Lung function in adults born preterm

Very preterm birth, before the gestational age (GA) of 32 weeks, increases the risk of obstructed airflow in adulthood. We examined whether all preterm births (GA<37 weeks) are associated with poorer adult lung function and whether any associations are explained by maternal, early life/neonatal, or current life factors. Participants of the ESTER Preterm Birth Study, born between 1985 and 1989 (during the pre-surfactant era), at the age of 23 years participated in a clinical study in which they performed spirometry and provided detailed medical history. Of the participants, 139 were born early preterm (GA<34 weeks), 239 late preterm (GA: 34-<37 weeks), and 341 full-term (GA≥37 weeks). Preterm birth was associated with poorer lung function. Mean differences between individuals born early preterm versus full-term were -0.23 standard deviation (SD) (95% confidence interval (CI): -0.40, -0.05)) for forced vital capacity z-score (zFVC), -0.44 SD (95% CI -0.64, -0.25) for forced expiratory volume z-score (zFEV1), and -0.29 SD (95% CI -0.47, -0.10) for zFEV1/FVC. For late preterm, mean differences with full-term controls were -0.02 SD (95% CI -0.17, 0.13), -0.12 SD (95% CI -0.29, 0.04) and -0.13 SD (95% CI -0.29, 0.02) for zFVC, zFEV1, and zFEV1/FVC, respectively. Examination of finer GA subgroups suggested an inverse non-linear association between lung function and GA, with the greatest impact on zFEV1 for those born extremely preterm. The subgroup means were GA<28 weeks: -0.98 SD; 28-<32 weeks: -0.29 SD; 32-<34 weeks: -0.44 SD; 34-<36 weeks: -0.10 SD; 36-<37weeks: -0.11 SD; term-born controls (≥37weeks): 0.02 SD. Corresponding means for zFEV1/FVC were -1.79, -0.44, -0.47, -0.48, -0.29, and -0.02. Adjustment for maternal pregnancy conditions and socioeconomic and lifestyle factors had no major impact on the relationship. Preterm birth is associated with airflow limitation in adult life. The association appears to be attributable predominantly to those born most immature, with only a modest decrease among those born preterm at later gestational ages.</p

Body composition among Malawian young adolescents:cross-validating predictive equations for bioelectric impedance analysis using deuterium dilution method

Abstract Background: Body composition can be measured by several methods, each with specific benefits and disadvantages. Bioelectric impedance offers a favorable balance between accuracy, cost and ease of measurement in a range of settings. In this method, bioelectric measurements are converted to body composition measurements by prediction equations specific to age, population and bioimpedance device. Few prediction equations exist for populations in low-resource settings. We formed a prediction equation for total body water in Malawian adolescents using deuterium dilution as reference. Methods: We studied 86 boys and 92 girls participating in the 11-14-year follow-up of the Lungwena Antenatal Intervention Study, a randomized trial of presumptive infection treatment among pregnant women. We measured body composition by Seca m515 bioimpedance analyser. Participants ingested a weight-standardized dose of deuterium oxide, after which we collected saliva at baseline, at 3 and 4 h post-ingestion, measured deuterium concentration using Fourier-transform infrared spectroscopy and calculated total body water. We formed predictive equations for total body water using anthropometrics plus resistance and reactance at a range of frequencies, applying multiple regression and repeated cross-validation in model building and in prediction error estimation. Results: The best predictive model for percentage total body water (TBW %) was 100*(1.11373 + 0.0037049*height (cm)²/resistance(Ω) at 50 kHz– 0.25778*height(m)– 0.01812*BMI(kg/m²)– 0.02614*female sex). Calculation of absolute TBW (kg) by multiplying TBW (%) with body weight had better predictive power than a model directly constructed to predict absolute total body water (kg). This model explained 96.4% of variance in TBW (kg) and had a mean prediction error of 0.691 kg. Mean bias was 0.01 kg (95% limits of agreement -1.34, 1.36) for boys and -0.01 kg (1.41, 1.38) for girls. Conclusions: Our equation provides an accurate, cost-effective and participant-friendly body composition prediction method among adolescents in clinic-based field studies in rural Africa, where electricity is available

Out‐of‐home care placements of children and adolescents born preterm:a register‐based cohort study

Abstract Background: Preterm birth predisposes to child protection action in the form out‐of‐home care. The impact of the degree of preterm birth on the likelihood for OHC placement(s) and their timing is unknown. Methods: This population‐based register‐linkage study assessed the likelihood of OHC placement in different gestational age groups using multivariable Cox regression models. All 193 033 traceable singleton (8324 preterm, 4.3%) liveborn in Finland (January 1987‐September 1990), as the first index child of each mother within the cohort period, were followed up until their 18th birthday. Results: A total of 6562 children (3.4%) experienced OHC. In comparison with full‐term children (39‐41 weeks), those born at 23‐33 completed weeks were predisposed to OHC (hazard ratio [HR] 2.11, 95% confidence interval [CI] 1.74, 2.56). For those born late preterm (34‐36 weeks) and early term (37‐38 weeks), the HR were 1.54 (95% CI 1.37, 1.73) and 1.19 (95% CI 1.12, 1.26), respectively. Adjustment for parental and child characteristics attenuated the HRs: 23‐33 weeks: 1.31 (95% CI 1.07, 1.59), 34‐36 weeks: 1.17 (95% CI 1.04, 1.31), and 37‐38 weeks: 1.08 (95% CI 1.02, 1.16). However, the adjusted HRs for first OHC entries at 0‐5 years of age were higher: 23‐33 weeks 2.29 (95% CI 1.72, 3.05), 34‐36 weeks 1.76 (95% CI 1.46, 2.13), and 37‐38 weeks 1.40 (95% CI 1.25, 1.56). Among those born preterm or early term, in comparison with their term born peers, no excess risk for OHC was seen after 5 years. Conclusions: A dose‐response relationship exists between the level of preterm birth and OHC placement risk. OHC placements are more common among early and late preterm, and early term children, compared with those born full term, and occur at younger age. Perinatal and postnatal adverse circumstances appear to explain the phenomenon only partly

Preterm birth and asthma and COPD in adulthood:a nationwide register study from two Nordic countries

Abstract Background: Preterm birth affects lungs in several ways but few studies have follow-up until adulthood. We investigated the association of the entire spectrum of gestational ages with specialist care episodes for obstructive airway disease (asthma and chronic obstructive pulmonary disease (COPD)) at age 18–50 years. Methods: We used nationwide registry data on 706 717 people born 1987–1998 in Finland (4.8% preterm) and 1 669 528 born 1967–1999 in Norway (5.0% preterm). Care episodes of asthma and COPD were obtained from specialised healthcare registers, available in Finland for 2005–2016 and in Norway for 2008–2017. We used logistic regression to estimate odds ratios (ORs) for having a care episode with either disease outcome. Results: Odds of any obstructive airway disease in adulthood for those born at &lt;28 or 28–31 completed weeks were 2–3-fold of those born full term (39–41 completed weeks), persisting after adjustments. For individuals born at 32–33, 34–36 or 37–38 weeks, the odds were 1.1- to 1.5-fold. Associations were similar in the Finnish and the Norwegian data and among people aged 18–29 and 30–50 years. For COPD at age 30–50 years, the OR was 7.44 (95% CI 3.49–15.85) for those born at &lt;28 weeks, 3.18 (95% CI 2.23–4.54) for those born at 28–31 weeks and 2.32 (95% CI 1.72–3.12) for those born at 32–33 weeks. Bronchopulmonary dysplasia in infancy increased the odds further for those born at &lt;28 and 28–31 weeks. Conclusion: Preterm birth is a risk factor for asthma and COPD in adulthood. The high odds of COPD call for diagnostic vigilance when adults born very preterm present with respiratory symptoms

What more can be done? Prioritizing the most promising antenatal interventions to improve birth weight

BACKGROUND: Low birth weight (LBW) is associated with neonatal mortality and sequelae of lifelong health problems; prioritizing the most promising antenatal interventions may guide resource allocation and improve health outcomes. OBJECTIVE: We sought to identify the most promising interventions that are not yet included in the policy recommendations of the World Health Organization (WHO) but could complement antenatal care and reduce the prevalence of LBW and related adverse birth outcomes in low- and middle-income settings. METHODS: We utilized an adapted Child Health and Nutrition Research Initiative (CHNRI) prioritization method. RESULTS: In addition to procedures already recommended by WHO for the prevention of LBW, we identified six promising antenatal interventions that are not currently recommended by WHO with an indication for LBW prevention, namely: (1) provision of multiple micronutrients; (2) low-dose aspirin; (3) high-dose calcium; (4) prophylactic cervical cerclage; (5) psychosocial support for smoking cessation; and (6) other psychosocial support for targeted populations and settings. We also identified seven interventions for further implementation research and six interventions for efficacy research. CONCLUSION: These promising interventions, coupled with increasing coverage of currently recommended antenatal care, could accelerate progress toward the global target of a 30% reduction in the number of LBW infants born in 2025 compared to 2006-10

What more can be done? Prioritizing the most promising antenatal interventions to improve birth weight.

BACKGROUND: Low birth weight (LBW) is associated with neonatal mortality and sequelae of lifelong health problems; prioritizing the most promising antenatal interventions may guide resource allocation and improve health outcomes. OBJECTIVE: We sought to identify the most promising interventions that are not yet included in the policy recommendations of the World Health Organization (WHO) but could complement antenatal care and reduce the prevalence of LBW and related adverse birth outcomes in low- and middle-income settings. METHODS: We utilized an adapted Child Health and Nutrition Research Initiative (CHNRI) prioritization method. RESULTS: In addition to procedures already recommended by WHO for the prevention of LBW, we identified six promising antenatal interventions that are not currently recommended by WHO with an indication for LBW prevention, namely: (1) provision of multiple micronutrients; (2) low-dose aspirin; (3) high-dose calcium; (4) prophylactic cervical cerclage; (5) psychosocial support for smoking cessation; and (6) other psychosocial support for targeted populations and settings. We also identified seven interventions for further implementation research and six interventions for efficacy research. CONCLUSION: These promising interventions, coupled with increasing coverage of currently recommended antenatal care, could accelerate progress toward the global target of a 30% reduction in the number of LBW infants born in 2025 compared to 2006-10

Expiratory airflow in late adolescence and early adulthood in individuals born very preterm or with very low birthweight compared with controls born at term or with normal birthweight:a meta-analysis of individual participant data

Abstract Background: Maximal expiratory airflow peaks early in the third decade of life, then gradually declines with age. The pattern of airflow through adulthood for individuals born very preterm (at &lt;32 weeks’ gestation) or with very low birthweight (&lt;1501 g) is unknown. We aimed to compare maximal expiratory airflow in these individuals during late adolescence and early adulthood with that of control individuals born with normal birthweight (&gt;2499 g) or at term. Methods: We did a meta-analysis of individual participant data from cohort studies, mostly from the pre-surfactant era. Studies were identified through the Adults born Preterm International Collaboration and by searching PubMed and Embase (search date May 25, 2016). Studies were eligible if they reported on expiratory flow rates beyond 16 years of age in individuals born very preterm or with very low birthweight, as well as controls born at term or with normal birthweight. Studies with highly selected cohorts (eg, only participants with bronchopulmonary dysplasia) or in which few participants were born very preterm or with very low birthweight were excluded. De-identified individual participant data from each cohort were provided by the holders of the original data to a central site, where all the data were pooled into one data file. Any data inconsistencies were resolved by discussion with the individual sites concerned. Individual participant data on expiratory flow variables (FEV1, forced vital capacity [FVC], FEV1/FVC ratio, and forced expiratory flow at 25–75% of FVC [FEF25–75%]) were converted to Z scores and analysed with use of generalised linear mixed models in a one-step approach. Findings: Of the 381 studies identified, 11 studies, comprising a total of 935 participants born very preterm or with very low birthweight and 722 controls, were eligible and included in the analysis. Mean age at testing was 21 years (SD 3·4; range 16–33). Mean Z scores were close to zero (as expected) in the control group, but were reduced in the very preterm or very low birthweight group for FEV1 (−0·06 [SD 1·03] vs −0·81 [1·33], mean difference −0·78 [95% CI −0·96 to −0·61], p&lt;0·0001), FVC (−0·15 [0·98] vs −0·38 [1·18], −0·25 [–0·40 to −0·10], p=0·0012), FEV1/FVC ratio (0·14 [1·10] vs −0·64 [1·35], −0·74 [–0·85 to −0·64], p&lt;0·0001), and FEF25–75% (−0·04 [1·10] vs −0·95 [1·47], −0·88 [–1·12 to −0·65], p&lt;0·0001). Similar patterns were observed when we compared the proportions of individuals with values below the fifth percentile. Interpretation: Individuals born very preterm or with very low birthweight are at risk of not reaching their full airway growth potential in adolescence and early adulthood, suggesting an increased risk of chronic obstructive pulmonary disease in later adulthood