Sirenomelia: early prenatal diagnosis with combined two‐ and three‐dimensional sonography

Sirenomelia Sequence

“…Sirenomelia has been diagnosed in utero as early as 13 to 16 postmenstrual weeks with the use of transvaginal and 3D sonography. [4][5][6][7] Stevenson et al 12 described the pathogenetic mechanism after dissection of the abdominal vasculature of 11 cases of sirenomelia. They described a pattern of vascular abnormalities in which the common feature is a single large artery, arising high in the abdominal cavity, which takes over the function of the umbilical arteries and diverts nutrients from the caudal end of the embryo distal to the level of the origin.…”

“…1 In the literature there are 5 cases of prenatal diagnosis of sirenomelia during the early second trimester. [4][5][6][7] In this report we present 2 cases of sirenomelia diagnosed during the first trimester of pregnancy on the basis of both conventional transvaginal two-dimensional (2D) sonography with color Doppler imaging and 3-dimensional (3D) sonography. Our report is unique in that the diagnosis was made during the first trimester, and we used all the different scanning modalities available in our sonographic armamentarium to diagnose this rare anomaly.…”

Three‐Dimensional Sonography of Sirenomelia at 10 and 12 Weeks' Gestation

“…We think it is fundamental to diagnose sirenomelia during the first trimester to avoid facing anamnios. Although in a report by Blaicher et al 5 in 2001, only 3 cases of sirenomelia had been diagnosed before 19 weeks' gestation, since 2003, several cases have been diagnosed during the first trimester. In 2008, Akbayir et al 9 reported 5 discoveries in the literature during the first trimester.…”

“…Sirenomelia is a malformation characterized by a fusion of the lower limbs and absent kidneys, causing anamnios, which appears at the beginning of the second trimester of pregnancy 1 – 4 . Sirenomelia can be discovered easily during the first trimester of pregnancy, especially by endovaginal sonography 5 – 8 . This report provides 3‐dimensional (3D) sonograms of 2 cases of sirenomelia diagnosed at 12 and 10 weeks' gestation.…”

Three Dimensional Ultrasound: An Overview of Its Clinical Use

“…These include camptomelic and thanatophoric dysplasia, exencephaly, osteogenesis imperfecta, sirenomelia, short rib polydactyly and spinal defects. [160][161][162][163][164][165][166][167] The normal fetal skeleton has frequently been evaluated by 3DUS and compared to 2DUS by numerous authors. Although some authors regard detection rates for accurate assessment of skeletal dysplasias as almost equal between 2DUS and 3DUS, they do claim that the improved visualization of the dysplasia by 3DUS makes it a useful addition to standard 2DUS.…”