C-Reactive Protein Levels - Indicator for Prognosis of Spontaneous Preterm Birth in Bulgarian Women

Abstract

It is estimated that every year fifteen million premature babies are born worldwide mainly due to spontaneous preterm birth (sPTB). Furthermore, in clinical settings, there still are no reliable and accurate tools to predict preterm labor. Hence, the aim of this pioneering research was to estimate the relationship between the maternal inflammatory indicator and sPTB in a case-control study between 220 South Bulgarian women. The study was conducted at UMBAL, Stara Zagora, Bulgaria (2017-2020) and enrolled a total of 220 women, determined into two groups: 1) TB (n = 110), who were to give birth at term ≥ 37 to ≤ 39 + 6 gestation weeks with active labor at the time of hospitalization; and 2) sPTB (n = 110), women with preterm birth ≤ 32–34 + 6 gestation weeks and declared active labor, who were to give birth within 5-24 hrs. The inflammatory indicators/CRP concentration was quantified in plasma by immunoturbidimetric methods within 2 hrs. in mg/l. The median maternal CRP (8.77 ± 3.91), with cutoff = 4.9 mg/l was identified as optimal inflammation with highest risk of sPTB (sensitivity = 86.6%; specificity = 53.7%, р < 0.0001). Moreover, a cutoff CRP = 4.9 mg/l was found to be most effective in determining maternal age ≤ 19 years, the sensitivity of 68.6%, and positively correlated OR = 8.122 vs. OR = 2.354, with increased total sPTB risk at ≤ 32-34 + 6 weeks, respectively (p < 0.001).
 In conclusion, increased CRP concentrations and a decreased maternal age were associated with increased risks of sPTB, before ≤ 32-34 + 6 weeks. Minimal inflammation and other factors in combination may also act as sPTB prognosis.