The Uptake of Telemedicine in Obstetric Care During the Early Acute Phase of the Coronavirus 2019 Pandemic.

Introduction: The early acute phase of the coronavirus disease 2019 pandemic created rapid adaptation in health care delivery. Methods: Using electronic medical record data from two different institutions located in two different states, we examined how telemedicine was integrated into obstetric care. Results: With no telemedicine use prior, both institutions rapidly incorporated telemedicine into prenatal care (PNC). There were significant patient-level and institutional-level differences in telemedicine use. Telemedicine users initiated PNC earlier and had more total visits, earlier timing of ultrasounds, and earlier diabetes screening during pregnancy compared with nonusers. There were no significant differences in delivery mode or stillbirth associated with telemedicine use at either institution. Conclusions: Rapid adoption of obstetric telemedicine maintained adequate prenatal care provision during the early pandemic, but implementation varied across institutions.

Changes in prenatal testing during the COVID-19 pandemic.

Objective: The coronavirus disease 2019 (COVID-19) pandemic disrupted healthcare delivery, including prenatal care. The study objective was to assess if timing of routine prenatal testing changed during the COVID-19 pandemic. Methods: Retrospective observational cohort study using claims data from a regional insurer (Highmark) and electronic health record data from two academic health systems (Penn Medicine and Yale New Haven) to compare prenatal testing timing in the pre-pandemic (03/10/2018-12/31/2018 and 03/10/2019-12/31/2019) and early COVID-19 pandemic (03/10/2020-12/31/2020) periods. Primary outcomes were second trimester fetal anatomy ultrasounds and gestational diabetes (GDM) testing. A secondary analysis examined first trimester ultrasounds. Results: The three datasets included 31,474 pregnant patients. Mean gestational age for second trimester anatomy ultrasounds increased from the pre-pandemic to COVID-19 period (Highmark 19.4 vs. 19.6 weeks; Penn: 20.1 vs. 20.4 weeks; Yale: 18.8 vs. 19.2 weeks, all p < 0.001). There was a detectable decrease in the proportion of patients who completed the anatomy survey <20 weeks' gestation across datasets, which did not persist at <23 weeks' gestation. There were no consistent changes in timing of GDM screening. There were significant reductions in the proportion of patients with first trimester ultrasounds in the academic institutions (Penn: 57.7% vs. 40.6% and Yale: 78.7% vs. 65.5%, both p < 0.001) but not Highmark. Findings were similar with multivariable adjustment. Conclusion: While some prenatal testing happened later in pregnancy during the pandemic, pregnant patients continued to receive appropriately timed testing. Despite disruptions in care delivery, prenatal screening remained a priority for patients and providers during the COVID-19 pandemic.

Changes in preterm birth during the COVID-19 pandemic by duration of exposure and race and ethnicity.

OBJECTIVE: We aimed to determine whether coronavirus-disease-2019 (COVID-19) pandemic exposure duration was associated with PTB and if the pandemic modified racial disparities. STUDY DESIGN: We analyzed Philadelphia births and replicated in New Haven. Compared to matched months in two prior years, we analyzed overall PTB, specific PTB phenotypes, and stillbirth. RESULTS: Overall, PTB was similar between periods with the following exceptions. Compared to pre-pandemic, early pregnancy (<14 weeks') pandemic exposure was associated with lower risk of PTB < 28 weeks' (aRR 0.60 [0.30-1.10]) and later exposure with higher risk (aRR 1.77 [0.78-3.97]) (interaction p = 0.04). PTB < 32 weeks' among White patients decreased during the pandemic, resulting in non-significant widening of the Black-White disparity from aRR 2.51 (95%CI: 1.53-4.16) to aRR 4.07 (95%CI: 1.56-12.01) (interaction P = 0.41). No findings replicated in New Haven. CONCLUSION: We detected no overall pandemic effects on PTB, but potential indirect benefits for some patients which could widen disparities remains possible.

Postpartum Length of Stay and Hospital Readmission Before and During the Coronavirus Disease 2019 (COVID-19) Pandemic.

OBJECTIVE: To compare postpartum hospitalization length of stay (LOS) and hospital readmission among obstetric patients before (March 2017-February 2020; prepandemic) and during the coronavirus disease 2019 (COVID-19) pandemic (March 2020-February 2021). METHODS: We conducted a retrospective cohort study, using Epic Systems' Cosmos research platform, of obstetric patients who delivered between March 1, 2017, and February 28, 2021, at 20-44 weeks of gestation and were discharged within 7 days of delivery. The primary outcome was short postpartum hospitalization LOS (less than two midnights for vaginal births and less than three midnights for cesarean births) and secondary outcome was hospital readmission within 6 weeks of postpartum hospitalization discharge. Analyses compared outcomes before and during the pandemic using standardized differences and Bayesian logistic mixed-effects models, among all births and stratified by mode of delivery. RESULTS: Of the 994,268 obstetric patients in the study cohort, 742,113 (74.6%) delivered prepandemic and 252,155 (25.4%) delivered during the COVID-19 pandemic. During the COVID-19 pandemic, the percentage of short postpartum hospitalizations increased among all births (28.7-44.5%), vaginal births (25.4-39.5%), and cesarean births (35.3-55.1%), which was consistent with the adjusted analysis (all births: adjusted odds ratio [aOR] 2.35, 99% credible interval 2.32-2.39; vaginal births: aOR 2.14, 99% credible interval 2.11-2.18; cesarean births aOR 2.90, 99% credible interval 2.83-2.98). Although short postpartum hospitalizations were more common during the COVID-19 pandemic, there was no change in readmission in the unadjusted (1.4% vs 1.6%, standardized difference=0.009) or adjusted (aOR 1.02, 99% credible interval 0.97-1.08) analyses for all births or when stratified by mode of delivery. CONCLUSION: Short postpartum hospitalization LOS was significantly more common during the COVID-19 pandemic for obstetric patients with no change in hospital readmissions within 6 weeks of postpartum hospitalization discharge. The COVID-19 pandemic created a natural experiment, suggesting shorter postpartum hospitalization may be reasonable for patients who are self-identified or health care professional-identified as appropriate for discharge.

Neonatal intensive care unit admissions before and after the adoption of the baby friendly hospital initiative.

BACKGROUND: The Baby Friendly Hospital initiative (BFHI) is a global initiative of the World Health Organization developed in 1991 to promote and support successful breastfeeding. It has led to increased rates of exclusive breastfeeding. Exclusive breastfeeding may increase risk for hypoglycemia, hyperbilirubinemia, and dehydration requiring higher level of neonatal care. OBJECTIVE: To determine if there was a change in admissions to the Neonatal Intensive Care Unit (NICU) from the newborn nursery after the adoption of BFHI in a large urban hospital. METHODS: This is a retrospective analysis of all neonates admitted to the NICU from the newborn nursery between January 2007 and December 2016 at Thomas Jefferson University Hospital, in Philadelphia, PA, USA. Demographics, clinical characteristics and primary diagnosis for admission were compared between those admitted before (January 2007 to December 2011) and after (January 2012 to December 2016) the initiation of BFHI. RESULTS: A total of 20,124 infants were born and 3,684 infants (18.3%) were admitted to NICU. 570 infants (2.8% of live birth) were admitted to the NICU from the newborn nursery, 282 (49.5%) were born before and 288 (50.5%) born after BFHI. There was no significant difference in the number of infants admitted from the newborn nursery either as a percentage of total deliveries (2.8 versus 2.9%, p = .6) or percentage of total NICU admissions (15.5 versus 15.5%, p = 1.0) before and after the BFHI. Additionally, there was no difference in number of infants admitted with a diagnosis of possible sepsis, hypoglycemia, neonatal abstinence syndrome (NAS) and hyperbilirubinemia between the two groups. However, significantly more infants admitted with hypoglycemia required IV fluids for hypoglycemia after the initiation of BFHI (8 out of 27 versus 21 out of 28, p .001). The age of admission was higher and the duration of NICU stay was shorter in infants admitted after the initiation of the BFHI. CONCLUSIONS: The BFHI has not led to a significant change in the number of infants admitted to NICU from the newborn nursery or reasons for their admissions. However, since its adoption, there has been an increase in the use of IV fluids for treatment of hypoglycemia. These findings suggest a role for additional treatments other than formula to prevent IV fluid use, such as glucose gel. Change in NICU guidelines for the management of possible sepsis and NAS may have impacted the duration of hospitalization in infants born after BFHI.

Is Maternal Methadone Dose Associated with the Severity of Neonatal Abstinence Syndrome?

OBJECTIVE: The aim of the study is to assess the correlation between maternal methadone dose and severity of neonatal abstinence syndrome (NAS) in infants that required pharmacological treatment for NAS. STUDY DESIGN: This is a retrospective analysis of 574 infants ≥35 weeks' gestation exposed to methadone in utero, born between August 2006 and May 2018, and who required pharmacological therapy for NAS. Indicators of NAS severity (duration of morphine treatment, maximum morphine dose, use of phenobarbital, and length of hospitalization) were compared between infants exposed to high (≥200 mg), intermediate (100-199 mg), and low doses (<100 mg) of methadone. Logistic and linear regression models were used to adjust for the covariates. RESULTS: Median (interquartile range) duration of medical treatment with morphine was higher in infants exposed to higher doses of methadone (low dose 23 [14-37] days, intermediate dose 31 [18-45] days, and high dose 35 [20-48] days, p < 0.001). Higher methadone doses were also predictive of longer duration of hospitalization, higher maximum morphine dose, and increased likelihood of treatment with phenobarbital. The association between maternal methadone dose and the severity of NAS persisted in multivariable regression models. CONCLUSION: Infants exposed to higher methadone doses displayed more severe NAS, as indicated by longer durations of treatment, higher maximum morphine dose, longer duration of hospitalization, and increased likelihood of phenobarbital use. KEY POINTS: · Methadone maintenance therapy is used during pregnancy to control maternal withdrawal symptoms.. · Relationship between maternal methadone dose and severity of NAS is not adequately investigated.. · Increased doses of methadone during pregnancy correlate with increased severity of NAS..

Growth failure in infants with neonatal abstinence syndrome in the neonatal intensive care unit.

OBJECTIVE: To assess if infants with neonatal abstinence syndrome (NAS) are smaller at birth and have decreased growth parameters between birth and discharge from the neonatal intensive care unit (NICU). METHODS: Retrospective data analysis of term/late-preterm neonates with NAS at a single-center NICU between September 2006 and May 2018. Growth parameters (weight, length, HC) were measured at birth and discharge. Z scores and percentiles were calculated using WHO standard growth curves. RESULTS: A total of 864 infants ≥35 weeks were admitted for NAS. At birth, median percentiles were weight 30%, HC 23%, and length 37%; these decreased significantly (p < 0.001) at discharge to 12%, 6.5%, and 13%, respectively. The percentage of infants <3rd percentile increased significantly (p < 0.001) in all growth parameters from birth to discharge. CONCLUSION: Infants with NAS are smaller at birth and have significant growth retardation in all growth parameters at discharge. An ongoing long-term growth follow-up study will discern the impact of growth restriction in NAS infants.

Birth Hospital Length of Stay and Rehospitalization During COVID-19.

OBJECTIVES: To determine if birth hospitalization length of stay (LOS) and infant rehospitalization changed during the coronavirus disease 2019 (COVID-19) era among healthy, term infants. METHODS: Retrospective cohort study using Epic's Cosmos data from 35 health systems of term infants discharged ≤5 days of birth. Short birth hospitalization LOS (vaginal birth <2 midnights; cesarean birth <3 midnights) and, secondarily, infant rehospitalization ≤7 days after birth hospitalization discharge were compared between the COVID-19 (March 1 to August 31, 2020) and prepandemic eras (March 1 to August 31, 2017, 2018, 2019). Mixed-effects models were used to estimate adjusted odds ratios (aORs) comparing the eras. RESULTS: Among 202 385 infants (57 110 from the COVID-19 era), short birth hospitalization LOS increased from 28.5% to 43.0% for all births (vaginal: 25.6% to 39.3%, cesarean: 40.1% to 61.0%) during the pandemic and persisted after multivariable adjustment (all: aOR 2.30, 95% confidence interval [CI] 2.25-2.36; vaginal: aOR 2.12, 95% CI 2.06-2.18; cesarean: aOR 3.01, 95% CI 2.87-3.15). Despite shorter LOS, infant rehospitalizations decreased slightly during the pandemic (1.2% to 1.1%); results were similar in adjusted analysis (all: aOR 0.83, 95% CI 0.76-0.92; vaginal: aOR 0.82, 95% CI 0.74-0.91; cesarean: aOR 0.87, 95% CI 0.69-1.10). There was no change in the proportion of rehospitalization diagnoses between eras. CONCLUSIONS: Short infant LOS was 51% more common in the COVID-19 era, yet infant rehospitalization within a week did not increase. This natural experiment suggests shorter birth hospitalization LOS among family- and clinician-selected, healthy term infants may be safe with respect to infant rehospitalization, although examination of additional outcomes is needed.

Coronavirus Disease 2019 (COVID-19) Pandemic and Pregnancy Outcomes in a U.S. Population.

OBJECTIVE: To examine whether the coronavirus disease 2019 (COVID-19) pandemic altered risk of adverse pregnancy-related outcomes and whether there were differences by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection status among pregnant women. METHODS: In this retrospective cohort study using Epic's Cosmos research platform, women who delivered during the pandemic (March-December 2020) were compared with those who delivered prepandemic (matched months 2017-2019). Within the pandemic epoch, those who tested positive for SARS-CoV-2 infection were compared with those with negative test results or no SARS-CoV-2 diagnosis. Comparisons were performed using standardized differences, with a value greater than 0.1 indicating meaningful differences between groups. RESULTS: Among 838,489 women (225,225 who delivered during the pandemic), baseline characteristics were similar between epochs. There were no significant differences in adverse pregnancy outcomes between epochs (standardized difference<0.10). In the pandemic epoch, 108,067 (48.0%) women had SARS-CoV-2 testing available; of those, 7,432 (6.9%) had positive test results. Compared with women classified as negative for SARS-CoV-2 infection, those who tested positive for SARS-CoV-2 infection were less likely to be non-Hispanic White or Asian or to reside in the Midwest and more likely to be Hispanic, have public insurance, be obese, and reside in the South or in high social vulnerability ZIP codes. There were no significant differences in the frequency of preterm birth (8.5% vs 7.6%, standardized difference=0.032), stillbirth (0.4% vs 0.4%, standardized difference=-0.002), small for gestational age (6.4% vs 6.5%, standardized difference=-0.002), large for gestational age (7.7% vs 7.7%, standardized difference=-0.001), hypertensive disorders of pregnancy (16.3% vs 15.8%, standardized difference=0.014), placental abruption (0.5% vs 0.4%, standardized difference=0.007), cesarean birth (31.2% vs 29.4%, standardized difference=0.039), or postpartum hemorrhage (3.4% vs 3.1%, standardized difference=0.019) between those who tested positive for SARS-CoV-2 infection and those classified as testing negative. CONCLUSION: In a geographically diverse U.S. cohort, the frequency of adverse pregnancy-related outcomes did not differ between those delivering before compared with during the pandemic, nor between those classified as positive compared with negative for SARS-CoV-2 infection during pregnancy.

Influence of Patient Characteristics on Antibiotic Use Rates Among Preterm Infants.

BACKGROUND: The antibiotic use rate (AUR) has emerged as a potential metric for neonatal antibiotic use, but reported center-level AURs are limited by differences in case mix. The objective of this study was to identify patient characteristics associated with AUR among a large cohort of preterm infants. METHODS: Retrospective observational study using the Optum Neonatal Database, including infants born from January 1, 2010 through November 30, 2016 with gestational age 23-34 weeks admitted to neonatal units across the United States. Exposures were patient-level characteristics including length of stay, gestational age, sex, race/ethnicity, bacterial sepsis, necrotizing enterocolitis, and survival status. The primary outcome was AUR, defined as days with ≥ 1 systemic antibiotic administered divided by length of stay. Descriptive statistics, univariable comparative analyses, and generalized linear models were utilized. RESULTS: Of 17 910 eligible infants, 17 836 infants (99.6%) from 1090 centers were included. Median gestation was 32.9 (interquartile range [IQR], 30.3-34) weeks. Median length of stay was 25 (IQR, 15-46) days and varied by gestation. Overall median AUR was 0.13 (IQR, 0-0.26) and decreased over time. Gestational age, sex, and race/ethnicity were independently associated with AUR (P < .01). AUR and gestational age had an unexpected inverse parabolic relationship, which persisted when only surviving infants without bacterial sepsis or necrotizing enterocolitis were analyzed. CONCLUSIONS: Neonatal AURs are influenced by patient-level characteristics besides infection and survival status, including gestational age, sex, and race/ethnicity. Neonatal antibiotic use metrics that account for patient-level characteristics as well as morbidity case mix may allow for more accurate comparisons and better inform neonatal antibiotic stewardship efforts.

Do extremely preterm infants need retinopathy of prematurity screening earlier than 31 weeks postmenstrual age?

OBJECTIVE: To evaluate the utility of screening all extremely preterm infants for retinopathy of prematurity (ROP) at 4 weeks chronologic age, which is earlier than recommended by the 2018 AAP guidelines. STUDY DESIGN: Retrospective analysis of infants <27 weeks gestation from two tertiary NICUs between 2006 and 2018 who survived until first eye examination. RESULTS: 550 infants (gestational age 25.1 ± 1.2 weeks and birth weight 758 ± 323 g) had 1310 examinations performed by 32 weeks postmenstrual age (PMA), and 676 (51.6%) of these were prior to 31 weeks PMA. No examinations in infants prior to 31 weeks PMA met the criteria for laser therapy. Of 87/550 infants (15.8%) who required laser therapy, none did so prior to 32 weeks PMA. CONCLUSIONS: No infants born <27 weeks gestation were found to have severe ROP prior to 31 weeks PMA, supporting the most recent AAP recommendation of initiating ROP screening at 31 weeks PMA for extremely preterm infants.

DNA Methylation Profile in Human Cord Blood Mononuclear Leukocytes From Term Neonates: Effects of Histological Chorioamnionitis.

Background: Histological chorioamnionitis (HCA) is an infection/inflammation of fetal membranes and complicates 5.2-28.5% of all live births. Exposure to HCA can have long-term consequences including abnormal neurodevelopment and an increased risk for allergic disorders and asthma later in childhood. HCA may incite epigenetic changes, which have the potential to modulate both the immune and neurological systems as well as increase the risk of related disorders later in life. However, there is limited data on the impact of HCA on epigenetics, in particular DNA methylation, and changes to immune and neurological systems in full-term human neonates. Objective: To determine differential DNA methylation in cord blood mononuclear leukocytes from neonates exposed to HCA. Methods: Cord blood was collected from 10 term neonates (5 with HCA and 5 controls without HCA) and mononuclear leukocytes were isolated. Genome-wide DNA methylation screening was performed on Genomic DNA extracted from mononuclear leukocytes. Results: Mononuclear leukocytes from cord blood of HCA-exposed neonates showed differential DNA methylation of 68 probe sets compared to the control group (44 hypermethylated, 24 hypomethylated) with a p ≤ 0.0001. Several genes involved in immune modulation and nervous system development were found to be differentially methylated. Important canonical pathways as revealed by Ingenuity Pathway Analysis (IPA) were CREB Signaling in Neurons, FcγRIIB Signaling in B Lymphocytes, Cell Cycle: G1/S Checkpoint Regulation, Interleukin-1, 2, 3, 6, 8, 10, 17, and 17A signaling, p53 signaling, dopamine degradation, and serotonin degradation. The diseases and disorders picked up by IPA were nervous system development and function, neurological disease, respiratory disease, immune cell trafficking, inflammatory response, and immunological disease. Conclusions: HCA induces differential DNA methylation in cord blood mononuclear leukocytes. The differentially methylated genes may contribute to inflammatory, immunological and neurodevelopmental disorders in neonates exposed to HCA.

Prevalence and Utility of Low Mean Corpuscular Volume in Infants Admitted to the Neonatal Intensive Care Unit.

OBJECTIVE: To determine the prevalence of low mean corpuscular volume (MCV) in newborn infants admitted to the neonatal intensive care unit and to assess low MCV as a diagnostic test for alpha thalassemia. STUDY DESIGN: Retrospective analysis of all infants admitted to the neonatal intensive care unit between January 2010 and October 2018 for which a complete blood count was performed during the first 3 postnatal days. Infants with a low MCV were compared with those with a normal MCV. Infants with positive hemoglobin Bart (Hb Bart) were compared with those withnegative Hb Bart. Low MCV was also evaluated as a diagnostic test for alpha thalassemia. RESULTS: A total of 3851 infants (1386 preterm, 2465 term) met the inclusion criteria and 853 (22.2%) had a low MCV. A low MCV was more common in term (25%) compared with preterm infants (17.1%, P < .001). Hb Bart positive newborn screening was identified in 133 infants (3.5%). Hb Bart was positive in 11.1% of infants with low MCV compared with 1.3% with normal MCV (P < .001). The sensitivity, specificity, positive predictive value, and negative predictive value of low MCV for the diagnosis of alpha thalassemia were 71.4%, 79.6%, 11.3%, and 98.7%, respectively. CONCLUSIONS: As Hb Bart positive newborn screens were seen in only 11.1% of infants with microcytosis, further diagnostic investigation may be warranted in individual infants. Further research to correlate microcytosis with iron status in infants and mothers is needed as well as studies using DNA analysis for the evaluation of alpha thalassemia variants.

Prolonging gavage feeds for reduction of gastroesophageal reflux in infants.

OBJECTIVE: To determine if prolonging gavage feedings in infants for ≥60 min is associated with decreased gastroesophageal reflux (GER) compared with bolus feeding using multiple-channel intraluminal impedance with pH probe (MII-pH). STUDY DESIGN: Retrospective analysis of infants who underwent MII-pH between October 2009 and July 2018 and received gavage feedings. Infants were divided into two groups: bolus (<30 min) or prolonged (≥60 min). Symptoms, number of reflux events and percent time pH < 4 was compared. RESULT: Fifty-eight infants underwent evaluation. Thirty-one (54%) received bolus gavage feedings and 27 (46%) received prolonged feedings. Groups differed in postmenstrual age. Total reflux episodes were significantly lower with prolonged feeding (median 19 vs. 28 episodes, p = 0.015), with no difference in acid exposure time. There was no significant difference in GER symptoms between the two groups. CONCLUSION: Prolongation of gavage feedings was associated with decreased total numbers of GER events without reduction in GER symptoms.

Exclusive breast feeding and dehydration fever in newborns during the first days of life.

Objectives: To determine the prevalence of dehydration fever in infants admitted to the Neonatal Intensive Care Unit (NICU) from the well newborn nursery with fever in the first days of life.Study design: Retrospective data analysis of term infants admitted to the NICU from the well newborn nursery with fever (n = 75). Infants were divided into two groups based on hydration status using clinical and laboratory signs of dehydration. Clinical and laboratory variables were compared between the two groups.Results: Fifty-three of the 75 infants admitted to the NICU with fever had clinical and laboratory signs of dehydration (71%). Infants with dehydration were more likely to be exclusively breast fed and present with fever at >24 h of age. There were no positive blood or cerebrospinal fluid cultures in infants with dehydration. The incidence of dehydration fever increased after implementation of an "Exclusive Breast Feeding" policy from 1.4/1000 to 3.5/1000 live births (p ≤ .01).Conclusions: Dehydration is associated with fever in exclusively breast fed infants during the first several days of life. There were no cases of serious bacterial or viral infections in the cohort of febrile infants with clinical and laboratory signs of dehydration.

Hypertensive disorders during pregnancy are associated with reduced severe intraventricular hemorrhage in very-low-birth-weight infants.

OBJECTIVE: To determine differences in severe intraventricular hemorrhage (IVH) between very-low-birth-weight (≤1500 g, VLBW) infants born to mothers with and without hypertensive disorders (HD). DESIGN/METHODS: Retrospective analysis from the Optum Neonatal Database. The primary outcome of interest was severe IVH (grade 3 or 4). Secondary outcomes included other neonatal morbidities, mortality, and length of hospitalization. Outcomes were compared between VLBW infants born to mothers with and without HD. RESULTS: A total of 5456 infants met inclusion criteria. After multivariable regression analysis, risks of severe IVH and bronchopulmonary dysplasia (BPD) were lower ([OR 0.42, 95% CI 0.33-0.89, p = 0.01] and [OR 0.75, 95% CI 0.58-0.97, p = 0.03], respectively) and median length of hospitalization was decreased in the HD group (49 versus 61 days, p < 0.001). CONCLUSIONS: VLBW infants born to mothers with HD have a decreased risk of severe IVH, BPD, and a shorter duration of hospitalization.

Use of a Modified Early-Onset Sepsis Risk Calculator for Neonates Exposed to Chorioamnionitis.

OBJECTIVE: To validate the recently modified Kaiser Permanente early-onset sepsis (EOS) calculator with a higher baseline incidence in chorioamnionitis exposed neonates. STUDY DESIGN: This is a retrospective study of chorioamnionitis-exposed neonates born at ≥35 weeks of gestation with a known EOS incidence of 4.3/1000. The risk and management categories were calculated using the calculator with an incidence of 4/1000. The results were compared with a previous analysis of the same cohort that used an EOS incidence of 0.5/1000. RESULTS: In our sample, the EOS calculator recommends at least a blood culture in 834 of 896 (93.1%) and empiric antibiotics in 533 of 896 (59.5%) chorioamnionitis-exposed neonates when using an EOS incidence of 4/1000. This captures 5 of 5 neonates (100%) with EOS. When using a baseline EOS incidence of 0.5/1000, the calculator recommends at least a blood culture in only 289 of 896 (32.2%) and empiric antibiotics in only 209 of 896 (23.3%) neonates, but fails to recommend empiric antibiotics in 2 of 5 neonates with EOS (40%). CONCLUSIONS: When using an EOS risk of 4 of 1000 in infants exposed to mothers with chorioamnionitis, the EOS calculator has the ability to capture an increased number of neonates with culture-positive EOS. However, this change also leads to nearly a 3-fold increase in the use of empiric antibiotics and an evaluation with blood culture in almost all infants born to mothers with chorioamnionitis.