Infection prevention for extremely low birth weight infants in the NICU

Association between endometrial thickness and birthweight of singletons from vitrified-warmed cycles: a retrospective cohort study

RESEARCH QUESTION

What is the association between endometrial thickness (EMT) and the birthweight of singleton infants born from frozen-thawed embryo transfer cycles?

DESIGN

This retrospective cohort study was conducted from January 2016 to December 2019. Participants were categorized into a natural cycle (NC, n = 8132) group and hormone replacement therapy (HRT, n = 4975) group. Only singleton deliveries were included. The primary outcomes were measures of birthweight and relevant indexes. Multivariable logistic regression and multivariable-adjusted linear regression models that incorporated restricted cubic splines were used.

RESULTS

In the HRT group, the risk of delivering a small for gestational age (SGA) infant was increased in women with an EMT <8.0 mm (adjusted odds ratio [aOR] 1.85, 95% confidence interval [CI] 1.17-2.91) compared with women with an EMT of 8.0 to <12.0 mm, and increased with an EMT ≥12.0 mm (aOR 1.85, 95% CI 1.03-3.33). An inverted U-shaped relationship was found between EMT and birthweight in women with HRT. No significant differences were shown in birthweight z-score, or being SGA or large for gestational age, in singletons among the three EMT groups in the natural cycles.

CONCLUSIONS

A thinner endometrium seen in women undergoing HRT cycles was associated with a lower birthweight z-score, as well as a higher risk of SGA. However, no significant association was observed between EMT and birthweight z-score or SGA in the NC group. It is noteworthy that a thicker endometrium was not associated with a higher birthweight in frozen-thawed embryo transfer (FET) cycles. Women with a thin endometrium who achieve pregnancy require specialized attention, particularly if they are undergoing FET with HRT cycles.

Epidemiology and Outcomes of Neonatal Sepsis: Experience from a Tertiary Australian NICU

INTRODUCTION

Neonatal sepsis is associated with significant mortality and morbidity. Low-middle-income countries are disproportionately affected, but late-onset sepsis (LOS) still occurs in up to 20% of infants <28 weeks in high-income countries. Understanding site-specific data is vital to guide management.

METHODS

A retrospective cohort study was conducted at King Edward Memorial Hospital (KEMH), Perth. Infants admitted between January 2012 and June 2022 were included. Data were extracted from routine electronic databases. Incidence and aetiology of sepsis were determined and the association of sepsis with neonatal outcomes analysed.

RESULTS

During the study period, 23,395 newborns were admitted with a median gestation of 37 weeks and birth weight of 2,800 g. There were 370 sepsis episodes in 350 infants; 102 were early-onset sepsis (EOS) (1.6 per 1,000 live births), predominantly Streptococcus agalactiae (35, 34.3%) and Escherichia coli (27, 26.5%); 268 were LOS (0.9 per 1,000 inpatient days), predominantly coagulase-negative staphylococci (CONS) (156, 57.6%) and E. coli (30, 11.1%). The incidence of LOS declined from 2012 to 2022 (p = 0.002). Infants with EOS had increased brain injury (25.7% vs. 4.1%; p = 0.002) and mortality (18.8% vs. 1.6%; p < 0.001). Those with LOS had increased hospital stay (median 95 vs. 15 days; p < 0.001), mortality (15.3% vs. 1.6%; p = 0.018), necrotising enterocolitis (NEC) (7.4% vs. 0.5%; p < 0.001), and chronic lung disease (CLD) (58.1% vs. 5.9%; p = 0.005). Infants <28 weeks with sepsis were at increased risk of neurodevelopmental impairment compared to those without infection (43.2% vs. 30.9%, p = 0.027).

CONCLUSIONS

While we observed a reduction in LOS incidence, sepsis remains associated with higher mortality, and in survivors with longer hospital stay and increased risk of brain injury, NEC, CLD, and neurodevelopmental impairment.

Impact of Whole Genome Sequencing to investigate transmission of Serratia marcescens in Neonatal Intensive Care Unit

Newborns admitted to neonatal intensive care units (NICU) are at increased risk of health care-associated infections. Serratia marcescens represent the third most common pathogen in NICU outbreaks. Here we present an outbreak investigation performed using Whole Genome Sequencing (WGS) analyses and the control measures implemented to limit the spread of S. marcescens in the NICU of an Italian hospital. In February 2023 S. marcescens was isolated from six newborns, when in 2022 this pathogen was isolated only from two samples in the same ward. Measures for infection prevention were adopted. Routinary surveillance screening, performed with rectal swabs collected at admission and weekly thereafter, was implemented to search for S. marcescens presence. Environmental samples were collected. All the isolates, obtained from the conjunctival swab of six newborns, from rectal swab of two newborns who did not develop infections, as well as from the aerators of two faucets, were sequenced. WGS analyses showed no correlation between the isolates from newborns and environmental isolates. The implementation of the measures for infection prevention and control had enabled us to successfully control the outbreak within a short period. WGS analyses proved to be crucial in outbreak investigation to limit the spreading of the pathogens.

Clinical Impact of Supplementation with Pasteurized Donor Human Milk by High-Temperature Short-Time Method versus Holder Method in Extremely Low Birth Weight Infants: A Multicentre Randomized Controlled Trial

Nosocomial infections are a frequent and serious problem in extremely low birth weight (ELBW) infants. Donor human milk (DHM) is the best alternative for feeding these babies when mother's own milk (MOM) is not available. Recently, a patented prototype of a High-Temperature Short-Time (HTST) pasteurizer adapted to a human milk bank setting showed a lesser impact on immunologic components. We designed a multicentre randomized controlled trial that investigates whether, in ELBW infants with an insufficient MOM supply, the administration of HTST pasteurized DHM reduces the incidence of confirmed catheter-associated sepsis compared to DHM pasteurized with the Holder method. From birth until 34 weeks postmenstrual age, patients included in the study received DHM, as a supplement, pasteurized by the Holder or HTST method. A total of 213 patients were randomized; 79 (HTST group) and 81 (Holder group) were included in the analysis. We found no difference in the frequency of nosocomial sepsis between the patients of the two methods-41.8% (33/79) of HTST group patients versus 45.7% (37/81) of Holder group patients, relative risk 0.91 (0.64-1.3), p = 0.62. In conclusion, when MOM is not available, supplementing during admission with DHM pasteurized by the HTST versus Holder method might not have an impact on the incidence of catheter-associated sepsis.

Rate of Urinary Tract Infections, Bacteremia, and Meningitis in Preterm and Term Infants

BACKGROUND AND OBJECTIVES

There are very limited data on the rate of urinary tract infections (UTI), bacteremia, and meningitis in preterm infants with fever. Many of the studies on the incidence of these infections excluded preterm infants. This study compared the rate of these infections in preterm infants born at 32-36 weeks to term infants born at 37-42 weeks.

METHODS

A multicenter observational cohort study was conducted to evaluate rates of UTI, bacteremia, and meningitis in term and preterm infants 8-60 days of age with a diagnosis of fever from 2016 through 2022 using encounter data from children's hospitals in the Pediatric Health Information System.

RESULTS

There were 19 507 total febrile infants identified, of which 2162 were preterm and 17 345 were term. Preterm infants had a lower rate of UTI than term infants (1.8% confidence interval [CI] [1.3-2.5] vs 3.0% CI [2.7-3.2], P = .001). Preterm and term infants did not have statistically different rates of bacteremia (1.5% CI [1.3-1.7] vs 1.2% CI [0.8-1.8], P = .44) or meningitis (0.16% CI [0.1-0.2] vs 0.05% CI [0-0.2], P = .36).

CONCLUSIONS

There was no difference in the rate of bacteremia or meningitis between term and preterm infants in a large multicenter cohort of febrile infants. Preterm infants had a lower rate of UTI than term infants. This is the first multicenter study to compare UTI, bacteremia, and meningitis between term and preterm febrile infants.

Health care-associated infections in neonatology

Health care-associated infections are common in neonatology, but there is no consensus on their definitions. This makes it difficult to compare their incidence or assess the effectiveness of prevention bundles. This is why we think it is very important to achieve a consensus on the definitions and diagnostic criteria for one of the most frequent causes of morbidity in hospitalised neonates. This document aims to standardise the definitions for the most frequent health care-associated infections, such as catheter-associated bloodstream infection, ventilator-associated pneumonia and surgical wound infection, as well as the approach to their diagnosis and treatment.

Histologic chorioamnionitis in extremely preterm births, microbiological findings and infant outcome

BACKGROUND

Histologic chorioamnionitis (HCA) is most often caused by ascending bacterial infection originating from the cervicovaginal tract.

OBJECTIVES

To investigate whether HCA with a fetal inflammatory response (FIR) has a worse clinical outcome than HCA alone. Further, if FIR or a positive maternal microbiologic culture obtained prior to birth were related to adverse neonatal outcomes in a cohort of extremely preterm (EP) neonates.

METHODS

Prospective observational cohort study recruiting EP singleton pregnancies (gestational age at birth ≤28 weeks) with confirmed HCA. FIR was defined by fetal neutrophils in the chorionic vessels and/or umbilical vessels. Positive culture was defined as growth of potentially pathogenic bacteria in a sample from the cervicovaginal tract prior to birth, or if a cervicovaginal culture was lacking, a culture result from the placenta was used. Logistic regression was used to estimate odds ratios and 95% confidence intervals for the associations between FIR, a positive culture result and adverse outcomes, defined as bronchopulmonary dysplasia (BPD), brain pathology assessed by magnetic resonance imaging, retinopathy of prematurity, necrotizing enterocolitis, early-onset neonatal sepsis, and perinatal death. A composite outcome variable included one or more adverse outcomes.

RESULTS

We included 71 cases with HCA, of which 51 (72%) had FIR. Maternal age, rate of clinical chorioamnionitis (CCA), preterm pre-labor rupture of membranes (PPROM), the number of women receiving antenatal steroids and antibiotics, and the rate of positive maternal cultures of potentially pathogenic bacteria were all significantly higher in the HCA with FIR. Neonates in the FIR group had significantly higher levels of blood leukocytes compared to those without. FIR was associated with a longer interval from PPROM to delivery (log-rank test: p = .022). Microbiological sampling had been performed in 63 (89%) cases, of which 60 (95%) were cervicovaginal samples. No associations were found between a positive culture and adverse neonatal outcomes, in contrast to FIR, that was significantly associated to BPD and brain pathology.

CONCLUSIONS

In a cohort of EP pregnancies with confirmed HCA, the presence of FIR was associated with advanced maternal age, CCA, PPROM, antenatal steroids and antibiotics, and a positive maternal culture of potentially pathogenic bacteria. However, the presence of FIR, and not a positive culture, was associated with adverse neonatal outcomes.

Apgar Score and Neurodevelopmental Outcomes at Age 5 Years in Infants Born Extremely Preterm

Importance

The Apgar score is used worldwide as an assessment tool to estimate the vitality of newborns in their first minutes of life. Its applicability to estimate neurodevelopmental outcomes in infants born extremely preterm (EPT; <28 weeks' gestation) is not well established.

Objective

To investigate the association between the Apgar score and neurodevelopmental outcomes in infants born EPT.

Design, Setting, and Participants

This cohort study was conducted using data from the Effective Perinatal Intensive Care in Europe-Screening to Improve Health in Very Preterm Infants in Europe (EPICE-SHIPS) study, a population-based cohort in 19 regions of 11 European countries in 2011 to 2012. Clinical assessments of cognition and motor function at age 5 years were performed in infants born EPT and analyzed in January to July 2023.

Exposures

Apgar score at 5 minutes of life categorized into 4 groups (0-3, 4-6, 7-8, and 9-10 points).

Main Outcomes and Measures

Cognitive and motor outcomes were assessed using the Wechsler Preschool and Primary Scale of Intelligence test of IQ derived from locally normed versions by country and the Movement Assessment Battery for Children-Second Edition. Parents additionally provided information on communication and problem-solving skills using the Ages and Stages Questionnaire, third edition (ASQ-3). All outcomes were measured as continuous variables.

Results

From the total cohort of 4395 infants born EPT, 2522 infants were live born, 1654 infants survived to age 5 years, and 996 infants (478 females [48.0%]) followed up had at least 1 of 3 outcome measures. After adjusting for sociodemographic variables, perinatal factors, and severe neonatal morbidities, there was no association of Apgar score with IQ, even for scores of 3 or less (β = -3.3; 95% CI, -10.5 to 3.8) compared with the score 9 to 10 category. Similarly, no association was found for ASQ-3 (β = -2.1; 95% CI, -24.6 to 20.4). Congruent results for Apgar scores of 3 or less were obtained for motor function scores for all children (β = -4.0; 95% CI, -20.1 to 12.1) and excluding children with a diagnosis of cerebral palsy (β = 0.8, 95% CI -11.7 to 13.3).

Conclusions and Relevance

This study found that low Apgar scores were not associated with longer-term outcomes in infants born EPT. This finding may be associated with high interobserver variability in Apgar scoring, reduced vitality signs and poorer responses to resuscitation after birth among infants born EPT, and the association of more deleterious exposures in the neonatal intensive care unit or of socioeconomic factors with greater changes in outcomes during the first 5 years of life.

Next Steps for Health Care-Associated Infections in the Neonatal Intensive Care Unit

We discuss the burden of health care-associated infections (HAIs) in the neonatal ICU and the role of quality improvement (QI) in infection prevention and control. We examine specific QI opportunities and approaches to prevent HAIs caused by Staphylococcus aureus , multidrug-resistant gram-negative pathogens, Candida species, and respiratory viruses, and to prevent central line-associated bloodstream infections (CLABSIs) and surgical site infections. We explore the emerging recognition that many hospital-onset bacteremia episodes are not CLABSIs. Finally, we describe the core tenets of QI, including engagement with multidisciplinary teams and families, data transparency, accountability, and the impact of larger collaborative efforts to reduce HAIs.