|IMAGES IN CLINICAL NEONATOLOGY
|Year : 2015 | Volume
| Issue : 2 | Page : 147-148
Sirenomelia, the mermaid syndrome
Manisha Goyal, Seema Kapoor
Department of Pediatrics, Division of Genetics and Metabolism, Maulana Azad Medical College, New Delhi, India
|Date of Web Publication||6-Apr-2015|
Dr. Seema Kapoor
Department of Pediatrics, Division of Genetics and Metabolism, Maulana Azad Medical College, New Delhi
Source of Support: None, Conflict of Interest: None
Sirenomelia is a rare congenital malformation and is characterized by complete fusion of the lower limbs, commonly associated with lethal urogenital and gastrointestinal malformations. Here, we are presenting a case of sirenomelia diagnosed at birth.
Keywords: Congenital, gastrointestinal, urogenital
|How to cite this article:|
Goyal M, Kapoor S. Sirenomelia, the mermaid syndrome. J Clin Neonatol 2015;4:147-8
| Introduction|| |
Our case was a second in birth order of first-degree consanguineous marriage. The fetus was delivered died at term by normal vaginal delivery. The mother was diagnosed with type 2 diabetes mellitus at 10 weeks of pregnancy and was treated with injectable insulin. She had no history of any drug exposure in the pregnancy. Initial ultrasound (USG) performed at 13 weeks showed oligohydramnios and the fetus was presented compressed in between the placenta and the myometrium. She was advised for repeat USG on the next day, but she did not follow the advice. USG at 18 weeks showed the fetus lying in a markedly flexed position, severe oligohydramnios and non-visualization of kidneys and bladder. She was lost to follow-up since then. She came at 36 weeks of pregnancy with labor pains and delivered a mermaid baby. On examination, the stillborn fetus weighted 1850 g. The fetus had a normal upper part while the lower extremities were fused. External genitalia and anal opening were absent [Figure 1]a and b. Post-mortem radiological examination suggested an abnormal bony pelvis and a single femur [Figure 2]. Dissection of the umbilical cord revealed a single umbilical artery. Autopsy was not possible because of refusal.
|Figure 1: (a) External view of the fetus; a normal fetal upper part. The fused lower extremities are present. (b) A view on the sacral region with the aberrant lower limbs and the anus imperforatus|
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|Figure 2: Post-mortem radiograph confirming the hemipelvis, single femur, absent tibia, fibula and foot|
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Sirenomelia is a rare congenital malformation and is characterized by complete fusion of the lower limbs, commonly associated with lethal urogenital and gastrointestinal malformations such as agenesis or dysgenesis of the kidneys, absent external genitalia, imperforated anus or blind ending colon, lumbosacral and pelvic bone abnormalities and a single umbilical artery.  The incidence is about one in 60,000 births, and males are three times more often affected than females, with higher incidence in one of identical twins.  Prenatal diagnosis of sirenomelia has been made by ultrasound. Unfortunately, in our case, a proper skeletal evaluation was not possible on ultrasound owing to the oligohydramnios. Etiology is still controversial. Pathogenetic hypotheses include the vascular steal theory, described as the blood being shunted away from the absent or hypoplastic pelvic arteries into the single umbilical vitelline artery. The diminution of blood flow distal to the aberrant artery results in maldevelopment of the caudal portion of the embryo.  Other proposed theories are a teratogenic effect of cadmium, cocaine and retinoic acid. In our case, the mother had diabetes mellitus. Although embryopathic effects of maternal diabetes are reported with development of the caudal regression syndrome or sacrococcygeal association, no association with sirenomelia is found.
| References|| |
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Stevenson RE, Jones KL, Phelan MC, Jones MC, Barr M Jr, Clericuzio C, et al
. Vascular steal: The pathogenetic mechanism producing sirenomelia and associated defects of the viscera and soft tissues. Pediatrics 1986;78:451-7.
[Figure 1], [Figure 2]