Late preterm birth is associated with short-term morbidity but not with adverse neurodevelopmental and physical outcomes at 1 year

Morbidities and rehospitalizations during the first year of life in moderate and late preterm infants: more similarities than differences?

BACKGROUND

The aim was to compare neonatal morbidities in moderate and late preterm infants and to analyze rates and causes for rehospitalizations during the first year of life.

METHODS

Prospective follow-up of a group of moderate and late preterm infants at a tertiary care hospital.

RESULTS

The study population comprised 215 infants (58% males; 60% singletons; 99 moderate and 116 late preterm infants) with a median gestational age of 34 weeks and birth weight of 2100 grams; 20% of them were small for gestational age. Moderate preterm infants more often had a diagnosis of mild respiratory distress syndrome (26% vs. 13%, P<0.01) and feeding problems with longer need for nasogastric tube feeding (median 9.5 vs. 4.2 days, P<0.01) and parenteral nutrition (3.5 vs. 2.7 days, P<0.01), and longer duration of stay at either NICU (10.6 vs. 3.7 days; P<0.01) or hospital (13 vs. 11 days; P<0.01). Fifty-two infants (24.3%) were hospitalized at 67 occasions without differences regarding readmission rates and causes between groups. Median age at readmission was 3 months, median stay 4 days. The most common diagnosis was respiratory illness (43.3%).

CONCLUSIONS

Moderate preterm infants had more neonatal morbidities diagnosed, but the same rehospitalization rates than late preterm infants.

Neurodevelopment outcome of late prematurity: a retrospective cohort study from a developing country

The late preterm infants (34 0/7 to 36 6/7 weeks of gestation) account for at least 70% of all preterm birth. Our aim was to detect growth and neurodevelopment outcome, incidence of neurodevelopmental disability, and its association with maternal and neonatal risk factors among sick late preterm population. Two hundred and ninety-nine late preterm infants were followed up till corrected 2 years of age in this retrospective cohort study. Assessment was done by anthropometry and Developmental Assessment Scale for Indian Infants (DASII) scale at corrected 2 years of age. Presence of visual and hearing impairment, cerebral palsy, and overall neurodevelopmental impairment were also recorded. At 2 years of corrected age, average motor development quotient (DMoQ) was 93.55 (95% CI 90.9 to 96.20) and average mental development quotient (DMeQ) was 89.59 (95% CI 87.13 to 92.04). The incidence of bilateral severe to profound hearing loss and visual loss were found in 6 (2%) and 4 (1.33%) infants, respectively. Severe neurodevelopmental impairment was found in 19 (6.35%) infants. Central nervous system disease and sepsis were found as independent predictors of moderate to severe neurodevelopmental disability.   Conclusion: Late preterm infants admitted in neonatal units were at risk of growth and neurodevelopmental impairment requiring close neurodevelopmental follow-up. In a resource limited setting, this may best be achieved by using DASII in follow-up clinic. What is Known: • Late preterm infants are at a high risk of prematurity-related morbidities. • There is increased risk of cognitive defect, learning difficulties, and behavior problems found at school age for sick late preterm infants. What is New: • Central nervous system disease and sepsis were found as independent predictors of early moderate to severe neurodevelopmental impairment for sick late preterm infants in developing countries like India.

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.

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.

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.

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.

Neurodevelopmental outcomes following late and moderate prematurity: a population-based cohort study

OBJECTIVE

There is a paucity of data relating to neurodevelopmental outcomes in infants born late and moderately preterm (LMPT; 32(+0)-36(+6) weeks). This paper present the results of a prospective, population-based study of 2-year outcomes following LMPT birth.

DESIGN

1130 LMPT and 1255 term-born children were recruited at birth. At 2 years corrected age, parents completed a questionnaire to assess neurosensory (vision, hearing, motor) impairments and the Parent Report of Children's Abilities-Revised to identify cognitive impairment. Relative risks for adverse outcomes were adjusted for sex, socio-economic status and small for gestational age, and weighted to account for over-sampling of term-born multiples. Risk factors for cognitive impairment were explored using multivariable analyses.

RESULTS

Parents of 638 (57%) LMPT infants and 765 (62%) controls completed questionnaires. Among LMPT infants, 1.6% had neurosensory impairment compared with 0.3% of controls (RR 4.89, 95% CI 1.07 to 22.25). Cognitive impairments were the most common adverse outcome: LMPT 6.3%; controls 2.4% (RR 2.09, 95% CI 1.19 to 3.64). LMPT infants were at twice the risk for neurodevelopmental disability (RR 2.19, 95% CI 1.27 to 3.75). Independent risk factors for cognitive impairment in LMPT infants were male sex, socio-economic disadvantage, non-white ethnicity, preeclampsia and not receiving breast milk at discharge.

CONCLUSIONS

Compared with term-born peers, LMPT infants are at double the risk for neurodevelopmental disability at 2 years of age, with the majority of impairments observed in the cognitive domain. Male sex, socio-economic disadvantage and preeclampsia are independent predictors of low cognitive scores following LMPT birth.