Prenatal diagnosis and management of intrauterine growth restriction: A long-term prospective study on outcome and maternal stress

Rethinking stress in parents of preterm infants: a meta-analysis

BACKGROUND

With improved medical outcome in preterm infants, the psychosocial situation of their families is receiving increasing attention. For parents, the birth of a preterm infant is generally regarded as a stressful experience, and therefore many interventions are based on reducing parental stress. Nevertheless, it remains unclear whether parents of children born preterm experience more stress than parents of term-born children, which would justify these interventions. This meta-analysis provides a comprehensive account of parental stress in parents of preterm infants, from birth of the infant through to their adolescence. Mean levels of stress in specific domains of family functioning were investigated, and stress levels in parents of preterm and term infants, and fathers and mothers of preterm infants, were compared. Furthermore, we investigated moderators of parental stress.

METHODS AND FINDINGS

A random-effects meta-analysis was conducted including 38 studies describing 3025 parents of preterm (<37 wk) and low birth weight (<2500 g) infants. Parental stress was measured with two parent-reported questionnaires, the Parenting Stress Index and the Parental Stressor Scale: Neonatal Intensive Care Unit. The results indicate that parents of preterm-born children experience only slightly more stress than parents of term-born children, with small effect sizes. Furthermore, mothers have slightly more stress than fathers, but these effect sizes are also small. Parents report more stress for infants with lower gestational ages and lower birth weights. There is a strong effect for infant birth year, with decreasing parental stress from the 1980s onward, probably due to increased quality of care for preterm infants.

CONCLUSIONS

Based on our findings we argue that prematurity can best be regarded as one of the possible complications of birth, and not as a source of stress in itself.

Intrauterine growth-restricted neonates born at term or preterm: how different?

Late onset intrauterine growth restriction is a common form of growth restriction, mainly caused by placenta-vascular insufficiency. Whether the intrauterine or extrauterine environment offers a better long-term outcome for the growth-restricted fetus remains unclear. We compared the risk factors and long-term outcomes of late onset growth-restricted neonates delivered between 31-36 weeks of gestation vs those delivered at term. This prospective cohort study included 114 preterm and 193 term born growth-restricted neonates. They underwent a neurobehavioral examination (neonatal period), a neurodevelopmental assessment and the Bayley Scales of Infant Development (age 2 years), and neuromotor assessment and the Wechsler Preschool and Primary Scale of Intelligence (age 6 years). Growth-restricted neonates born prematurely exhibited a significantly higher incidence of maternal hypertension, a maternal history of abortions and stillbirths, increased intrapartum and postnatal complication rates, and abnormal neonatal neurobehavioral scores than expected. Both preterm and term born growth-restricted groups, however, exhibited comparable long-term neurodevelopmental and cognitive outcomes at ages 2 and 6 years. Although prematurely born neonates undergo an earlier growth restriction process and exhibit a higher perinatal risk factor profile, their long-term outcomes are comparable to those of growth-restricted neonates born at term.

The Mother-Infant Feeding Relationship Across the First Year and the Development of Feeding Difficulties in Low-Risk Premature Infants

Although feeding problems are common during infancy and are typically accompanied by relational difficulties, little research observed the mother-infant feeding relationship across the first year as an antecedent to the development of feeding difficulties. We followed 76 low-risk premature infants and their mothers from the transition to oral feeding in the neonatal period to the end of the first year. Prior to hospital discharge, microlevel patterns of maternal touch and gaze were coded during feeding and nonfeeding interactions, global patterns of maternal adaptation were assessed, and infants' neurobehavioral status was tested. Psychomotor development was evaluated at 4 months. At 1 year, feeding difficulties were determined on the basis of maternal interview and direct observations of feeding interactions. Mothers of infants who exhibited feeding difficulties at 1 year showed less affectionate touch and gaze during nonfeeding interactions and more gaze aversion and lower adaptability during feeding interactions already in the neonatal period. Infants with feeding difficulties demonstrated poorer psychomotor performance at 4 months. Feeding interactions of infants with feeding difficulties at 1 year were characterized by higher maternal intrusiveness, lower infant involvement, and greater infant withdrawal. Less maternal affectionate touch and lower maternal adaptation in the neonatal period, poor infant psychomotor skills, and higher maternal intrusiveness and lower infant involvement at 1 year predicted feeding difficulties. The findings underscore the role of the relational components across the first year in the development of feeding difficulties.

Verbal short-term memory span in children: long-term modality dependent effects of intrauterine growth restriction

BACKGROUND

Recent reports showed that children born with intrauterine growth restriction (IUGR) are at greater risk of experiencing verbal short-term memory span (STM) deficits that may impede their learning capacities at school. It is still unknown whether these deficits are modality dependent.

METHODS

This long-term, prospective design study examined modality-dependent verbal STM functions in children who were diagnosed at birth with IUGR (n = 138) and a control group (n = 64). Their STM skills were evaluated individually at 9 years of age with four conditions of the Visual-Aural Digit Span Test (VADS; Koppitz, 1981): auditory-oral, auditory-written, visuospatial-oral and visuospatial-written. Cognitive competence was evaluated with the short form of the Wechsler Intelligence Scales for Children--revised (WISC-R95; Wechsler, 1998).

RESULTS

We found IUGR-related specific auditory-oral STM deficits (p < .036) in conjunction with two double dissociations: an auditory-visuospatial (p < .014) and an input-output processing distinction (p < .014). Cognitive competence had a significant effect on all four conditions; however, the effect of IUGR on the auditory-oral condition was not overridden by the effect of intelligence quotient (IQ).

CONCLUSIONS

Intrauterine growth restriction affects global competence and inter-modality processing, as well as distinct auditory input processing related to verbal STM functions. The findings support a long-term relationship between prenatal aberrant head growth and auditory verbal STM deficits by the end of the first decade of life. Empirical, clinical and educational implications are presented.

A neurobiological model for the effects of early brainstem functioning on the development of behavior and emotion regulation in infants: implications for prenatal and perinatal risk

Neurobiological models propose an evolutionary, vertical-integrative perspective on emotion and behavior regulation, which postulates that regulatory functions are processed along three core brain systems: the brainstem, limbic, and cortical systems. To date, few developmental studies applied these models to research on prenatal and perinatal risk. We propose a conceptual model that incorporates three integrated levels of observations for the study of early risk: (a) brainstem-related physiological regulation of cyclic processes and sensory integration, e.g., vagal regulation, circadian rhythms; (b) emotion and attention regulation capacities that draw on the integration of brainstem and limbic systems; and (c) higher-level outcomes that draw on the intactness of brainstem and limbic networks, including socio-emotional self-regulation, inhibitory control, and cognitive processing. We discuss implications of the model for the development of regulatory capacities during the prenatal and early postnatal stages in infants born with specific perinatal risk. We underscore the importance of assessing sub-cortical and brainstem systems and the longitudinal effects of transitory brainstem dysfunction on physiological homeostasis, motivation, arousal-modulated attention, stress reactivity, and mother-infant co-regulation. The assessment of brainstem dysfunction can be conducted during hospitalization and may help detect infants at risk for the development of self-regulatory deficits at the first weeks of life.

Memory functions of children born with asymmetric intrauterine growth restriction

OBJECTIVE

Learning difficulties are frequently diagnosed in children born with intrauterine growth restriction (IUGR). Models of various animal species with IUGR were studied and demonstrated specific susceptibility and alterations of the hippocampal formation and its related neural structures. The main purpose was to study memory functions of children born with asymmetric IUGR in a large-scale cohort using a long-term prospective paradigm.

METHODS

One hundred and ten infants diagnosed with IUGR were followed-up from birth to 9 years of age. Their performance was compared with a group of 63 children with comparable gestational age and multiple socioeconomic factors. Memory functions (short-term, super- and long-term spans) for different stimuli types (verbal and visual) were evaluated using Visual Auditory Digit Span tasks (VADS), Rey Auditory Verbal Learning Test (Rey-AVLT), and Rey Osterrieth Complex Figure Test (ROCF).

RESULTS

Children with IUGR had short-term memory difficulties that hindered both serial verbal processing system and simultaneous processing of high-load visuo-spatial stimuli. The difficulties were not related to prematurity, neonatal complications or growth catch-up, but were augmented by lower maternal education. Recognition skills and benefits from reiteration, typically affected by hippocampal dysfunction, were preserved in both groups.

CONCLUSIONS

Memory profile of children born with IUGR is characterized primarily by a short-term memory deficit that does not necessarily comply with a typical hippocampal deficit, but rather may reflect an executive short-term memory deficit characteristic of anterior hippocampal-prefrontal network. Implications for cognitive intervention are discussed.