(709) Shorter maternal leukocyte telomere length following cesarean birth: Implications for future research

Objective: Investigators are increasingly studying telomeres given their potential as a transgenerational stress marker and association with longevity. Despite this, little is known about peripartum telomere dynamics. To examine whether leukocyte telomere length (LTL) can be measured reliably postpartum, we evaluated whether LTL is affected by mode of delivery.

Study Design: Maternal blood samples were obtained up to 6 months postpartum from a prospectively enrolled cohort of 323 pregnant people at one institution. Term, singleton livebirths between 2012 and 2018 were included. Postpartum LTL was measured using quantitative PCR, reported in basepairs (bp), and compared between people with vaginal versus cesarean births. Multivariable linear regression models were conducted sequentially adjusting for age and delivery leukocyte count. These were stratified into two mutually exclusive groups according to timing of postpartum sampling. A subgroup analysis was conducted that included only nulliparas.

Results: 72 people met inclusion criteria and had postpartum samples, of whom 52 (72.2%) had a vaginal birth and 20 (27.8%) had a cesarean. Groups did not differ in demographics, leukocyte counts, or blood draw timing (Table 1). The most common indications for cesarean were labor arrest (45%) and elective (35%). LTL was significantly shorter in the cesarean group on postpartum day 1 (PPD1) (5,716.4 versus 6,300.9 bp, p=0.001), as well as beyond PPD1 (5,573.8 versus 5,945.6 bp, p=0.03, Table 2). Differences persisted after adjustments (p=0.004, p=0.04) and after restricting to nulliparas for PPD1 (p=0.01).

Conclusion:

Maternal LTL on PPD1 were nearly 600 bp shorter following cesarean compared to vaginal birth, which is more than 10 times the typical LTL shortening in 1 year. Differences were also evident several weeks postpartum, which was unexpected as post-surgical inflammation is typically resolved by this time. Mode of delivery should be considered in analyses of postpartum LTL, and further characterization of this link and its implications for longevity are warranted.