Clinical treatment outcomes and their changes in extremely preterm twins: a multicenter retrospective study in Guangdong Province, China / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical treatment outcomes and the changes of the outcomes over time in extremely preterm twins in Guangdong Province, China.@*METHODS@#A retrospective analysis was performed for 269 pairs of extremely preterm twins with a gestational age of <28 weeks who were admitted to the department of neonatology in 26 grade A tertiary hospitals in Guangdong Province from January 2008 to December 2017. According to the admission time, they were divided into two groups: 2008-2012 and 2013-2017. Besides, each pair of twins was divided into the heavier infant and the lighter infant subgroups according to birth weight. The perinatal data of mothers and hospitalization data of neonates were collected. The survival rate of twins and the incidence rate of complications were compared between the 2008-2012 and 2013-2017 groups.@*RESULTS@#Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of severe asphyxia and smaller head circumference at birth (P<0.05). The mortality rates of both of the twins, the heavier infant of the twins, and the lighter infant of the twins were lower in the 2013-2017 group compared with the 2008-2012 group (P<0.05). Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of pulmonary hemorrhage, patent ductus arteriosus (PDA), periventricular-intraventricular hemorrhage (P-IVH), and neonatal respiratory distress syndrome (NRDS) and a higher incidence rate of bronchopulmonary dysplasia (P<0.05).@*CONCLUSIONS@#There is a significant increase in the survival rate over time in extremely preterm twins with a gestational age of <28 weeks in the 26 grade A tertiary hospitals in Guangdong Province. The incidences of severe asphyxia, pulmonary hemorrhage, PDA, P-IVH, and NRDS decrease in both the heavier and lighter infants of the twins, but the incidence of bronchopulmonary dysplasia increases. With the improvement of diagnosis and treatment, the multidisciplinary collaboration between different fields of fetal medicine including prenatal diagnosis, obstetrics, and neonatology is needed in the future to jointly develop management strategies for twin pregnancy.

Angiogenesis and its regulatory factors in brain tissue of neonatal rat hypoxic-ischemic encephalopathy / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate possible mechanism of angiogenesis in brain tissue of neonatal rat hypoxic-ischemic encephalopathy (HIE).</p><p><b>METHODS</b>Forty seven-day old neonatal rats were randomly assigned to hypoxic-ischemic (Model group) or sham treatment (Sham group), each group had 20 rats. Five rats from each group were sacrificed on days 1, 3, 7 and 14 after hypoxia-ischemia. Paraffin sections of the brain were stained with anti-endothelial cell, anti-proliferating cell nuclear antigen (PCNA) or anti-vascular endothelial growth factor (VEGF) by using single or double immunohistochemistry. The brain capillary density index (BCDI), brain proliferating capillary density index (BPCDI) and the expression of VEGF were analyzed under the microscope. The expression of VEGF and hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA in hypoxic-ischemic side of the brain was measured by RT-PCR.</p><p><b>RESULTS</b>BCDI around infarct brain tissue in the model group began to rise on day 3 and remained higher than that of the sham group from day 3 to day 14 [day 3: (9.80 +/- 1.05)/HPF vs. (4.90 +/- 0.66)/HPF, P < 0.01;day 14: (13.29 +/- 3.90)/HPF vs. (6.08 +/- 1.50)/HPF, P < 0.01]. Occasional proliferating capillary was found in brain tissue of normal neonatal rats. The density of proliferating brain capillary on day 3 and day 7 of Model group [(0.54 +/- 0.15)/HPF vs. (0.90 +/- 0.25)/HPF] were significantly higher than those of Sham group [(0.12 +/- 0.05)/HPF vs. (0.13 +/- 0.07)/HPF, P < 0.01]. VEGF was mainly expressed in the cytoplasm of neurons, capillary endothelial cells and pial cells. Viable neurons and endothelial cells in the infarct areas also expressed VEGF. The expression of VEGF mRNA in hypoxic-ischemic brain tissue was significantly higher than that of normal control (P < 0.01) and temporally preceded angiogenesis. The expression of VEGF mRNA at 12 hours of HIE model was significantly higher than that of normal control (1.56 +/- 0.27 vs. 0.95 +/- 0.21, P < 0.05). It reached its peak on day 1 and day 3 (1.85 +/- 0.31 vs. 1.86 +/- 0.39), significantly higher than that of normal control (P < 0.01), and decreased by day 7 and day 14, without significant difference compared with normal control (P > 0.05). The expression of HIF-1alpha mRNA was also up-regulated after hypoxic-ischemic treatment. The expression of HIF-1alpha mRNA (1.07 +/- 0.21) was significantly higher than that of normal control (0.64 +/- 0.28, P = 0.048) at 3-hour of HIE model, reached its peak on day 1 (1.73 +/- 0.42, P < 0.01), remained at high expression level on day 3 (1.44 +/- 0.36, P < 0.05) and began to decline by day 7 and day 14 when it was not significantly different from normal control.</p><p><b>CONCLUSIONS</b>Angiogenesis exists in the brain tissue of neonatal rat HIE model. Up-regulation of VEGF expression mediated by HIF-1 may play an important role in the process of angiogenesis.</p>