ABSTRACT
In many countries, preterm birth, defined as birth before 37 completed weeks of gestation, is the primary cause of infant death and morbidity. An increasing body of research suggests that inflammation (both clinical and subclinical) plays a significant role in inducing preterm labor or developing pregnancy problems that lead to premature birth. Consequently, the purpose of this research was to determine the predictive value of the Neutrophil-Lymphocyte Ratio (NLR), derived Neutrophil-Lymphocyte Ratio (dNLR), Monocytes-to-Lymphocyte Ratio (MLR), Platelets-to-Lymphocyte Ratio (PLR), Systemic immune-inflammation index (SII), and systemic inflammatory response index (SIRI), for premature delivery. A retrospective study analyzed a total of 243 eligible pregnancies that resulted in a preterm birth during 2020 and 2021. A control group without a history of preterm birth was matched by age and trimester of laboratory analysis at a 1:1 ratio. Although the number of comorbidities was similar among study groups, the body-mass index estimated for the week of gestation was significantly higher among the patients from the prematurity group, as well as the prevalence of urinary tract infections and smoking. Laboratory data showed that patients with a preterm birth had significantly higher white blood cell count and monocytes, but significantly lower lymphocytes, platelets, and hemoglobin. The NLR, dNLR, PLR, and MLR scores showed to be significantly higher among patients from the prematurity group, but SII and SIRI were not significantly different between the study groups. It was observed that the AUC values of NLR, dNLR, PLR, and MLR were higher than 0.600, respectively NLR had the highest value among the tested scores (AUC = 0.694) and the highest sensitivity in this study (71%). The highest sensibility was achieved by dNLR, with 70%, and an AUC value of 0.655 (p-value = 0.022). PLR had the second-highest AUC value (0.682) and the best score in terms of sensitivity (70%) and sensibility (69%) (p-value = 0.015). Lastly, MLR had the lowest significant AUC score (0.607) and lowest sensitivity/sensibility. The significant cut-off values for the inflammatory scores were 9.0 for NLR, 9.8 for dNLR, 250 for PLR, and 4.07 for MLR. After evaluating the importance of these inflammatory scores, further clinical applications should be conducted to confirm the results and improve therapy and care to reduce the burden of premature deliveries.
ABSTRACT
Studies observed that women infected with SARS-CoV-2 during pregnancy had a higher risk of preterm birth. Although it is likely that COVID-19 during the late trimester of pregnancy can trigger premature birth, prematurity remains a concern, and it is vital to study additional clinical and biological patient factors that are highly associated with this negative pregnancy outcome and allow for better management based on the existing predictors. In order to achieve this goal, the current study retrospectively recruited 428 pregnant patients that were separated into three study groups using a 1:2:4 matching ratio and a nearest-neighbor matching method. Sixty-one pregnant patients had a history of COVID-19 during pregnancy and gave birth prematurely; 124 pregnant patient controls had COVID-19 and gave birth full-term, while the second control group of 243 pregnant patients had a premature birth but no history of COVID-19. It was observed that a symptomatic SARS-CoV-2 infection during the third trimester was significantly more likely to be associated with premature birth. Even though the rate of ICU admission was higher in these cases, the mortality rate did not change significantly in the COVID-19 groups. However, SARS-CoV-2 infection alone did not show statistical significance in determining a premature birth (ß = 1.09, CI = 0.94−1.15, p-value = 0.067). Maternal anemia was the strongest predictor for prematurity in association with SARS-CoV-2 infection (ß = 3.65, CI = 1.46−5.39, p-value < 0.001), followed by elevated CRP (ß = 2.11, CI = 1.20−3.06, p-value < 0.001), and respectively IL-6 (ß = 1.92, CI = 1.20−2.47, p-value = 0.001. SARS-CoV-2 infection is associated with an increased risk of preterm birth, as shown by our data. If SARS-CoV-2 infection arises during the third trimester, it is recommended that these patients be hospitalized for surveillance of clinical evolution and biological parameters, such as anemia and high inflammatory markers, which have a multiplicative influence on the pregnancy result.