Does the delivery mode affect post-birth neonatal serum C-reactive protein levels? A causal effect analysis.

AIM: To determine if the delivery mode has a causal effect on neonatal serum C-reactive protein (CRP) levels. If such a causal effect exists, we aim to quantify its magnitude. METHODS: We investigated the causal effect of the delivery mode on serum CRP levels 6-8 h after delivery, with appropriate statistical tools for retrospective studies, combining classical and machine-learning methods. The statistical inference is followed by sensitivity analysis to quantify the magnitude of unobserved bias required in order to alter the study's conclusion. RESULTS: This retrospective study reviewed laboratory records of neonates after birth who underwent blood tests due to suspected sepsis. A total of 440 newborns were included, 324 of which underwent a vaginal delivery, 59 an urgent caesarean delivery, and 57 an elective caesarean delivery. Our results revealed that serum CRP values following elective caesarean deliveries were 50% less than those following a vaginal delivery (P = 0.030; -0.907; 95% CI [-1.545, -0.268] in log-CRP units). No significant effect was found for urgent caesarean deliveries compared to vaginal deliveries (P = 0.887). Those results were strengthened by (1) a sensitivity magnitude of 1.6 to unobserved bias and (2) non-significant effects when analysis is repeated on blood collected 12-24 h after birth. CONCLUSION: CRP concentrations in neonatal blood during the first 6-8 h of life are higher following vaginal deliveries compared to elective caesarean deliveries. Further studies with the intent of improving EONS detection should include information on the delivery mode.

C-reactive protein and the neonatal early-onset sepsis calculator for the diagnosis of neonatal sepsis.

Our aim was to evaluate the utility of the neonatal early-onset sepsis risk calculator (NEOSC) to the utility of C-reactive protein (CRP) for diagnosing neonatal EOS. This retrospective study reviewed the records of neonates who underwent sepsis workups due to equivocal symptoms and compared their CRP values to the calculator's recommendations and their cultures. A total of 382 newborns who underwent sepsis work-up due to equivocal symptoms were included in our study. The calculator's recommendations would have reduced the number of newborns who underwent sepsis workups by 82.5% and antibiotic treatment by 83.4% (n = 315). Considering that 373 of 382 (97.6%) ultimately had no sepsis, the calculator's specificity was higher than that of CRP (83.9% versus 76.1%). When comparing the maximal CRP value with the risk according to the neonatal sepsis calculator, a significant correlation was found between them (P < 0.01), but the relationship was not strong (Pearson's correlation = 0.27). We found a significant correlation between the risk of sepsis according to the NEOSC and the CRP values, although the correlation was not strong. The calculator's high specificity enables safe avoidance of multiple blood tests and antibiotic treatments for suspected neonates who are not infected. CRP tests can reduce the number of infected newborns the calculator may miss, at the cost of unnecessary blood tests and antibiotic therapy to many newborns.

C-reactive protein in early-onset neonatal sepsis - a cutoff point for CRP value as a predictor of early-onset neonatal sepsis in term and late preterm infants early after birth?

OBJECTIVE: To identify whether the first plasma C-reactive protein values taken 6-8 h postpartum are predictive of the clinical early-onset neonatal sepsis (cEONS). STUDY DESIGN: We retrospectively analyzed C-reactive protein (CRP) values of 400 neonates, including 28 with cEONS, who underwent plasma CRP measurements as part of sepsis work-up. To determine whether the first CRP measurement is predictive of cEONS, logistic regression was used with CRP as an independent variable and cEONS (yes/no) as a dependent variable. RESULT: A moderate predictive ability of the first CRP measurement (odds ratio 1.4, CI: [1.13, 1.76], p=.003) was revealed, at a 5.3 mg/L threshold. However, it resulted in poor sensitivity of 50%, and a false positive rate of 30%. Increasing the sensitivity to 75% or 90% lead to increased false-positive rates of 55% and 75%, respectively. CONCLUSIONS: Our findings suggest that the first CRP value taken in neonates is a weak predictor of cEONS.