Youn YA, et al. J Korean Med Sci. 2015 Oct;30(Suppl 1):S75-S80. https://doi.org/10.3346/jkms.2015.30.S1.S75

The government of South Korea implemented social distancing measures to control the coronavirus disease 2019 (COVID-19) outbreak. This study aimed to compare the composite preterm (PT) or low birth weight (LBW) birth rates during the COVID-19 pandemic period in South Korea to those during the prior decade, and to find out the associations of childbirth during the pandemic period with PT or LBW births. Over a ten-year period, this retrospective cohort study was performed in a single hospital in the Seoul metropolitan city. The COVID-19 period was defined as running from 22 March 2020, to 31 October 2020, and the pre-COVID-19 period as the sum of parallel periods from 2011 to 2019. Trends in composite birth rates were investigated, and logistic regression analysis was conducted to investigate independent factors associated with composite births. There were 246 and 2765 singleton deliveries during the COVID-19 period and the pre-COVID-19 period, respectively. The composite birth rate decreased from 16.5% to 9.8%. Childbirth during the pandemic was independently associated with a decreased composite birth rate (adjusted odds ratio, 0.563; 95% confidence interval, 0.355−0.844, p = 0.015). These findings suggested that the COVID-19 pandemic might provide an opportunity to find out preventive factors for PT or LBW births.

The aim of this study was to investigate whether some associations between histological chorioamnionitis (HCA) and favorable neonatal outcomes might be linked to those of antenatal steroids (AS) by determining the separate as well as the combined associations of HCA and AS with neonatal outcomes in very low birth weight infants (VLBWIs). This was a population-based study of VLBWIs born at 20–33 weeks’ gestation between January 2013 and December 2015 from the Korean Neonatal Network. A total of 4652 VLBWIs were enrolled for prevalence study. Of these, 2900 singleton VLBWIs were used for outcome analyses to evaluate individual associations of HCA and AS simultaneously with correction for potential perinatal factors and an interaction term of HCA and AS. The overall prevalence of HCA was 34.9% (1623 VLBWIs). Multivariable logistic regression demonstrated that HCA was associated with decreased mortality (adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.29–0.91; P = 0.022), AS were associated with reduction in mortality (aOR, 0.59; 95% CI, 0.39–0.90; P = 0.014) and neonatal seizure (aOR, 0.57; 95% CI, 0.37–0.86; P = 0.008), and a combination of HCA and AS was associated with remarkably lowered severe intraventricular hemorrhage by interacting with each other (aOR, 0.47; 95% CI, 0.25–0.88; P = 0.019). We suggest that in VLBWIs HCA and AS may be favorable independent factors for neonatal outcome and may also work in synergy for neuroprotection.

Purpose The objective was to identify the risk factors associated with nephrocalcinosis (NC) in preterm infants. Methods NC was diagnosed by renal sonography at 4 or 8 weeks of life, and 10 infants who had findings of type 3 or 4 NC were classified as the NC group. Various clinical and laboratory factors were compared between NC and control groups. Results Serum sodium (Na) on day 1, serum creatinine and fractional excretion of calcium (FeCa) at 1 and 2 weeks, and serum calcium (Ca), fractional excretion of sodium (FeNa), and urine Na on 2 weeks of life were significantly different between the two groups: the NC group showed significantly higher serum creatinine, FeNa, and FeCa than the control group, suggesting a greater decrease in renal function in the NC group. Differences of the laboratory findings disappeared after 4 weeks of life. The strongest risk factor was birth weight. Conclusion A transient decrease in renal function during the first 2 weeks of life was associated with development of NC in preterm very low-birth-weight infants, and the risk of NC increased as birth weight decreased.

Kim SY. J Korean Med Assoc. 2016 Jul;59(7):498-505. http://dx.doi.org/10.5124/jkma.2016.59.7.498