First-Trimester Diagnosis of Sirenomelia

Abstract

We report a case of sirenomelia diagnosed at 13 gestational weeks. This rare malformation sequence is characterized by fusion and rotation of the lower limbs to various degrees and anorectal atresia, usually associated with absence of bladder and agenesis or dysgenesis of the kidneys. Diagnosis is commonly made later in the second trimester of pregnancy with oligohydramnios as the alerting sign. Survival is extremely rare, and only possible in the absence of bilateral renal agenesis. In view of the dismal prognosis, early diagnosis allows for earlier and less traumatic therapeutic abortion.

3D/4D sonography moved prenatal diagnosis of fetal anomalies from the second to the first trimester of pregnancy

“…Most skeletal anomalies are recognizable in the second trimester. However, several reports on congenital skeletal abnormalities (such as sirenomelia and others) in the first trimester have been documented [35][36][37][38][39]. Short limb abnormality of achondrogenesis in the first trimester was shown in Figure 42.…”

Sirenomelia: a case report with literature review

“…Oligohydramnios secondary to severe renal dysplasia is universal. Male to Female ratio being 3:1, the malformation sequence consists of varying degrees of lower limb fusion bearing a resemblance to the mermaid of ancient Greek mythology 6,7 Sirenomelia does not recur in families and no chromosomal abnormalities are observed. 5 The maternal blood glucose levels should be optimal in preconception period and in first trimester.…”

An unusual case of Sirenomelia Sympus Dipus (Mermaid Syndrome)

“…like in our case. There are many cases with severe oligohydramnios reported in the literature, in which sirenomelia was diagnosed only following delivery of the baby [10]. The first trimester prenatal diagnosis of the syndromes is very rare as because of the size of the fetus, which can make it challenging.…”