Association of systemic chronic inflammation during pregnancy in different periods and its trajectories with preterm birth.

Problem: Systemic chronic inflammation (SCI) is a prevalent characteristic observed in various diseases originating from different tissues, while the association of SCI with preterm birth (PTB) remains uncertain. This study aimed to analyze the association between a nonspecific biomarker of SCI and PTB, while also exploring the trajectories of SCI in pregnant women at risk of PTB.

Method Of Study: The study used data from the Electronic Medical Record System (EMRS) of a hospital in Zhejiang, China and 9226 pregnant women were included. The duration of pregnancy was categorized into four distinct periods: the first, early-second, late-second, and third trimester. Latent class trajectory modeling (LCTM) was used to identify the trajectories of SCI during pregnancy.

Results: The elevated WBC counts in the late-second (OR = 1.14, 95% CI: 1.06-1.23) and third (OR = 1.16, 95% CI: 1.09-1.24) trimester were both positively associated with an evaluated risk of PTB. Moreover, significant dose-response relationships were observed. There were three distinct SCI trajectories found: progressing SCI (2.89%), high SCI (7.13%), and low SCI (89.98%). Pregnant women with progressive SCI had the highest risk of PTB (OR = 3.03, 95% CI: 1.47-6.25).

Conclusions: In conclusion, elevated SCI after 23 weeks was a risk factor for PTB in healthy women, even if the SCI indicator was within normal range. Pregnant women with progressive SCI during pregnancy had the highest risk of PTB.