Changes in blood parameters in spontaneous preterm birth during pregnancy: An observational study.

Spontaneous preterm birth (sPTB) accounts for two-thirds of preterm births and leads to morbidity and death in newborns under 5 years of age. This study aimed to examine the changes in complete blood count parameters in pregnant women with sPTB during pregnancy. This was a retrospective case-control study, with 138 sPTB cases and 138 age- and delivery date-matched healthy controls. Baseline data and the complete blood count parameters examined during the 1st, 2nd, and 3rd trimesters of all the participants were recorded. The χ2 test, t-test, and multivariate linear regression analysis methods were used to analyze the changes in parameters between the 2 groups at 3 time points. The gestational age at delivery was shorter and the birth weight was lower in the sPTB group, compared with the term birth group. The nulliparity and male sex distribution, maternal age, and gestational age at the 1st, 2nd, and 3rd assessments were balanced between the 2 groups. White blood cell and monocyte counts increased throughout pregnancy in both groups, and the sPTB group was consistently higher than the term group. The current findings demonstrated that blood inflammation- and infection-related parameters, such as white blood cell and monocyte counts, changed significantly during pregnancy in women with sPTB. This study may have important implications for the diagnostic and therapeutic management of sPTB.