sets. Logistic regression and neural network models were developed on the training set, validated, and outcome (mortality) predicted on the test set. Stepwise regression identified significant variables in the full set. Regression models and neural networks were then tested using data sets with only the identified significant variables, and then with variables excluded one at a time.

RESULTS

The area under the curve (AUC) of receiver operating characteristic (ROC) curves for neural networks and regression was similar (AUC 0.87+/-0.03; p=0.31). Birthweight or gestational age and the 5-min Apgar score contributed most to AUC.

CONCLUSIONS

Both neural networks and regression analysis predicted mortality with reasonable accuracy. For both models, analyzing selected variables was superior to full data set analysis. We speculate neural networks may not be superior to regression when no clear non-linear relationships exist.

The outcome of extreme prematurity

Significant advances in perinatology and neonatology in the last decade have resulted in increased survival of extremely premature infants. Survival rates for infants born in tertiary perinatal and neonatal care centers in the United States in the 1990s increase with each week of gestational age from 22 through 26 weeks. Reported survival rates at 22 weeks range from 0% to 21% in the few reporting studies. Reported survival rates at 23 and 24 weeks range from 5% to 46% and from 40% to 59%, respectively. These may not be the maximum survival rates possible because at these gestational ages information is either insufficient to determine that obstetric and neonatal intensive care strategies to maximize neonatal survival were used or it is specified that such strategies were not used. Reported survival rates at 25 and 26 weeks range from 60% to 82% and from from 75% to 93%, respectively. The literature regarding the prevalence of major neurodevelopmental disabilities among extremely premature survivors in the last 25 years is heteogeneous, and the reported prevalances of major disability vary much more than do survival rates. However, the majority of extremely premature infants who survive will be free of major disability. Overall, approximately one fifth to one quarter of survivors have at least one major disability-impaired mental development, cerebral palsy, blindness, or deafness. Impaired mental development is the most prevalent disability (17%-21% [95% CI] of survivors affected), followed by cerebral palsy (12%-15% of survivors affected). Blindness and deafness are less common (5% to 8% and 3% to 5% of survivors affected, respectively). Approximately one half of disabled survivors have more than one major disability. Based on studies of infants less than 750 to 1,000 grams birth weight, it can be anticipated that approximately another half of all extremely premature survivors will have one or more subtle neurodevelopmental disabilities in the school and teenage years. There is little evidence to suggest that long-term neurodevelopmental outcome has changed from the late 1970s to the early 1990s or with increasing survival. Survival of individual extremely premature infants cannot be accurately predicted in the immediate perinatal period. Major disability cannot be accurately predicted for individual survivors during the course in the newborn intensive care unit.