First trimester diagnosis of sirenomelia: a case report and review of the literature

Abstract

Sirenomelia sequence is a rare lethal pattern of congenital anomalies characterized by a number of hallmark skeletal anomalies, including fusion of the lower extremities or a single lower limb, bilateral renal agenesis or dysgenesis with absent or hypoplastic renal arteries, oligohydramnios, and the presence of aberrant vasculature. The etiology is still controversial. Prognosis is very poor, with the babies being stillborn or succumbing soon after birth. In the second trimester, oligohydramnios due to renal agenesis makes the diagnosis of sirenomelia difficult. Conversely, in the first trimester, the amniotic fluid volume is usually normal, unrelated to the fetal urine production. Therefore, a first-trimester or early second trimester anatomic survey of the fetus is proposed as preferable and more accurate for the diagnosis of this rare anomaly. In this article, we report a case of sirenomelia detected by two- and three-dimensional ultrasound in the 11th week of gestation and the associated literature is discussed.

An unusual case of Sirenomelia Sympus Dipus (Mermaid Syndrome)

“…Early scanning is recommended to identify these gross anomalies early in order to provide alternative management to the pregnancy. Ultrasound usually makes prenatal diagnosis mostly during the late second and third trimesters with the confirmation of combination of malformation of the lower limbs and decreased amniotic fluid volume, related to urinary tract agenesis or dysgenesis; these findings become visible after the end of the first trimester [9]. like in our case.…”

Prenatal Diagnosis of Sirenomelia in the Late Second Trimester with Three-Dimensional Helical Computed Tomography

“…A diagnosis of sirenomelia may be easier to make during the first trimester because the amniotic fluid volume is relatively normal, since amniotic fluid is secreted by the amniotic membrane covering the placenta and the umbilical cord in the first trimester (Lind et al 1972). Several authors have reported on the diagnosis of sirenomelia during the first trimester by ultrasound (Akbayir et al 2008;Contu et al 2009;Clemente et al 2010). A diagnosis of sirenomelia is made in early pregnancy by confirmation of the existence of a single lower limb, but few ultrasonographs confirm all of the limbs in early pregnancy because sirenomelia is so rare.…”

“…In contrast, during the first trimester, the amniotic fluid volume is usually normal, unrelated to the fetal urine production. Therefore, anatomic survey of the fetus during the first trimester or early second trimester is preferable for more accurate diagnosis of this rare anomaly (Akbayir et al 2008). However, we should diagnose sirenomelia correctly even if we examine a suspected fetus for the first time in late second trimester or third trimester.…”

Mermaid baby

“…1,2 Prenatal diagnosis is possible in the first trimester with the important role of colour and power Doppler to estimate vascular abnormalities including aberrant ileal vessels, abnormal small abdominal aorta, and two-vessel umbilical cord. [1][2][3] In rare cases of surviving neonates, angiography, CT and MRI can also be used to document anatomical findings. Although syrenomelia has been described as a rare lethal pattern of congenital anomalies, 9 mermaid cases surviving after reconstructive surgery have been reported.…”