Late preterm infants have worse 24-month neurodevelopmental outcomes than term infants

Regional brain volumes, microstructure and neurodevelopment in moderate-late preterm children

OBJECTIVE

To explore whether regional brain volume and white matter microstructure at term-equivalent age (TEA) are associated with development at 2 years of age in children born moderate-late preterm (MLPT).

STUDY DESIGN

A cohort of MLPT infants had brain MRI at approximately TEA (38-44 weeks' postmenstrual age) and had a developmental assessment (Bayley Scales of Infant and Toddler Development and Infant Toddler Social Emotional Assessment) at 2 years' corrected age. Relationships between cortical grey matter and white matter volumes and 2-year developmental outcomes were explored using voxel-based morphometry. Relationships between diffusion tensor measures of white matter microstructure (fractional anisotropy (FA) and axial (AD), radial (RD) and mean (MD) diffusivities) and 2-year developmental outcomes were explored using tract-based spatial statistics.

RESULTS

189 MLPT children had data from at least one MRI modality (volumetric or diffusion) and data for at least one developmental domain. Larger cortical grey and white matter volumes in many brain regions, and higher FA and lower AD, RD and MD in several major white matter regions, were associated with better cognitive and language scores. There was little evidence that cortical grey matter and white matter volumes and white matter microstructure were associated with motor and behavioural outcomes.

CONCLUSIONS

Regional cortical grey matter and white matter volumes and white matter microstructure are associated with cognitive and language development at 2 years of age in MLPT children. Thus, early alterations to brain volumes and microstructure may contribute to some of the developmental deficits described in MLPT children.

Altered DNA methylation in human placenta after (suspected) preterm labor

Aim: The aim of this study was to determine if alterations in DNA methylation in the human placenta would support suspected preterm labor as a pathologic insult associated with diminished placental health. Methods: We evaluated placental DNA methylation at seven loci differentially methylated in placental pathologies using targeted bisulfite sequencing, in placentas associated with preterm labor (term birth after suspected preterm labor [n = 15] and preterm birth [n = 15]), and controls (n = 15). Results: DNA methylation levels at the NCAM1 and PLAGL1 loci in placentas associated with preterm labor did differ significantly (p < 0.05) from controls. Discussion: Specific alterations in methylation patterns indicative of an unfavourable placental environment are associated with preterm labor per se and not restricted to preterm birth.

(Rad 8)Caffeine prophylaxis to improve intermittent hypoxaemia in infants born late preterm: a randomised controlled dosage trial (Latte Dosage Trial)

INTRODUCTION

Infants born late preterm (34+0 to 36+6 weeks' gestational age) have frequent episodes of intermittent hypoxaemia compared with term infants. Caffeine citrate reduces apnoea and intermittent hypoxaemia and improves long-term neurodevelopmental outcomes in infants born very preterm and may have similar effects in late preterm infants. Clearance of caffeine citrate increases with gestational age and late preterm infants are likely to need a higher dose than very preterm infants. Our aim is to determine the most effective and best-tolerated dose of caffeine citrate to reduce transient intermittent hypoxaemia events in late preterm infants.

METHODS AND ANALYSIS

A phase IIB, double-blind, five-arm, parallel, randomised controlled trial to compare the effect of four doses of oral caffeine citrate versus placebo on the frequency of intermittent hypoxaemia. Late preterm infants will be enrolled within 72 hours of birth and randomised to receive 5, 10, 15 or 20 mg/kg/day caffeine citrate or matching placebo daily until term corrected age. The frequency of intermittent hypoxaemia (events/hour where oxygen saturation concentration is ≥10% below baseline for ≤2 min) will be assessed with overnight oximetry at baseline, 2 weeks after randomisation (primary outcome) and at term corrected age. Growth will be measured at these timepoints, and effects on feeding and sleeping will be assessed by parental report. Data will be analysed using generalised linear mixed models.

ETHICS AND DISSEMINATION

This trial has been approved by the Health and Disability Ethics Committees of New Zealand (reference 18/NTA/129) and the local institutional research review committees. Findings will be disseminated to peer-reviewed journals to clinicians and researchers at local and international conferences and to the public. The findings of the trial will inform the design of a large multicentre trial of prophylactic caffeine in late preterm infants, by indicating the most appropriate dose to use and providing information on feasibility.

TRIAL REGISTRATION NUMBER

ACTRN12618001745235; Pre-results.

Trajectories of Overprotective Parenting and Hyperactivity-Impulsivity and Inattention Among Moderate-Late Preterm Children: A Population-Based Study

Parents of preterm children are more likely to adopt non-optimal parenting behaviors than parents of full-term (FT) children. However, there is a lack of studies on parents of children born moderate to late preterm (MLP; 32-36 gestational weeks). In this study, we aimed to examine: (1) the association between MLP birth status and the trajectory of parental overprotection throughout preschool years, and (2) the role of parental overprotection, MLP birth status, and their interaction in the prediction of the trajectories of hyperactivity-impulsivity and inattention throughout childhood. Data comes from a Canadian representative population-based cohort including 2028 FT, 100 MLP children, and their parents. Overprotective parenting was measured when children were 5, 17, and 29 months old. Hyperactivity-impulsivity and inattention symptoms were measured repeatedly from 4 to 8 years of age. Trajectories of parents' overprotectiveness and children's hyperactivity-impulsivity and inattention were modeled. MLP birth status was associated with an increase in parental overprotectiveness across the preschool period. MLP birth status and parental overprotection were both found to be associated with higher levels of hyperactivity-impulsivity symptoms across childhood. No interaction was found between birth status and parental overprotection. The results suggest that parents of MLP children become more overprotective across time compared to parents of FT children and that children born MLP and/or exposed to higher levels of parental overprotection demonstrated higher levels of hyperactivity-impulsivity symptoms across childhood.

Early Neurological Assessment and Long-Term Neuromotor Outcomes in Late Preterm Infants: A Critical Review

Background and Objectives: Late preterm (LP) infants (born between 34 and 36 weeks of gestational age) are considered at higher risk of neonatal morbidities, mortality, and neurological impairments than full-term born infants (FT). The aim of this study was to provide a critical review of the literature outlining the different aspects of neurological function reported both in the neonatal period and in the follow up of late preterm infants. Materials and Methods: A comprehensive search of the MEDLINE, Embase, PsycINFO, and CINAHL electronic databases was made, using the following search terms: ‘Late preterm infants’, ‘Near term infants’, ‘neurological assessment’, ‘neurological outcome’, ‘neuromotor outcome’, cerebral palsy’, ‘CP’, ‘motor impairment’, including all the studies reporting clinical neurological assessment of LP (including both neonatal period and subsequent ages). Results: A total of 35 articles, comprising 301,495 children, were included as fulfilling the inclusion criteria: ten reported neonatal neurological findings, seven reported data about the first two years after birth, eighteen reported data about incidence of CP and motor disorder during the infancy. Results showed a more immature neurological profile, explored with structured neurological assessments, in LP infants compared with FT infants. The LP population also had a higher risk of developing cerebral palsy, motor delay, and coordination disorder. Conclusion: LP had a higher risk of neurological impairments than FT infants, due to a brain immaturity and an increased vulnerability to injury, as the last weeks of gestational age are crucial for the development of the brain.

Trends in preterm birth in twin pregnancies in Victoria, Australia, 2007-2017

BACKGROUND

Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries, the preterm birth rate in women with a multiple pregnancy is increasing, mostly due to an increase in iatrogenic preterm birth.

AIMS

To investigate trends in preterm birth in twin pregnancies in Victoria, Australia, in relation to maternal and perinatal complications.

MATERIALS AND METHODS

We conducted a retrospective population-based cohort study in all women with a twin pregnancy who delivered at or after 20 weeks of gestation in the state of Victoria, Australia between 2007 and 2017. Annual spontaneous and iatrogenic preterm birth rates were calculated and trends analysed. Incidence of adverse pregnancy outcomes, maternal complications and risk factors for preterm birth were analysed.

RESULTS

We studied 12 757 women with a twin pregnancy. Between 2007 and 2017 the preterm birth rate increased from 641/1231 (52%) to 803/1158 (69%), mainly due to an increase in iatrogenic preterm birth from 342/1231 (28%) to 567/1158 (49%). This was irrespective of the presence of pregnancy complications. Our study showed neither a decrease in perinatal mortality from 28 weeks of gestation nor in preterm average weekly prospective stillbirth risk.

CONCLUSION

Preterm birth rates in twins in Victoria are increasing, mainly driven by an increase in iatrogenic preterm birth. This occurred both in complicated and non-complicated twin pregnancies, and has not been accompanied by reduction in perinatal mortality from 28 weeks.

Late preterm infants - Changing trends and continuing challenges

Late preterm infants, defined as newborns born between 340/7-366/7 weeks of gestational age, constitute a unique group among all premature neonates. Often overlooked because of their size when compared to very premature infants, this population is still vulnerable because of physiological and structural immaturity. Comprising nearly 75% of babies born less than 37 weeks of gestation, late preterm infants are at increased risk for morbidities involving nearly every organ system as well as higher risk of mortality when compared to term neonates. Neurodevelopmental impairment has especially been a concern for these infants. Due to various reasons, the rate of late preterm births continue to rise worldwide. Caring for this high risk population contributes a significant financial burden to health systems. This article reviews recent trends in regarding rate of late preterm births, common morbidities and long term outcomes with special attention to neurodevelopmental outcomes.

Association between phthalate exposure and blood pressure during pregnancy

BACKGROUND

Phthalates are endocrine disrupting chemicals (EDCs) that pose a serious hazard to the human health. Many epidemiological studies revealed a relationship between phthalates exposure and blood pressure in general population, while the relationship in pregnant women remains unknown.

OBJECTIVES

Aimed to elucidate whether phthalate exposure is associated with blood pressure among pregnant women.

METHODS

This study included 636 participants from Wuhan, China. Urine samples were conducted repeatedly in three trimesters, and 9 phthalates were measured in these samples. After each urine was sampled, all the participants completed blood pressure measurements. Associations between repeated measurements of phthalate concentration and blood pressure were evaluated by using generalized estimating equations. Stratified analysis by fetus gender was conducted.

RESULTS

Among the pregnant women with male fetuses, mono-i-butyl phthalate (MiBP) exposed in the 1st trimester was associated with the increased diastolic blood pressure (DBP) measured in the 2nd trimester, while the environmental risk score (ERS) measured in the 1st and 2nd trimester was positively associated with systolic blood pressure (SBP) and DBP in the 2nd trimester. No significant relationships were observed among all the population or pregnant women with female fetuses.

CONCLUSIONS

Exposure to higher levels of MiBP may be related to increased blood pressure during pregnancy in pregnant women with male fetuses.

Improved Referral of Very Low Birthweight Infants to High-Risk Infant Follow-Up in California

OBJECTIVE

To examine changes in referral rates of very low birthweight (birthweight <1500 g) infants to high-risk infant follow-up in California and identify factors associated with referral before and after implementation of a statewide initiative in 2013 to address disparities in referral.

STUDY DESIGN

We included very low birthweight infants born 2010-2016 in the population-based California Perinatal Quality Care Collaborative who survived to discharge home. We used multivariable logistic regression to examine factors associated with referral and derive risk-adjusted referral rates by neonatal intensive care unit (NICU) and region.

RESULTS

Referral rate improved from 83.0% (preinitiative period) to 94.9% (postinitiative period); yielding an OR of 1.48 (95% CI, 1.26-1.72) for referral in the postinitiative period after adjustment for year. Referral rates improved the most (≥15%) for infants born at ≥33 weeks of gestation, with a birthweight of 1251-1500 g, and born in intermediate and lower volume NICUs. After the initiative, Hispanic ethnicity, small for gestational age status, congenital anomalies, and major morbidities were no longer associated with a decreased odds of referral. Lower birthweight, outborn status, and higher NICU volume were no longer associated with increased odds of referral. African American race was associated with lower odds of referral, and higher NICU level with a higher odds of referral during both time periods. Referral improved in many previously poor-performing NICUs and regions.

CONCLUSIONS

High-risk infant follow-up referral of very low birthweight infants improved substantially across all sociodemographic, perinatal, and clinical variables after the statewide initiative, although disparities remain. Our results demonstrate the benefit of a targeted initiative in California, which may be applicable to other quality collaboratives.

Neurodevelopmental outcome of late-preterm infants: Literature review

Late-preterm infants are characterized by a birth term from 34^0/7 to 36^6/7 weeks of gestation. A foetal brain at 34^0/7 weeks of gestation weighs only 65% of the full-term newborn brain, which suggests a particular cerebral vulnerability to injury during this 6-week period. Epidemiological studies reporting the neurological outcomes of late-preterm infants exhibit large methodological heterogeneity that inhibits clarity on this issue. However, contradictory results and odds ratio values near neutral reveal probable moderate neurodevelopmental delay in late-preterm infants. This observation reflects the variable neurological outcomes of this population according to multiple perinatal factors. Therefore, the current challenge is to define efficient screening strategies to determine infants requiring specific follow-up.

Late preterm: a new high risk group in neonatology

Late preterm infants are those infants born between 34 0/7 weeks through 36 6/7 week of gestation. These are physiologically less mature and have limited compensatory responses to the extrauterine environment compared with term infants. Despite their increased risk for morbidity and mortality, late preterm newborns are often cared in the well-baby nurseries of hospital after birth and are discharged from the hospital by 2-3 days of postnatal age. They are usually treated like developmentally mature term infants because many of them are of same birth weight and same size as term infants. There is a steady increase in the late preterm birth rate in last decade because of either maternal, fetal, or placental/uterine causes. There has been shift in the distribution of births from term and post-term toward earlier gestations. Although late preterm infants are the largest subgroup of preterm infants, there has been little research on this group until recently. This is mainly because of labeling them as "near-term". Such infants were being looked upon as "almost mature", and were thought as neonate requiring either no or minimal concern. In the obstetric and pediatric practice, late preterm infants are often considered functionally and developmentally mature and often managed by protocols developed for full-term infants. Thus, limited efforts are taken to prolong pregnancy in cases of preterm labor beyond 34 weeks, moreover after 34 weeks most centers do not administer antenatal prophylactic steroids. These practices are based on previous studies reporting neonatal mortality and morbidity in the late preterm period to be only slightly higher in comparison with term infants and whereas in the current scenario the difference is significant. Late preterm infants have 2-3-fold increased risk of morbidities such as hypothermia, hypoglycemia, delayed lung fluid clearance, respiratory distress, poor feeding, jaundice, sepsis, and readmission rates after initial hospital discharge. This leads to huge impact on the overall health care resources. In this review, we cover various aspects of these late preterm infants like etiology, immediate and long-term outcome.

Maternal and neonatal outcomes associated with infertility

Objective: To investigate perinatal outcomes in a cohort of fertile and infertile nulliparous women. Design: Retrospective cohort study. Setting: Academic medical center. Patients: All nulliparous women delivering singletons ≥24-week gestation at our center from 1 January 2012 to 31 December 2012 were included. Women were classified into two groups - fertile and infertile - based on a chart review at the time of delivery. Outcome measure: Perinatal outcomes of interest included mode of delivery, gestational age at delivery, and birth weight. Results: A total of 3293 mother/infant dyads fulfilled the inclusion criteria. Of these, 277 women (8.4%) were classified as infertile. Infertile women were significantly older than fertile women. In bivariate analyses, infertile women were more likely to undergo cesarean delivery (51.8 versus 36.1%, p < .001) and deliver at an earlier gestational age (38.9 ± 2.3 versus 39.4 ± 1.7 weeks, p < .0001). Infertility was no longer significantly associated with cesarean delivery after adjusting for maternal age. Infertility remained associated with an earlier gestational age at delivery after adjusting for maternal age and maternal race (β coefficient -0.42, 95%CI -0.64, -0.2). There was no difference in infant birth weight. Late preterm deliveries (34-36 completed gestational weeks) accounted for 8.3% of deliveries for infertile women compared to 4.3% for fertile women (p = .032). Conclusions: We conclude that the increased risk of cesarean section associated with infertility is driven by maternal age. Late preterm infants represent a key cohort for further evaluation in the perinatal outcomes of infertile women.

The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment

Background: Sub-Saharan Africa bears a disproportionate burden of preterm birth and other adverse outcomes. A better understanding of the demographic, clinical, and biologic underpinnings of these adverse outcomes is urgently needed to plan interventions and inform new discovery.  Methods: The Zambian Preterm Birth Prevention Study (ZAPPS) is a prospective observational cohort established at the Women and Newborn Hospital (WNH) in Lusaka, Zambia. We recruit pregnant women from district health centers and the WNH and offer ultrasound examination to determine eligibility. Participants receive routine obstetrical care, lab testing, midtrimester cervical length measurement, and serial fetal growth monitoring. At delivery, we assess gestational age, birthweight, vital status, and sex and assign a delivery phenotype. We collect blood, urine, and vaginal swab specimens at scheduled visits and store them in an on-site biorepository. In September 2017, enrollment of the ZAPPS Phase 1-the subject of this report-was completed. Phase 2, which is limited to HIV-uninfected women, reopened in January 2018.  Results: Between August 2015 and September 2017, we screened 1784 women, of whom 1450 (81.2%) met inclusion criteria and were enrolled. The median age at enrollment was 27 years (IQR 23-32) and median gestational age was 16 weeks (IQR 13-18). Among women with a previous pregnancy (n=1042), 19% (n=194) reported a prior miscarriage.  Among parous women (n=992), 41% (n=411) reported a prior preterm birth and 14% (n=126) reported a prior stillbirth. The HIV seroprevalence was 24%. Discussion: We have established a large cohort of pregnant women and newborns at the WNH to characterize the determinants of adverse birth outcomes in Lusaka, Zambia. Our overarching goal is to elucidate biological mechanisms in an effort to identify new strategies for early detection and prevention of adverse outcomes. We hope that findings from this cohort will help guide future studies, clinical care, and policy.

The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment

Background: Sub-Saharan Africa bears a disproportionate burden of preterm birth and other adverse outcomes. A better understanding of the demographic, clinical, and biologic underpinnings of these adverse outcomes is urgently needed to plan interventions and inform new discovery.  Methods: The Zambian Preterm Birth Prevention Study (ZAPPS) is a prospective observational cohort established at the Women and Newborn Hospital (WNH) in Lusaka, Zambia. We recruit pregnant women from district health centers and the WNH and offer ultrasound examination to determine eligibility. Participants receive routine obstetrical care, lab testing, midtrimester cervical length measurement, and serial fetal growth monitoring. At delivery, we assess gestational age, birthweight, vital status, and sex and assign a delivery phenotype. We collect blood, urine, and vaginal swab specimens at scheduled visits and store them in an on-site biorepository. In September 2017, enrollment of the ZAPPS Phase 1-the subject of this report-was completed. Phase 2, which is limited to HIV-uninfected women, reopened in January 2018.  Results: Between August 2015 and September 2017, we screened 1784 women, of whom 1450 (81.2%) met inclusion criteria and were enrolled. The median age at enrollment was 27 years (IQR 23-32) and median gestational age was 16 weeks (IQR 13-18). Among women with a previous pregnancy (n=1042), 19% (n=194) reported a prior miscarriage.  Among parous women (n=992), 41% (n=411) reported a prior preterm birth and 14% (n=126) reported a prior stillbirth. The HIV seroprevalence was 24%. Discussion: We have established a large cohort of pregnant women and newborns at the WNH to characterize the determinants of adverse birth outcomes in Lusaka, Zambia. Our overarching goal is to elucidate biological mechanisms in an effort to identify new strategies for early detection and prevention of adverse outcomes. We hope that findings from this cohort will help guide future studies, clinical care, and policy.

Reduced Neurosteroid Exposure Following Preterm Birth and Its' Contribution to Neurological Impairment: A Novel Avenue for Preventative Therapies

Children born preterm are at an increased risk of developing cognitive problems and neuro-behavioral disorders such as attention deficit hyperactivity disorder (ADHD) and anxiety. Whilst neonates born at all gestational ages, even at term, can experience poor cognitive outcomes due to birth-complications such as birth asphyxia, it is becoming widely known that children born preterm in particular are at significant risk for learning difficulties with an increased utilization of special education resources, when compared to their healthy term-born peers. Additionally, those born preterm have evidence of altered cerebral myelination with reductions in white matter volumes of the frontal cortex, hippocampus and cerebellum evident on magnetic resonance imaging (MRI). This disruption to myelination may underlie some of the pathophysiology of preterm-associated brain injury. Compared to a fetus of the same post-conceptional age, the preterm newborn loses access to in utero factors that support and promote healthy brain development. Furthermore, the preterm ex utero environment is hostile to the developing brain with a myriad of environmental, biochemical and excitotoxic stressors. Allopregnanolone is a key neuroprotective fetal neurosteroid which has promyelinating effects in the developing brain. Preterm birth leads to an abrupt loss of the protective effects of allopregnanolone, with a dramatic drop in allopregnanolone concentrations in the preterm neonatal brain compared to the fetal brain. This occurs in conjunction with reduced myelination of the hippocampus, subcortical white matter and cerebellum; thus, damage to neurons, astrocytes and especially oligodendrocytes of the developing nervous system can occur in the vulnerable developmental window prior to term as a consequence reduced allopregnanolone. In an effort to prevent preterm-associated brain injury a number of therapies have been considered, but to date, other than antenatal magnesium sulfate and corticosteroid therapy, none have become part of standard clinical care for vulnerable infants. Therefore, there remains an urgent need for improved therapeutic options to prevent brain injury in preterm neonates. The actions of the placentally derived neurosteroid allopregnanolone on GABAA receptor signaling has a major role in late gestation neurodevelopment. The early loss of this intrauterine neurotrophic support following preterm birth may be pivotal to development of neurodevelopmental morbidity. Thus, restoring the in utero neurosteroid environment for preterm neonates may represent a new and clinically feasible treatment option for promoting better trajectories of myelination and brain development, and therefore reducing neurodevelopmental disorders in children born preterm.

Improving preterm newborn identification in low-resource settings with machine learning

Background

Globally, preterm birth is the leading cause of neonatal death with estimated prevalence and associated mortality highest in low- and middle-income countries (LMICs). Accurate identification of preterm infants is important at the individual level for appropriate clinical intervention as well as at the population level for informed policy decisions and resource allocation. As early prenatal ultrasound is commonly not available in these settings, gestational age (GA) is often estimated using newborn assessment at birth. This approach assumes last menstrual period to be unreliable and birthweight to be unable to distinguish preterm infants from those that are small for gestational age (SGA). We sought to leverage machine learning algorithms incorporating maternal factors associated with SGA to improve accuracy of preterm newborn identification in LMIC settings.

Methods and findings

This study uses data from an ongoing obstetrical cohort in Lusaka, Zambia that uses early pregnancy ultrasound to estimate GA. Our intent was to identify the best set of parameters commonly available at delivery to correctly categorize births as either preterm (<37 weeks) or term, compared to GA assigned by early ultrasound as the gold standard. Trained midwives conducted a newborn assessment (<72 hours) and collected maternal and neonatal data at the time of delivery or shortly thereafter. New Ballard Score (NBS), last menstrual period (LMP), and birth weight were used individually to assign GA at delivery and categorize each birth as either preterm or term. Additionally, machine learning techniques incorporated combinations of these measures with several maternal and newborn characteristics associated with prematurity and SGA to develop GA at delivery and preterm birth prediction models. The distribution and accuracy of all models were compared to early ultrasound dating. Within our live-born cohort to date (n = 862), the median GA at delivery by early ultrasound was 39.4 weeks (IQR: 38.3–40.3). Among assessed newborns with complete data included in this analysis (n = 468), the median GA by ultrasound was 39.6 weeks (IQR: 38.4–40.3). Using machine learning, we identified a combination of six accessible parameters (LMP, birth weight, twin delivery, maternal height, hypertension in labor, and HIV serostatus) that can be used by machine learning to outperform current GA prediction methods. For preterm birth prediction, this combination of covariates correctly classified >94% of newborns and achieved an area under the curve (AUC) of 0.9796.

Conclusions

We identified a parsimonious list of variables that can be used by machine learning approaches to improve accuracy of preterm newborn identification. Our best-performing model included LMP, birth weight, twin delivery, HIV serostatus, and maternal factors associated with SGA. These variables are all easily collected at delivery, reducing the skill and time required by the frontline health worker to assess GA.

Trial registration

ClinicalTrials.gov Identifier:NCT02738892

Neurodevelopmental outcomes of the late preterm infant

Late preterm infants (born at 34^0/7-36^6/7 weeks gestation) have been found to have increased morbidity and mortality compared to full term infants. Research has also been done to explore longer-term neurodevelopmental outcomes. This review details neurodevelopmental outcomes from birth to adulthood for late preterm infants. Outcome studies indicate that they are at increased risk of developmental disability, school failure, behavior problems, social and medical disabilities, and death. Many questions still remain regarding late preterm infant neurodevelopmental outcomes and future research should be done into this topic. Given the high prevalence of late preterm births, even small differences in abilities, special education, and length of education may have broader consequences.

Nutritional policies for late preterm and early term infants - can we do better?

Late preterm (LP) and early term (ET) infants can be considered the "great dissemblers": they resemble healthy full-term infants in appearance, but their immaturity places them at increased risk of poor short- and long-term outcomes. Nutritional requirements are greater than for full-term babies, but there are few good data on the nutritional requirements for LP and ET babies, leading to substantial variation in practice. Recent data indicate that rapid growth may be beneficial for neurocognitive function but not for body composition and later metabolic health. Breastfeeding the LP or ET infant can be challenging, and mothers of these infants may need additional support to breastfeed successfully. Future research should investigate nutritional requirements of LP and ET infants for optimal growth, addressing both short- and long-term outcomes and the potential trade-off between neurocognitive and metabolic benefits.

Intermittent Hypoxemia in Infants Born Late Preterm: A Prospective Cohort Observational Study

OBJECTIVE

To determine if late preterm infants are at increased risk of intermittent hypoxemic events compared with term infants.

STUDY DESIGN

Prospective, cohort, observational study of late preterm infants (34^0/7-36^6/7 weeks gestational age) and term infants (39^0/7-41^6/7 weeks gestational age). Overnight pulse oximetry recordings were performed on days 2-3 after birth, at term equivalent age, and at 45 weeks postmenstrual age. The primary outcome was the frequency of intermittent hypoxemic events per hour (desaturation ≥10% below the preceding baseline SpO₂) on the oximetry recording on days 2-3 after birth. Data were analyzed by the Student t test and general linear mixed model.

RESULTS

Eighty-five infants were enrolled (late preterm n = 43; term infants n = 42). On days 2-3 after birth, late preterm infants had more intermittent hypoxemic events than term infants (events per hour, mean ± standard error of the mean, 2.5 ± 1.2 vs 1.0 ± 1.2; P < .0001). On mixed model analysis, late preterm infants had a higher frequency of intermittent hypoxemic events at term equivalent age, which decreased to a similar frequency as in term infants by 45 weeks postmenstrual age (events per hour; term equivalent age, late preterm: least squares mean, 3.7 [95% CI, 2.7-5.1] vs term: least squares mean, 1.7 [95% CI, 1.2-2.3]; 45 weeks postmenstrual age, late preterm: least squares mean, 1.5 [95% CI, 1.1-2.1] vs term: least squares mean, 1.9 [95% CI, 1.4-2.6]; P < .0005).

CONCLUSIONS

Late preterm infants are at greater risk of intermittent hypoxemia than term infants soon after birth. We speculate that preventing intermittent hypoxemia in late preterm infants may improve neurodevelopmental outcomes.

Neuroprotection of the preterm brain

Despite notable advances in the care and survival of preterm infants, a significant proportion of preterm neonates will have life-long cognitive, behavioral, and motor deficits, and robustly effective neuroprotective strategies are still missing. These therapies must target the pathophysiologic mechanisms observed in contemporaneous infants and rely on modern epidemiology, imaging, and experimental models and assessment techniques. Two drugs, magnesium sulfate and caffeine, are already in use in several units, and although their targets are apnea of prematurity and myometrial contractility (respectively), they do offer improved odds of positive outcomes. Nevertheless, these drugs have limited efficacy, and NICU-to-NICU administration varies greatly. As such, there is an obvious need for additional specific neurotherapeutic strategies to further enhance the outcome of this very fragile population of neonates. The chapter reviews these issues, highlights bottlenecks that need to be solved for meaningful progress in the field, and proposes future innovative avenues for intervention, including delayed interventions.

Lung-Specific Extracellular Superoxide Dismutase Improves Cognition of Adult Mice Exposed to Neonatal Hyperoxia

Lung and brain development is often altered in infants born preterm and exposed to excess oxygen, and this can lead to impaired lung function and neurocognitive abilities later in life. Oxygen-derived reactive oxygen species and the ensuing inflammatory response are believed to be an underlying cause of disease because over-expression of some anti-oxidant enzymes is protective in animal models. For example, neurodevelopment is preserved in mice that ubiquitously express human extracellular superoxide dismutase (EC-SOD) under control of an actin promoter. Similarly, oxygen-dependent changes in lung development are attenuated in transgenic Sftpc^EC−SOD mice that over-express EC-SOD in pulmonary alveolar epithelial type II cells. But whether anti-oxidants targeted to the lung provide protection to other organs, such as the brain is not known. Here, we use transgenic Sftpc^EC−SOD mice to investigate whether lung-specific expression of EC-SOD also preserves neurodevelopment following exposure to neonatal hyperoxia. Wild type and Sftpc^EC−SOD transgenic mice were exposed to room air or 100% oxygen between postnatal days 0–4. At 8 weeks of age, we investigated neurocognitive function as defined by novel object recognition, pathologic changes in hippocampal neurons, and microglial cell activation. Neonatal hyperoxia impaired novel object recognition memory in adult female but not male mice. Behavioral deficits were associated with microglial activation, CA1 neuron nuclear contraction, and fiber sprouting within the hilus of the dentate gyrus (DG). Over-expression of EC-SOD in the lung preserved novel object recognition and reduced the observed changes in neuronal nuclear size and myelin basic protein fiber density. It had no effect on the extent of microglial activation in the hippocampus. These findings demonstrate pulmonary expression of EC-SOD preserves short-term memory in adult female mice exposed to neonatal hyperoxia, thus suggesting anti-oxidants designed to alleviate oxygen-induced lung disease such as in preterm infants may also be neuroprotective.

The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment

Background:Sub-Saharan Africa bears a disproportionate burden of preterm birth and other adverse outcomes. A better understanding of the demographic, clinical, and biologic underpinnings of these adverse outcomes is urgently needed to plan interventions and inform new discovery.  Methods:The Zambian Preterm Birth Prevention Study (ZAPPS) is a prospective observational cohort established at the Women and Newborn Hospital (WNH) in Lusaka, Zambia. We recruit pregnant women from district health centers and the WNH and offer ultrasound examination to determine eligibility. Participants receive routine obstetrical care, lab testing, midtrimester cervical length measurement, and serial fetal growth monitoring. At delivery, we assess gestational age, birthweight, vital status, and sex and assign a delivery phenotype. We collect blood, urine, and vaginal swab specimens at scheduled visits and store them in an on-site biorepository. In September 2017, enrollment of the ZAPPS Phase 1 - the subject of this report - was completed. Phase 2 - which is limited to HIV-uninfected women - reopened in January 2018.  Results:Between August 2015 and September 2017, we screened 1784 women, of whom 1450 (81.2%) met inclusion criteria and were enrolled. The median age at enrollment was 27 years (IQR 23-32) and thee median gestational age was 16 weeks (IQR 13-18). Among parous women (N=866; 64%), 21% (N=182) reported a prior miscarriage, 49% (N=424) reported a prior preterm birth, and 13% (N=116) reported a prior stillbirth. The HIV seroprevalence was 24%. Discussion:We have established a large cohort of pregnant women and newborns at the WHN to characterize the determinants of adverse birth outcomes in Lusaka, Zambia. Our overarching goal is to elucidate biological mechanisms in an effort to identify new strategies for early detection and prevention of adverse outcomes. We hope that findings from this cohort will help guide future studies, clinical care, and policy.

Outcomes of infants born near term: not quite ready for the "big wide world"?

Until recently, there has been a strongly held belief on the part of neonatal and pediatric clinicians that outcomes for infants born close to term are not different from those of babies born at full term. In the last decade, however, this assumption has been challenged by reports suggesting that this is not correct, and highlighting differences in morbidity and mortality both in the short and long term. This has led to development of new terminology to more accurately reflect the impact of immaturity associated with birth at 32-33 weeks (moderately preterm) and 34-36 weeks (late preterm) of gestation. These babies account for around 5-7% of all births and more than 75% of the preterm births in developed countries, so this new recognition of the associated increase in adverse outcomes may have a substantial impact on health care services. This review article will discuss the changing perceptions and concepts of gestational age in the preterm population, and explore the recent and emerging evidence around neonatal, early childhood, school-age, adolescent and adult outcomes for babies who are born moderately preterm and late preterm. It highlights important neonatal and childhood morbidities and will summarize associated health care, developmental and educational problems of affected children. The implications for the provision of ongoing primary and secondary health care, educational and social support to this large and heterogeneous group of individuals will be discussed.

Parenting style impacts cognitive and behavioural outcomes of former preterm infants: A systematic review

We sought to evaluate published evidence in aggregate regarding the impact of parenting style on the cognitive and behavioural outcomes of former preterm infants. We searched 5 databases using germane MeSH terms. Parenting style was defined as any descriptor of parenting using ≥2 dimensions on published parenting axes. We evaluated studies for quality of evidence and strength of recommendations using standardized tools and categorized summative recommendations by parenting axis and child outcome. Twenty-seven articles met our inclusion criteria. Parental responsivity is the only parenting axis strongly associated with both improved child cognition and behaviour. Parental demandingness is associated only with improved child cognition, and parental warmth and rejection are associated only with child behaviour. Parental coercion is not associated with subsequent child outcomes. Parental responsivity may be essential in optimizing neurodevelopment in former preterm infants. More targeted studies are needed to inform this relationship and identify opportunities for intervention.

Neurological outcome at 6 and 12 months corrected age in hospitalised late preterm infants -a prospective study

Late preterm infants (34-0/7 to 36-6/7 weeks" gestation) account for 10-20% of NICU admissions and are at increased risk for morbidity and mortality. Although they are prone to developmental delays, reports on neurological outcome during the first 2 years of life are scarce. The aim of the study was to assess neurological/neuromotor outcome in high risk late preterm infants at 6 and 12 months corrected age and the change in neurological scores over time, and to identify factors associated with the neurological outcome. The Hammersmith Infant Neurological Examination was performed in a cohort of 157 late preterm infants admitted in the NICU. The infants were examined at 6 and 12 months corrected age respectively and scored with the optimality score system including 26 items assessing cranial nerve function, posture, movements, tone and reflexes. Also parents reported neurological milestones in the follow up visit. Infants at 6 months had a global score of 59 (47-76) and optimal scores achieved in 25.4%. At 12 months they had a global score of 70 (58-78) and achieved optimal scores in 63.2%. The subscores of posture, tone and reflexes gradually increased from 6 to 12 months corrected age. Being born small for gestational age was the only factor that adversely influenced HINE score at 6 and 12 months. At 12 months 58.5% achieved independent walking. High risk late preterm infants have suboptimal HINE scores at 6 and 12 months of age, suggesting a need for closer follow up and early intervention programs.

Associations between mixtures of urinary phthalate metabolites with gestational age at delivery: a time to event analysis using summative phthalate risk scores

BACKGROUND

Preterm birth is a significant public health concern and exposure to phthalates has been shown to be associated with an increased odds of preterm birth. Even modest reductions in gestational age at delivery could entail morbid consequences for the neonate and analyzing data with this additional information may be useful. In the present analysis, we consider gestational age at delivery as our outcome of interest and examine associations with multiple phthalates.

METHODS

Women were recruited early in pregnancy as part of a prospective, longitudinal birth cohort at the Brigham and Women's Hospital in Boston, Massachusetts. Urine samples were collected at up to four time points during gestation for urinary phthalate metabolite measurement, and birth outcomes were recorded at delivery. From this population, we selected all 130 cases of preterm birth (< 37 weeks of gestation) as well as 352 random controls. We conducted analysis with both geometric average of the exposure concentrations across the first three visits as well as using repeated measures of the exposure. Two different time to event models were used to examine associations between nine urinary phthalate metabolite concentrations and time to delivery. Two different approaches to constructing a summative phthalate risk score were also considered.

RESULTS

The single-pollutant analysis using a Cox proportional hazards model showed the strongest association with a hazard ratio (HR) of 1.21 (95% confidence interval (CI): 1.09, 1.33) per interquartile range (IQR) change in average log-transformed mono-2-ethyl-5-carboxypentyl phthalate (MECPP) concentration. Using the accelerated failure time model, we observed a 1.19% (95% CI: 0.26, 2.11%) decrease in gestational age in association with an IQR change in average log-transformed MECPP. We next examined associations with an environmental risk score (ERS). The fourth quartile of ERS was significantly associated with a HR of 1.44 (95% CI: 1.19, 1.75) and a reduction of 2.55% (95% CI: 0.76, 4.30%) in time to delivery (in days) compared to the first quartile.

CONCLUSIONS

On average, pregnant women with higher urinary metabolite concentrations of individual phthalates have shorter time to delivery. The strength of the observed associations are amplified with the risk scores when compared to individual pollutants.

The Interplay Between Early Father Involvement and Neonatal Medical Risk in the Prediction of Infant Neurodevelopment

The current study examines the association between early father involvement and infant neurodevelopment, and whether neonatal medical risk moderates this association. Data from approximately 6000 fathers and their children were obtained from the Early Childhood Longitudinal Study: Birth Cohort (ECLS-B). Hierarchical regression was employed to analyze the data. The findings reveal that the association between early father involvement and infant neurodevelopment is contingent on both the timing of involvement (i.e., prenatal/perinatal or infancy) and offspring medical status at birth. The neurodevelopment of medically at-risk neonates was enhanced when fathers were involved during the gestational period and at the time of their birth. This relationship was not detected, however, in the case of infants who did not experience medical risks as neonates. Neonatal medical risk appears to be an important moderating factor in the link between father involvement during pregnancy and childbirth and infant neurodevelopment. Practitioners should continue to make efforts to involve fathers during gestation and childbirth. The findings of the present study suggest that doing so may protect against neurodevelopmental delays in neonates with medical risks.

Development and validation of a simplified algorithm for neonatal gestational age assessment - protocol for the Alliance for Maternal Newborn Health Improvement (AMANHI) prospective cohort study

OBJECTIVE

The objective of the Alliance for Maternal and Newborn Health Improvement (AMANHI) gestational age study is to develop and validate a programmatically feasible and simple approach to accurately assess gestational age of babies after they are born. The study will provide accurate, population-based rates of preterm birth in different settings and quantify the risks of neonatal mortality and morbidity by gestational age and birth weight in five South Asian and sub-Saharan African sites.

METHODS

This study used on-going population-based cohort studies to recruit pregnant women early in pregnancy (<20 weeks) for a dating ultrasound scan. Implementation is harmonised across sites in Ghana, Tanzania, Zambia, Bangladesh and Pakistan with uniform protocols and standard operating procedures. Women whose pregnancies are confirmed to be between 8 to 19 completed weeks of gestation are enrolled into the study. These women are followed up to collect socio-demographic and morbidity data during the pregnancy. When they deliver, trained research assistants visit women within 72 hours to assess the baby for gestational maturity. They assess for neuromuscular and physical characteristics selected from the Ballard and Dubowitz maturation assessment scales. They also measure newborn anthropometry and assess feeding maturity of the babies. Computer machine learning techniques will be used to identify the most parsimonious group of signs that correctly predict gestational age compared to the early ultrasound date (the gold standard). This gestational age will be used to categorize babies into term, late preterm and early preterm groups. Further, the ultrasound-based gestational age will be used to calculate population-based rates of preterm birth.

IMPORTANCE OF THE STUDY

The AMANHI gestational age study will make substantial contribution to improve identification of preterm babies by frontline health workers in low- and middle- income countries using simple evaluations. The study will provide accurate preterm birth estimates. This new information will be crucial to planning and delivery of interventions for improving preterm birth outcomes, particularly in South Asia and sub-Saharan Africa.

Associations of caesarean delivery and the occurrence of neurodevelopmental disorders, asthma or obesity in childhood based on Taiwan birth cohort study

OBJECTIVES

Whether birth by caesarean section (CS) increases the occurrence of neurodevelopmental disorders, asthma or obesity in childhood is controversial. We tried to demonstrate the association between children born by CS and the occurrence of the above three diseases at the age of 5.5 years.

METHODS

The database of the Taiwan Birth Cohort Study which was designed to assess the developmental trajectories of 24 200 children born in 2005 was used in this study. Associations between children born by CS and these three diseases were evaluated before and after controlling for gestational age (GA) at birth, children's characteristics and disease-related predisposing factors.

RESULTS

Children born by CS had significant increases in neurodevelopmental disorders (20%), asthma (14%) and obesity (18%) compared with children born by vaginal delivery. The association between neurodevelopmental disorders and CS was attenuated after controlling for GA at birth (OR 1.15; 95% CI 0.98 to 1.34). Occurrence of neurodevelopmental disorders steadily declined with increasing GA up to ≤40-42 weeks. CS and childhood asthma were not significantly associated after controlling for parental history of asthma and GA at birth. Obesity in childhood remained significantly associated with CS (OR 1.13; 95% CI 1.04 to 1.24) after controlling for GA and disease-related factors.

CONCLUSIONS

Our results implied that the association between CS birth and children's neurodevelopmental disorders was significantly influenced by GA. CS birth was weakly associated with childhood asthma since parental asthma and preterm births are stronger predisposing factors. The association between CS birth and childhood obesity was robust after controlling for disease-related factors.

Performance of a postnatal metabolic gestational age algorithm: a retrospective validation study among ethnic subgroups in Canada

OBJECTIVES

Biological modelling of routinely collected newborn screening data has emerged as a novel method for deriving postnatal gestational age estimates. Validation of published models has previously been limited to cohorts largely consisting of infants of white Caucasian ethnicity. In this study, we sought to determine the validity of a published gestational age estimation algorithm among recent immigrants to Canada, where maternal landed immigrant status was used as a surrogate measure of infant ethnicity.

DESIGN

We conducted a retrospective validation study in infants born in Ontario between April 2009 and September 2011.

SETTING

Provincial data from Ontario, Canada were obtained from the Institute for Clinical Evaluative Sciences.

PARTICIPANTS

The dataset included 230 034 infants born to non-landed immigrants and 70 098 infants born to immigrant mothers. The five most common countries of maternal origin were India (n=10 038), China (n=7468), Pakistan (n=5824), The Philippines (n=5441) and Vietnam (n=1408). Maternal country of origin was obtained from Citizenship and Immigration Canada's Landed Immigrant Database.

PRIMARY AND SECONDARY OUTCOME MEASURES

Performance of a postnatal gestational age algorithm was evaluated across non-immigrant and immigrant populations.

RESULTS

Root mean squared error (RMSE) of 1.05 weeks was observed for infants born to non-immigrant mothers, whereas RMSE ranged from 0.98 to 1.15 weeks among infants born to immigrant mothers. Area under the receiver operating characteristic curve for distinguishing term versus preterm infants (≥37 vs <37 weeks gestational age or >34 vs ≤34 weeks gestational age) was 0.958 and 0.986, respectively, in the non-immigrant subgroup and ranged from 0.927 to 0.964 and 0.966 to 0.99 in the immigrant subgroups.

CONCLUSIONS

Algorithms for postnatal determination of gestational age may be further refined by development and validation of region or ethnicity-specific models. However, our results provide reassurance that an algorithm developed from Ontario-born infant cohorts performs well across a range of ethnicities and maternal countries of origin without modification.

Parental Perception of Risk Associated With Their Premature Infant

BACKGROUND

Preterm birth has been linked to increased parental stress, depression, and anxiety. Although the rate of neonatal morbidity and mortality decreases with increasing gestational age, recent research has revealed that there is no threshold age for risk or parental concern.

PURPOSE

This study examines parental concern about medical and developmental outcomes of their premature infant.

METHODS

Parents of 60 premature infants were surveyed in a follow-up clinic regarding their level of concern about 11 morbidities and their child's gestation-adjusted age; these were compared with the infant's inpatient chart. "Concern scores" were tallied and compared across gestational age groups and knowledge of gestation-adjusted age using Chi-square tests of independence.

FINDINGS

Many parents reported concerns about morbidities that were unsupported by their child's diagnoses. Across parents of extremely, very, and moderate-late preterm children, the mean concern scores were 13.9, 15.7, and 19.7, respectively. Overall, 62% of parents incorrectly reported the gestation-adjusted age of their child. Parents who were correct were significantly more likely to correctly anticipate abnormal developmental patterns (70%) and growth patterns (65%) than those who were incorrect (33% and 31%, respectively).

IMPLICATIONS FOR RESEARCH

Future research should focus on whether NICU graduate parental stress levels are directly linked to the severity of their child's condition, and how physicians can help decrease NICU graduate parental stress.

IMPLICATIONS FOR PRACTICE

Parental anxiety regarding all gestational age neonatal intensive care unit infant outcomes can be decreased by a thorough explanation of gestation-adjusted age and a discussion of expected prematurity-related issues.

Developmental pathways in infants from 4 to 24 months

BACKGROUND

There has been limited epidemiological research describing population-based samples regarding developmental pathways throughout infancy, and the research that exists has revealed substantial diversity. Identifying predictors for developmental pathways can inform early intervention services.

METHODS

The Ages and Stages Questionnaire was used to measure communication, gross motor, fine motor, problem-solving and personal-social skills longitudinally in a large, population-based sample of 1555 infants recruited from well-baby clinics in five municipalities in southeast Norway. We conducted latent class analyses to identify common pathways within the five developmental areas.

RESULTS

Our results indicated that most classes of infants showed generally positive and stable normative developmental pathways. However, for communication and gross motor areas, more heterogeneity was found. For gross motor development, a class of 10% followed a U-shaped curve. A class of 8% had a declining communication pathway and did not reach the level of the high stable communication class at 24 months. Low gestational age, low Apgar score, male sex, maternal depression symptoms, non-Scandinavian maternal ethnicity and high maternal education significantly predict less beneficial communication pathways.

CONCLUSION

The results suggest that infants with low gestational age, low Apgar score, male sex and a mother with depression symptoms or non-Scandinavian ethnicity may be at risk of developing less beneficial developmental pathways, especially within the communication area. Targeting these infants for surveillance and support might be protective against delayed development in several areas during a critical window of development.

The impact of the Neonatal Intensive Care Unit on sensory and developmental outcomes in infants born preterm: A scoping review

Introduction

Preterm infants admitted to the Neonatal Intensive Care Unit are at higher risk of poor neurodevelopmental and sensory outcomes. There is interest in establishing whether elements of the Neonatal Intensive Care Unit sensory environment may influence the sensory and overall development of these infants.

Method

The purpose of this scoping review was to provide a comprehensive overview of relevant research regarding the sensory elements of the Neonatal Intensive Care Unit, and their short- and long-term influence on preterm infants. This scoping review is underpinned by the six-stage framework by Arksey and O’Malley.

Results

There are few studies that have directly examined the influence of the Neonatal Intensive Care Unit environment upon the sensory and developmental outcomes of infants born preterm, in infancy. The findings of the studies included in this review suggest that the Neonatal Intensive Care Unit sensory environment may alter developmental trajectories of preterm infants. However, low-quality evidence exists in this field, with much of the literature being preliminary.

Conclusion

Further experimental studies are required that combine multiple methods of assessment to more rigorously understand the sensory characteristics of the Neonatal Intensive Care Unit, and their relationship with developmental outcomes across early childhood.

Is level of prematurity a risk/plasticity factor at three years of age?

Children born preterm have poorer outcomes than children born full-term, but the caregiving environment can ameliorate some of these differences. Recent research has proposed that preterm birth may be a plasticity factor, leading to better outcomes for preterm than full-term infants in higher quality environments. This analysis uses data from two waves of an Irish study of children (at 9 months and 3 years of age, n=11,134 children) and their caregivers (n=11,132 mothers, n=9998 fathers) to investigate differences in how caregiving affects social, cognitive, and motor skills between full-term, late preterm, and very preterm children. Results indicate that parental emotional distress and quality of attachment are important for child outcomes. Both being born very preterm and late preterm continue to be risk factors for poorer outcomes at 3 years of age. Only fathers' emotional distress significantly moderated the effect of prematurity on infants' cognitive and social outcomes-no other interactions between prematurity and environment were significant. These interactions were somewhat in line with diathesis stress, but the effect sizes were too small to provide strong support for this model. There is no evidence that preterm birth is a plasticity factor.

Longitudinal patterns of early development in Canadian late preterm infants: A prospective cohort study

This prospective, longitudinal cohort study examined longitudinal patterns of early development in Canadian children born late preterm. A convenience sample of 82 mothers and their healthy, singleton, late preterm children participated. Mothers completed the Ages and Stages Questionnaires at 4, 8, and 18 months corrected age. Concerns were most commonly reported in the communication and gross motor domains, especially early in development. The proportion of children scoring below the referral cut-off in at least one domain at 4, 8, and 18 months was, respectively, 25.6, 25.6, and 14.6%. Only two children (2.4%) scored below referral cut-off in at least one domain at all three time points. At ages four and eight months, the late preterm sample had significantly lower communication and gross motor scores than the Ages and Stages Questionnaires normative sample. At age four months, there was also a significant difference on the fine motor domain. There were no significant differences at age 18 months. Healthy late preterm children appear to catch up to population norms by age 18 months corrected age. Longer term studies are needed to further clarify early indicators of delay in late preterm children and identity those who require close developmental monitoring.

[Neurodevelopmental features of preterm infants at the corrected age of 1 year]

OBJECTIVE

To investigate the neurodevelopmental level of preterm infants at the corrected age of 1 year and the effect of complications on neurodevelopment.

METHODS

The clinical data and follow-up data of hospitalized preterm infants were retrospectively studied. The Bayley Scales of Infant Development was used to assess the neurodevelopmental level. Preterm infants were divided into groups according to gestational age, birth weight, and the presence or absence of complications. The mental development index (MDI) and psychomotor development index (PDI) were compared between groups.

RESULTS

At the corrected age of 1 year, compared with the late preterm infants, the early preterm infants had significantly lower MDI and PDI (P<0.05) and significantly higher rates of retarded intellectual and psychomotor development (P<0.01). Compared with the normal birth weight group, the low birth weight group had significantly lower MDI and PDI (P<0.01) and significantly higher rates of retarded intellectual and psychomotor development (P<0.01). The preterm infants with hyperbilirubinemia, birth asphyxia or neonatal respiratory distress syndrome (NRDS) had significantly lower MDI and PDI than those without such complications (P<0.05).

CONCLUSIONS

Lower gestational age and birth weight are associated with worse intellectual and psychomotor development in preterm infants. Complications, such as hyperbilirubinemia, birth asphyxia and NRDS, have adverse effects on neurodevelopment of preterm infants.

Threatened preterm labor is a risk factor for impaired cognitive development in early childhood

BACKGROUND

Threatened preterm labor is a leading cause of hospital admission during pregnancy. Patients with an episode of threatened preterm labor who deliver at term are considered to have false preterm labor. However, threatened preterm labor has been proposed as a pathologic insult that is not always sufficient to induce irreversible spontaneous preterm birth but that could alter the normal course of pregnancy.

OBJECTIVE

The aim of this study was to evaluate threatened preterm labor during pregnancy as a risk factor of neurodevelopmental deficits of children at 2 years of age.

STUDY DESIGN

Two-year-old children who were born late preterm (n=22) or at term after threatened preterm labor (n=23) were compared with at-term control children (n=42). Neurodevelopment was evaluated at a corrected age of 24-29 months with the use of the Merrill-Palmer-Revised Scales of Development.

RESULTS

Children who were born at term after threatened preterm labor had lower scores than control children on global cognitive index (95.4 vs 104.2; P=.011), cognition (95.1 vs 103.1; P=.021), fine motor (95.2 vs 103.4; P=.003), gross motor (84.7 vs 99.8; P=.001), memory (92.9 vs 100.4; P=.015), receptive language (93.9 vs 102.9; P=.03), speed of processing (105.7 vs 113.3; P=.011), and visual motor coordination (98.8 vs 106.7; P=.003) subtests. Children born at term after threatened preterm labor had an increased risk of mild neurodevelopmental delay compared with control children (odds ratio for global cognitive index, 2.06; 95% confidence interval, 1.09-3.88; P=.033). There were no significant differences in any cognitive domain between children who were born late preterm and children who were born at term after threatened preterm labor.

CONCLUSIONS

Threatened preterm labor is a risk factor for impaired cognitive development at 2 years of age, even if birth occurred at term.

Developmental trajectories in children with prolonged NICU stays

OBJECTIVE

To evaluate the relationship between prolonged neonatal intensive care unit (NICU) stay after birth and childhood neurodevelopmental measures from age 9 months to kindergarten.

DESIGN

Longitudinal birth cohort study.

SETTING AND PATIENTS

This study examined a nationally representative sample of 10 700 participants from the Early Childhood Longitudinal Sample-Birth Cohort and selected those who had a NICU stay (n=2100). These children were followed from birth to kindergarten.

PREDICTORS

Days in the NICU.

MAIN OUTCOME MEASURES

Childhood neurodevelopmental and early academic scores.

RESULTS

Increasing length of stay in the NICU had a significant negative relationship with the 9-month and 24-month Bayley mental and motor scores. Each additional week in the NICU increased the odds of scoring in the lowest 10% on the Bayley 9-month mental (OR 1.08, 95% CI 1.034 to 1.122) and motor (OR 1.11, CI 1.065 to 1.165) assessments and 24-month mental (OR 1.09, CI 1.041 to 1.144) and motor assessments (OR 1.07 CI 1.017 to 1.123). Gestational age was not significantly related with these measures in our model. Increasing socioeconomic status had a significant positive relationship with preschool and kindergarten reading and math scores and a lower odds of scoring in the lowest 10% in these measures.

CONCLUSION

Increasing length of NICU stay was predictive of decreased child development measures in early childhood (9 and 24 months), while socioeconomic status was a better predictor at later assessments (preschool and kindergarten entries). Gestational category did not account for these differences. These data may have implications for counselling parents regarding potential neurodevelopmental consequences following NICU stay.

Clinical Outcomes Associated with a Failed Infant Car Seat Challenge

OBJECTIVE

To assess comorbid conditions and clinical outcomes among late preterm and low birth weight term infants (<2.5 kg) who failed the Infant Car Seat Challenge (ICSC) on the Mother-Baby Unit.

STUDY DESIGN

This was a retrospective chart review of consecutive infants who failed ICSC on the Mother-Baby Unit and were subsequently admitted to the neonatal intensive care unit at Prentice Women's Hospital between January 1, 2009, and December 31, 2015. Regression models were used to estimate risk differences (RDs) with 95% CIs for factors related to length of stay.

RESULTS

A total of 148 infants were studied (43% male; 37% delivered via cesarean). ICSC failure in the Mother-Baby Unit was due to desaturation, bradycardia, and tachypnea in 59%, 37%, and 4% of infants, respectively. During monitoring on the neonatal intensive care unit, 39% of infants experienced apnea (48% in preterm vs 17% in term infants) in the supine position, 19% received phototherapy, and 2% and 6.8% received nasogastric and thermoregulatory support, respectively. Univariate predictors of increased duration of stay (days) were younger gestational age, apnea, nasogastric support, intravenous fluids, and antibiotics (all P < .05). In multivariable analysis adjusted for gestational age and discharge weight, only apnea (RD, 4.87; 95% CI, 2.99-6.74; P < .001), administration of antibiotics (RD, 3.25; 95% CI, 0.29-6.21; P < .032), and intravenous fluid support (RD, 4.87; 95% CI, 0.076-9.66; P < .047) remained independent predictors of a longer duration of stay.

CONCLUSION

Infants who failed ICSC were at risk for comorbid conditions that prolonged hospital stay beyond the neonatal intensive care unit observation period. Almost one-half of late preterm infants who failed ICSC had apnea events in the supine position.

Early developmental outcomes predicted by gestational age from 35 to 41weeks

BACKGROUND

Recent studies have indicated that children born only a few weeks earlier than their due date experience more health and cognitive problems than previously realized.

AIMS

Our study investigated whether gestational age (GA) at birth (35-41weeks) predicted developmental outcomes at 8, 12, 20, or 24months of age.

STUDY DESIGN

Archival records of developmental screening scores collected between 2006 and 2012 were analyzed using negative binomial and logistic regressions models.

SUBJECTS

Eight-month (N=3319), 12-month (N=2303), 20-month (N=1461) and 24-month (N=1222) old children were assessed in a county-wide developmental screening program.

OUTCOME MEASURES

Ages and Stage Questionnaires (ASQs) scores.

RESULTS

After controlling for demographic covariates, from 35weeks of gestation on, each additional week of gestation (through 41) significantly reduced the overall risk for developmental delay at 8,12, 20 and 24-months of age. Gestational age also uniquely predicted specific risk for delay in the domains of communication, personal-social, fine-motor, and problem solving at various time-points during the first two years of life.

CONCLUSIONS

With each additional week of gestation past 35weeks there was a graded decrease in the overall risk of developmental delay as well as in specific domains such as communication across the first two years of life. This evidence for the "dose-response" effect of GA on later development suggests that close monitoring of developmental outcomes for children born before 40weeks is warranted.

Association of Gestational Age and Severe Neonatal Morbidity with Mortality in Early Childhood

BACKGROUND

Although infant and child mortality rates have decreased substantially worldwide over the past two decades, efforts continue in many nations to further these declines. The identification of pertinent perinatal factors that are associated with early childhood mortality would help with these efforts. We investigated the association of two crucial perinatal factors, gestational age and severe neonatal morbidity at birth, with mortality during infancy (29-364 days) and early childhood (1-5 years).

METHODS

The study population included all singleton livebirths, ≥32 weeks' gestation in New South Wales, Australia in 2001-11. Birth data were linked to hospitalisation morbidity data and deaths data (linked birth cohort n = 871 916), and multivariable Cox regression models were used to assess mortality.

RESULTS

The median follow-up time per child was 4.95 years (range 0.00-5.92 years; 3 614 738 total person-years), with 984 deaths observed. Gestational age was associated with increased mortality, and specifically from deaths attributable to infections, respiratory conditions, and injuries during infancy, but not during early childhood. Severe neonatal morbidity strongly mediated the effects of gestational age during infancy, but not during early childhood, and was associated with increased mortality from circulatory, nervous, and respiratory system causes.

CONCLUSIONS

The direct effects of gestational age on mortality extended up to 1 year of age, whereas severe neonatal morbidity remained associated with heightened mortality into early childhood. Efforts to maximise the health and well-being of vulnerable infants, with emphasis on preventing infections and injuries, may help further reduce early childhood mortality.

Prenatal versus Postnatal Screening for Familial Retinoblastoma

PURPOSE

To compare overall outcomes of conventional postnatal screening of familial retinoblastoma and prenatal RB1 mutation identification followed by planned early-term delivery.

DESIGN

Retrospective, observational study.

PARTICIPANTS

Twenty children with familial retinoblastoma born between 1996 and 2014 and examined within 1 week of birth.

METHODS

Cohort 1 included spontaneously delivered neonates examined within 1 week of birth and confirmed postnatal to carry their family's RB1 mutant allele. Cohort 2 included infants identified by amniocentesis to carry their family's RB1 mutant allele, and therefore scheduled for early-term delivery (36-38 weeks' gestation). Treatment for retinoblastoma was performed at the Hospital for Sick Children, Toronto, Canada.

MAIN OUTCOME MEASURES

Age at first tumor in each eye, eye stage, treatments given, ocular salvage, treatment success (defined as avoidance of enucleation, external-beam irradiation, or both), visual outcome, number of anesthetics, pregnancy or delivery complications, and estimated treatment burden.

RESULTS

Vision-threatening tumors were present at birth in 4 of 8 infants in cohort 1 and in 3 of 12 infants in cohort 2. Eventually, all infants demonstrated tumors in both eyes. At the first treatment, 1 of 8 infants in cohort 1 had eyes in stage cT1a/cT1a or cT1a/cT0 (smallest and least vision-threatening tumors), compared with 8 of 12 infants in cohort 2 (P = 0.02). Null RB1 germline alleles induced earlier tumors than low-penetrance alleles (P = 0.03). Treatment success was achieved in 3 of 8 children in cohort 1 compared with 11 of 12 children in cohort 2 (P = 0.002). Acceptable vision (better than 0.2 decimal) was achieved for 8 of 16 eyes in cohort 1 compared with 21 of 24 eyes in cohort 2 (P = 0.014). Useful vision (better than 0.1, legal blindness) was achieved for 8 of 9 children in cohort 1 compared with 12 of 12 children in cohort 2. There were no complications related to early-term delivery. Median follow-up was 5.6 years, cohort 1 and 5.8 years, cohort 2.

CONCLUSIONS

When a parent had retinoblastoma, prenatal molecular diagnosis with early-term delivery increased the likelihood of infants born with no detectable tumors, better vision outcomes, and less invasive therapy. Prenatal molecular diagnosis facilitates anticipatory planning for both the child and family.

Early neurodevelopmental outcomes of infants with intestinal failure

BACKGROUND

The survival rate of infants and children with intestinal failure is increasing, necessitating a greater focus on their developmental trajectory.

AIMS

To evaluate neurodevelopmental outcomes in children with intestinal failure at 0-15months corrected age.

STUDY DESIGN

Analysis of clinical, demographic and developmental assessment results of 33 children followed in an intestinal rehabilitation program between 2011 and 2014. Outcome measures included: Prechtl's Assessment of General Movements, Movement Assessment of Infants, Alberta Infant Motor Scale and Mullen Scales of Early Learning. Clinical factors were correlated with poorer developmental outcomes at 12-15months corrected age.

RESULTS

Thirty-three infants (17 males), median gestational age 34weeks (interquartile range 29.5-36.0) with birth weight 1.98kg (interquartile range 1.17-2.50). Twenty-nine (88%) infants had abnormal General Movements. More than half had suspect or abnormal scores on the Alberta Infant Motor Scale and medium to high-risk scores for future neuromotor delay on the Movement Assessment of Infants. Delays were seen across all Mullen subscales, most notably in gross motor skills. Factors significantly associated with poorer outcomes at 12-15months included: prematurity, low birth weight, central nervous system co-morbidity, longer neonatal intensive care admission, necrotizing enterocolitis diagnosis, number of operations and conjugated hyperbilirubinemia.

CONCLUSION

Multiple risk factors contribute to early developmental delay in children with intestinal failure, highlighting the importance of close developmental follow-up.

Vitamin D and bronchopulmonary dysplasia in preterm infants

OBJECTIVE

Vitamin D deficiency is associated with asthma and reactive airway disease in childhood but its potential contribution to bronchopulmonary dysplasia (BPD) in preterm infants is unknown. Preterm infants have lower levels of 25-hydroxyvitamin D (25(OH)D) at birth and are at risk for nutritional deficiencies after birth. The objective of the study was to evaluate the association of 25(OH)D concentrations at birth and at 36 weeks' corrected gestational age with BPD in preterm infants born before 29 completed weeks of gestation.

STUDY DESIGN

We collected umbilical cord blood samples from 44 preterm infants (gestational age <29 weeks) delivered at Brigham and Women's Hospital in Boston. In addition, with parental consent we collected venous samples at 36 weeks' corrected age from 20 preterm infants born before 29 weeks' gestation (including 6 infants with previously collected cord blood). Samples were frozen at -80 °C until subsequent measurement of 25(OH)D levels by chemiluminescence. We used multivariable logistic models to adjust for gestational age and considered other confounding variables, including maternal race, age, mode of delivery and infant sex.

RESULTS

Among 44 infants, 41 (93.2%) survived and 3 (6.8%) died before 36 weeks' corrected age. Median 25(OH)D levels at birth were 30.4 ng ml(-1) in preterm infants who subsequently died or developed BPD and 33.8 ng ml(-1) in infants who survived without BPD (P=0.6). Median 25(OH)D levels at corrected age of 36 weeks were 59.0 ng ml(-1) among survivors without BPD and 64.2 ng ml(-1) among survivors with BPD (P=0.9). Neither cord blood nor 36 weeks' corrected 25(OH)D levels were associated with odds of death or BPD (adjusted odds ratio (OR) 1.00, 95% confidence interval (CI): 0.73 to 1.37; and OR 0.93, 95% CI: 0.61 to 1.43, respectively).

CONCLUSIONS

Among this population of extremely preterm infants neither cord blood nor the 36 weeks' corrected age 25(OH)D levels were associated with development of BPD. Notably, at the current level of supplementation, all extremely preterm infants in our cohort had achieved 25(OH)D levels >30 ng ml(-1) by 36 weeks' corrected age, which is thought to represent sufficiency in adult and pediatric populations.

Risk of developmental delay: Comparison of late preterm and full term Canadian infants at age 12 months

BACKGROUND

Late preterm (34(0/7) to 36(6/7)weeks gestation) infants may experience developmental delays greater than those found in term (≥ 37(0/7)weeks gestation) infants.

AIM

The aim of this study was to compare the risk of developmental delay between late preterm and full-term Canadian born infants at age 12months, and to determine infant and maternal factors associated with risk of delay.

METHODS

A descriptive comparative study was conducted from data available from the All Our Babies community-based, prospective, pregnancy cohort in Calgary, Alberta. Participants were a sample of mothers of 52 infants born late preterm and 156 randomly selected mothers of term infants, matched for infant sex; eligible infants were singleton births. Mothers completed a developmental screening tool, the Ages and Stages Questionnaire, version 3 (ASQ-3), when their infant was age 12months. Corrected age (CA) was used for preterm infants.

RESULTS

Both late preterm and term infants who required neonatal intensive care (NICU) were more likely to demonstrate risk of developmental delay. Compared to term infants, there was a trend for late preterm infants to be at risk of communication and gross motor delay at age 12months CA that was attenuated to the null when adjustments were made for NICU admission and other covariates.

CONCLUSIONS

Infants born between 34 and 41weeks who are admitted to NICU are at increased risk of developmental delay. Early identification of risk provides an opportunity for referral for developmental assessment and early intervention programming.

Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis

OBJECTIVE

To determine the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, and Cochrane databases (until December 2015).

REVIEW METHODS

Databases were searched without language restrictions for studies of women with uncomplicated twin pregnancies that reported rates of stillbirth and neonatal outcomes at various gestational ages. Pregnancies with unclear chorionicity, monoamnionicity, and twin to twin transfusion syndrome were excluded. Meta-analyses of observational studies and cohorts nested within randomised studies were undertaken. Prospective risk of stillbirth was computed for each study at a given week of gestation and compared with the risk of neonatal death among deliveries in the same week. Gestational age specific differences in risk were estimated for stillbirths and neonatal deaths in monochorionic and dichorionic twin pregnancies after 34 weeks' gestation.

RESULTS

32 studies (29 685 dichorionic, 5486 monochorionic pregnancies) were included. In dichorionic twin pregnancies beyond 34 weeks (15 studies, 17 830 pregnancies), the prospective weekly risk of stillbirths from expectant management and the risk of neonatal death from delivery were balanced at 37 weeks' gestation (risk difference 1.2/1000, 95% confidence interval -1.3 to 3.6; I(2)=0%). Delay in delivery by a week (to 38 weeks) led to an additional 8.8 perinatal deaths per 1000 pregnancies (95% confidence interval 3.6 to 14.0/1000; I(2)=0%) compared with the previous week. In monochorionic pregnancies beyond 34 weeks (13 studies, 2149 pregnancies), there was a trend towards an increase in stillbirths compared with neonatal deaths after 36 weeks, with an additional 2.5 per 1000 perinatal deaths, which was not significant (-12.4 to 17.4/1000; I(2)=0%). The rates of neonatal morbidity showed a consistent reduction with increasing gestational age in monochorionic and dichorionic pregnancies, and admission to the neonatal intensive care unit was the commonest neonatal complication. The actual risk of stillbirth near term might be higher than reported estimates because of the policy of planned delivery in twin pregnancies.

CONCLUSIONS

To minimise perinatal deaths, in uncomplicated dichorionic twin pregnancies delivery should be considered at 37 weeks' gestation; in monochorionic pregnancies delivery should be considered at 36 weeks.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014007538.