Serologic evolution and follow-up to IgG antibodies of infants born to mothers with gestational COVID.

BACKGROUND: It is known that SARS-CoV-2 antibodies from pregnant women with SARS-CoV-2 infection during pregnancy cross the placenta but the duration and the protective effect of these antibodies in infants is scarce. METHODS: This prospective study included mothers with SARS-COV-2 infection during pregnancy and their infants from April 2020 to March 2021. IgG antibodies to SARS-CoV-2 spike protein were performed on women and infants at birth and at two and six months during follow-up. Anthropometrical measures and physical and neurological examinations and a clinical history of symptoms and COVID-19 diagnosis were collected. Simple linear regression was performed to compare categorical and continuous variables. To compare the mother's and infant's antibody titers evolution, a mixed linear regression model was used. A predictive model of newborn antibody titers at birth has been established by means of simple stepwise linear regression. RESULTS: 51 mother-infant couples were included. 45 (90%) of the mothers and 44 (86.3%) of the newborns had a positive serology al birth. These antibodies were progressively decreasing and were positive in 34 (66.7%) and 7 (13.7%) of infants at 2 and 6 months, respectively. IgG titers of newborns at birth were related to mothers' titers, with a positive moderate correlation (Pearson's correlation coefficient: 0.82, p < 0,001). Fetal/maternal antibodies placental transference rate was 1.3 (IQR: 0.7-2.2). The maternal IgG titers at delivery and the type of maternal infection (acute, recent, or past infection) was significantly related with infants' antibody titers at birth. No other epidemiological or clinical factors were related to antibodies titers. Neurodevelopment, psychomotor development, and growth were normal in 94.2% of infants in the third follow-up visit. No infants had a COVID-19 diagnosis during the follow-up period. CONCLUSIONS: Transplacental transfer of maternal antibodies is high in newborns from mothers with recent or past infection at delivery, but these antibodies decrease after the first months of life. Infant's IgG titers were related to maternal IgG titers at delivery. Further studies are needed to learn about the protective role of maternal antibodies in infants.

Total intrapartum fetal reperfusion time (fetal resilience) and neonatal acidemia.

OBJECTIVE: The main objective is to study the predictive capacity of intrapartum total fetal reperfusion (fetal resilience) by itself or in combination with other parameters as a predictor of neonatal acidemia. STUDY DESIGN: A retrospective case-control study was carried out at the Miguel Servet University Hospital (Zaragoza, Spain) on a cohort of 5694 pregnant women between June 2017 and October 2018. Maternal, perinatal, and cardiotocographic records were collected. Two reviewers blindly described the monitors with the American College of Obstetricians and Gynecologists (ACOG) categorizations and parameters and the non-ACOG parameters. Neonatal acidemia was defined as pH <7.10. The parameters analyzed to predict acidemia were evaluated using the sensitivity for specificity 90% value, and the area under the receiver operating characteristic curve. RESULTS: We recorded 192 infants with acidemia, corresponding to a global acidemia rate of 3.4%. Of these, 72 were excluded for lack of criteria, leaving 120 patients with arterial acidemia included in the study and 258 in the control group. The sensitivity (specificity 90%) of detection of acidemia was 42% for the ACOG III categorization (AUC, 0.524: 95% CI, 0.470-0.578), 24% for fetal reperfusion (AUC, 0.704: 95% CI, 0.649-0.759), 27% for total area of decelerations (AUC, 0.717: 95% CI, 0.664-0.771) and 50% for the multivariate model built from total reperfusion time (AUC, 0.826: 95% CI, 0.783-0.869). The total reperfusion time corresponding to a false negative rate of 10% is 23.75 min, with 28% of fetuses above this time. The AUC and sensitivity for a false negative rate of 10% are equivalent for deceleration area and time of reperfusion (p = .504). CONCLUSION: The total reperfusion time (fetal resilience) and total deceleration area are non-ACOG parameters with a good predictive ability for neonatal acidemia, higher than the ACOG III classification and without statistical differences between them. The discrimination ability of total reperfusion time can be improved using a multivariate model. As a cutoff for its use we suggest 23.75 min in 30 min corresponding to an acidemic classification rate of 90%. New parameters in combination with other maternal, obstetrics, or fetal variables, are required for the interpretation of fetal well-being.

Diagnostic capacity and interobserver variability in FIGO, ACOG, NICE and Chandraharan cardiotocographic guidelines to predict neonatal acidemia.

OBJECTIVE: Despite its routine use in intrapartum care, the technique of fetal cardiotocography has some limitations. The aim of this study is to analyze the predictive capacity and interobserver agreement in the latest versions of four international cardiotocography guidelines: Federation of Gynecology and Obstetrics (FIGO), American College of Obstetrics and Gynecology (ACOG), the National Institute for Health and Care Excellence (NICE) and Chandraharan, used to predict neonatal acidemia. STUDY DESIGN: The last 30 min of 150 cardiotocographic records were analyzed over all the pH ranges and were blindly evaluated by three independent reviewers. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated to assess the predictive capacity of each fetal cardiotocographic guideline. The degree of interobserver agreement was evaluated with the Fleiss Kappa coefficient. RESULTS: Observers found fetal cardiotocography guidelines to have a variable sensitivity and specificity. The Chandraharan classification reached the highest sensitivity (78.79%), while ACOG had the highest specificity (95.73%). On average for the three observers, Chandraharan had the highest discrimination capacity for neonatal acidemia, although this was only moderate (AUC 0.66; 95%CI, 0.55-0.77) and did not differ significantly from the remaining guidelines. The degree of agreement among the three observers, assessed according to the Fleiss Kappa coefficient, was generally acceptable or moderate for all items and classifications, being highest with the FIGO classification (ĸ = 0.35; 95%CI, 0.28-0.41) and lowest with the ACOG (ĸ = 0.23; 95%CI, 0.16-0.30). CONCLUSION: Although all the guidelines have a moderate capacity to predict neonatal acidemia, the Chandraharan guideline has the highest capacity. This follows a different approach from the others in that it relies on interpretations of cardiotocographic traces based on fetal physiology. The degree of interobserver agreement is, in general, acceptable for the four guidelines, and is the highest for FIGO.