Maternal inflammation during the second trimester of pregnancy with adverse birth outcomes: a prospective cohort study.

Background: Distinct characteristics of maternal inflammation at midgestation related to fetal and neonatal health are not clear. This study aims to explore the associations between the maternal circulating inflammatory profile during the second trimester of pregnancy and a series of adverse birth outcomes.

Methods: The present study was a prospective cohort study based on the Born in Guangzhou Cohort Study conducted in Guangzhou, China. Peripheral blood samples from women were obtained during the second trimester. Adverse newborn outcomes were collected through electronic medical records at birth and within the first week after birth. We used logistic, Poisson and generalized linear regressions to assess the impact of inflammatory indicators during pregnancy on different outcomes.

Results: A total of 1567 singleton pregnant women were included. The proportions of preterm birth, small for gestational age (SGA), low birth weight (LBW), neonatal asphyxia and hyperbilirubinemia cases were 4.3%, 6.6%, 3.9%, 1.1% and 12.6%, respectively. The maternal circulating level of log2-transformed interleukin (IL)-7 was positively associated with preterm birth [adjusted odds ratio (OR) = 1.58, 95% confidence interval (CI) = 1.03-2.41]. A higher level of log2-transformed IL-2 was correlated with increased LBW risk (adjusted OR = 1.48, 95% CI = 1.09-2.02) and a decreased birth weight Z-score (adjusted β = - 0.06, 95% CI = - 0.11, - 0.01). IL-7 was associated with an increased risk of LBW (adjusted OR = 1.80, 95% CI = 1.14-2.86), whereas log2-transformed IL-15 was positively related to SGA (adjusted OR = 1.39, 95% CI = 1.02-1.91). There were no significant associations of maternal inflammatory indicators with neonatal asphyxia or hyperbilirubinemia.

Conclusion: Maternal circulating IL-2, IL-7 and IL-15 levels during the second trimester of pregnancy were associated with preterm birth or birth weight.