Association between inflammatory markers and preeclampsia in twin pregnancies: a retrospective cohort study

INTRODUCTION: Preeclampsia is a serious pregnancy-specific complication and a major cause of perinatal morbidity. While inflammatory markers have been associated with preeclampsia in singleton pregnancies, their role in twin pregnancies remains poorly understood. This study aimed to explore the relationship between inflammatory markers and preeclampsia in twin pregnancies. MATERIAL AND METHODS: In this retrospective cohort study, we recruited 2712 women with twin pregnancies who delivered at Fujian Maternal and Child Health Hospital from January 2014 to December 2021. Participants were divided into control group (n = 2200), gestational hypertension group (n = 126) and preeclampsia group(n = 386). We compared baseline data and inflammatory markers between groups. The correlation between inflammatory markers and preeclampsia in twin pregnancies was further analyzed using logistics regression adjusted for confounders. Fitted smoothing curves and threshold effect analysis were used to describe the nonlinear relationship. RESULT: Systemic immune inflammation index (SII), monocyte/high-density lipoprotein ratio (MHR), lymphocyte/high-density lipoprotein ratio (LHR) and platelet-to-lymphocyte ratio (PLR) exhibited statistical significance between the preeclampsia and control groups. Smooth curve fitting indicated that the relationships between SII, MHR and PLR with preeclampsia were nonlinear. After full adjustment, breakpoints were found to be 666.32, 0.84 and 88.28, respectively. Decreased levels of SII, PLR and increased levels of MHR levels were associated with greater prevalences of PE before the breakpoints. CONCLUSION: The relationships between SII, MHR and PLR with preeclampsia were nonlinear. Twin pregnancies with decreased levels of SII, PLR and elevated levels of MHR should be attentive to the potential risks to preeclampsia before their thresholds.