Purpose: To investigate the risk factors for retinopathy of prematurity (ROP) requiring laser treatment in preterm infants born before a gestational age (GA) of 28 weeks. Methods: This was a single-institution retrospective case-control study of high-risk preterm infants (GA ≤28 weeks) with ROP who were, born between January 2008 and December 2016. Patients who underwent laser treatment for severe ROP were enrolled. Infants in the control group were matched to preterm infants with a similar GA and mild ROP who, did not require laser treatment. Various prenatal and postnatal risk factors were compared between the two groups. Results: One hundred and twenty-two infants were included in this study (61 cases and 61 controls). The average birth weight was similar between the two groups (895.2±172.9 g vs. 938.5±168.0 g, P=0.164). There was no significant difference in the duration of invasive ventilation; however, the duration of noninvasive mechanical ventilation was significantly longer in patients (with ROP) who underwent laser treatment (P=0.036). The proportion of infants at a postnatal age of 28 days who were receiving oxygen treatment was significantly higher (60/61 [98.4%] vs. 51/61 [83.6%], P=0.004) in the severe ROP group. However, the rates of oxygen treatment for infants with a GA of 36 weeks were not significantly different (59%, for both groups). Other prematurity-associated morbidities were similar between the two groups. Conclusion: Altogether, a judicious reduction of oxygen therapy might reduce the incidence of laser treatment. Early diagnosis and treatment through periodic ophthalmologic examination are necessary in preterm infants receiving oxygen treatment at 28 days after birth.

Purpose: Meconium aspiration is assumed to be a risk factor for bacterial infection, and patients with meconium aspiration syndrome (MAS) are commonly treated with empiric antibiotics in clinical settings. However, little is known about the effectiveness of the empirical antibiotics treatment. Here, we compared the short-term clinical outcomes associated with empirical antibiotics treatment in non-ventilated cases of MAS. Methods: A retrospective study was conducted on infants admitted with non-ventilated cases of MAS from March 2008 to September 2016. The infants enrolled in the study were divided into two groups based on the antibiotics treatment, and their clinical outcomes were compared. The incidence of sepsis during the hospitalization period and the incidence of delayed sepsis up to 3 months were evaluated. The effects of empirical antibiotic use on respiratory symptoms were evaluated, and the complications were compared. Results: A total of 109 infants were evaluated, of which 61 (56.0%) received antibiotics and 48 (44.0%) did not receive antibiotics. No differences in clinical characteristics were noted between the two groups. However, the empirical antibiotics group showed a significantly higher mean of respiratory rates, C-reactive protein levels, and positive rates, as well as a significantly longer hospitalization period. In clinical outcomes, there were no differences in sepsis rates or respiratory support duration. Furthermore, there were no differences in complications. Conclusion: The empirical use of antibiotics did not affect the clinical outcomes in cases of non-ventilated MAS. The role of empirical antibiotics in these infants may need to be reevaluated.

Purpose: This study investigated the incidence of adverse events (AEs) and risk factors associated with sedation using chloral hydrate (CH) for brain magnetic resonance imaging (MRI) in the neonatal intensive care unit (NICU). Methods: This was a retrospective study of infants who received CH for brain MRI in the NICU. Among the enrolled infants (n=143), 12.6% (n=18) were included in the AE group and 87.4% (n=125) were in the non-adverse event group (NAE) Results: Gestational age (GA) at birth and corrected GA at sedation were 35⁺⁰±7⁺² and 39⁺⁵±3⁺¹ respectively. The rate of AEs was 12.6%, included oxygen desaturation (5.6%), aspiration (4.9%), paradoxical agitation (0.7%), tachycardia or bradycardia (0.7%), and arrest (0.7%). In univariate analysis, the AE group was younger in corrected GA at sedation than the NAE group (37⁺² [range, 36⁺⁰ to 40⁺⁰] vs. 40⁺¹ [range, 38⁺² to 41⁺⁴], P=0.015). There was no significant difference in CH dosage (50.0 [range, 50.0 to 50.0] vs. 50.0 [range, 50.0 to 50.0], P=0.092), cardiopulmonary (33.3% [n=6] vs. 17.6% [n= 22], P=0.209) and central nervous system (61.1% [n=11] vs. 65.6% [n=82], P=0.054) morbidity. In multivariate analysis, CH dosage was the only significant risk factor for AEs associated with sedation (odds ratio, 1.04; 95% confidence interval, 1.01 to 1.07; P=0.0186). Conclusion: AEs associated with sedation using CH are not uncommon and should be considered when using high dose CH for diagnostic testing in the NICU.

Purpose: To evaluate the efficacy of oral rehabilitation therapy (ORT) in terms of prematurity-associated morbidities in preterm infants born before a gestational age of 33 weeks. Methods: This was a single-institution retrospective case-control study including 78 high-risk preterm infants born between January 2015 and December 2016, who were administered with ORT for at least 15 minutes, 2 to 5 times/week by an occupational therapist. Various factors associated with feeding progression and neonatal morbidities were compared between the two groups. Results: Seventy-eight subjects, of whom 39 were cases and 39 controls, were included in this study. Infants in the case group achieved a greater total feeding volume (122.9±85.3 mL vs. 48.9±25.7 mL, P<0.001), i.e., 8 times/day with oral feeding only, and showed significantly higher body weight (1,852.1±303.3 g vs. 1,592.3±444.1 g, P=0.003) than those in the control group with complete oral feeding day. The duration from the first day of oral feeding to full enteral feeding, i.e., 150 mL/day, was significantly shorter in the cases than that in the controls (15.4±1.4 days vs. 23.1±1.8 days, P=0.004). The body weight at discharge was higher in the cases than that in the controls (3,102.6± 619.3 g vs. 2,744.6±436.8 g, P=0.008). Moreover, the incidence of late-onset sepsis was lower in the cases than that in the controls (12.8% vs. 25.6%, P=0.033). Other prematurity-associated morbidities were not different between the two groups. Conclusion: ORT in preterm infants facilitated the transition process from tube feeding to full oral feeding and reduced the incidence of late-onset sepsis.

Purpose: To investigate clinical markers for the diagnosis of congenital cytomegalovirus (CMV) infection and determine the correlation between abnormal newborn hearing screening results and asymptomatic congenital CMV infection. Methods: Medical records of newborns with congenital CMV infection, born at Cheil General Hospital & Women's Healthcare Center from July 2008 to June 2018, were retrospectively reviewed. Infants with congenital CMV infection were classified into "symptomatic," "asymptomatic," and "asymptomatic with isolated abnormal automated auditory brainstem response (AABR)" groups. Clinical data were analyzed based on this classification. Results: Among the 59,424 live births, congenital CMV infection was found in 25 neonates, including 19 symptomatic (0.03%) infants, two asymptomatic, and four asymptomatic with isolated abnormal AABR. Diagnostic clues for the identification of congenital CMV infection were intrauterine growth restriction (IUGR), including microcephaly in 10 infants (40.0%), abnormal AABR in four (16.0%), initial complicated signs in four (16.0%), and abnormal findings on brain ultrasonography in three (12.0%). Other less common markers included petechiae, abnormal findings on antenatal ultrasonography, and co-twin with CMV infection. During the recent 10 years, 53,094 of 59,424 newborns (89.3%) had AABR for hearing screening and 493 (0.9%) did not pass. Among them, 477 (96.8%) were screened for CMV, and results were positive for seven (1.5%). Among the seven infants, four had asymptomatic congenital CMV infection. Overall, 0.8% of the newborns with abnormal AABR (four of 477 infants) were diagnosed as having asymptomatic congenital CMV infection. Conclusion: The incidence of symptomatic congenital CMV infection was 0.03%, and 0.8% of infants who failed in the newborn hearing screening tests had asymptomatic congenital CMV infection. The most common clinical marker to diagnose congenital CMV infection was IUGR, including microcephaly, and the second isolated marker was abnormal AABR.

Purpose: We investigated the effect of delayed elevation of thyrotropin (TSH) (deTSH) on gastrointestinal motility in very low birth weight infants (VLBWI). Methods: This study retrospectively investigated 228 premature VLBWI aged ≥4 weeks with normal neonatal TSH screening test results and free serum thyroxine levels. Infants with serum TSH levels ranging from 5 to 10 µIU/mL were categorized as the deTSH group (n=76), when TSH was measured at 4 (n=53), 8 (n=20), or 12 (n=3) weeks of age. Serum TSH levels in the control group (n=152) were <5 µIU/mL. Multivariate logistic regression analysis was used to determine the risk factors for the development of deTSH. Covariance analysis was used to analyze the relationship between deTSH and gastrointestinal motility. Results: The mean gestational age and birth weight were 29.11±2.25 weeks and 1,157.4±218.0 g, respectively. Risk factors affecting deTSH were dopamine administration (odds ratio [OR], 8.71; 95% confidence interval [CI], 1.80 to 42.05; P=0.007) and operation time (OR, 6.95; 95% CI, 1.43 to 33.75; P=0.016) when the cumulative operating time was ≥1 hour. The mean±standard deviation (SD) duration of a nil per os (NPO) status was significantly higher in the deTSH (99.57±134.99 hours) than in the control group (37.25±59.02 hours) (P from analysis of covariance [ANCOVA]=0.001). The mean±SD duration (33.84±22.34 days) of total parenteral nutrition (TPN) was considerably longer in the deTSH group than in the control group (27.68±13.08 days) (P from ANCOVA=0.003). Conclusion: Clinicians must consider deTSH in VLBWI showing feeding intolerance with a prolonged NPO and TPN status.

Resistance to thyroid hormone (RTH) is a condition caused by a mutation in the thyroid hormone receptor gene. It is rarely reported in individuals with no family history of RTH or in premature infants, and its clinical presentation varies. In our case, a premature infant with no family history of thyroid diseases had a thyroid stimulating hormone level of 85.0 µIU/mL and free thyroxine level of 1.64 ng/dL on a thyroid function test. The patient also presented with clinical signs of hypothyroidism, including difficulties in feeding and weight gain. The patient was treated with levothyroxine; however, only free thyroxine and triiodothyronine levels increased without a decrease in thyroid-stimulating hormone levels. Taken together with thyroid gland hypertrophy observed on a previous ultrasound examination, RTH was suspected and the diagnosis was eventually made based on a genetic test. A de novo mutation in the thyroid hormone receptor β gene in the infant was found that has not been previously reported. Other symptoms included tachycardia and pulmonary hypertension, but gradual improvement in the symptoms was observed after liothyronine administration. This report describes a case involving a premature infant with RTH and a de novo mutation, with no family history of thyroid disease.

Congenital pancreatic cysts are rare in newborn babies, and this makes prenatal diagnosis difficult. Diagnosis can be delayed for a few months after birth until the infant presents with an abdominal mass, abdominal distension, or vomiting due to gastric outlet obstruction. Excision of the cyst is the treatment of choice. A congenital pancreatic cyst should be considered if the fetus has an abdominal cyst without a definite origin. A prompt diagnosis is crucial to prevent fatal complications such as cholangitis, pancreatitis, cyst rupture, and peritonitis. We report a case of neonate with multiple congenital pancreatic cysts suspected prenatally to be stomach diverticulum or duplication cysts of the intestine.