A Systematic Review of Telomere Length and Telomerase Activity in Preeclampsia: Maternal, Placental, and Cord Blood Perspectives

<b>Background/Objectives</b>: Preeclampsia represents a significant obstetric complication, frequently linked to elevated levels of perinatal morbidity. This review sought to systematically examine the existing literature regarding associations between telomere length in maternal blood, placental tissue, and umbilical cord blood, and the occurrence of preeclampsia. <b>Methods</b>: A comprehensive search of PubMed/MEDLINE and ScienceDirect was conducted to identify studies published up to January 2025 that investigated telomere length in relation to preeclampsia. All observational studies comparing telomere length between women with preeclampsia and healthy pregnant controls were included. <b>Results</b>: A total of 838 studies were assessed. Although findings regarding the association between telomere length in leukocytes in maternal peripheral blood, placental tissue, and cord blood with preeclampsia remain inconsistent, the studies with the largest sample sizes for maternal blood and placental tissue have reported shorter telomere lengths in preeclamptic cases. In cases of preeclampsia, telomerase levels in leukocytes in maternal peripheral blood are elevated, whereas telomerase expression in placental tissue is reduced. <b>Conclusions</b>: Current evidence regarding the role of telomere length in preeclampsia remains inconsistent, precluding definitive conclusions. To clarify its potential as a biomarker, large-scale prospective studies are warranted to longitudinally assess telomere length in leukocytes in maternal peripheral blood, placental tissue, and cord blood, and to establish optimal threshold values.