OC158: Association of single umbilical artery with aneuploidy, congenital malformations and perinatal outcome: Findings in 49,698 unselected pregnant women

Abstract

Objectives: To determine the possible association between single umbilical artery (SUA) in the second trimester and the incidence of fetal aneuploidy (T21,13&18) and other malformations. To report the incidence of associated perinatal mortality. Methods: Colour flow imaging undertaken between20–23 weeks of gestation during routine scan in 49,698 cases in two tertiary referral centres between the period of 2000–2007. Referred cases for second opinion have been excluded as well as Fetuses diagnosed with single umbilical artery and no other anomalies or markers (isolated SUA). Retrospective analysis of associated aneuploidy, malformations and intrauterine deaths (IUD). Results: SUA was diagnosed in 219/49698 (0.44%). Among the 219 fetuses with SUA, 156 (71.2%) had no associated markers or anomalies and 63 (28.2%) had associated findings. 31/63 (49.2%) fetuses had only soft markers (one or two). 32/63 (50.8%) had associated anomalies (at least one structure defect). 8/63 (12.7%) fetuses had aneuploidy (4 cases of T18, 3 cases of T13, one case with unbalanced translocation 18-Y). 55/63 (82.5%) fetuses had structure anomalies of which 13/63 (20.6%) had multiple anomalies (>3 anomalies).14/63 (22.2%) had cardiac anomalies, 8/63 (12.7%) had CNS anomalies, 6/63 (9.5%) had renal anomalies (3cases of hydronephrosis, 2cases of renal agenesis and one case of multicystic dysplastic kidney). 4/63 (6.3%) had cleft palate, 4.8% had skeletal anomalies, 3.2% had NTD, and 2/63 (3.2%) had diaphragmatic hernia. Perinatal mortality rate reported in 14/63 (22.2%). 10 fetuses had intrauterine death while 4 fetuses were terminated. Conclusion: This case series of unselected population indicate high association of aneuploidy in particular T18 and T13 and many other structure anomalies. No case of T21 was detected. We conclude that second trimester sonographic detection of SUA and other findings is not associated with increased risk of T21.