International Journal of Preventive Medicine (Int J Prev Med)2008-780210112020022521942194ENMaternal Fetal and Neonatal Research Center, Family Health Institute, Tehran University of Medical Sciences, TehranMaternal Fetal and Neonatal Research Center, Family Health Institute, Tehran University of Medical Sciences, TehranMaternal Fetal and Neonatal Research Center, Family Health Institute, Tehran University of Medical Sciences, TehranMaternal Fetal and Neonatal Research Center, Family Health Institute, Tehran University of Medical Sciences, TehranMaternal Fetal and Neonatal Research Center, Family Health Institute, Tehran University of Medical Sciences, Tehran20200225<p><span class="fontstyle0"><strong>Background</strong>: </span><span class="fontstyle2">To compare the umbilical cord diameter (UCD) at early second trimester (at<br />17–19 weeks of gestation) in trisomy 21 and normal fetuses and determined value of measuring<br />UCD in screening trisomy 21. </span></p><p><span class="fontstyle0"><strong>Methods</strong>: </span><span class="fontstyle2">This was a case–control study. The UCD was measured<br />in 39 fetuses with trisomy 21 (documented by chorionic villus sampling or amniocentesis) and 39<br />fetuses in control group at 17–19 weeks of gestation. The control groups were low‑risk fetuses for<br />aneuploidy in routine screening and were shown not to have aneuploidy after birth. </span></p><p><span class="fontstyle0"><strong>Results</strong>: </span><span class="fontstyle2">Mean<br />of UCD in fetuses with trisomy 21 was lower than normal fetuses, but there were no significant<br />differences between them (7.48 ± 0.99 mm vs. 7.66 ± 0.91 mm; </span><span class="fontstyle3">P </span><span class="fontstyle2">= 0.41). Mean of UCD had no<br />significant difference between other maternal variable, for example, body mass index and obstetric<br />history. Mean of UCD among mothers who had previous cesarean section was significantly lower<br />than without it (7.21 ± 0.97 vs. 7.71 ± 0.97; </span><span class="fontstyle3">P </span><span class="fontstyle2">= 0.03). </span></p><p><span class="fontstyle0"><strong>Conclusions</strong>: </span><span class="fontstyle2">At 17–19 weeks of gestation,<br />the UCD of fetuses with trisomy 21 is thinner than normal, but the importance of this difference is<br />too small for using this measurement in screening.<br /></span></p><p><span class="fontstyle0" style="color: #00652e;"><strong>Keywords</strong>: </span><span class="fontstyle3">Aneuploidy, fetal screening, second trimester, trisomy 21, umbilical cord diameter</span></p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/2194http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2194/717718067