Telomeres are shorter in placental trophoblasts of pregnancies complicated with intrauterine growth restriction (IUGR)

Objective: Telomeres are nucleoprotein structures located at the termini of chromosomes, and protect them from fusion and degradation. Telomeres are progressively shortened with each mitotic cycle and by environmental factors. We hypothesized that antepartum stress can lead to accelerated telomere shortening in placental trophoblasts, and plays a role in intrauterine growth restriction (IUGR). Methods: Placental biopsies were derived from 16 pregnancies complicated with IUGR and from 13 uncomplicated pregnancies. Fluorescence-in-situ protocol was used to determine telomere length. Immunohistochemistry for hTERT was performed to assess telomerase activity. Clinical and histopathological characteristics were collected to ensure that IUGR was secondary to placental insufficiency. Fluorescence-in-situ-hybridization was used to rule out aneuploidy as a reason for shortened telomeres. Results: The number and intensity of telomeres staining and telomerase activity were significantly lower in the IUGR placentas. No aneuploidy was detected for the chromosomes checked in the placental biopsies. Conclusions: Telomeres are shorter in trophoblasts of IUGR placentas.