Application of the postnatal urinary tract dilation classification system to predict the need for surgical intervention among neonates and young infants

Purpose@#The aim of this study was to validate the postnatal urinary tract dilation (UTD) classification system by correlating it with the need for surgical intervention. @*Methods@#Young infants who underwent ultrasound (US) examinations for prenatal hydronephrosis were retrospectively identified. The kidney units (KUs; right, left, or bilateral) were graded from UTD P0 (very low risk) to P3 (high risk) based on seven US criteria from the UTD system. Surgery-free survival curves were constructed using the Kaplan-Meier method. Univariable and multivariable Cox proportional-hazards regression analysis clustered by patients was performed. Interobserver agreement was analyzed using the weighted kappa coefficient. @*Results@#In total, 504 KUs from 336 patients (mean age, 18.3±15.9 days; range, 1 to 94 days; males, n=276) were included, with a median follow-up of 24.2 months. Fifty-eight KUs underwent surgical intervention. Significant differences were observed among the Kaplan-Meier curves stratified into UTD groups (P<0.001). The presence of anterior-posterior renal pelvic diameter ≥15 mm (hazard ratio [HR], 8.602; 95% confidence interval [CI], 1.558 to 43.065), peripheral calyceal dilation (HR, 8.190; 95% CI, 1.558 to 43.065), ureteral dilation (HR, 2.619; 95% CI, 1.274 to 5.380), parenchymal thickness abnormality (HR, 3.371; 95% CI, 1.574 to 7.223), bladder abnormality (HR, 12.209; 95% CI, 3.616 to 41.225) were significantly associated with the occurrence of surgery. The interobserver agreement was moderate to almost perfect agreement for US features (κ=0.564-0.898) and substantial for final UTD grades (κ=0.716). @*Conclusion@#The UTD classification system is reliable and appropriately stratifies the risk of surgical intervention.

Comparison of upper and lower body forced air blanket to prevent perioperative hypothermia in patients who underwent spinal surgery in prone position: a randomized controlled trial / 대한마취과학회지

Background@#We compared upper- and lower-body forced-air blankets in terms of their ability to prevent perioperative hypothermia, defined as a reduction in body temperature to < 36.0°C, during the perioperative period in patients undergoing spine surgery in the prone position. @*Methods@#In total, 120 patients scheduled for elective spine surgery under general anesthesia were divided into an upper-warming group (n = 60) and a lower-warming group (n = 60). After inducing anesthesia and preparing the patient for surgery, including prone positioning, the upper and lower bodies of the patients in the upper- and lower-warming groups, respectively, were warmed using a forced-air warmer with specified upper and lower blankets. Body temperature was measured using a tympanic membrane thermometer during the pre- and post-operative periods and using a nasopharyngeal temperature probe during the intraoperative period. Patients were evaluated in terms of shivering, thermal comfort, and satisfaction in the post-anesthesia care unit (PACU). @*Results@#The incidence of intraoperative and postoperative hypothermia was lower in the upper-warming group than in the lower-warming group ([55.2% vs. 75.9%, P = 0.019] and [21.4% vs. 49.1%, P = 0.002]). Perioperative body temperature was higher in the upper-warming group (P < 0.001). However, intraoperative blood loss, postoperative thermal comfort scale and shivering scores, patient satisfaction, and PACU duration were similar in the two groups. @*Conclusions@#The upper-body blanket was more effective than the lower-body blanket for preventing perioperative hypothermia in patients who underwent spine surgery in the prone position.

Immunosuppressive Drug Measurement by Liquid Chromatography Coupled to Tandem Mass Spectrometry: Interlaboratory Comparison in the Korean Clinical Laboratories

Background@#Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is increasingly used for immunosuppressive drug tests. However, most LC-MS/MS tests are laboratory-developed and their agreement is unknown in different Korean laboratories.This interlaboratory comparison study evaluated test reproducibility and identified potential error sources. @*Methods@#Test samples containing three concentrations of tacrolimus, sirolimus, everolimus, cyclosporine, and mycophenolic acid were prepared by pooling surplus samples from patients undergoing routine therapeutic drug monitoring and tested in duplicate in the participating 10 clinical laboratories. Reconstitution and storage experiments were conducted for the commonly used commercial calibrator set. The robust estimators of reproducibility parameters were calculated. Spearman’s rank correlation coefficient (rho, ρ) was used to evaluate the correlation between drugs. Multiple linear regression was used to determine whether the experimental conditions alter the calibration curves. @*Results@#The reproducibility coefficient of variation exceeded 10% only for sirolimus concentrations 1 and 2 (10.8% and 12.5%, respectively) and everolimus concentrations 1 and 2 (12.3% and 11.4%, respectively). The percent difference values showed weak correlations between sirolimus and everolimus (ρ = 0.334, P = 0.175). The everolimus calibration curve slope was significantly altered after reconstitution following prolonged 5°C storage (P = 0.015 for 14 days; P = 0.025 for 28 days); the expected differences at 6 ng/mL were 0.598% for 14 days and 0.384% for 28 days. @*Conclusions@#LC-MS/MS test reproducibility for immunosuppressive drugs seems to be good in the Korean clinical laboratories. Continuous efforts are required to achieve test standardization and harmonization, especially for sirolimus and everolimus.

Surveillance of Coronavirus Disease 2019 (COVID-19) Testing in Clinical Laboratories in Korea

In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, an online laboratory surveillance system was established to monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcription-PCR (rRT-PCR) testing capacities and results. SARS-CoV-2 rRT-PCR testing data were collected from 97 clinical laboratories, including 84 medical institutions and 13 independent clinical laboratories in Korea. We assessed the testing capacities to utilize SARS-CoV-2 rRT-PCR based on surveillance data obtained from February 7th to June 4th, 2020 and evaluated positive result characteristics according to the reagents used and sample types. A total of 1,890,319 SARS-CoV-2 rRT-PCR testing were performed, 2.3% of which were positive. Strong correlations were observed between the envelope (E ) gene and RNA-dependent RNA polymerase (RdRp )ucleocapsid (N ) genes threshold cycle (Ct) values for each reagent. No statistically significant differences in gene Ct values were observed between the paired upper and lower respiratory tract samples, except in the N gene for nasopharyngeal swab and sputum samples. Our study showed that clinical laboratories in Korea have rapidly expanded their testing capacities in response to the COVID-19 outbreak, with a peak daily capacity of 34,193 tests. Rapid expansion in testing capacity is a critical component of the national response to the ongoing pandemic.

Establishment of Pediatric Reference Intervals for Routine Laboratory Tests in Korean Population: A Retrospective Multicenter Analysis

Background@#Reference intervals defined for adults or children of other ethnicities cannot be applied in the evaluation of Korean pediatric patients. Pediatric reference intervals are difficult to establish because children are in their growing stage and their physiology changes continuously. We aimed to establish reference intervals for routine laboratory tests for Korean pediatric patients through retrospective multicenter data analysis. @*Methods@#Preoperative laboratory test results from 1,031 pediatric patients aged 0 month–18 years who underwent minor surgeries in four university hospitals were collected. Age- and sex-specific reference intervals for routine laboratory tests were defined based on the Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines. @*Results@#The pediatric reference intervals determined in this study were different from existing adult reference intervals and pediatric reference intervals for other ethnicities. Most tests required age-specific partitioning, and some of those required sex-specific partitioning for at least one age-partitioned subgroup. Erythrocyte sedimentation rate, monocyte percentage, basophil percentage, activated partial thromboplastin time, glucose, cholesterol, albumin, bilirubin, chloride, and C-reactive protein did not show any difference between age- or sex-partitioned subgroups. @*Conclusions@#We determined Korean pediatric reference intervals for hematology, coagulation, and chemistry tests by indirect sampling based on medical record data from multiple institutions. These reference intervals would be valuable for clinical evaluations in the Korean pediatric population.

A Prospective Comparative Study of Mobile Acoustic Uroflowmetry and Conventional Uroflowmetry / 대한배뇨장애요실금학회지

Purpose@#The aim of this study was to assess the performance of a mobile acoustic Uroflowmetry (UFM) application compared with standard UFM in the pediatric population. @*Methods@#A mobile acoustic UFM application represents a noninvasive method to estimate the urine flow rate by recording voiding sounds with a smartphone. Male pediatric patients who were undergoing UFM testing were prospectively recruited, and the voiding sounds were recorded and analyzed. The intraclass correlation coefficient (ICC) was used to compare the maximum flow rate (Qmax), average flow rate (Qavg), voiding time (VT), and voiding volume (VV) as estimated by acoustic UFM with those calculated by standard UFM. Differences in Qmax, Qavg, VT, and VV between the 2 UFM tests were determined using 95% Bland-Altman limits of agreement. @*Results@#A total of 16 male patients were evaluated. Their median age was 9 years. With standard UFM, the median Qmax, Qavg, VT, and VV were 18.7 mL/sec, 11.1 mL/sec, 15.2 seconds, and 157.8 mL, respectively. Strong correlations were observed between the 2 methods for Qmax (ICC=0.755, P=0.005), VT (ICC=0.974, P<0.001), and VV (ICC=0.930, P<0.001), but not for Qavg (ICC=0.442, P=0.135). The Bland-Altman plot showed good agreement between the 2 UFM tests. Flow patterns recorded by acoustic UFM and conventional UFM showed good visual correlations. @*Conclusions@#Acoustic UFM was comparable to standard UFM for male pediatric patients. Further validation of its performance in different toilet settings is necessary for broader use.

Estimating the time of onset of testicular torsion using ultrasonography in an experimental rat model

Purpose@#We aimed to document the time of onset of ultrasonographic and histologic changes in the testes of a rat model following testicular torsion. @*Methods@#Twenty-five Sprague-Dawley rats were divided into four groups. All animals underwent preoperative Doppler ultrasonography. Groups 1, 2, and 3 underwent unilateral surgical torsion of the testis lasting for 72, 24, and 6 hours, respectively. Group 4 underwent a sham operation. The animals were followed with Doppler ultrasonography at 6, 24, 48, and 72 hours postoperatively. Histologic examinations were performed at the designated final time point for each group. @*Results@#After torsion, enlargement of the epididymal head and thickening of the spermatic cord over time were noted. Based on the ultrasonographic dimensions, the ratio of the epididymal volume increased with time following torsion (p=0.002). The torsed testes had an average weight gain of 0.27 g at 6 hours compared to the control testes, but an average weight loss of 0.22 g at 72 hours (P=0.006). Changes in testicular echotexture were noted as soon as 6 hours after torsion, but there was no consistent pattern of echotexture change thereafter. Histologically, viable tubules were seen 6 hours after torsion, while extensive hemorrhagic necrosis was found at 72 hours. @*Conclusion@#In evaluating testicular torsion, the enlargement ratio of the epididymis and thickening of the spermatic cord on Doppler ultrasonography may be useful for determining the urgency of immediate surgery. Changes in testicular echotexture may not be a reliable indicator of the time of onset.

In vitro activity of lopinavir/ritonavir and hydroxychloroquine against severe acute respiratory syndrome coronavirus 2 at concentrations achievable by usual doses

Background/Aims@#As the coronavirus disease-2019 global pandemic progresses, screening of antiviral agents effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is urgently needed. In addition, considering the viral load kinetics of SARS-CoV-2, which peaks early in the illness, and the massive burden of the disease, which may increase in the near future, identifying well-tolerated oral antivirals becomes increasingly important. We examined the in vitro activity of lopinavir/ritonavir and hydroxychloroquine on SARS-CoV-2, at concentrations which can be used to treat coronavirus-19 patients with little concern of toxicity. @*Methods@#Lopinavir/ritonavir (7/1.75 μg/mL), hydroxychloroquine base (1 or 2 μg/mL), or a combination thereof were administered 1 hour after the inoculation of SARS-CoV-2 to Vero cells at a multiplicity of infection of 0.05. We examined cytopathic effects of virus 48 hours after administration of the respective treatments and measured viral loads at three time points (0, 24, and 48 hours post-treatment) by quantitative real-time reverse-transcription polymerase chain reaction, and compared the results obtained from the different antiviral regimens tested. @*Results@#The severity of cytopathic effects was lower in lopinavir/ritonavir-treated cells, and viral load was significantly reduced in this group compared with the control group (p < 0.001). However, hydroxychloroquine did not show significant inhibitory effects on anti-SARS-CoV-2-mediated cytotoxicity or on viral load at either concentration. @*Conclusions@#Lopinavir/ritonavir showed significant inhibitory effects on SARS-CoV-2 in vitro at its usual plasma concentration. However, the in vitro antiviral activity of hydroxychloroquine at concentrations commonly used in humans was minimal, whether used alone or in combination with lopinavir/ritonavir.

A Case of Breakthrough COVID-19 during Hydroxychloroquine Maintenance

There have been controversies on the prophylactic effect of hydroxychloroquine against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We describe a patient, 60-year old Korean woman, with coronavirus disease 2019 (COVID-19) who had been taking hydroxychloroquine for 6 months. Her serum and saliva concentrations of hydroxychloroquine were 280 μg/L and 4,890 μg/L, respectively. The present case raises concerns on hydroxychloroquine's role as a prophylactic agent for COVID-19.

Copeptin with high-sensitivity troponin at presentation is not inferior to serial troponin measurements for ruling out acute myocardial infarction

Objective@#We aimed to compare the multi-marker strategy (copeptin and high-sensitivity cardiac troponin I [hs-cTnI]) with serial hs-cTnI measurements to rule out acute myocardial infarction (AMI) in patients with chest pain. @*Methods@#This prospective observational study was performed in a single emergency department. To test the non-inferiority margin of 4% in terms of negative predictive value (NPV) between the multi-marker strategy (0 hour) and serial hs-cTnI measurements (0 and 2 hours), 262 participants were required. Samples for copeptin and hs-cTnI assays were collected at presentation (0 hour) and after 2 hours. The measured biomarkers were considered abnormal when hs-cTnI was >26.2 ng/L and when copeptin was >10 pmol/L. @*Results@#AMI was diagnosed in 28 patients (10.7%). The NPV of the multi-marker strategy was 100% (160/160; 95% confidence interval [CI], 97.7% to 100%), which was not inferior to that of serial hs-cTnI measurements (201/201; 100%; 95% CI, 98.2% to 100%). The sensitivity, specificity, and positive predictive value of the multi-marker strategy were 100% (95% CI, 87.7% to 100%), 68.1% (95% CI, 61.7% to 74.0%), and 27.2% (95% CI, 18.9% to 36.8%), respectively. The sensitivity, specificity, and positive predictive value of serial hs-cTnI measurements were 100% (95% CI, 87.7% to 100%), 85.5% (95% CI, 80.4% to 89.8%), and 45.2% (95% CI, 32.5% to 58.3%), respectively. @*Conclusion@#The multi-marker strategy (copeptin and hs-cTnI measurement) was not inferior to serial hs-cTnI measurements in terms of NPV for AMI diagnosis, with a sensitivity and NPV of 100%. Copeptin may help in the early rule-out of AMI in patients with chest pain.

Recommendations for the Use of Liquid Chromatography-Mass Spectrometry in the Clinical Laboratory: Part I. Implementation and Management

Recommendations for Liquid Chromatography-Mass Spectrometry in the Clinical Laboratory: Part III. Quality Assurance

The use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) in clinical laboratories is increasing and is likely to expand into even more clinical venues in the future. Mass spectrometry is the standard method for analyte identification in the clinical chemistry field; however, differences in mass spectrometry protocols and handling affect the accuracy and reliability of these tests and prevent direct comparisons of results between laboratories. For example, the results of laboratories using LC-MS/MS methods are less likely to be reproducible than those of laboratories using conventional, automated methods. This is due to inadequate handling of the equipment and/or poor quality control after the implementation of the method, which may result in unnecessary medical expenditures or even adverse outcomes for the patients. Unfortunately, guidelines to monitor the accuracy of LC-MS/MS-based clinical tests are still lacking. In general, the quality control methods used in conventional clinical tests could also be applied to LC-MS/MS. However, additional quality control methods specific to LC-MS/MS techniques must be continuously employed to maintain the same quality level achieved during method development and verification. This report is intended to help clinical laboratories that operate LC-MS/MS improve the accuracy and reliability of their testing by providing guidance for quality assurance and improvement, based on a collection of existing guidelines and expert opinions from the literature.

Inhibition of Cross-Reactive Carbohydrate Determinant–Specific IgEs Reduce False Positive Reponses to Multiple Allergen Simultaneous Test–Immunoblot Assay: A Case Study

Cross-reactive carbohydrate determinants (CCDs) are simple carbohydrates linked to amino acid chains; they are found in pollens, vegetable foods, insect, and Hymenoptera venoms and are broadly cross-reactive with CCD-specific IgE antibodies. A man in his fifties was evaluated using a multiple allergen simultaneous test–immunoblot assay. On the PROTIA Allergy-Q 64 inhalant panel (ProteomeTech, Korea), reactions to 37 of 59 antigens were observed except mammalian antigens, and cross-reactivity owing to anti-CCD antibodies was suspected. After ProGlycAn CCD-blocker (ProGlycAn, Austria) treatment, the patient exhibited no response to CCD allergens, and the number of allergens showing positive reactions was reduced to 15. We further tested a total of 7 samples from patients who were suspected to have CCD-related cross-reactivity. For these 8 patients, the average number of positive reactions to allergens was reduced from 33 (range 24-36) to 8 (range 0-19) after CCD-blocker treatment. We concluded that CCD-blocker treatment in sample with anti-CCD antibodies can reduce the false positive reponse and provide more specific information about allergens.

Recent progress in laboratory diagnosis of thalassemia and hemoglobinopathy: a study by the Korean Red Blood Cell Disorder Working Party of the Korean Society of Hematology

Genetic hemoglobin disorders are caused by mutations and/or deletions in the α-globin or β-globin genes. Thalassemia is caused by quantitative defects and hemoglobinopathies by structural defect of hemoglobin. The incidence of thalassemia and hemoglobinopathy is increased in Korea with rapid influx of people from endemic areas. Thus, the awareness of the disease is needed. α-thalassemias are caused by deletions in α-globin gene, while β-thalassemias are associated with decreased synthesis of β-globin due to β-globin gene mutations. Hemoglobinopathies involve structural defects in hemoglobin due to altered amino acid sequence in the α- or β-globin chains. When the patient is suspected with thalassemia/hemoglobinopathy from abnormal complete blood count findings and/or family history, the next step is detecting hemoglobin abnormality using electrophoresis methods including high performance liquid chromatography and mass spectrometry. The development of novel molecular genetic technologies, such as massively parallel sequencing, facilitates a more precise molecular diagnosis of thalassemia/hemoglobinopathy. Moreover, prenatal diagnosis using genetic testing enables the prevention of thalassemia birth and pregnancy complications. We aimed to review the spectrum and classification of thalassemia/hemoglobinopathy diseases and the diagnostic strategies including screening tests, molecular genetic tests, and prenatal diagnosis.

A Questionnaire Survey on General Status and Opinions about Clinical Mass Spectrometric Analysis in Korea (2018)

The Clinical Mass Spectrometry Research Committee (CMSRC), in affiliation with the Korean Society of Clinical Chemistry (KSCC), conducted a questionnaire survey on opinions about the general status of clinical mass spectrometric analysis in Korea. As a result, we understand that this field has passed through the introductory stage and is settled as a field of clinical laboratory testing in Korea, with the number of new laboratories performing mass spectrometric analysis being low. In spite of the many difficulties in introducing and operating clinical mass spectrometric analysis, there is a strong interest in this field, and even though further expansion is expected, there are still many issues to be resolved. In the future, it will be necessary to make concrete and thorough efforts to further develop the laboratory tests using clinical mass spectrometric analysis in Korea, centering on the CMSRC affiliated with the KSCC.

Development of Statistical Software for the Korean Laboratory Accreditation Program Using R Language: LaboStats

BACKGROUND: In Korea, the Korean Laboratory Accreditation Program (KLAP) has set minimum standards for verification of clinical test performance. This verification process is time-consuming and labor-intensive when performed manually. We developed a free, statistical software program for KLAP, using the R language (R Foundation for Statistical Computing, Vienna, Austria). METHODS: We used CLSI guidelines for the algorithm. We built graphic user interfaces, including data input, with Embarcadero Delphi EX4 (Embarcadero Technologies, Inc., Texas, USA). The R Base Package and MCR Package for Method Comparison Regression were used to implement statistical and graphical procedures. RESULTS: Our program LaboStats has six modules: parallel test, linearity, method comparison, precision, reference interval, and cutoff. Data can be entered into the field either manually or by copying and pasting from an MS Excel worksheet. Users can print out precise reports. CONCLUSIONS: LaboStats can be useful for evaluating clinical test performance characteristics and preparing documents requested by KLAP.

A Multiplex Phytosterol Assay Utilizing Gas Chromatography-Mass Spectrometry for Diagnosis of Inherited Lipid Storage Disorders

No abstract available.

Clinicopathological Characteristics of Urinary Bladder Tumors in Korean Patients 20 Years or Younger

BACKGROUND: To investigate the clinicopathological characteristics of urinary bladder tumors, a rare malignancy, in patients 20 years or younger. METHODS: Using a retrospective chart review among patients who received bladder surgery at 2 institutions between July 1996 and January 2013, we analyzed the clinicopathological characteristics of urinary bladder tumors in 21 pediatric patients (male:female = 4.25:1.00; mean age, 12.1 years). RESULTS: Pathology revealed 9 urothelial tumors, 6 rhabdomyosarcomas, 1 low-grade leiomyosarcoma, 1 large cell neuroendocrine carcinoma, 1 inflammatory myofibroblastic tumor, and 3 cases of chronic inflammation without tumors (including 1 xanthogranulomatous inflammation). Urothelial tumors (mean patient age, 16.0 years) were benign or low-grade; and only transurethral resection of the bladder tumor was necessary for treatment. Patients with rhabdomyosarcomas (mean age, 5 years) underwent radiotherapy (if unresectable) or transurethral resection of the bladder tumor (if resectable), after chemotherapy. Of these patients, 2 underwent radical cystectomy, with the remaining patients not receiving a cystectomy. With the exception of one patient, all patients are currently alive and recurrence-free. CONCLUSION: Urothelial tumors were the most commonly found pediatric bladder tumor, with embryonal rhabdomyosarcoma being the second most common. Urothelial tumors are common in relatively older age. Since urothelial tumors in children typically have a good prognosis and rarely recur, transurethral resection of the bladder tumor is the treatment of choice. Rhabdomyosarcomas are common in younger patients. Since rhabdomyosarcoma is generally chemosensitive, chemotherapy and radiotherapy are the treatment of choice for bladder preservation in these patients.

Long-term Outcomes of Endoscopic Anti-reflux Surgery in Pediatric Patients with Vesicoureteral Reflux: Urinary Tract Infection, Renal Scarring, and Predictive Factors for Success

BACKGROUND: To report the long-term outcomes of endoscopic surgery (ES) in pediatric patients with vesicoureteral reflux in terms of success rate, urinary tract infection, and renal function. METHODS: We retrospectively reviewed the records of 73 pediatric patients (110 ureters) who underwent ES for vesicoureteral reflux. Ultrasonography was performed 1, 3, and 12 months postoperatively. Voiding cystourethrography was performed 3 months postoperatively and repeated after 1 year if vesicoureteral reflux persisted. Success was defined as the absence of reflux at the first voiding cystourethrography. Renal scans were performed at least 12 months postoperatively. Renal function deterioration was defined as a new scar or a greater than 5% decrease in function. RESULTS: The median follow-up duration was 24 (12–118) months. The overall success was 65.6%, while it was 78.9%, 87.0%, 62.5%, 37.5%, 66.7% for grades I, II, III, IV, and V, respectively. In multivariate analyses, significant predictive factors for success were vesicoureteral reflux grade (odds ratio [OR], 0.28; P < 0.001) and mound detection at the first postoperative ultrasonography (OR, 13.53; P < 0.001). Renal function deterioration was found in 8 (15.3%) ureters and was less common in those with successful surgeries than in those with failures (9.5% vs. 40.0%; P = 0.035). No significant predictive factor for renal function deterioration or urinary tract infection was found. CONCLUSION: Successful short-term outcomes of ES are expected in low-grade vesicoureteral reflux, especially when a mound is detected by postoperative ultrasonography. However, unpredictable long-term renal deterioration warrants continued follow-up.

Effects of Maternal Iodine Status during Pregnancy and Lactation on Maternal Thyroid Function and Offspring Growth and Development: A Prospective Study Protocol for the Ideal Breast Milk Cohort

BACKGROUND: Iodine is an intrinsic element of thyroid hormone, which is essential for childhood growth and development. The Ideal Breast Milk (IBM) cohort study aims to evaluate the effects of maternal iodine status during pregnancy and lactation on maternal thyroid function, offspring growth and development, and offspring thyroid function. METHODS: The IBM cohort study recruited pregnant women from Seoul National University Hospital between June 2016 and August 2017, followed by enrollment of their offspring after delivery. For the maternal participants, iodine status is evaluated by urinary iodine concentration (UIC) and dietary records in the third trimester and at 3 to 4 weeks and 12 to 15 months postpartum. For the child participants, cord blood sampling and UIC measurements are performed at birth. At 3 to 4 weeks of age, UIC and breastmilk iodine concentrations are measured. At 12 to 15 months of age, growth and development are assessed and measurements of UIC, a thyroid function test, and ultrasonography are performed. RESULTS: A total of 198 pregnant women in their third trimester were recruited. Their mean age was 35.1±3.5 years, and 78 (39.4%) of them were pregnant with twins. Thirty-three (16.7%) of them had a previous history of thyroid disease. CONCLUSION: Korea is an iodine-replete area. In particular, lactating women in Korea are commonly exposed to excess iodine due to the traditional practice of consuming brown seaweed soup postpartum. The study of the IBM cohort is expected to contribute to developing guidelines for optimal iodine nutrition in pregnant or lactating women.