Morbidity and trends in length of hospitalisation of very and extremely preterm infants born between 2008 and 2021 in the Netherlands: a cohort study.

OBJECTIVES: This study investigated changes in the length of stay (LoS) at a level III/IV neonatal intensive care unit (NICU) and level II neonatology departments until discharge home for very preterm infants and identified factors influencing these trends. DESIGN: Retrospective cohort study based on data recorded in the Netherlands Perinatal Registry between 2008 and 2021. SETTING: A single level III/IV NICU and multiple level II neonatology departments in the Netherlands. PARTICIPANTS: NICU-admitted infants (n=2646) with a gestational age (GA) <32 weeks. MAIN OUTCOME MEASURES: LoS at the NICU and overall LoS until discharge home. RESULTS: The results showed an increase of 5.1 days (95% CI 2.2 to 8, p<0.001) in overall LoS in period 3 after accounting for confounding variables. This increase was primarily driven by extended LoS at level II hospitals, while LoS at the NICU remained stable. The study also indicated a strong association between severe complications of preterm birth and LoS. Treatment of infants with a lower GA and more (severe) complications (such as severe retinopathy of prematurity) during the more recent periods may have increased LoS. CONCLUSION: The findings of this study highlight the increasing overall LoS for very preterm infants. LoS of very preterm infants is presumably influenced by the occurrence of complications of preterm birth, which are more frequent in infants at a lower gestational age.

[Average prematurity: medical and developmental aspects]. / Prématurité moyenne : aspects médicaux et développementaux.

Children born with moderate prematurity are at increased risk of neonatal morbidity, rehospitalization during the first year, and subsequent medical and neurodevelopmental disorders. Care in a specialized environment, at best without separation of mother and child, is necessary. Early developmental support, particularly through skin-to-skin contact, breastfeeding and couplet care, is recommended.

[Discharge of infants with complex care needs from the neonatal intensive care unit : Ensuring continued inpatient care via the Bunter Kreis aftercare model]. / Entlassung von Kindern mit komplexen Versorgungsbedarfen von der neonatologischen Intensivstation : Sicherung der stationären Anschlussversorgung durch das Nachsorgemodell des Bunten Kreises e. V.

After discharge of premature infants with complex care needs from the neonatal intensive care unit, a care gap arises due to the transition from inpatient to outpatient care. Consequences can be rehospitalization, revolving door effects, and high costs. Therefore, following hospitalization or inpatient rehabilitation, the patient is intended to transition to sociomedical aftercare. The legal basis for this is formed by § 43 paragraph 2 of the Fifth Book of the German Social Code (SGB V). Over 80 aftercare institutions in Germany work according to the model of the Bunter Kreis. The comprehensive concept describes possibilities for networking which exceed the services provided by sociomedical aftercare. Simultaneously, depending on their stage of development, young adults can receive aftercare according to this model up to their 27th year of life. The interdisciplinary team at the Bunter Kreis comprises nurses, social workers, social education workers, psychologists, and specialist physicians. The largest group of supported persons, with 6000-8000 children per year, is comprised of premature and at-risk babies as well as multiple births, followed by 3000-5000 children with neurologic and syndromic diseases. Other common diseases are metabolic diseases, epilepsy, and diabetes, as well as children after trauma and with rare diseases. Overall, the various diseases sum up to around 20 clinical pictures. The current article presents the Bunter Kreis aftercare process based on case examples.

Safety and Effectiveness of Probiotics in Preterm Infants with Necrotizing Enterocolitis.

Although necrotizing enterocolitis is a leading cause of morbidity and mortality among preterm infants, its underlying pathophysiology is not fully understood. Gut dysbiosis, an imbalance between commensal and pathogenic microbes, in the preterm infant is likely a major contributor to the development of necrotizing enterocolitis. In this review, we will discuss the increasing use of probiotics in the NICU, an intervention aimed to mitigate alterations in the gut microbiome. We will review the existing evidence regarding the safety and effectiveness of probiotics, and their potential to reduce rates of necrotizing enterocolitis in preterm infants.

Safety and Effectiveness of Probiotics in Preterm Infants with Necrotizing Enterocolitis.

Although necrotizing enterocolitis is a leading cause of morbidity and mortality among preterm infants, its underlying pathophysiology is not fully understood. Gut dysbiosis, an imbalance between commensal and pathogenic microbes, in the preterm infant is likely a major contributor to the development of necrotizing enterocolitis. In this review, we will discuss the increasing use of probiotics in the NICU, an intervention aimed to mitigate alterations in the gut microbiome. We will review the existing evidence regarding the safety and effectiveness of probiotics, and their potential to reduce rates of necrotizing enterocolitis in preterm infants.

Post-ligation cardiac syndrome after surgical versus transcatheter closure of patent ductus arteriosus in low body weight premature infants: a multicenter retrospective cohort study.

Transcatheter patent ductus arteriosus (PDA) closure is a safe and effective alternative to surgical ligation in low-body-weight infants. Post-ligation cardiac syndrome (PLCS) is defined as severe hemodynamic and respiratory collapse within 24 h of PDA closure, requiring initiation or an increase of an inotropic agent by > 20% of preligation dosing and an absolute increase of at least 20% in ventilation parameters compared with the preoperative value. Whilst PLCS is routinely observed after surgery, its incidence remains poorly described following transcatheter closure. This study aimed to compare the incidence of PLCS after surgical versus transcatheter closure of PDA in low-body-weight premature infants. Propensity scores were used to compare surgical (N = 78) and transcatheter (N = 76) groups of preterm infants who underwent PDA closure at a procedural weight less than 2000 g in two tertiary institutions between 2009 and 2021. The primary outcome was the incidence of PLCS. Secondary outcomes included overall mortality before discharge, risk factors for PLCS, and post-procedural complications. Procedural success was 100% in both groups. After matching, transcatheter group experienced no PLCS vs 15% in the surgical group (p = 0.012). Furthermore, overall mortality (2% vs 17%; p = 0.03) and major complications (2% vs 23%; p = 0.002) were higher in the surgical group. Surgery (100% vs 47%; p < 0.01), gestation age (25 ± 1 vs 26 ± 2 weeks, p < 0.05) and inotropic support before closure (90% vs 29%; p < 0.001) were associated with PLCS occurrence.          Conclusion: Transcatheter PDA closure may be equally effective but safer than surgical PDA closure in low-body-weight premature infants. What is Known: • Post-ligation cardiac syndrome is a serious and common complication of surgical closure of the ductus arteriosus in preterm infants. • Transcatheter closure of preterm ductus arteriosus is a safe and effective technique that is becoming more and more common worldwide. What is New: • Device closure is safer than surgical ligation for patent ductus arteriosus closure in preterm infants and may be the first-line non-pharmacological therapeutic option in this indication in experienced teams. • Our findings should encourage neonatologists and pediatric cardiologists to start and/or strengthen a durable interventional program for transcatheter PDA closure in premature infants.

Process and Outcome Measures for Infants Born Moderate and Late Preterm in Tertiary Canadian Neonatal Intensive Care Units.

OBJECTIVE: To describe the prevalence of and between-center variations in care practices and clinical outcomes of moderate and late preterm infants (MLPIs) admitted to tertiary Canadian neonatal intensive care units (NICUs). STUDY DESIGN: This was a retrospective cohort study including infants born at 320/7 through 366/7 weeks of gestation and admitted to 25 NICUs participating in the Canadian Neonatal Network between 2015 and 2020. Patient characteristics, process measures represented by care practices, and outcome measures represented by clinical in-hospital and discharge outcomes were reported by gestational age weeks. NICUs were compared using indirect standardization after adjustment for patient characteristics. RESULTS: Among 25 669 infants (17% of MLPIs born in Canada during the study period) included, 45% received deferred cord clamping, 7% had admission hypothermia, 47% received noninvasive respiratory support, 11% received mechanical ventilation, 8% received surfactant, 40% received antibiotics in the first 3 days, 4% did not receive feeding in the first 2 days, and 77% had vascular access. Mortality, early-onset sepsis, late-onset sepsis, or necrotizing enterocolitis occurred in <1% of the study cohort. Median (IQR) length of stay was 14 (9-21) days among infants discharged home from the admission hospital and 5 (3-9) days among infants transferred to community hospitals. Among infants discharged home, 33% were discharged on exclusive breastmilk and 75% on any breastmilk. There were significant variations between NICUs in all process and outcome measures. CONCLUSIONS: Care practices and outcomes of MLPIs varied significantly between Canadian NICUs. Standardization of process and outcome quality measures for this population will enable benchmarking and research, facilitating systemwide improvements.

Early red blood cell transfusion and the occurrence of intraventricular hemorrhage in very preterm infants.

BACKGROUND: Preterm infants are at risk of developing both intraventricular hemorrhage (IVH) and anemia of prematurity. Several studies reported an association between early postnatal red blood cell (RBC) transfusion and IVH, however the timing and causality between these two remains unclear. AIMS: To describe the temporal sequence between administration of early RBC transfusion (within the first week of life) and diagnosis of IVH in very preterm infants. STUDY DESIGN: Retrospective single center case-series. SUBJECTS: 132 very preterm infants (<32 weeks' gestation), admitted to a level III neonatal intensive care unit, studied with serial cranial ultrasound (CUS), and diagnosed with any grade of IVH. OUTCOME MEASURES: Number and timing of early RBC transfusions in relation to the timing of IVH. RESULTS: Median time of IVH diagnosis was 20.5 h after birth (interquartile range [IQR], 6.25-49.00 h). Of those who received an early RBC transfusion (36 %, 47/132), only 15 % (20/132) received it before the IVH diagnosis. Infants with RBC transfusion before IVH more frequently had lower birth weight, received less fequently antenatal steroids, required more often invasive mechanical ventilation and surfactant administration, had more often hypo- and hypercapnia, and received more fluid boluses, NaHCO3, and inotropes compared to the rest. CONCLUSIONS: In the majority of infants, IVH was already present at the time of the first RBC transfusion. Studies including pre- and post RBC transfusion CUS are needed to assess the effect of early RBC transfusions on the development of IVH in preterm neonates.

Resuscitation, survival and morbidity of extremely preterm infants in California 2011-2019.

OBJECTIVE: To describe changes over time in resuscitation, survival, and morbidity of extremely preterm infants in California. STUDY DESIGN: This population-based, retrospective cohort study includes infants born ≤28 weeks. Linked birth certificates and hospital discharge records were used to evaluate active resuscitation, survival, and morbidity across two epochs (2011-2014, 2015-2019). RESULTS: Of liveborn infants, 0.6% were born ≤28 weeks. Active resuscitation increased from 16.9% of 22-week infants to 98.1% of 25-week infants and increased over time in 22-, 23-, and 25-week infants (p-value ≤ 0.01). Among resuscitated infants, survival to discharge increased from 33.2% at 22 weeks to 96.1% at 28 weeks. Survival without major morbidity improved over time for 28-week infants (p-value < 0.01). CONCLUSION: Among infants ≤28 weeks, resuscitation and survival increased with gestational age and morbidity decreased. Over time, active resuscitation of periviable infants and morbidity-free survival of 28-week infants increased. These trends may inform counseling around extremely preterm birth.

Treating very preterm European infants with inhaled nitric oxide increased in-hospital mortality but did not affect neurodevelopment at 5 years of age.

AIM: We examined the outcomes of using inhaled nitric oxide (iNO) to treat very preterm born (VPT) infants across Europe. METHODS: This was a sub-study of the Screening to Improve Health in Very Preterm Infants in Europe research. It focused on all infants born between 22 + 0 and 31 + 6 weeks/days of gestation from 2011 to 2012, in 19 regions in 11 European countries. We studied 7268 infants admitted to neonatal care and 5 years later, we followed up the outcomes of 103 who had received iNO treatment. They were compared with 3502 propensity score-matched controls of the same age who did not receive treatment. RESULTS: All countries used iNO and 292/7268 (4.0%) infants received this treatment, ranging from 1.2% in the UK to 10.5% in France. There were also large regional variations within some countries. Infants treated with iNO faced higher in-hospital mortality than matched controls (odds ratio 2.03, 95% confidence interval 1.33-3.09). The 5-year follow-up analysis of 103 survivors showed no increased risk of neurodevelopmental impairment after iNO treatment. CONCLUSION: iNO was used for VPT patients in all 11 countries. In-hospital mortality was increased in infants treated with iNO, but long-term neurodevelopmental outcomes were not affected in 103 5-year-old survivors.

Changes in neonatal morbidity, neonatal care practices, and length of hospital stay of surviving infants born very preterm in the Netherlands in the 1980s and in the 2000s: a comparison analysis with identical characteristics definitions.

BACKGROUND: This study evaluates changes in the neonatal morbidity, the neonatal care practices, and the length of hospital stay of surviving very preterm (VP) infants born in the Netherlands in the 1980s and in the 2000s; a period over which historical improvements were introduced into neonatal care. We, herein, also study whether these changes in neonatal morbidity, neonatal care practices and length of hospital stay are associated with sociodemographic, prenatal, and infant characteristics. METHODS: Two community-based cohorts from 1983 (POPS) and 2002-03 (LOLLIPOP) have provided the perinatal data for our study. The analysis enrolled 1,228 participants born VP (before the 32nd week of gestation) and surviving to 2 years of age without any severe congenital malformation. A rigorous harmonisation protocol ensured a precise comparison of the cohorts by using identical definitions of the perinatal characteristics. RESULTS: In 2003, mothers were older when giving birth, had higher multiple birth rates, and significantly more parents had received higher education. In 2003, less VP infants had severe intraventricular haemorrhage and sepsis and relatively more received continuous positive airway pressure, mechanical ventilation and caffeine therapy than in 1983. Antenatal corticosteroids and surfactant therapy were provided only in 2003. The length of the stay in the neonatal intensive care unit and in hospital had decreased in 2003 by 22 and 11 days, respectively. Differences persisted after adjustment for sociodemographic, prenatal, and infant characteristics. CONCLUSIONS: Neonatal morbidities of the surviving VP infants in this study have not increased, and exhibit improvements for various characteristics in two cohorts born 20 years apart with comparable gestational age and birth weight. Our data suggest that the improvements found are associated with more advanced therapeutic approaches and new national protocols in place, and less so with sociodemographic changes. This analysis provides a basis for further comparative analyses of the health and the development of VP children, particularly with regard to long-term outcomes.

[Treatment of patent ductus arteriosus in very preterm infants in China].

Objective: To describe the current status and trends in the treatment of patent ductus arteriosus (PDA) among very preterm infants (VPI) admitted to the neonatal intensive care units (NICU) of the Chinese Neonatal Network (CHNN) from 2019 to 2021, and to compare the differences in PDA treatment among these units. Methods: This was a cross-sectional study based on the CHNN VPI cohort, all of 22 525 VPI (gestational age<32 weeks) admitted to 79 tertiary NICU within 3 days of age from 2019 to 2021 were included. The overall PDA treatment rates were calculated, as well as the rates of infants with different gestational ages (≤26, 27-28, 29-31 weeks), and pharmacological and surgical treatments were described. PDA was defined as those diagnosed by echocardiography during hospitalization. The PDA treatment rate was defined as the number of VPI who had received medication treatment and (or) surgical ligation of PDA divided by the number of all VPI. Logistic regression was used to investigate the changes in PDA treatment rates over the 3 years and the differences between gestational age groups. A multivariate Logistic regression model was constructed to compute the standardized ratio (SR) of PDA treatment across different units, to compare the rates after adjusting for population characteristics. Results: A total of 22 525 VPI were included in the study, with a gestational age of 30.0 (28.6, 31.0) weeks and birth weight of 1 310 (1 100, 1 540) g; 56.0% (12 615) of them were male. PDA was diagnosed by echocardiography in 49.7% (11 186/22 525) of all VPI, and the overall PDA treatment rate was 16.8% (3 795/22 525). Of 3 762 VPI who received medication treatment, the main first-line medication used was ibuprofen (93.4% (3 515/3 762)) and the postnatal day of first medication treatment was 6 (4, 10) days of age; 59.3% (2 231/3 762) of the VPI had been weaned from invasive respiratory support during the first medication treatment, and 82.2% (3 092/3 762) of the infants received only one course of medication treatment. A total of 143 VPI underwent surgery, which was conducted on 32 (22, 46) days of age. Over the 3 years from 2019 to 2021, there was no significant change in the PDA treatment rate in these VPI (P=0.650). The PDA treatment rate decreased with increasing gestational age (P<0.001). The PDA treatment rates for VPI with gestational age ≤26, 27-28, and 29-31 weeks were 39.6% (688/1 737), 25.9% (1 319/5 098), and 11.4% (1 788/15 690), respectively. There were 61 units having a total number of VPI≥100 cases, and their rates of PDA treatment were 0 (0/116)-47.4% (376/793). After adjusting for population characteristics, the range of standardized ratios for PDA treatment in the 61 units was 0 (95%CI 0-0.3) to 3.4 (95%CI 3.1-3.8). Conclusions: From 2019 to 2021, compared to the peers in developed countries, VPI in CHNN NICU had a different PDA treatment rate; specifically, the VPI with small birth gestational age had a lower treatment rate, while the VPI with large birth gestational age had a higher rate. There are significant differences in PDA treatment rates among different units.

Thresholds for Red Blood Cell Transfusion in Preterm Infants: Evidence to Practice.

Rapid blood loss with circulatory shock is dangerous for the preterm infant as cardiac output and oxygen-carrying capacity are simultaneously imperilled. This requires prompt restoration of circulating blood volume with emergency transfusion. It is recommended that clinicians use both clinical and laboratory responses to guide transfusion requirements in this situation. For preterm infants with anemia of prematurity, it is recommended that clinicians use a restrictive algorithm from one of two recently published clinical trials. Transfusion outside these algorithms in very preterm infants is not evidence-based and is actively discouraged.

Case Comparison of Preterm Infant Stability During Packed Red Blood Cell Transfusions.

BACKGROUND: Very preterm infants (less than 32 weeks gestational age) experience acute morbidity during their stay in a neonatal intensive care unit. Because of their prematurity and frequent laboratory testing, they experience anemia, requiring correction with packed red blood cell (PRBC) transfusion(s). PRBC transfusions have been linked to neonatal morbidity, such as necrotizing enterocolitis, but never signs and symptoms of physiological stability. OBJECTIVE: The secondary data analysis aimed to examine very preterm infants' physiological stability before, during, and after PRBC transfusions. METHODS: A within-case, mixed-methods design was used in a secondary data analysis for 16 transfusion cases from 13 very preterm infants. RESULTS: The findings showed very preterm infants with physiological variables falling within defined limits based on gestational age during the transfusion. Two contrasting case exemplars will be presented. DISCUSSION: PRBC transfusions are necessary and prevent morbidity in very preterm infants. Observing instability during transfusions and prospectively studying hypothermia, cardiac instability, and thermal gradients is essential to design interventions to decrease morbidity associated with PRBC transfusions.

A French nationwide survey of phototherapy in very preterm and moderately preterm infants.

Phototherapy for jaundice in preterm infants should always be administered in accordance with specific guidelines. However, guidelines on phototherapy in very preterm and moderately preterm infants are currently lacking in France. We performed a nationwide quality improvement study of the management of jaundice in these preterm infants and compared the results with the international guidelines. Of the 275 maternity units initially contacted, 165 (60.0%) replied. Our results showed that clinical practice differs markedly from one unit to another - notably with regard to the prescription, administration, and monitoring of phototherapy and the reference curves used. Even though there is limited evidence on the safety and efficacy of phototherapy in very or moderately preterm infants, a French expert committee should be encouraged to develop consensus guidelines and thus improve quality of care in this setting.

Cerebral Oximetry Monitoring in Extremely Preterm Infants.

BACKGROUND: The use of cerebral oximetry monitoring in the care of extremely preterm infants is increasing. However, evidence that its use improves clinical outcomes is lacking. METHODS: In this randomized, phase 3 trial conducted at 70 sites in 17 countries, we assigned extremely preterm infants (gestational age, <28 weeks), within 6 hours after birth, to receive treatment guided by cerebral oximetry monitoring for the first 72 hours after birth or to receive usual care. The primary outcome was a composite of death or severe brain injury on cerebral ultrasonography at 36 weeks' postmenstrual age. Serious adverse events that were assessed were death, severe brain injury, bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and late-onset sepsis. RESULTS: A total of 1601 infants underwent randomization and 1579 (98.6%) were evaluated for the primary outcome. At 36 weeks' postmenstrual age, death or severe brain injury had occurred in 272 of 772 infants (35.2%) in the cerebral oximetry group, as compared with 274 of 807 infants (34.0%) in the usual-care group (relative risk with cerebral oximetry, 1.03; 95% confidence interval, 0.90 to 1.18; P = 0.64). The incidence of serious adverse events did not differ between the two groups. CONCLUSIONS: In extremely preterm infants, treatment guided by cerebral oximetry monitoring for the first 72 hours after birth was not associated with a lower incidence of death or severe brain injury at 36 weeks' postmenstrual age than usual care. (Funded by the Elsass Foundation and others; SafeBoosC-III ClinicalTrials.gov number, NCT03770741.).

Harnessing the therapeutic potential of the stem cell secretome in neonatal diseases.

Preterm birth and intrapartum related complications account for a substantial amount of mortality and morbidity in the neonatal period despite significant advancements in neonatal-perinatal care. Currently, there is a noticeable lack of curative or preventative therapies available for any of the most common complications of prematurity including bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage, periventricular leukomalacia and retinopathy of prematurity or hypoxic-ischemic encephalopathy, the main cause of perinatal brain injury in term infants. Mesenchymal stem/stromal cell-derived therapy has been an active area of investigation for the past decade and has demonstrated encouraging results in multiple experimental models of neonatal disease. It is now widely acknowledged that mesenchymal stem/stromal cells exert their therapeutic effects via their secretome, with the principal vector identified as extracellular vesicles. This review will focus on summarizing the current literature and investigations on mesenchymal stem/stromal cell-derived extracellular vesicles as a treatment for neonatal diseases and examine the considerations to their application in the clinical setting.

Inhaled nitric oxide in premature infants for preventing bronchopulmonary dysplasia: a meta-analysis.

BACKGROUND: The effectiveness of nitric oxide (NO) in reducing the risk of bronchopulmonary dysplasia (BPD) remains debatable. In this study, we performed a meta-analysis to guide clinical decision-making regarding the significance of inhaled NO (iNO) on the potential occurrence and outcomes of BPD in premature infants. METHODS: Data from clinical randomized controlled trials (RCTs) published in PubMed, Embase, Cochrane Library, Wanfang, China National Knowledge Infrastructure (CNKI) and Chinese Scientific Journal Database VIP databases for premature infants were searched from inception to March 2022. Review Manager 5.3 statistical software was used for heterogeneity analysis. RESULTS: Of the 905 studies retrieved, 11 RCTs met the screening criteria of this study. Our analysis showed that the iNO group was associated with a significantly lower incidence of BPD than the control group (relative risk [RR] = 0.91, 95% confidence interval (CI) 0.85-0.97, P = 0.006). We also observed no significant difference in the incidence of BPD between the two groups at the initial dose of 5 ppm (ppm) (P = 0.09) but those treated with 10 ppm iNO had a significantly lower incidence of BPD (RR = 0.90, 95%CI 0.81-0.99, P = 0.03). However, it should be noted that although the iNO group had an increased risk for necrotizing enterocolitis (NEC) (RR = 1.33, 95%CI 1.04-1.71, P = 0.03), cases treated with an initial dose of 10 ppm revealed no significant difference in the incidence of NEC compared with the control group (P = 0.41), while those treated with an initial dosage of 5 ppm of iNO had a significantly greater NEC rates than the control group (RR = 1.41, 95%CI 1.03-1.91, P = 0.03). Further, we observed no statistically significant differences in the incidence of in-hospital mortality, intraventricular hemorrhage (IVH) (Grade 3/4) or periventricular leukomalacia (PVL) and pulmonary hemorrhage (PH) between the two treatment groups. CONCLUSIONS: This meta-analysis of RCTs showed that iNO at an initial dosage of 10 ppm seemed more effective in reducing the risk of BPD than conventional treatment and iNO at an initial dosage of 5 ppm in preterm infants at a gestational age of ≤34 weeks who required respiratory support. However, the incidence of in-hospital mortality and adverse events between the overall iNO group and Control were similar.

Clinical outcomes of different patent ductus arteriosus treatment in preterm infants born between 28 and 32 weeks in Taiwan.

BACKGROUND: The patent ductus arteriosus (PDA) treatment in very preterm infants is controversial. This study focused on preterm infants born at 28-32 weeks of gestation and analyzed the association between various PDA treatments and clinical outcomes. METHODS: We conducted a retrospective cohort study of infants born at 28-32 weeks of gestation between 2016 and 2019 at 22 hospitals in the Taiwan Premature Infant Follow-up Network. We categorized the infants into four groups according to treatment strategies: medication, primary surgery, medication plus surgery, or conservative treatment. RESULTS: A total of 1244 infants presented with PDA, and 761 (61.1%) were treated. Medication was the predominant treatment (50.0%), followed by conservative treatment (38.9%), medication plus surgery (7.6%), and primary surgery (3.5%). The risk of mortality was not reduced in the active treatment group compared to the conservative treatment group. There was a higher prevalence of severe intraventricular hemorrhage, necrotizing enterocolitis (NEC), and any degree of bronchopulmonary dysplasia (BPD) in both the primary surgery and medication plus surgery groups than in the conservative treatment group. After adjustment, both the primary surgery and medication plus surgery groups still had higher odds ratios for the occurrence of NEC and any degree of BPD. CONCLUSIONS: Compared with active PDA treatment, conservative treatment for PDA did not increase the risk of mortality and morbidity in very preterm infants born at 28-32 weeks of gestation. The risks and benefits of surgery (PDA ligation) in these infants must be considered cautiously.