Prevalence of single umbilical artery, clinical outcomes and its risk factors: A cross-sectional study
Background: Single umbilical artery (SUA) is found in 0.5–6% of all pregnancies worldwide. Although the association of SUA with some congenital malformations is mainly accepted, its effect on pregnancy/neonatal outcomes is still controversial.
Objective: This is the first study aimed to approximate the SUA prevalence in southern part of Iran. SUA epidemiologic features accompanied by some of its effects on pregnancy/neonatal outcomes are investigated as well.
Materials and Methods: In this cross-sectional study, data from two referral centers in Southern Iran were analyzed. In total, 1,469 pregnancies, fetuses, and neonates were examined for epidemiological features associated with SUA. SUA was confirmed by pathological examination, while congenital anomalies were diagnosed by clinical, ultrasound, and echocardiographical examinations. Data on pregnancy outcome were recorded based on the patients’ medical records.
Results: The prevalence of SUA was 3.47% (95% CI: 2.6–4.6%). Fetal anomalies including renal, cardiac, and other congenital anomalies, intrauterine fetal death, early neonatal death, low birth weight, low placental weight, and preterm birth were significantly higher in the SUA group (OR = 68.02, 31.04, 16.03, 3.85, 11.31, 3.22, 2.70, and 2.47, respectively). However, the maternal multiparity was lower in the SUA group (OR = 0.65; 95% CI: 0.44–0.98).
Conclusion: A significant association was observed between SUA and increased risk of intrauterine fetal death and early neonatal death, as well as low birth weight and preterm birth. Obstetrical history of the mother like parity was identified as an important predictor of SUA. Further investigations are suggested on risk stratification of neonates in this regard.
Key words: Umbilical cord, Single umbilical artery, Pregnancy outcome, Congenital abnormalities.
 Collins JH. Umbilical cord accidents. BMC 2012; 12: A7.1–2.
 Alfirevic Z, Stampalija T, Medley N. Fetal and umbilical Doppler ultrasound in normal pregnancy. Cochrane Database Syst Rev 2015; 15: CD001450: 1–65.
 Ferreira V, Vaz I, Reis AP, Mendes MJ, Rodrigues MC. Antenatal detection of single umbilical artery: What does it mean?. Nascer E Crescer 2013; 22: 140–144.
 Nayak SS, Shukla A, Girisha KM. Anomalies associated with single umbilical artery at perinatal autopsy. Indian Pediatr 2015; 52: 73–74.
 Rembouskos G, Cicero S, Longo D, Sacchini C, Nicolaides KH. Single umbilical artery at 11-14 weeks' gestation: Relation to chromosomal defects. UOG 2003; 22: 567–570.
 Klatt J, Kuhn A, Baumann M, Raio L. Single umbilical artery in twin pregnancies. UOG 2012; 39: 505–509.
 Staribratova D, Belovezhdov V, Milchev N, Batashki I, Apiosjan ZH. Single umbilical artery (SUA). Akusherstvo I Ginekologiia 2010; 49: 17–20.
 Kim HJ, Kim JH, Chay DB, Park JH, Kim MA. Association of isolated single umbilical artery with perinatal outcomes: Systemic review and meta-analysis. Obstet Gynecol Sci 2017; 60: 266–273.
 Tasha I, Brook R, Frasure H, Lazebnik N. Prenatal detection of cardiac anomalies in fetuses with single umbilical artery: Diagnostic accuracy comparison of maternal-fetal-medicine and pediatric cardiologist. J Pregnancy 2014; 2014: 265421: 1–8.
 Dagklis T, Defigueiredo D, Staboulidou I, Casagrandi D, Nicolaides KH. Isolated single umbilical artery and fetal karyotype. UOG 2010; 36: 291–295.
 Burshtein SH, Levy A, Holcberg G, Zlotnik A, Sheiner E. Is single umbilical artery an independent risk factor for perinatal mortality? Arch Gynecol Obstet 2011; 283: 191–194.
 Voskamp BJ, Fleurke‐Rozema H, Oude‐Rengerink K, Snijders RJM, Bilardo CM, Mol BWJ, et al. Relationship of isolated single umbilical artery to fetal growth, aneuploidy and perinatal mortality: Systematic review and meta‐analysis. UOG 2013; 42: 622–628.
 Chetty-John SH, Zhang J, Chen ZH, Albert P, Sun L, Klebanoff M, et al. Long-term physical and neurologic development in newborn infants with isolated single umbilical artery. Am J Obstet Gynecol 2010; 203: 368. e1–e7.
 Bombrys AE, Neiger R, Hawkins S, Sonek J, Croom C, McKenna D, et al. Pregnancy outcome in isolated single umbilical artery. Am J Perinatol 2008; 25: 239–242.
 Bryan EM, Kohler HG. The missing umbilical artery: I. Prospective study based on a maternity unit. Arch Dis Child 1974; 49: 844–852.
 Hua M, Odibo AO, Macones GA, Roehl KA, Crane JP, Cahill AG. Single umbilical artery and its associated findings. Obstet Gynecol 2010; 115: 930–934.
 Arizawa M. Three categories of causes of single umbilical artery (SUA). Placenta 2015; 36: A8.
 Prefumo F, Güven MA, Carvalho JS. Single umbilical artery and congenital heart disease in selected and unselected populations. UOG 2010; 35: 552–555.
 Prucka S, Clemens M, Craven C, McPherson E. Single umbilical artery: What does it mean for the fetus? A case-control analysis of pathologically ascertained cases. Genet Med 2004; 6: 54–57.
 Doğan S, Özyüncü Ö, Atak Z, Turgal M. Perinatal outcome in cases of isolated single umbilical artery and its effects on neonatal cord blood gas indices. J Obstet Gynaecol 2014; 34: 576–579.
 Khalil MI, Sagr ER, Elrifaei RM, Abdelbasit OB, Halouly TAL. Outcomes of an isolated single umbilical artery in singleton pregnancy: A large study from the middle east and gulf region. Eur J Obstet Gynecol Reprod Biol 2013; 171: 277–280.
 Granese R, Coco C, Jeanty P. The value of single umbilical artery in the prediction of fetal aneuploidy: Findings in 12,672 pregnant women. Ultrasound Q 2007; 23: 117–121.
 Murphy-Kaulbeck L, Dodds L, Joseph KS, Van den Hof M. Single umbilical artery risk factors and pregnancy outcomes. Obstet Gynecol 2010; 116: 843–850.
 Martinez-Payo C, Ana G, Inés T, Manuel GE, Enrique IG. Perinatal results following the prenatal ultrasound diagnosis of single umbilical artery. Acta Obstet Gynecol Scand 2005; 84: 1068–1074.
 De Figueiredo D, Dagklis T, Zidere V, Allan L, Nicolaides KH. Isolated single umbilical artery: Need for specialist fetal echocardiography? UOG 2010; 36: 553–555.
 Gurram P, Figueroa R, Sipusic E, Kuhnly N, Clark S, Janicki MB. Isolated single umbilical artery and fetal echocardiography: A 25‐year experience at a tertiary care city hospital. J Ultrasound Med 2018; 37: 463–468.
 Predanic M, Perni SC, Friedman A, Chervenak FA, Chasen ST. Fetal growth assessment and neonatal birth weight in fetuses with an isolated single umbilical artery. Obstet Gynecol 2005; 105: 1093–1097.
 Baron J, Weintraub AY, Sciaky Y, Mastrolia SA, Speigel E, Hershkovitz R. Umbilical artery blood flows among pregnancies with single umbilical artery: A prospective case-control study. J Matern Fetal Neonatal Med 2015; 28: 1803–1805.
 Battarbee AN, Palatnik A, Ernst LM, Grobman WA. Association of isolated single umbilical artery with small for gestational age and preterm birth. Obstet Gynecol 2015; 126: 760–764.
 Christensen KM, Heilbrun ME, Patel N, Woodward PJ, Kennedy A. Estimated fetal weight and birth weight associated with isolated single umbilical artery: The university of utah experience. Ultrasound Q 2015; 31: 19–22.
 Mailath-Pokorny M, Worda K, Schmid M, Polterauer S, Bettelheim D. Isolated single umbilical artery: Evaluating the risk of adverse pregnancy outcome. Eur J Obstet Gynecol Reprod Biol 2015; 184: 80–83.
 Ashwal E, Melamed N, Hiersch L, Edel S, Bardin R, Wiznitzer A, et al. The impact of isolated single umbilical artery on labor and delivery outcome. Prenat Diagn 2014; 34: 581–585.
 Gutvirtz G, Walfisch A, Beharier O, Sheiner E. Isolated single umbilical artery is an independent risk factor for perinatal mortality and adverse outcomes in term neonates. Arch Gynecol Obstet 2016; 294: 931–935.
 Shen N, Zhang W, Li G. Impact of isolated single umbilical artery on pregnancy outcome and delivery in full‐term births. J Obstet Gynaecol Res 2016; 42: 399–403.