Objective To investigate the dynamic changes and influencing factors of peripheral blood white blood cells (WBC), differential counts (DCs) and platelet (PLT) count in preterm infants to understand the changing characteristics of these blood parameters in preterm infants of different postnatal age, gestational age, and birth weight.Methods Totally 2 849 preterm infants admitted to the Department of Neonatology of Northwest Women's and Children's Hospital from November 30, 2011 to November 30, 2014 were retrospectively analyzed except for those diagnosed with infectious diseases, hematological system diseases, or immunologic diseases.All of the subjects were divided into seven groups based on their postnatal age, three groups based on gestational age and three groups based on birth weight, or male and female groups, respectively.Peripheral blood samples were obtained for determination of WBC, DCs and PLT.Statistical analysis was performed with oneway analysis of variance, t-test and Spearman linear correlation analysis.Results WBC, neutrophil (Ne), lymphocyte (Ly), monocyte (Mo), eosinophil (Eo), basophil (Ba) and PLT counts were significantly different among the seven groups of preterm babies of different postnatal age (F=172.00, 364.90, 34.88, 14.22, 80.82, 168.10 and 86.64, respectively, all P ＜ 0.01).WBC was found to be at the peak value within one day after birth [(18.40±6.87)× 109/L], followed by remarkable decrease in day ＞ 2-≤ 5 [(10.62±4.68)× 109/L], further gradual decrease thereafter, and then being stable in day ＞ 14-≤ 21 and ＞ 21 ≤≤ 30 [(10.54±3.09)× 109/L and (10.27 ± 3.70) × 109/L, respectively].PLT counts showed no significant change within one day after birth and in day ＞ 1-≤ 2 [(240.56± 63.54)× 109/L and (240.85 ± 71.47) × 109/L, respectively], then began to increase in day ＞ 2-≤ 5 [(249.21 ±80.55)× 109/L], peaked in day ＞ 7-≤ 14 [(339.11 ± 121.84)× 109/L], and decreased gently and became stable finally.The changing trends of Ne and Ly were cross and inverted in day ＞ 5-≤ 7.WBC, Ne, Ly, Mo, Eo, Ba and PLT counts of the preterm infants were all correlated with the postnatal age shown by Spearman linear correlation analysis (r=-0.46,-0.60, 0.18,-0.07, 0.33,-0.47 and 0.29, respectively, all P ＜ 0.01).With the increase of gestational age, WBC, Ne, Mo, and PLT counts increased, but Ly and Eo counts decreased.And all of the above showed significant difference (F=81.00, 124.49, 13.34, 18.35, 5.35 and 4.11, respectively, all P ＜ 0.05).While, the WBC, Ne, Mo, Ba and PLT counts showed positive relationship with the increase of birth weight (F=122.12, 133.09, 39.38, 13.77 and 21.24, respectively, all P ＜ 0.05).WBC, Ne and PLT counts of female infants were higher than those of male babies (t=l 6.35, 16.72 and 13.19, respectively, all P ＜ 0.05).Conclusions The peripheral WBC, DCs and PLT counts of preterm infants change dynamically with postnatal age with the remarkable variations on day ＞2-≤ 5 after birth and stable after 14 days of age.WBC, DCs and PLT counts might all be influenced by gestational age, birth weight and gender to some cxtend.

Objective To explore the influencing factors of the vaginal birth after cesarean section (VBAC), and establish a model for predicting the risk of trial of the trial of labor after cesarean section (TOLAC). Methods From January 2016 to December 2018, total 694 pregnant women who underwent TOLAC in Northwest Women's and Children's Hospital were retrospectively analyzed. Those cases were divided into two groups according to the mode of delivery: the VBAC group and the failed TOLAC group. At the same time, 700 cases in the elective repeat cesarean section (ERCS) group were randomly selected as control group. The influencing factors of VBAC were analyzed by univariate and multivariate logistic regression, and the pregnancy outcomes between the three groups were compared. Results (1) The VBAC rate was 76.1% (528/694) and 166 women underwent the failed TOLAC (23.9%, 166/694). (2) Univariate analysis found that, the pre-pregnancy body mass index (BMI) [(22.0±3.0),(23.3±2.7) kg/m2], the previous vaginal delivery history [10.4%(55/528),3.6%(6/166)], the cervical score (5.2±1.9,4.3±1.6) and the neonatal birth weight [(3 315 ± 468), (3 484 ± 274) g] of the VBAC group were significantly different from the failed TOLAC group (P<0.05). (3) The comparison of pregnancy outcomes: the neonatal birth weight was (3 315± 468) g, and the intrapartum hemorrhage volume was (255 ± 121) ml in the VBAC group, which were significantly lower than those in the failed TOLAC group [intrapartum hemorrhage (325 ± 173) ml] and the ERCS group [(3 572±344) g, (281±125) ml], there were statistically significant differences in the comparison among the three groups (all P<0.05). Two cases of bladder injury occurred during cesarean section in the TOLAC failure group (1.2%,2/166). The rates of the blood transfusion, puerperal infection, 5-minute Apgar score and neonatal ICU admission among the three groups were no statistically significantly different (all P>0.05). There was no maternal or perinatal death. (4) Multivariate logistic regression analysis showed that the delivery age of pregnant women ( OR=0.92, 95% CI : 0.87-0.98), pre-pregnancy BMI ( OR=0.92, 95% CI :0.86-0.98), vaginal delivery history ( OR=3.31, 95% CI : 1.35-8.01), cervical score ( OR=1.29, 95% CI :1.13-1.42) and the birth weight of the neonates <3 300 g ( OR=3.15, 95% CI : 2.02-4.90) were independent influencing factors for VBAC. The area under curve of the receiver operating characteristic curve was 0.74. Conclusions The influencing factors of VBAC are delivery age, pre-pregnancy BMI, vaginal delivery history, cervical score and neonatal birth weight <3 300 g. The adequate individualized management and assessment of the TOLAC may be helpful to improve the VBAC rate.

Respiratory distress syndrome(RDS) remains a significant problem for preterm babies, although management has evolved gradually over the years.Since 2006, neonatal experts from many European countries have reviewed the latest literature every 3 years to reach consensus on the prevention and treatment of premature infants at risk of RDS or RDS, aiming at improving neonatal prognosis in Europe.The guidelines update the previous for guidelines after critical examination of the most recent evidence available in late 2018.