Telomere length analysis in Down syndrome birth

•In this study we include 170 mothers of Down syndrome child and 186 age matched mothers of euploid child with their newly born babies as participants.•We categorised the mothers of Down syndrome child according to age (old >35 years, young <35 years) and stage of meiotic nondisjunction NDJ (NDJ in meiosis I=MI, and II=MII respectively). Telomere length (TL) was measured for each participants.•The result reveals that MII old mothers do have shortest TL (p<0.001).•The study shows that the babies from older mother have longer TL (p<0.001).•Down syndrome babies have longer TL than euploid individual (p<0.001).