Objective:To describe the current status and trends in the outcomes and care practices of extremely preterm infants at 22-25 weeks′ gestation age from the Chinese Neonatal Network (CHNN) from 2019 to 2021.Methods:This cross-sectional study used data from the CHNN cohort of very preterm infants. All 963 extremely preterm infants with gestational age between 22-25 weeks who were admitted to neonatal intensive care units (NICU) of the CHNN from 2019 to 2021 were included. Infants admitted after 24 hours of life or transferred to non-CHNN hospitals were excluded. Perinatal care practices, survival rates, incidences of major morbidities, and NICU treatments were described according to different gestational age groups and admission years. Comparison among gestational age groups was conducted using χ2 and Kruskal-Wallis tests. Trends by year were evaluated by Cochran-Armitage and Jonckheere-Terpstra tests for trend. Results:Of the 963 extremely preterm infants enrolled, 588 extremely preterm infants (61.1%) were male. The gestational age was 25.0 (24.4, 25.6) weeks, with 29 extremely preterm infants (3.0%), 88 extremely preterm infants (9.1%), 264 extremely preterm infants (27.4%), and 582 extremely preterm infants (60.4%) at 22, 23, 24, and 25 weeks of gestation age, respectively. The birth weight was 770 (680, 840) g. From 2019 to 2021, the number of extremely preterm infants increased each year (285, 312, and 366 extremely preterm infants, respectively). Antenatal steroids and magnesium sulfate were administered to 67.7% (615/908) and 51.1% (453/886) mothers of extremely preterm infants. In the delivery room, 20.8% (200/963) and 69.5% (669/963) extremely preterm infants received noninvasive positive end-expiratory pressure support and endotracheal intubation. Delayed cord clamping and cord milking were performed in 19.0% (149/784) and 30.4% (241/794) extremely preterm infants. From 2019 to 2021, there were significant increases in the usage of antenatal steroids, antenatal magnesium sulfate, and delivery room noninvasive positive-end expiratory pressure support (all P<0.05). Overall, 349 extremely preterm infants (36.2%) did not receive complete care, 392 extremely preterm infants (40.7%) received complete care and survived to discharge, and 222 extremely preterm infants (23.1%) received complete care but died in hospital. The survival rates for extremely preterm infants at 22, 23, 24 and 25 weeks of gestation age were 10.3% (3/29), 23.9% (21/88), 33.0% (87/264) and 48.3% (281/582), respectively. From 2019 to 2021, there were no statistically significant trends in complete care, survival, and mortality rates (all P>0.05). Only 11.5% (45/392) extremely preterm infants survived without major morbidities. Moderate to severe bronchopulmonary dysplasia (67.3% (264/392)) and severe retinopathy of prematurity (61.5% (241/392)) were the most common morbidities among survivors. The incidences of severe intraventricular hemorrhage or periventricular leukomalacia, necrotizing enterocolitis, and sepsis were 15.3% (60/392), 5.9% (23/392) and 19.1% (75/392), respectively. Overall, 83.7% (328/392) survivors received invasive ventilation during hospitalization, with a duration of 22 (10, 42) days. The hospital stay for survivors was 97 (86, 116) days. Conclusions:With the increasing number of extremely preterm infants at 22-25 weeks′ gestation admitted to CHNN NICU, the survival rate remained low, especially the rate of survival without major morbidities. Further quality improvement initiatives are needed to facilitate the implementation of evidence-based care practices.

This case report described the sucussful treatment of a male infant born at 21 weeks and 4 days through assisted reproductive technology. After prenatal consultation and with the strong desire of the parents, active resuscitation and treatment were performed. The infant received 52 days of mechanical ventilation and was extubated to non-invasive ventilation at a corrected gestational age of 28 weeks and 6 days. During hospitalization, no vasoactive drugs were used, and necrotizing enterocolitis did not occur. The gastric tube was removed at a corrected gestational age of 37 weeks and 4 days. At a corrected gestational age of 40 weeks, cranial MRI showed no abnormalities. The infant was discharged at a corrected gestational age of 42 weeks after 143 days of treatment, without the need for any respiratory support. Follow-up until a corrected age of 6 months showed good growth and development.

Objective:To observe the impacts of using heated and humidified gas sources for delivery room resuscitation on the short-term outcomes of extremely preterm infants.Methods:A retrospective study was conducted on 231 extremely preterm infants admitted to the neonatal intensive care unit of Shenzhen Maternity & Child Healthcare Hospital, the First School of Clinical Medicine, Southern Medical University, from January 2020 to December 2022. The infants were divided into two groups based on whether heated and humidified gas sources were used during delivery room resuscitation: the heated and humidified group (103 cases) and the non-heated and humidified group (128 cases). Independent sample t-tests, Chi-square tests, and Mann-Whitney U tests were used to compare general conditions and short-term outcomes between the groups. Multivariate logistic regression analysis was used to assess the impact of using heated and humidified gas sources during delivery room resuscitation on the short-term outcomes of extremely preterm infants. Results:Compared to the non-heated and humidified group, the heated and humidified group had a lower incidence of intubation resuscitation [28.2% (29/103) vs. 41.4% (53/128), χ 2=4.38], moderate to severe bronchopulmonary dysplasia (BPD)/death [22.3% (23/103) vs. 39.1% (50/128), χ 2=7.39] and low rectal temperature upon admission (<36.7 ℃) [57.3% (59/103) vs. 79.7% (102/128), χ 2=13.57], while the rectal temperature upon admission was higher [36.3 ℃ (36.0-36.7 ℃) vs. 35.9 ℃ (35.5-36.3 ℃), U=－5.05], with all differences being statistically significant (all P<0.05). After adjusting for gender, gestational age, mode of delivery, amniotic fluid condition, weight on admission, maternal premature rupture of membranes, assisted reproductive technology, and full course of prenatal steroid use, multivariate logistic regression analysis showed that the use of heated and humidified gas sources during delivery room resuscitation could increase the hospital admission rectal temperature ( β=0.46, 95% CI: 0.28-0.64), and decrease the risks of severe BPD/death ( aOR=0.39, 95% CI: 0.20-0.75), and low rectal temperature upon admission ( aOR=0.29, 95% CI: 0.16-0.55)(all P<0.05). Compared to the non-heated and humidified group, the heated and humidified group showed no statistically significant differences in the use of pulmonary surfactant [37.9% (39/103) vs. 43.8% (56/128), χ 2=1.45], incidence of stage Ⅲ or higher necrotizing enterocolitis [2.0% (2/103) vs. 5.5% (7/128), χ 2=2.06], grade Ⅲ or higher intracranial hemorrhage [2.9% (3/103) vs. 3.9% (5/128), χ 2=0.22], and retinopathy of prematurity requiring surgical treatment [3.9% (4/103) vs. 10.2% (13/128), χ 2=3.60] (all P>0.05). Conclusion:The use of heated and humidified gas sources during resuscitation of extremely preterm infants can reduce the risk of moderate to severe BPD/death, help maintain warmth during resuscitation, and do not adversely affect other short-term outcomes.

Objective:To summarize the survival rate, complications, and outcomes of 32 periviable extremely preterm infants (PEPIs) born at ≤23 gestational weeks.Methods:This was a retrospective observational study involving PEPIs born at the Shenzhen Maternity & Child Healthcare Hospital from January 1, 2015, to December 31, 2021. Clinical data of all subjects were collected and analyzed. The survival rates of PEPIs born from 2015 to 2019 and 2020 to 2021 were compared. Chi-square (or Fisher's exact) test was used for statistical analysis. Results:(1) During the study period, 32 PEPIs were admitted, accounting for 0.024% (32/132 534) of all newborns born in the same hospital during the study period. The median gestational age of the 32 PEPIs was 23 weeks (21 +4-23 +6 weeks), and the birth weight was 480 g (350-720 g). (2) The survival rate of PEPIs born between 2020 and 2021 was 10/19, which appears to be a trend higher than that between 2015 and 2019 (3/13, χ2=2.79, P=0.095), while the rate of withdrawal of treatment was 8/13 and 3/19, respectively, with a statistically significant difference ( χ2=7.16, P=0.007). (3) Thirteen of the 32 PEPIs survived on discharge, including four born at 22 weeks and nine at 23 weeks. The birth weights of these surviving infants were 300-<400 g in one case, 400-<500 g in five cases, 500-<600 g in four cases, 600-<700 g in one case, and ≥700 g in two cases. (4) The most common complication was moderate and severe bronchopulmonary dysplasia (10/13), followed by retinopathy of prematurity requiring surgical intervention (5/13), patent ductus arteriosus requiring ligation (4/13), late-onset sepsis (2/13), necrotizing enterocolitis (stage Ⅱa or above) (2/13) and grade Ⅲ-Ⅳ intraventricular hemorrhage or periventricular leukomalacia (2/13). The median duration of follow-up was ten months (6-69 months), and motor retardation occurred in three infants. Conclusions:The overall survival rate of PEPIs in our hospital is relatively high, with a lower incidence of complications during hospitalization and relatively better outcome. However, further studies are required for the long-term prognosis in this group of infants.

Objective:To study the early use of inhaled nitric oxide (iNO) as a rescue therapy in extremely premature infants (EPIs) with refractory hypoxic respiratory failure (HRF).Methods:Between January 2021 and December 2021, EPIs with refractory HRF receiving iNO within the first week of life in our NICU were enrolled. Their clinical characteristics and outcomes were retrospectively analyzed.Results:A total of 11 EPIs were included with 5 males and 6 females. The median gestational age (GA) was 24(22.6, 25.2) weeks. The median birth weight (BW) was 580(490, 770) g. The most common primary diagnoses were moderate/severe respiratory distress syndrome (RDS) (5/11) and early-onset sepsis (3/11). The median age starting iNO therapy was 6.5(4.5, 34.0)h and the median duration of iNO was 24(12, 36)h. The median iNO starting dose was 5(5, 8) ppm and the therapeutic range was 5-20 ppm. Therapeutic efficacy was defined as ≥30% FiO 2 reduction after 6 h of iNO treatment. The treatment was effective in 8 cases. The oxygenation index (OI) decreased more than 10% from baseline 1 h after initiation in 9 patients and in all 11 patients after 12 h of iNO. The reduction of OI was more prominent in EPIs with a higher OI at baseline. Of the 11 patients, 8 survived, 1 died and 2 abandoned further treatments. Conclusions:As an early rescue therapy for EPIs with refractory HRF, iNO can improve oxygenation without obvious short-term adverse effects.

Objective:To analyze the cases referred to a higher-level hospital from the Department of Neonatology in a primary hospital, and evaluate the efficiency of clinical works related to the referrals.Methods:Data of neonates admitted to the Department of Neonatology at Maternal and Child Health Hospital of Dabu County from January 2018 to December 2020 and referred to the superior hospital were retrospectively analyzed.Results:A total of 1 670 neonates were included and 128 neonates were referred.The median age of the neonates referred was 0.5 hours(0 hours, 25 days), the median gestational age was 38 + 3(29 + 1, 42 + 4) weeks, the median weight was 3 000(1 250, 4 800) g, and the transport distance was 78 km.Twenty-four cases were assessed as critical cases before the referral, 125 cases were improved and discharged after treatment in the superior hospital, and three cases died.The referral rate in 2018, 2019 and 2020 showed a downward trend year by year (10.3%, 7.6% and 4.0%, respectively), and the difference was statistically significant( χ2=14.362, P=0.001). The proportion of critical cases in referral cases increased year by year (9.4%, 23.9% and 38.9%, respectively), and the difference was statistically significant( χ2=9.289, P=0.010). The incidence of critical case was higher in those whose mothers didn′t have regular prenatal examination during pregnancy( χ2=5.129, P=0.032). Conclusion:The ability of neonatal treatment in primary hospitals has been improved.The neonates need to be referred and critical cases are not rare in primary hospitals.More attention should be paid to the safety and effectiveness of the regional transport network.Also, enhancing the health awareness of residents and improving the primary medical technics are important to maximize the life safety and optimal transition of newborns.

Objective:To study the incidence and risk factors of periventricular- intraventricular hemorrhage (PIVH) in extremely preterm infants (EPI) with gestational age (GA)<28 weeks.Methods:A retrospective study was performed in 304 cases of EPI hospitalized between January 2016 and December 2018. The infants were assigned into two groups according to whether PIVH occurred. Univariate analysis and Logistic regression analysis were used to determine the risk factors of PIVH.Results:Among the 304 cases,101 (33.2%) developed PIVH and 44 (14.5%) developed severe PIVH.The incidences of PIVH and severe PIVH in EPI with birth weight (BW) <750 g were 50.6% and 31.0%. The incidences of PIVH and severe PIVH in EPI with GA<26 weeks were 51.4% and 27.5%. Logistic regression analysis revealed that advanced GA ( OR=0.697, 95% CI 0.543~0.895, P=0.005) decreased the risk of PIVH. Prolonged invasive mechanical ventilation ( OR=1.121, 95% CI 1.007~1.249, P=0.037) and use of vasoactive drugs ( OR=1.373, 95% CI 1.040~1.812, P=0.025) within the first week of life increased the risk of PIVH. Conclusions:The incidences of PIVH and severe PIVH in EPI are quite high. Smaller GA, longer use of invasive mechanical ventilation and vasoactive drugs within the first week will increase the risk of PIVH in EPI.

Objective:To study the effects of breastfeeding within 2 weeks after birth on late-onset sepsis in very low birth weight infants (VLBWI).Methods:From July 2018 to June 2019, clinical data of VLBWI (birth weight <1 500 g) born in our hospital were retrospectively reviewed. According to the proportion of breastfeeding volume in total feeding volume within 2 weeks after birth, the infants were assigned into high-proportion breastfeeding group (breastfeeding >50%), low-proportion breastfeeding group (breastfeeding ≤50%) and formula group. The incidences of late-onset sepsis among the three groups were compared using the chi-square test or Fisher's exact probability method. Logistic regression was used to analyze the effects of breastfeeding within 2 weeks after birth on late-onset sepsis.Results:The incidences of late sepsis in high-proportion breastfeeding group, low-proportion breastfeeding group and formula group were 0.4% (1/216), 8.1% (5/62) and 8.0% (2/25), respectively ( P<0.001). Logistic regression analysis showed that compared with the high-proportion breastfeeding group, the low-proportion breastfeeding group ( OR=17.844, 95% CI 2.005~158.775) and the formula group ( OR=23.261, 95% CI 1.916~282.350) had increased risks of late-onset sepsis. Conclusions:For VLBWI, high proportion breastfeeding (breastfeeding >50%) within 2 weeks after birth may reduce the risk of late-onset sepsis.

Bronchopulmonary dysplasia is a common respiratory complication in premature infants.With the improvement of neonatal treatment, premature infants are surviving more than ever.However, the incidence of bronchopulmonary dysplasia remains high, which seriously affects the outcomes of premature infants.The immature lung of preterm infants are susceptible to damage from a variety of factors, which are modifiable by the early use of lung-protective strategies of respiratory support.This review focused on summarizing the research progress of early lung-protective ventilation techniques for preventing bronchopulmonary dysplasia in premature infants.

Objective:To study the trends and ranges of blood pressure in extremely premature infants (EPIs) during the first 7 days after birth.Methods:From January 2016 to December 2020, EPIs born in our hospital were retrospectively analyzed. Their blood pressure were monitored using umbilical arterial catheters and no patients needed anti-hypotension treatment. The clinical data of the infants and their mothers, blood pressure data during the first 7 days after birth, clinical outcomes and complications were collected. The trends of blood pressure in untreated EPIs were analyzed and the blood pressure ranges of EPIs of different gestational ages (GA) were established.Results:A total of 145 cases of EPIs were included and their systolic pressure, diastolic pressure and mean blood pressure showed upward trends during 2~168 h after birth ( P<0.001). The diastolic pressure increased significantly within 24 h after birth ( P<0.05), systolic pressure and mean blood pressure increased significantly within 72 h after birth ( P<0.05). Blood pressure increased with age and GA. Conclusions:The blood pressure of EPIs will increase spontaneously during 7 days after birth. The ranges of blood pressure are measured for infants with different GA to provide clinical evidence for blood pressure management of EPIs during early postnatal period.