Hani khorram:Several studies in the past have proved the relationship between perinatal outcome and the UCI.  In this study UCI of 142 neonates were compared with Apgar score at first minute and fifth minute after childborn, meconium staining and umbilical cord PH. In our study the mean UCI was 2.4 which was similar to the study which was done by Ezimokhai et al(2001) and another one which was conducted by  Chitra.T et al(2012).15,20  With comparing hyper-coiled , hypo-coiled and normo-coiled cord with Apgar score, we found that there was no statistical significance between UCI and Apgar score .Also there was no association between hypo-coiled, hyper-coiled , normo-coiled and meconium staining and umbilical cord PH. Perhaps we could not find any association between UCI and perinatal outcome because there was only one neonate had Apgar score less than 4 ,one minute and less than 7 ,five minute after delivery, although our  number of cases was similar to previous studies .  In this survey, there was not any correlation between hypo-coiled or hyper-coiled and meconium staining. Though in some previous studies there was direct relationship between hypo-coiled and meconium staining, and in several studies hyper-coiled cord had association with meconium staining.It is still a question that how the physiological coiling forms. Maybe it would occur due to fetal activity and hemodynamic factors.It may be related to some anatomical occurrences like the Roach muscle presence16, 21 .Two criteria needed to stablish a causal relationship between two factors:?   plausibility:Knowledge of pathologic process of the disease or biologic effect that would reasonably support an association.?  Consistency:Whether the association was repeatedly observed by different investigators, in different location and circumstancees.22  Sohow could we explain these differences between hypo and hyper-coiled and their association with meconium staining, because they did not offer a specific explanation for these observations.  Also in one study which was done in 2011, there was not any statistical differences between each following groups:•  The cases whose score of Apgar was <7, at the first minute of birth.•  the cases with umbilical artery pH below 7.2 did not show.23  In our study all cases terminated by cesarean section, mostly due to previous cesarean section, may be they would become more complicated and having less Apgar score if they had normal vaginal delivery. As in the Niveditaet al study, hypo-coiled cords were significantly associated with LSCS.24