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Placentas from pregnancies complicated with IUGR (intrauterine growth restriction) express altered telomere homeostasis. In the current study, we examined mechanisms of telomere shortening in these placentas.Placental biopsies from 15 IUGR and 15 healthy control pregnancies were examined. The percentage of trophoblasts with fragmented nuclei: senescence-associated heterochromatin foci (SAHF), was calculated using DAPI staining. The amount of human telomerase reverse transcriptase (hTERT) mRNA was evaluated using RtPCR levels of telomere capture using FISH in those samples were estimated.The percentage of trophoblasts with SAHF was higher in IUGR compared to control samples, (25±13.4% vs. 1.6±1.6%, P0.0001), hTERT mRNA was decreased (0.5±0.2 vs. 0.9±0.1, P0.0001) and telomere capture was increased (13.2±9.7% vs.1.3±2.5%, P0.001).We suggest that IUGR placentas express increased signs of senescence as part of the impaired telomere homeostasis. One factor that mediates telomere shortening in these placentas is decreased hTERT mRNA, leading to decreased protein expression and therefore, reduced telomere elongation. Telomere capture, which is a healing process, is increased in IUGR trophoblasts as a compensatory mechanism.

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.

Background Fetal cells exfoliate in the uterine cavity during early pregnancy and are a potential source of material for NIPD. Aims This study was designed to test the hypothesis that fetal cells obtained from the uterine cervix during the first trimester of pregnancy could be utilized for prenatal diagnosis of chromosomal aneuploidy. Study design Fetal cells retrieved from the distal endocervical canal during the first trimester of pregnancy were hybridized with chromosome 21 specific FISH probes and analyzed with an automated fluorescence microscope. Subjects and outcome measures Cells with 3 copies of chromosome 21 were detected in 5 out of 5 trisomy 21 pregnancies. Results The number of trisomic cells detected ranged from 1 to 27 with a median value of 5. Conclusions FISH-based scanning can identify trisomy 21 pregnancies by analysis of routine cervical brushings. The approach offers the potential for non-invasive prenatal diagnosis as early as 5 weeks gestation.