Association between vitamin D level and respiratory distress syndrome: A systematic review and meta-analysis.

BACKGROUND: Growing evidence suggests an association between the vitamin D levels and respiratory outcomes of preterm infants. The objective of this systematic review and meta-analysis was to explore whether premature neonates with a vitamin D deficiency have an increased risk of respiratory distress syndrome (RDS). METHODS: We searched PubMed, EMBASE, and the Cochrane Library up through July 20, 2021. The search terms were 'premature infant', 'vitamin D', and 'respiratory distress syndrome'. We retrieved randomized controlled trials and cohort and case-control studies. For statistical analysis, we employed the random-effects model in Comprehensive Meta-Analysis Software ver. 3.3. We employed the Newcastle-Ottawa Scales for quality assessment of the included studies. RESULTS: A total of 121 potentially relevant studies were found, of which 15 (12 cohort studies and 3 case-control studies) met the inclusion criteria; the studies included 2,051 preterm infants. We found significant associations between RDS development in such infants and vitamin D deficiency within 24 h of birth based on various criteria, thus vitamin D levels < 30 ng/mL (OR 3.478; 95% CI 1.817-6.659; p < 0.001), < 20 ng/mL (OR 4.549; 95% CI 3.007-6.881; p < 0.001), < 15 ng/mL (OR 17.267; 95% CI 1.084-275.112; p = 0.044), and < 10 ng/ml (OR 1.732; 95% CI 1.031-2.910; p = 0.038), and an even lower level of vitamin D (SMD = -0.656; 95% CI -1.029 to -0.283; p = 0.001). CONCLUSION: Although the vitamin D deficiency definitions varied and different methods were used to measure vitamin D levels, vitamin D deficiency or lower levels of vitamin D within 24 h of birth were always associated with RDS development. Monitoring of neonatal vitamin D levels or the maintenance of adequate levels may reduce the risk of RDS.

Impact of Cerebellar Injury on Neurodevelopmental Outcomes in Preterm Infants With Cerebral Palsy.

OBJECTIVE: We aimed to analyze brain imaging findings and neurodevelopmental outcomes of preterm infants diagnosed with cerebral palsy. DESIGN: Brain magnetic resonance imaging of preterm infants born between 23 and 32 wks' gestation and diagnosed with cerebral palsy at 2 yrs of corrected age were evaluated. Brain lesions were categorized as periventricular leukomalacia, intraventricular hemorrhage, and cerebellar hemorrhage and graded by the severity. Neurodevelopmental outcomes were assessed using the Bayley Scales of Infant and Toddler Development, Third Edition, at 18-24 mos corrected age, and the Korean Ages and Stages Questionnaire at 18 and 24 mos of corrected age. RESULTS: Cerebral palsy was found in 38 children (6.1%) among 618 survivors. Cerebellar injury of high-grade cerebellar hemorrhage and/or atrophy accounted for 25%. Among patients with supratentorial lesions, those having cerebellar injury showed significantly lower scores on each Korean Ages and Stages Questionnaire domain except gross motor than patients without cerebellar injury. They also revealed a high proportion of patients below the cutoff value of Korean Ages and Stages Questionnaire in language, fine motor, and problem-solving domains ( P < 0.05) and lower Bayley Scales of Infant and Toddler Development, Third Edition, language composite scores ( P = 0.038). CONCLUSIONS: Poor neurodevelopmental outcomes other than motor function were associated with cerebellar injury. Evaluation of the cerebellum may help predict functional outcomes of patients with cerebral palsy.

Risk factors of early pulmonary hypertension and its clinical outcomes in preterm infants: a systematic review and meta-analysis.

The aim of this meta-analysis was to determine the incidence and risk factors of early pulmonary hypertension (PHT) in preterm infants and evaluate the association of early PHT with morbidities such as bronchopulmonary dysplasia (BPD), late PHT, and in-hospital mortality. We searched the PubMed (1980-2021), Embase (1968-2021), CINAHL (2002-2021), Cochrane library (1989-2021), and KoreaMed (1993-2021). Observational studies on the association between early PHT diagnosed within the first 2 weeks after birth and its clinical outcomes in preterm infants born before 37 weeks of gestation or with very low birth weight (< 1500 g) were included. Two authors independently extracted the data and assessed the quality of each study using a modified Newcastle-Ottawa Scale. We performed meta-analysis using Comprehensive Meta-Analysis version 3.3. A total of 1496 potentially relevant studies were found, of which 8 studies (7 cohort studies and 1 case-control study) met the inclusion criteria comprising 1435 preterm infants. The event rate of early PHT was 24% (95% confidence interval [CI] 0.174-0.310). The primary outcome of our study was moderate to severe BPD at 36 weeks postmenstrual age, and it was associated with early PHT (6 studies; odds ratio [OR] 1.682; 95% CI 1.262-2.241; P < 0.001; heterogeneity: I2 = 0%; P = 0.492). Preterm infants with early PHT had higher OR of in-hospital mortality (6 studies; OR 2.372; 95% CI 1.595-3.528; P < 0.001; heterogeneity: I2 = 0%; P = 0.811) and developing late PHT diagnosed after 4 weeks of life (4 studies; OR 2.877; 95% CI 1.732-4.777; P < 0.001; heterogeneity: I2 = 0%; P = 0.648). Infants with oligohydramnios (4 studies; OR 2.134; 95% CI 1.379-3.303; P = 0.001) and those who were small-for-gestational-age (5 studies; OR 1.831; 95% CI 1.160-2.890; P = 0.009) had an elevated risk of developing early PHT. This study showed that early PHT is significantly associated with mortality and morbidities, such as BPD and late PHT. Preterm infants with a history of oligohydramnios and born small-for-gestational-age are at higher risk for developing early PHT; however, high-quality studies that control for confounders are necessary.

Association of Maternal Hypertensive Disorders During Pregnancy With Severe Bronchopulmonary Dysplasia: A Systematic Review and Meta-Analysis.

BACKGROUND: This meta-analysis was performed to examine the association between maternal hypertension during pregnancy (HDP) and neonatal bronchopulmonary dysplasia (BPD). METHODS: We systematically searched PubMed, EMBASE, the Cochrane Library, and the KoreaMed database for relevant studies. We used the Newcastle-Ottawa Scale for quality assessment of all included studies. The meta-analysis was performed using Comprehensive Meta-Analysis software (version 3.3). RESULTS: We included 35 studies that fulfilled the inclusion criteria; the total number of infants evaluated came to 97,399 through review process. Maternal HDP was not significantly associated with any definition of BPD, i.e., oxygen dependency at 36 weeks of gestation (odds ratio [OR], 1.162; 95% confidence interval [CI], 0.991-1.362; P = 0.064) in pooled analysis of 29 studies or oxygen dependency at 28 days of age (OR, 1.084; 95% CI, 0.660-1.780; P = 0.751) in pooled analysis of 8 studies. Maternal HDP was significantly associated only with severe BPD (OR, 2.341; 95% CI, 1.726-3.174; P < 0.001). BPD was not associated with HDP in the overall analysis (OR, 1.131; 95% CI, 0.977-1.309; P = 0.100) or subgroup analysis according to the definition of HDP. CONCLUSION: Maternal HDP was not associated with neonatal BPD defined by the duration of oxygen dependency (at either 36 weeks of gestation or 28 days of life) but was associated with severe BPD.

Impact of size at birth and postnatal growth on metabolic and neurocognitive outcomes in prematurely born school-age children.

Prematurity, size at birth, and postnatal growth are important factors that determine cardiometabolic and neurodevelopmental outcomes later in life. In the present study, we aimed to investigate the associations between the size at birth and growth velocity after birth with cardiometabolic and neurodevelopmental outcomes in preterm infants. Fifty-six preterm infants born at < 32 weeks of gestation or having a birth weight of < 1500 g were enrolled and categorized into small for gestational age (SGA) and appropriate for gestational age (AGA) groups. Anthropometric and cardiometabolic parameters were assessed at school-age, and the Korean Wechsler Intelligence Scale for Children, fourth edition (K-WISC-IV) was used for assessing the intellectual abilities. The growth velocity was calculated by changes in the weight z-score at each time period. Multivariate analysis was conducted to investigate the associations of growth velocity at different periods with cardiometabolic and neurodevelopmental outcomes. Forty-two (75%) were classified as AGA and 25% as SGA. At school-age, despite the SGA children showing significantly lower body weight, lean mass index, and body mass index, there were no differences in the cardiometabolic parameters between SGA and AGA groups. After adjusting for gestational age, birth weight z-score, weight z-score change from birth to discharge and sex, change in weight z-score beyond 12 months were associated with a higher systolic blood pressure, waist circumference, and insulin resistance. Full-scale intelligent quotient (ß = 0.314, p = 0.036) and perceptional reasoning index (ß = 0.456, p = 0.003) of K-WISC-IV were positively correlated with postnatal weight gain in the neonatal intensive care unit. Although cardiometabolic outcomes were comparable in preterm SGA and AGA infants, the growth velocity at different time periods resulted in different cardiometabolic and neurocognitive outcomes. Thus, ensuring an optimal growth velocity at early neonatal period could promote good neurocognitive outcomes, while adequate growth after 1 year could prevent adverse cardiometabolic outcomes in preterm infants.