Prenatal diagnosis of fetal intra-abdominal umbilical vein varix: Report of 2 cases

Case Report

Prenatal Diagnosis of Fetal Intra-abdominal Umbilical Vein Varix: Report of 2 Cases ¨ zgu ¨ r Tosun, MD, Mehmet Gu ¨ mu ¨ s˛, MD, Kemal Rıdvan Yazıcıog˘lu, MD, Ali I˙pek, MD, Aydın Kurt, MD, O Elif As˛ık, MD, I˙smet Tas˛, MD Department of Radiology, Ankara Atatu¨rk Education and Research Hospital, 06800 Eskis˛ehir Yolu 8.km No. 3, Bilkent, Ankara, Turkey Received 12 September 2006; accepted 6 January 2007

ABSTRACT: Fetal intra-abdominal umbilical vein varix (FIUVV) is a focal aneurysmal dilatation of the umbilical vein. Its clinical importance has not yet been clearly established, but it has been reported to be associated with increased fetal death rate (in nearly 44% of cases) and chromosomal abnormalities (in 12% of cases). We report 2 cases of FIUVV diagnosed via sonography in C 2007 the third trimester. V Wiley Periodicals, Inc. J Clin Ultrasound 36:48–50, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20334 Keywords: umbilical vein; varix; ultrasound; Doppler; obstetrics

etal intra-abdominal umbilical vein varix (FIUVV) is defined as a focal aneurysmal dilatation of the umbilical vein. Approximately 100 cases have been reported in the literature. Only 4% of umbilical cord malformations are FIUVV.1,2 With the development of sonography and Doppler sonography, diagnosis has become easier than in the past. The clinical importance of FIUVV has not yet been clearly established, but it has been reported to be associated with increased fetal death rate (in nearly 44% of cases) and chromosomal abnormalities (in 12% of cases).1–3 We report 2 cases of FIUVV diagnosed via sonography in the third trimester.

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graphic examination. Her first pregnancy was normal. A second-trimester sonographic examination at another institution was unremarkable. The examination was performed with a Voluson 730 Expert (GE Medical Systems, Milwaukee, WI) equipped with a 2–5-MHz curved-array probe. A normal intrauterine fetus of nearly 29 weeks’ gestational age was present according to the patient’s last menstrual period and sonographic measurements. The biparietal diameter was 69 mm, the femur length was 55 mm, and the abdominal circumference was 248 mm. The estimated fetal weight was 1,300 g with normal amniotic fluid index, umbilical artery, and uterine artery pulsatility index. However, intra-abdominal umbilical vein varix with transverse diameter of 11 mm over an 18-mm segment was diagnosed near the anterior abdominal wall (Figure 1A). Color Doppler analysis also showed turbulent flow in the varicose segment (Figure 1B). Otherwise, the fetus was structurally normal. The patient declined chromosomal investigation. Weekly sonographic monitoring was recommended, but the patient did not return for follow-up examinations. She delivered a healthy girl weighing 2,600 g via cesarean section peformed at 35 gestational weeks at another institution.

CASE REPORTS

Case 1

Case 2

A 31-year-old healthy woman, gravida 2, para 1, was referred to our radiology department for sono-

A 29-year-old woman, gravida 1, para 0, was referred for sonographic examination at approximately 36 weeks’ gestation according to her last menstrual period and sonographic measurements. The patient had a second-trimester examination at another institution that was reportedly

Correspondence to: A. Kurt ' 2007 Wiley Periodicals, Inc.

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FETAL INTRA-ABDOMINAL UMBILICAL VEIN VARIX

FIGURE 1. (A) Transabdominal oblique sonogram shows FIUVV (arrow) near the anterior abdominal wall. (B) Color Doppler axial sonogram shows turbulent venous flow in the FIUVV.

unremarkable. The examination was performed with the same equipment as in case 1. The biparietal diameter was 89 mm, the femur length was 72 mm, and the abdominal circumference was 315 mm. The estimated fetal weight was 2,780 g with normal amniotic fluid index, umbilical artery, and uterine artery pulsatility index. FIUVV with a diameter of 12 mm was diagnosed near the anterior abdominal wall (Figure 2A). Spectral Doppler analysis confirmed venous flow in the varicose segment (Figure 2B). Otherwise, the fetus was structurally normal. Chromosomal investigation was declined by the patient. The patient delivered a healthy boy with induction within a week. DISCUSSION

The diagnosis of FIUVV is made when the diameter of the intra-abdominal part of the umbilical VOL. 36, NO. 1, JANUARY 2008—DOI 10.1002/jcu

FIGURE 2. (A) Transabdominal sonogram shows FIUVV (arrow) resembling a cyst near the anterior abdominal wall. (B) Spectral Doppler analysis confirms venous flow in the FIUVV.

vein exceeds 9 mm. The typical sonographic appearance of the FIUVV is the craniocaudally oriented cyst-like mass located between the inferior part of the liver and the anterior abdominal wall. Doppler or color Doppler analysis confirms venous flow in its lumen.4,5 Syphilis, degenerative changes, decreased resistance due to icterus, and congenital thinning have been proposed as the etiology of FIUVV. The most likely etiology—and the only pathologic finding in most cases—is the thinning of the vessel’s wall near the anterior abdominal wall. The most common complications described in the literature are the rupture of the aneurysm, thrombosis, compression of the umbilical artery and other veins, and cardiac failure due to the increased pre-load.2,6 Hydrops fetalis, fetal anemia, diaphragmatic hernia, shortening of the long limbs, hydrocephaly, oligo- and polyhydramnios, and growth retardation are anomalies that 49

I˙PEK ET AL

have been described in association with FIUVV. Trisomy 21, 9, and 18 and triploidy are also possibly associated with FIUVV.1,2,4 The fetal mortality rates due to varix rupture and thrombosis are 50% and 80%, respectively.2,6,7 Fetal demise is most likely to occur at the gestational age of 27–30 weeks5 because of the increased risk of rupture and thrombosis of the FIUVV due to increased fetal blood flow. This explains why FIUVV diagnosed late in pregnancy may not cause any problem, as in our 2 cases. Although FIUVV is a very rare fetal anomaly, it is associated with a high mortality rate and associated congenital anomalies and thus should not be overlooked. Patients with FIUVV should be closely monitored with sonography and should be informed about the possible adverse outcomes.1,7,8 Delivery should be induced at 34–36 gestational weeks, when the fetal lung is mature.1

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umbilical vein varix despite close monitoring. Prenat Diagn 2004;24:451. Rahemtullah A, Lieberman E, Benson C, et al. Outcome of pregnancy after prenatal diagnosis of umbilical vein varix. J Ultrasound Med 2001;20:135. Fung TY, Leung TN, Leung TY, et al. Fetal intra-abdominal umbilical vein varix: what is the clinical significance? Ultrasound Obstet Gynecol 2005;25: 149. Zalel Y, Lehavi O, Aizenstein O, et al. Varix of the fetal intra-abdominal umbilical vein: prenatal sonographic diagnosis and suggested in utero management. Ultrasound Obstet Gynecol 2000;16:476. Prefumo F, Thilaganathan B, Tekay A. Antenatal diagnosis of fetal intra-abdominal umbilical vein dilatation. Ultrasound Obstet Gynecol 2001;17:82. Nathalie MA, Vandevijver MD, Hermans RHM, et al. Aneurysm of the umbilical vein: case report and review of the literature. Eur J Obstet Gynecol Rep Biol 2000;89:85. Sepulveda W, Mackenna A, Sanchez J, et al. Fetal prognosis in varix of the intrafetal umbilical vein. J Ultrasound Med 1998;17:171. Viora E, Sciarrone A, Bastonero S, et al. Anomalies of the fetal venous system: a report of 26 cases and review of the literature. Fet Diag Ther 2004;19: 440.

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