ObjectiveTo investigate the incidence and related factors of extrauterine growth retardation (EUGR) and “true EUGR” in very preterm infants (VPI) from different regions of China.Materials and methodsClinical data of VPI were prospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. The infants were divided into a small for gestational age (SGA) group or non-SGA group at birth, with non-SGA infants at 36 weeks of gestation or at discharge being further divided into a EUGR group or a non-EUGR group. Infants in the EUGR and non-SGA group were defined as “true EUGR.” The general information of VPI, such as maternal complications during pregnancy, use of enteral nutrition and parenteral nutrition, and complications during hospitalization were compared between the groups.ResultsAmong the 2,514 VPI included in this study, 47.3, 41.5, and 33.3% of VPI were below the 10th percentile, and 22.6, 22.4, and 16.0% of VPI were below the 3rd percentile for weight, height, and head circumference at 36 weeks of gestation or at discharge, respectively, by the percentile on the 2013 Fenton curve. The incidences of EUGR and “true EUGR” evaluated by weight were 47.3 and 44.5%, respectively. Univariate analysis showed that there were statistically significant differences in the aspects of perinatal and nutritional characteristics, treatment, and complications between the groups. Multivariate analysis showed that in non-SGA infants, the cumulative caloric intake during the first week was a protective factor for “true EUGR,” while days to reach total enteral nutrition, late initiation of human milk fortifier, and moderate to severe bronchopulmonary dysplasia were independent risk factors for “true EUGR.”ConclusionMore attention should be paid to the nutritional management of VPI to prevent “true EUGR.” Cumulative caloric intake should be ensured and increased during the first week, total enteral nutrition should be achieved as early as possible, human milk fortifier should be added early, and moderate to severe bronchopulmonary dysplasia should be prevented. These strategies are very important for reducing the incidence of “true EUGR” in VPI.

The gut microbiota plays a key role in the pathogenesis of diseases affecting preterm infants and gestational age is one of the important factors which affect the gut microbiota of infants. To determine the characteristics of the gut microbiota in preterm infants of different gestational ages from birth to 1 year after birth, we collected 622 fecal samples from neonates of different gestational ages at different time points after birth. According to the gestational ages, the samples were divided into four groups, extremely preterm, very preterm, moderate to late preterm, and term group. Meconium and fecal samples at day 14, 28, 120, and 365 after birth were collected. 16S rRNA sequencing was performed and the composition and structure of the gut microbiota in preterm infants of different gestational age was compared with that of term infants. In our study, alpha diversity of meconium in extremely preterm group was higher than very preterm group, moderate to late preterm group and term group and alpha diversity of meconium in preterm group was decreased with increasing of gestational age. At day 14 to day 120 after birth, alpha diversity of term and moderate to late preterm group were significantly higher than other two preterm groups. However, moderate to late preterm group owned the highest alpha diversity which was higher than term group at day 365 after birth. Besides, the results shown the duration of opportunistic pathogen such as Klebsiella and Enterococcus which dominant colonization was different in different gestational age groups. As well as the probiotics, such as Bifidobacterium, which abundance enriched at different time point in different gestational age groups. We profiled the features of dynamic changes of gut microbiome from different gestational ages infants. The results of our research provide new insights for individualized interventions of specific microbes of preterm infants with different gestational ages at different time points after birth.

Background: Extremely low birth weight (ELBW, <1,000 g) infants have a high risk of metabolic bone disease (MBD). Because of the late appearance of radiological signs, diagnosis of MBD in ELBW infants might be delayed, and its prevalence underestimated in this group of patients. This study adopted serial screening of serum alkaline phosphatase (ALP) and phosphate (P) of ELBW infants to determine whether such screening is helpful for the early detection of MBD.Materials and Methods: We performed a retrospective study of preterm infants with a gestational age ≤ 31 weeks and birth weight <1,000 g. MBD was absent (ALP ≤500 IU/L), mild (ALP >500 IU/L, P ≥4.5 mg/dL), and severe (ALP >500 IU/L, P <4.5 mg/dL); MBD was divided into early MBD (≤4 weeks after birth) and late MBD (>4 weeks after birth) according to the time of onset.Results: A total of 142 ELBW infants were included, with a median gestational age of 28.1 (26.5–29.7) weeks and a median birth weight of 875 (818–950) g. Seventy-three cases of MBD were diagnosed, and the total prevalence was 51.4% (mild MBD, 10.6%; and severe MBD, 40.8%). Male sex, breastfeeding, and sepsis would increase the risk of severe MBD. Most MBD in ELBW infants occurred at 3–4 weeks after birth. Sixty-two percent (45/73) of infants were diagnosed as having early MBD, which are diagnosed earlier than late MBD [24 (21–26) vs. 39 (36–41), t = −7.161; P < 0.001]. Male sex [odds ratio (OR), 2.86; 95% confidence interval (CI), 1.07–7.64; P = 0.036], initial high ALP levels (OR, 1.02; 95% CI, 1.01–1.03; P < 0.001), and breastfeeding (OR, 5.97; 95% CI, 1.01–25.12; P = 0.049) are independent risk factors for the development of early MBD.Conclusion: The risk of MBD among ELBW infants is very high. Most cases occurred early and were severe. Male sex, initial high ALP levels, and breastfeeding are closely related to the increased risk of early MBD. Serial screening of serum ALP and P helps early detection of MBD; it is recommended to start biochemical screening for ELBW infants 2 weeks after birth and monitor their biochemical markers weekly.

Objective Nutritional deficiency soon after birth is a risk factor of chronic lung disease (bronchopulmonary dysplasia, BPD). Afflicted infants are further prone to inadequate growth during hospitalization (extrauterine growth restriction, EUGR). This multi-center retrospective study investigated risk factors of EUGR, specifically in very preterm infants with BPD. Method Data of infants with BPD who were born less than 32 weeks gestation (n = 1010) were collected from 7 regions of China. All infants were non-small for gestational age at birth. Infants were characterized as EUGR or non-EUGR at 36 weeks gestation or discharge, or stratified by gestational age or birthweight. Logistic regression analysis was applied. Results In 65.5% of the population, the BPD was mild. Infants with severe BPD (8.3%) had the highest rate of EUGR (72.6%, P < 0.001). Groups stratified by gestational age did not differ in rates of EUGR, but the birthweight of the EUGR group was significantly lower than that of the non-EUGR (P < 0.001). Birthweights of < 1000, 1000–1499, and ≥ 1500 g showed EUGR rates of 65.9%, 43.4%, and 23.8%, respectively (P < 0.001). Overall, the independent risk factors of EUGR were: moderate-to-severe BPD, gestational hypertension, cesarean section, cumulative fasting time, time required to achieve 110 kcal/kg/d, and hemodynamically significant patent ductus arteriosus (hsPDA). Conclusion In very preterm infants with BPD, the lower the birthweight or the more severe the BPD, the greater the risk of EUGR. In those with hsPDA, or moderate-to-severe BPD, it is especially important to prevent EUGR through perinatal management, enteral nutrition, and nutritional strategies.

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