Neuropsychological screening of a group of preterm twins: comparison with singletons

Neurodevelopmental outcome of preterm twins at 5 years of age

BACKGROUND

Twins are considered to be at an increased risk for perinatal mortality and morbidities, but it is unclear whether preterm twins are at an increased risk for poor developmental outcomes when compared to preterm singletons. Our aim was to compare the neurodevelopmental outcome of preterm twins vs singletons at 5 years of age.

METHODS

Very low birth weight and very low gestational age infants (twins n = 66, singletons n = 157) were recruited as a part of the PIPARI project in the Turku University Hospital, covering a regional population. Cognitive development, neuropsychological performance, and neurodevelopmental impairments (including cerebral palsy, hearing deficit, visual impairment, and intellectual disability) were evaluated at 5 years of age.

RESULTS

Twins and singletons had otherwise similar perinatal background factors, except for the higher proportion of preterm rupture of membranes in singletons. Twins had cognitive and neuropsychological outcomes that were otherwise comparable with singletons, but they had a slightly lower verbal intelligence quotient (estimate -5.81, 95% CI -11.14 to -0.48, p = 0.03). Being a twin was not a risk for neurodevelopmental impairments.

CONCLUSIONS

Our study shows that, contrary to a common hypothesis, the overall neurodevelopment of very preterm twins does not significantly differ from that of preterm singletons.

Associations of gestational age with child health and neurodevelopment among twins: A nationwide Japanese population-based study

BACKGROUND

The prevalence of multiple births has recently increased. However, the association between gestational age and long-term morbidity among twins remains unclear.

AIMS

To examine the association of gestational age with child health and neurological development in early childhood among twins.

STUDY DESIGN

Population-based longitudinal study.

SUBJECTS

We included 947 children from 479 pairs of twins with information on gestational age.

OUTCOME MEASURES

Hospitalization was used as an indicator of physical health, and responses to questions about age-appropriate behaviors were used as an indicator of neurobehavioral development. We conducted binomial log-linear regression analyses, controlling for both child and maternal variables in the model. We accounted for correlations within the pairs with generalized estimating equations.

RESULTS

The early term group (i.e., 37 to 38 weeks of gestation) had a lower risk of poor child health and unfavorable neurodevelopment compared with the full term group (≥39 weeks of gestation) and preterm group (<37 weeks of gestation). Compared with the early term group, the adjusted risk ratios for hospitalization for all causes during the period from 7 to 18 months of age was 2.2 (95% confidence interval: 1.3-3.8) for very preterm children (<32 weeks of gestation), 1.1 (0.8-1.6) for moderately and late preterm children (32 to 36 weeks of gestation), and 1.8 (1.0-3.2) for full term children.

CONCLUSION

We observed a U-shaped association of gestational age with child health and neurodevelopment. The early term group had the lowest risk of poor outcomes among twins.

Neuropsychological Functioning in Preterm-Born Twins and Singletons at Preschool Age

OBJECTIVES

A limited body of research is available on the relationships between multiplicity of birth and neuropsychological functioning in preterm children who were conceived in the age of assisted reproductive technology and served by the modern neonatal intensive care unit. Our chief objective was to evaluate whether, after adjustment for sociodemographic factors and perinatal complications, twin birth accounted for a unique portion of developmental outcome variance in children born at-risk in the surfactant era.

METHODS

We compared the neuropsychological functioning of 77 twins and 144 singletons born preterm (<34 gestational weeks) and served by William Beaumont Hospital, Royal Oak, MI. Children were evaluated at preschool age, using standardized tests of memory, language, perceptual, and motor abilities.

RESULTS

Multiple regression analyses, adjusting for sociodemographic and perinatal variables, revealed no differences on memory or motor indices between preterm twins and their singleton counterparts. In contrast, performance of language and visual processing tasks was significantly lower in twins despite reduced perinatal risk in comparison to singletons. Effect sizes ranged from .33 to .38 standard deviations for global language and visual processing ability indices, respectively. No significant group by sex interactions were observed, and comparison of first-, or second-born twins with singletons yielded medium effect sizes (Cohen's d=.56 and .40, respectively).

CONCLUSIONS

The modest twin disadvantage on language and visual processing tasks at preschool-age could not be readily attributable to socioeconomic or perinatal variables. The possibility of biological or social twinning-related phenomena as mechanisms underlying the observed performance gaps are discussed. (JINS, 2016, 22, 865-877).

The Prenatal Environment in Twin Studies: A Review on Chorionicity

A literature search was conducted to identify articles examining the association of chorionicity (e.g., whether twins share a single chorion and thus placenta or have separate chorions/placentas) and genetics, psychiatry/behavior, and neurological manifestations in humans twins and higher-order multiples. The main aim was to assess how frequently chorionicity has been examined in relation to heritability estimates, and to assess which phenotypes may be most sensitive to, or affected by, bias in heritability estimates because of chorionicity. Consistent with the theory that some chorionicity effects could lead to overestimation and others to underestimation of heritability, there were instances of each across the many phenotypes reviewed. However, firm conclusions should not be drawn since some of the outcomes were only examined in one or few studies and often sample sizes were small. While the evidence for bias due to chorionicity was mixed or null for many outcomes, results do, however, consistently suggest that heritability estimates are underestimated for measures of birth weight and early growth when chorionicity is not taken into account.

Prematurity and twinning

AIM OF THE STUDY

Newborns from multiple pregnancies are increasing in number and demonstrate a higher perinatal morbidity and mortality compared to singletons. Prematurity is the main reason for most neonatal diseases in twins, but other variables may play a role and their prenatal evaluation may improve the overall outcome.

MAIN FINDINGS

Prematurity is six times more frequent in twins and therefore birth weight is significantly lower compared to singletons. Thus, twins are more exposed to prematurity related diseases (respiratory, cardiovascular, infectious, etc.) and to long-term complications (especially neurological disabilities).

RESULTS

It is very difficult to estimate the increased risk of neonatal morbidity related to twinning independently to the increased risk of prematurity and therefore to interpret data on morbidity rates, in particular regarding the neurodevelopmental outcome.

CONCLUSION

Prevention of preterm birth is a primary goal in managing multiple pregnancies, together with prophylaxis with corticosteroids in order to improve foetal lung maturity. Accurate risk assessment strategies and adequate obstetrical-neonatological management of multiple pregnancies may reduce the increasing need for neonatal intensive care and for health resources in the long-term follow-up that has been observed over the last decades.

Quality of life of early school-age French children born preterm: a cohort study

OBJECTIVES

To describe the health-related quality of life (HRQL) of a cohort of children aged 6-10 years who were born preterm; and to determine whether sociodemographic factors, neonatal features and neurocognitive status were affecting their HRQL.

STUDY DESIGN

All singleton infants born between 24 and 32 weeks of gestation between January 1997 and December 2001 at the study hospital, who were still alive in 2007 (age 6-10 years), and who had undergone complete clinical paediatric follow-up were included in the study. Maternal and perinatal data were obtained by chart review and regular clinical examination. The 'Battery for Rapid Evaluation of Cognitive Functions' (BREV) was used for cognitive evaluation when children were aged 4-8 years. HRQL data were collected in 2007 using the 'Vécu et Santé Perçue de l'Adolescent et de l'Enfant' (VSP-A) questionnaire (parent version). The HRQL of the preterm children was compared with that of a French reference population.

RESULTS

Of 202 children who fulfilled the inclusion criteria, 82 children participated in the study. Their mean age was 7.9 years [standard deviation (SD) 1.4], mean birth weight was 1130.0 g (SD 361.4), 23 children were born before 28 weeks of gestation, 46 were female and 11 had major neurocognitive disorders. These data were not significantly different for the non-respondents (n=120). Parents of preterm children reported a significantly lower perception of HRQL of their child compared with parents of children in the reference population, as reflected by VSP-A global index scores and scores for the 'body image', 'vitality', 'psychological well-being' and 'school performance' dimensions. In multivariate analyses, three factors were found to be significantly associated with at least one dimension in the VSP-A scale in the preterm children: presence of major neurocognitive disorders, negatively correlated with 'vitality', 'relationships with friends', 'physical well-being' and 'school performance' dimensions; maternal parity, positively correlated with the 'psychological well-being' dimension; and socio-economic status of family, positively correlated with the 'relationships with friends' dimension. The maximum R(2) was 15%.

CONCLUSION

In addition to neurocognitive disorders, other variables such as socio-economic status of the family have a significant impact on the HRQL of preterm children at 6-10 years of age. Given the low proportion of variability in HRQL explained by the models, there is a need to explore other factors (e.g. environmental).

Oxidative stress in twin neonates is influenced by birth weight and weight discordance

OBJECTIVES

To evaluate the extent of oxidative stress in neonates born from multiple gestation pregnancies who are at high risk of prematurity and growth abnormalities.

DESIGN AND METHODS

Blood samples were collected from umbilical cord of 72 twins, born at gestational age of 28-38 weeks, and 20 consecutive control singletons. Oxidative stress parameters (15-F(2t)-isoprostane, a marker of lipid peroxidation, and total antioxidant capacity, tAOC), were measured in cord plasma.

RESULTS

Levels of 15-F(2t)-isoprostane showed a moderate negative correlation with birth weight and were higher in small co-twins of discordant pairs; tAOC was positively correlated with birth weight but no significant difference was found between co-twins.

CONCLUSIONS

Oxidative stress levels in twins are mainly influenced by birth weight and weight discordance. We suggest that evaluation of cord blood 15-F(2t)-isoprostane might be of clinical value as maker of pre- and perinatal distress in twinning.

Preterm birth and neurodevelopmental outcome: a review

BACKGROUND

The incidence of preterm delivery and the survival rate of preterm newborns are rising, due to the increased use of assisted reproductive technology associated with multiple gestations and improved technology in obstetrics and neonatology, which allow saving preterm infants at earlier gestational ages. As a consequence, the risk of developmental disabilities in preterm children is high, and clinical pictures need to be fully defined.

METHODS

Narrative review including articles regarding neurodevelopmental disorders published in the international medical literature and reported in PubMed between the years 2000 and January 2010.

RESULTS

Although survival rates of extremely low birth weight infants (ELBW) significantly increased during the last decade, the substantial stability of disability trends in this population was disappointing. Late-preterm infants, who account for about 75% of all preterm births and had not been considered at risk for adverse long-term neurodevelopmental outcomes in the past, are now reconsidered as more likely to develop such events, though their risk remains lower than in ELBW.

CONCLUSIONS

The findings of the studies discussed in our article support the importance of early diagnosis in order to make decision about appropriate treatment of preterm infants.

Evaluation of a tool to screen at preschool age for minor cognitive disorders liable to affect schooling among children born premature

PURPOSE

To evaluate a detection tool designed to help paediatricians identify, at preschool age, minor neurocognitive disorders that interfere with normal schooling.

METHODS

One hundred-and-fourteen preterm singletons born between 1997 and 2001 at less than 32 weeks of amenorrhoea, in a tertiary perinatal care center, were invited to visit us for a medical examination and a rapid neurocognitive assessment (BREV) when they were aged between 4 and 8 years and were re-contacted at 6-10 years of age to evaluate their current schooling situation. Results of BREV and schooling parameters were compared.

RESULTS

Mean gestational age was 29 weeks and mean birth weight was 1,164 g. Fifteen children (13.2%) showed abnormal results on BREV testing and had unusual schooling histories. Among the 68 children with normal BREV, 65 (95.6%) had achieved normal schooling. The sensitivity of the BREV test in this population for detection of minor disorders interfering with schooling was thus 83.3% (95% CI = 57.7-95.6) and the predictive value of a negative test was 95.6% (95% CI = 86.8-98.9). For the 57 children (50%) assessed before the age of 5 years, the sensitivity and the predictive value of a negative test were both 100%.

CONCLUSION

Our survey shows that the BREV test can, in a population of preschool children who were born premature, screen for minor neurocognitive disorders that impact schooling parameters. BREV assessment, used in the setting of follow-up of premature infants, would identify children in need of early remedial education before schooling under-attainment or failure developed.