COVID-19 and vaccination during pregnancy: a systematic analysis using Korea National Health Insurance claims data.

OBJECTIVE: This study systematically analyzed coronavirus disease 2019 (COVID-19) and vaccination details during pregnancy by using the national health insurance claims data. METHODS: Population-based retrospective cohort data of 12,399,065 women aged 15-49 years were obtained from the Korea National Health Insurance Service claims database between 2019 and 2021. Univariate analysis was performed to compare the obstetric outcomes of pregnant women (ICD-10 O00-O94) and their newborns (ICD-10 P00-P96) with and without COVID-19. Univariate analysis was also performed to compare the age and obstetric outcomes of pregnant women receiving different types of vaccines. RESULTS: The percentage of pregnant women with COVID-19 during pregnancy was 0.11%. Some obstetric outcomes of pregnant women with COVID-19, including the rates of preterm birth or cesarean delivery, were significantly better than those of pregnant women without COVID-19. The rate of miscarriage was higher in pregnant women with COVID-19 than without COVID-19. However, the outcomes of newborns of women with and without COVID-19 were not significantly different. Regarding vaccination type, obstetric outcomes of pregnant women appeared to be worse with the viral vector vaccine than with the mRNA vaccine. CONCLUSION: To the best of our knowledge, this is the first study to systematically analyze COVID-19 and vaccination details during pregnancy using the national health insurance claims data in Korea. The obstetric outcomes in pregnant women with and without COVID-19 and their newborns were similar.

Urinary paraben concentrations among pregnant women and their matching newborn infants of Korea, and the association with oxidative stress biomarkers.

Parabens have been used in multiple products including personal care products, pharmaceuticals, and foods for more than 50 years but increasing numbers of studies have raised concerns on their safety. The present study was designed to determine urinary paraben levels among pregnant women and their matching newborn infants (<48 h after delivery), and the association between paraben levels and stress markers. Pregnant women (n=46) and their matching newborn infants were recruited from four university hospitals located in Seoul, Ansan and Jeju of Korea, 2011. Parabens including methyl paraben (MP), ethyl paraben (EP), n-propyl paraben (PP), and n-butyl paraben (BP) were measured in the urine using an automatic, high throughput online SPE-LC-MS/MS method. Urinary concentrations were normalized with specific gravity (SG). Free cortisol, malondealdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) were measured in the urine as stress marker. Urinary MP was detected as the highest, and BP was detected as the lowest paraben in the urine samples of both pregnant women and their infants. Significant correlations between paraben concentrations of maternal and their newborn infant's urine were observed. The levels of urinary parabens among Korean pregnant women are comparable to those reported elsewhere, except for EP which were 4-9 folds higher than pregnant women of other countries. The ratios of infant to maternal urinary paraben concentrations varied between 0.5 and 0.6 for MP and PP, but approximately 10 fold lower for EP. Urinary MP or EP levels were associated with several oxidative stress related biomarkers such as urinary 8-OHdG and MDA, even after the adjustment of relevant covariates such as maternal age, mode of delivery, pre-pregnancy BMI, gestational age and parity. This is the first study that reported the levels of major parabens in the first urine of newborn infants. Further studies are warranted to understand the implications of paraben exposure among biologically susceptible human populations.

Absolute CD4+ cell count using a plastic microchip and a microscopic cell counter.

We have designed and evaluated the performance of a simple, rapid, and affordable method for counting CD4(+) T-cells with the use of plastic microchips. This new system is an adaptation of a "no-lyse, no-wash," volumetric single platform assay, and absolute CD4(+) counts are determined with the use of a microscopic scanning cell counter. To assess the CD4(+) count test precision and linearity of the system, measured CD4(+) counts were compared with two other reference assays (single and dual platform flow cytometry) with the use of 123 clinical samples including samples obtained from 35 HIV-infected patients, and artificially diluted samples. A correlation between the results from the use of the new method and from the use of the two other reference assays was r = 0.98 for the clinical samples. A dilution test of the new method demonstrated a linearity of r >or= 0.99, with coefficients of variation

Evaluation of the Abbott Cell-Dyn 4000 hematology analyzer for detection and therapeutic monitoring of Plasmodium vivax in the Republic of Korea.

The Cell-Dyn 4000 automated hematology analyzer (CD4000) has the ability to detect malaria patients, but it remained unclear whether it could detect persistent malaria post-treatment. To investigate this, we used the CD4000 to evaluate 68 Korean patients with Plasmodium vivax malaria, and control groups of 50 patients with fever and 50 asymptomatic patients. The results from the instrument-generated scatter plot (derived by laser light depolarization) were compared with microscopy results. During the initial diagnosis, the sensitivity of the CD4000 in detecting malaria was 91.2%. On day 3 of follow-up, the CD4000 results matched those from microscopy by 96.7%. Malaria was not detected by either method beyond 14 days post-presentation. Interestingly, the atypical depolarizing events, which typify the presence of malaria in the analyzer, were highly correlated with the levels of parasitaemia in serially diluted samples of the leucocyte-depleted blood, and the CD4000 detected parasites down to the level of 288 +/- 17.7/microl. Our findings suggest that the phenomenon of atypical light depolarization could be influenced by parasitaemia levels, and be used as a screening method for P. vivax malaria patients, as well as for the therapeutic monitoring.