| Part Ⅰ Clinical characteristics of preterm infants and risk factors of short-term complications of prematurity:A retrospective study of 1848 patientsBackgrounds:Prematurity accounts for the majority of neonatal death,and preterm infants are at high risk of long-term health problems.The complications of prematurity are the underlying reasons for the higher rate of infant mortality in preterm infants.Most of the current researches are from the European and American population,while few research from Chinese population,and improved perinatal clinical practice has improved survival and outcome of preterm infants.Therefore,we designed this retrospective study to clarify the clinical characteristics of preterm infants and the risk factors of short-term complications of prematurity,which may provide more evidence for clinical practice.Methods:Clinical information of all preterm infants admitted to the NICU in the Children’s Hospital of Zhejiang University School of Medicine was retrospectively collected between 2013 and 2018.Multivariate logistic regression was used to identify risk factors for complications of prematurityResults:1848 preterm infants with average gestational age(GA)31.35±2.95 weeks and average birth weight(BW)1651.68±620.63 grams were included.Among all the preterm infants,9.8%were small for gestational age(SGA)at birth,and 61.3%were male.The major possible factors leading to preterm labor were premature rupture of membranes(PROM)(31.0%),spontaneous preterm labor(30.8%),multiple pregnancies(24.2%),fetal distress(12.7%),placental abnormalities(10.7%)and hypertensive disorders of pregnancy(10.2%).The most common short-term complications of prematurity were respiratory distress syndrome(RDS),intraventricular hemorrhage and periventricular leukomalacia(IVH-PVL),bronchopulmonary dysplasia(BPD),Ureaplasma urealyticum(UU)colonization of respiratory tract,hemodynamically significant patent ductus arteriosus(PDA),retinopathy of prematurity(ROP),necrotizing enterocolitis(NEC)and ventilator associated pneumonia(VAP).79.9%finished treatment and survived at discharge,while 10.8%didn’t complete treatment and left hospital.7.6%give up treatment and died while 1.4%died in hospital before discharge.Considerable proportions of those who didn’t complete treatment and left hospital or give up treatment and died were infants who were at the end stage of diseases when transferred into our unit or infants with severe refractory congenital malformation.Among the survived infants,24.8%were below 10th percentile weight for corrected gestational age at discharge,while 33.9%of these were SGA infants.The average length of stay of those who finished treatment and survived at discharge were 41.32±24.68 days.Male(OR=1.312,95%CI:1.077-1.597,P=0.007),cesarean(OR=1.237,95%CI:1.012-1.513,P=0.038)and frequencies of produce(OR=1.172,95%CI:1.008-1.362,P=0.039)were the independent risk factors of RDS,while temperature at admission and PROM(OR=0.654,95%CI:0.530-0.880,P<0.001)were the independent protective factors of RDS.Male(OR=1.472,95%CI:1.038-2.087,P=0.030),5min Apgar score<7(OR=1.823,95%CI:1.230-2.702,P=0.003),RDS(OR=1.844,95%CI:1.303-2.608,P=0.001),UU colonization of respiratory tract(OR=1.961,95%CI:1.294-2.973,P=0.002),PDA(OR=2.300,95%CI:1.488-3.555,P<0.001)and the length of the days of invasive mechanical ventilation(OR=1.153,95%CI:1.109-1.199,P<0.001)were the independent risk factors of BPD,while BW(OR=0.273,95%CI:0.142-0.523,P<0.001)and GA(OR=0.843,95%CI:0.756-0.940,P=0.002)were the independent protective factors of BPD.VAP was seen in 115 preterm infants(6.2%),while fungal infection in 4 cases(3.5%)and bacterial infection in 112 cases(97.4%).The most common pathogens of HAP were Acinetobacter baumannii(43,38.4%),Klebsiella pneumoniae(43,38.4%),Staphylococcus aureus(18,16.1%),Stenotrophomonas maltophilia(16,14.3%),Escherichia coli(7,6.3%),Enterobacter cloacae(7,6.3%),Enterobacter aerogenes(6,5.4%)and Pseudomonas aeruginosa(6,5.4%).UU colonization of respiratory tract was seen in 283 preterm infants(15.3%),and the prevalence of UU colonization of respiratory tract decreased with increasing GA and BW.1min Apgar score<7(OR=1.437,95%CI:1.137-1.815,P=0.002)and increasing days of mechanical ventilation(OR=1.010,95%CI:1.004-1.017,P=0.002)were the independent risk factors of IVH,while GA(OR=0.902,95%CI:0.862-0.943,P<0.001)was the independent protective factor of IVH.Multiple gestation(OR=1.534,95%CI:1.094-2.152.P=0.013),5min Apgar score<7(OR=1.473,95%CI:1.039-2.089,P=0.030)and RDS(OR=2.025,95%CI:1.479-2.772,P<0.001)were the independent risk factors of PDA,while GA(OR=0.655,95%CI:0.610-0.704,P<0.001)was the independent protective factor of PDA.GA(OR=0.756,95%CI:0.680-0.840,P<0.001),BW(OR=0.236,95%CI:0.116-0.479,P<0.001)and male(OR=0.702,95%CI:0.505-0.977,P=0.036)were the independent protective factors of ROP.Male(OR=1.464,95%CI:1.055-2.029,P=0.022)and multiple gestation(OR=1.428,95%CI:1.023-1.995,P=0.036)were the independent risk factors of NEC,while BW(OR=0.434,95%CI:0.316-0.598,P<0.001)was the independent protective factor of NEC.Conclusions:1 The most common complications of prematurity were respiratory diseases.2 Male,cesarean,increasing frequencies of production and decreasing temperature at admission were the independent risk factors of RDS,while PROM were the independent protective factor of RDS.3 Decreasing BW,decreasing GA,male,5min Apgar score<7,PDA and the increasing days of invasive mechanical ventilation were the independent risk factors of BPD.4 The most common pathogens of VAP were Gram-negative bacilli.5 UU colonization of respiratory tract was common among the preterm infants,and the prevalence of UU colonization of respiratory tract decreased with increasing GA and BW.6 Decreasing GA,1min Apgar score<7 and increasing days of mechanical ventilation were the independent risk factors of IVH.7 Decreasing GA,multiple gestation,5min Apgar score<7 and RDS were the independent risk factors of PDA.8 Decreasing GA,decreasing BW and female were the independent risk factors of ROP.9 Male,decreasing BW and multiple gestation were the independent risk factors of NEC.Part Ⅱ Role of breastfeeding in prevalence of complications and growth in VLBW infantsBackgrounds:Human milk is recommended as the exclusive nutrient source for feeding because of its acknowledged benefits to both infants and mother.Breastfeeding is associated with benefits with respect to gastrointestinal function,host defense,and psychological well-being.Since the establishment of the breast milk bank,our center has encouraged and supported breastfeeding of hospitalized infants,and the proportion of breastfeeding in hospitalized preterm infants improves.Therefore,we conducted this retrospective analysis to assess the role of breastfeeding in common short-term complications in VLBW infants and its impact on in-hospital growth.Methods:The data came from the cases in Part I.Inclusion criteria includes admission within the first 24 hours of life and BW<1500g.We excluded those who discharged or died within 72 hours since admission,or were seen with congenital digestive tract malformation.Human milk intake was categorized by percentage of total enteral intake during hospitalization(0%of diet,<75%of diet,and≥75%of diet).Results:383 VLBW infants were included.Infants receiving≥75%human milk had lower rate of Bell Stage Ⅱ-Ⅲ NEC compare to the others(1.5%vs6.8%,P=0.023).Increasing proportions of enteral intake as human milk were associated with the lower rate of Bell Stage Ⅱ-Ⅲ NEC(OR=0.985,P=0.028).The day reaching full enteral feeding was earlier in infants fed solely formula compared to infants receiving<75%human milk and infants receiving ≥75%human milk(30.73± 17.68vs41.16±19.62,38.80±17.41).Infants receiving≥75%human milk weighed 145.63g less than those fed<75%and 195.57g less than those fed solely formula at discharge.The weight,length and head circumstance z-score of infants receiving>75%human milk were respectively significantly lower than those fed solely formula at discharge.The rate of below 10th percentile weight for corrected gestational age at discharge was higher in infants receiving>75%human milk and infants receiving<75%human milk compared to those fed solely formula(41.4%,38.2%vs21.3%).The rate of below 10th percentile head circumstance at discharge was higher infants receiving≥75%human milk compared to the other groups(32.O%vs23.6%,19.1%).All groups experienced significant decreases in z-score from admission to discharge(P<0.001).Infants receiving>75%human milk and infants receiving<75%human milk had a larger decrease in weight z-score from admission to discharge compared to solely formula-fed infants(0.83 ± 0.67,0.78±0.78vs0.18±0.64).Infants receiving≥75%human milk had a larger decrease in head circumstance z-score from admission to discharge compared to solely formula-fed infants(1.04±1.50vs0.56±1.28).Infants receiving>75%human milk and infants receiving<75%human milk had a slower velocity of weight gain compared to solely formula-fed infants(24.27±4.50,25.19±5.89vs29.87±5.22).Infants receiving ≥75%human milk had a slower velocity of height gain compared to solely formula-fed infants(1.05 ± 0.43vs1.19 ± 0.50)Conclusions:1 VLBW infants fed human milk have lower rates of necrotizing enterocolitis.2 Growth can be optimized with human milk if diets are modified to provide adequate protein and caloric intake to bring out the best of breastfeeding.Prolonged parenteral nutrition days due to diseases may partly contribute to slower in-hospital growth rate in VLBW infants fed human milk. |
