Young adult outcomes following premature birth: A Western Australian experience.

BACKGROUND: Childhood outcomes following preterm birth are widely published, however long-term adult outcomes are less well described. We aimed to determine the quality of life and burden of co-morbidities experienced by preterm-born young adults in Western Australia. METHODS: A retrospective observational study was conducted. Participants born at 23-33 weeks gestation cared for at King Edward Memorial Hospital during 1990 and 1991 were recruited from a historical birth cohort. Participants completed general, medical and reproductive health questionnaires. Results were compared with contemporaneous cohort data and/or population statistics. RESULTS: Questionnaires were received from 73 young adults aged 28 to 30 years. The majority of respondents completed high school (94.5 %), were employed fulltime (74.0 %) and had close friends and family relationships. Almost all the participants considered their health to be good (94.0 %) and participated in light exercise (90.0 %). Increased hypertension, hypercholesterolaemia, asthma, neuropsychiatric conditions and visual impairment were reported. Depression Anxiety and Stress Scale (DASS-21) scoring identified increased mild anxiety. Increased consultation with healthcare workers and use of prescription medications were reported. CONCLUSION: The group of preterm-born adults surveyed reported a good quality of life, supportive interpersonal relationships and they provided significant contributions to society. They did report increased medical and psychological conditions than the general population.

Evaluation of the frequency and obstetric risk factors associated with term neonatal admissions to special care units.

INTRODUCTION: Approximately 10-15% of term babies may require admission to neonatal special care units. This level of care is frequently an unexpected event for parents. AIMS: To review the frequency and obstetric risk factors associated with the admission of term neonates to a tertiary hospital special care unit (SCN). MATERIALS AND METHODS: All babies born ≥37-weeks gestation admitted to the SCN at King Edward Memorial Hospital between 2004 and 2006 were identified from the institutional maternity and neonatal databases. Maternal and obstetric factors were reviewed to identify potential predictors of admission to the SCN. RESULTS: During the study period, 1671 term neonates born to 1624 women were admitted to the SCN (14.4% of term deliveries). Neonatal intensive care unit admissions accounted for 10.6% of the term admissions. The most common reasons for SCN admission were respiratory complications (n = 421, 25.2%), observation postresuscitation (n = 402, 24.1%) and hypoglycaemia (n = 152, 9.1%). Elective caesarean delivery was significantly associated with admission to the special care unit for respiratory complications compared with all other delivery modes (37 vs 23%, P < 0.001), particularly if the birth occurred at <39-weeks gestation (38 vs 24%, P < 0.001). CONCLUSIONS: In our population of women delivering at a tertiary maternity facility, approximately 1:8 term babies were admitted to the neonatal special care unit. Elective caesarean delivery was associated with a significant risk of admission for respiratory complications compared with other birth modes, especially when <39-weeks gestation.

The hypoxia challenge test does not accurately predict hypoxia in flight in ex-preterm neonates.

BACKGROUND: Air travel may pose risks to ex-preterm neonates due to the low oxygen environment encountered during flights. We aimed to study the utility of the preflight hypoxia challenge test (HCT) to detect in-flight hypoxia in such infants. METHODS: Ex-preterm (gestation < or = 35 completed weeks) infants ready for air transfer from the intensive/special care nursery to regional hospitals were studied. A pretransfer HCT was performed by exposing infants to 14% oxygen for 20 min. Failure was defined as a sustained fall in pulse oxygen saturation (Spo(2)) < or = 85%. A nurse blinded to the test result monitored the in-flight oxygen saturations in each infant. If Spo(2) fell to < or = 85%, oxygen was administered. RESULTS: Forty-six infants with median gestation of 32.2 weeks (range, 24 to 35.6 weeks) and birth weight of 1,667 g (range, 655 to 2,815 g) were recruited. No infants were receiving supplemental oxygen at the time of transfer. The HCT was performed at a median corrected age of 35.8 weeks (range, 33.1 to 43 weeks). Thirty-five infants (76%) passed the test, and the remainder failed. During the flight, 16 infants met the criteria for in-flight oxygen, but 12 of these infants (75%) had passed the preflight HCT. Of the 11 infants who failed the HCT, only 4 infants (36%) required in-flight oxygen. The HCT incorrectly predicted in-flight responses in 42% (19 of 46 infants). CONCLUSIONS: A significant percentage of ex-preterm neonates require in-flight oxygen supplementation. The HCT is not accurate for identifying which infants are at risk for in-flight hypoxia.

Functional maturation of CD4+CD25+CTLA4+CD45RA+ T regulatory cells in human neonatal T cell responses to environmental antigens/allergens.

A number of laboratories have reported cord blood T cell responses to ubiquitous environmental Ags, including allergens, by proliferation and cytokine secretion. Moreover, the magnitude of these responses has been linked with risk for subsequent expression of allergy. These findings have been widely interpreted as evidence for transplacental priming and the development of fetal T memory cells against Ags present in the maternal environment. However, we present findings below that suggest that neonatal T cell responses to allergens (and other Ags) differ markedly from those occurring in later life. Notably, in contrast to allergen-responsive adult CD4(+) T cell cultures, responding neonatal T cell cultures display high levels of apoptosis. Comparable responses were observed against a range of microbial Ags and against a parasite Ag absent from the local environment, but not against autoantigen. A notable finding was the appearance in these cultures of CD4(+)CD25(+)CTLA4(+) T cells that de novo develop MLR-suppressive activity. These cells moreover expressed CD45RA and CD38, hallmarks of recent thymic emigrants. CFSE-labeling studies indicate that the CD4(+)CD25(+) cells observed at the end of the culture period were present in the day 0 starting populations, but they were not suppressive in MLR responses. Collectively, these findings suggest that a significant component of the reactivity of human neonatal CD4(+) T cells toward nominal Ag (allergen) represents a default response by recent thymic emigrants, providing an initial burst of short-lived cellular immunity in the absence of conventional T cell memory, which is limited in intensity and duration via the parallel activation of regulatory T cells.

Development of interleukin-12-producing capacity throughout childhood.

Increasing evidence indicates that the capacity to induce protective Th1 immune responses is impaired in early childhood, an observation that can be partially attributed to deficiencies in antigen-presenting-cell function. Synthesis of interleukin 12 (IL-12), a key Th1-trophic cytokine, is markedly reduced in the neonatal period, though there is a paucity of knowledge concerning the ontogeny of IL-12-synthetic capacity throughout the childhood years. Hence, we examined the production of bioactive IL-12 p70 by circulating mononuclear cells in a population of healthy individuals. As expected, the capacity to synthesize IL-12 p70 in response to either lipopolysaccharide or heat-killed Staphylococcus aureus was markedly impaired at birth, even after priming of cells with gamma interferon. Surprisingly however, IL-12 p70 synthesis by peripheral blood mononuclear cells from both 5- and 12-year-old children was still substantially below that seen in adults, and this did not appear to be related to excessive production of IL-10. In contrast, dendritic cells from adults and neonates, derived from monocytes with granulocyte-macrophage colony-stimulating factor and IL-4, synthesized equivalent amounts of IL-12 p70 in response to microbial stimulation. This indicates that the impaired capacity for IL-12 synthesis in childhood is not an intrinsic property of circulating mononuclear cells but rather can be readily overcome in response to appropriate maturational stimuli. Because IL-12 arose predominantly from circulating HLA-DR(+) cells that lacked B-cell- and monocyte-specific markers, we propose that the slow maturation of IL-12-synthetic capacity in the childhood years can be attributed to deficiencies in the number and/or function of dendritic cells.