Hemodynamic evaluation in preterm infants using ultrasonic cardiac output monitor (USCOM).

We aimed to establish reference ranges for USCOM parameters in preterm infants, determine factors that affect cardiac output, and evaluate the measurement repeatability. This retro-prospective study was performed at Fondazione IRCCS San Gerardo dei Tintori, Monza, Italy. We included infants below 32 weeks of gestational age (GA) and/or 1500 g of birth weight (BW). We excluded infants with congenital heart diseases or hemodynamic instability. Measurements were performed at 3 ± 1, 7 ± 2, and 14 ± 2 postnatal days. We analyzed 204 measurements from 92 patients (median GA = 30.57 weeks, BW = 1360 g). The mean (SD) cardiac output (CO) was 278 (55) ml/min/kg, cardiac index (CI) was 3.1 (0.5) L/min/m2, and systemic vascular resistance (SVRI) was 1292 (294) d*s*cm-5/m2. CO presented a negative correlation with postmenstrual age (PMA), while SVRI presented a positive correlation with PMA. The repeatability coefficient was 31 ml/kg/min (12%).  Conclusion: This is the first study describing reference values for USCOM parameters in hemodynamically stable preterm infants and factors affecting their variability. Further studies to investigate the usefulness of USCOM for the longitudinal assessment of patients at risk for cardiovascular instability or monitoring the response to therapies are warranted. What is Known: • The ultrasonic cardiac output monitoring (USCOM) has been widely used on adult and pediatric patients and reference ranges for cardiac output (CO) by USCOM have been established in term infants. What is New: • We established reference values for USCOM parameters in very preterm and very-low-birth-weight infants; the reference ranges for CO by USCOM in the study population were 198-405 ml/kg/min. • CO normalized by body weight presented a significant negative correlation with postmenstrual age (PMA); systemic vascular resistance index presented a significant positive correlation with PMA.

Prenatal use of indomethacin for preterm labor and renal function among very low birth weight infants.

BACKGROUND: Indomethacin is administered as a tocolytic agent for threatening preterm labor <28weeks of gestation. Only a few, not conclusive, studies have investigated its nephrotoxicity in very low birth weight (VLBW) infants. We investigated whether indomethacin increases the incidence of acute kidney injury (AKI) among VLBW infants. METHODS: This is a retrospective study including all VLBW infants born at our center between January 1, 2005, and December 31, 2013. Indomethacin was administered to women with preterm labor and intact membranes. Neonatal AKI was defined according to KDIGO classification. Univariate analyses were performed comparing VLBW infants exposed to and not exposed to indomethacin. In the multivariable model, the association of indomethacin and AKI was adjusted for patent ductus arteriosus, use of nephrotoxic medications, birth weight, and gestational age. RESULTS: Five hundred seventy-five VLBW infants were included, 49 (8.5%) of whom were exposed to indomethacin in utero. The univariate analysis showed that infants exposed to indomethacin had lower birth weight, lower gestational age, and higher incidence of AKI than infants not exposed. The multivariable model adjusted for confounding factors confirmed an increased risk of AKI in relation to gestational age at birth <27 weeks, but not to indomethacin. CONCLUSIONS: Our data suggest that extreme prematurity, but not the use of indomethacin, is associated with AKI.

SARS-CoV-2 perinatal transmission and neonatal outcomes across four different waves of COVID-19 pandemic: A nationwide prospective cohort study from the Italian Society of Neonatology.

OBJECTIVES: To describe how SARS-CoV-2 infection at the time of delivery affected maternal and neonatal outcomes across four major waves of the COVID-19 pandemic in Italy. METHODS: This is a large, prospective, nationwide cohort study collecting maternal and neonatal data in case of maternal peripartum SARS-CoV-2 infection between February 2020 and March 2022. Data were stratified across the four observed pandemic waves. RESULTS: Among 5201 COVID-19-positive mothers, the risk of being symptomatic at delivery was significantly higher in the first and third waves (20.8-20.8%) than in the second and fourth (13.2-12.2%). Among their 5284 neonates, the risk of prematurity (gestational age <37 weeks) was significantly higher in the first and third waves (15.6-12.5%). The risk of intrauterine transmission was always very low, while the risk of postnatal transmission during rooming-in was higher and peaked at 4.5% during the fourth wave. A total of 80% of positive neonates were asymptomatic. CONCLUSION: The risk of adverse maternal and neonatal outcomes was significantly higher during the first and third waves, dominated by unsequenced variants and the Delta variant, respectively. Postnatal transmission accounted for most neonatal infections and was more frequent during the Omicron period. However, the paucity of symptoms in infected neonates should lead us not to separate the dyad.

Early Postnatal Infection of Neonates Born to Mothers Infected by SARS-CoV-2 Omicron Variant.

OBJECTIVES: To evaluate the rate of postnatal infection during the first month of life in neonates born to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive mothers during the predominant circulation of the omicron (B.1.1.529) variant. METHODS: This prospective, 10-center study enrolled mothers infected by SARS-CoV-2 at delivery and their infants, if both were eligible for rooming-in, between December 2021 and March 2022. Neonates were screened for SARS-CoV-2 RNA at 1 day of life (DOL), 2 to 3 DOL, before discharge, and twice after hospital discharge. Mother-infant dyads were managed under a standardized protocol to minimize the risk of viral transmission. Sequencing data in the study area were obtained from the Italian Coronavirus Disease 2019 Genomic platform. Neonates were included in the final analysis if they were born when the omicron variant represented >90% of isolates. RESULTS: Eighty-two percent (302/366) of mothers had an asymptomatic SARS-CoV-2 infection. Among 368 neonates, 1 was considered infected in utero (0.3%), whereas the postnatal infection rate during virtually exclusive circulation of the omicron variant was 12.1%. Among neonates infected after birth, 48.6% became positive during the follow-up period. Most positive cases at follow-up were detected concurrently with the peak of coronavirus disease 2019 cases in Italy. Ninety-seven percent of the infected neonates were asymptomatic. CONCLUSIONS: The risk of early postnatal infection by the SARS-CoV-2 omicron variant is higher than that reported for previously circulating variants. However, protected rooming-in practice should still be encouraged given the paucity of symptoms in infected neonates.

Association of intrauterine growth restriction and low birth weight with acute kidney injury in preterm neonates.

BACKGROUND: Preterm birth alters nephrogenesis and reduces the total nephron number. Intrauterine growth restriction (IUGR) seems to worsen nephron loss, but only a few studies have investigated its role in neonatal kidney impairment. We investigated whether IUGR, defined as reduced estimated fetal growth and/or placental flow alterations and low birth weight z-score, increases the risk of developing acute kidney injury (AKI) in very preterm infants. METHODS: We performed a retrospective study including infants born with a birth weight (BW) ≤ 1500 g and/or gestational age (GA) ≤ 32 weeks admitted to our center between January 2016 and December 2021. Neonatal AKI was defined according to the neonatal KDIGO classification based on the decline of urine output and/or creatinine elevation. We used multivariable linear regressions to verify the association between AKI and GA, BW z-score, IUGR definition, and hemodynamically significant patent ductus arteriosus (PDA). RESULTS: We included 282 infants in the analysis, with a median (IQR) GA = 29.4 (27.4, 31.3) weeks, BW = 1150 (870, 1360) g, and BW z-score = - 0.57 (- 1.64, 0.25). AKI was diagnosed in 36 (13%) patients, and 58 (21%) had PDA. AKI was significantly associated with BW z-score (beta (std. error) = - 0.08 (0.03), p = 0.008) and severe IUGR (beta (std. error) = 0.21 (0.08), p = 0.009), after adjusting for GA and PDA. CONCLUSIONS: Our data suggest that low BW z-score and IUGR could represent adjunctive risk factors for kidney impairment in preterm babies. A higher resolution version of the Graphical abstract is available as Supplementary information.

Early Neonatal SARS-CoV-2 Infection Manifesting With Hypoxemia Requiring Respiratory Support.

We describe a case of neonatal SARS-CoV-2 infection, in an infant diagnosed 3 days after birth, and manifesting with silent hypoxemia, requiring respiratory support.