Sirenomelia or mermaid syndrome is an extremely rare congenital lethal malformation with a frequency between 1.5 and 4.2 per 1 000 000 pregnancies.The association of sirenomelia with the VACTERL association is very rare, with twenty cases reported in the literature and only two cases with VACTERL-H. We present two cases of sirenomelia, type I and type II associated with VACTERL-H and VACTERL syndromes and we review the literature. First time pregnancy women aged 15 and 40 years, without harmful habits and diseases, where between 25-27 gestational week (GW) the prenatal study identifies malformative fetus and the pregnancy is interrupted by medical evidence. The fetopathological examination in the first case identified sirenomelia type I associated with myelomeningocele, hydrocephalus, anal imperforation, single umbilical artery, bilateral renal agenesis, ureteral and bladder agenesis, tracheo-esophageal fistule, agenesis of external genitals, monkey fold of the left palm of the hand - VACTERL-H. In the second case, where genetic testing is normal, sirenomelia type II associated with agenesis of external genitalia, anal imperforation, myelomeningocele, dolichocrania, macroglossia, low set ears, left preauricular skin tag, long philtrum, lung hypoplasia, split cadiac apex, single umbilicalis artery, blind end colon, hepatomegaly, accessory spleen, polycystic horseshoe kidney, uterine and vaginal agenesis, presence of two ovaries and duodenal stenosis - VACTERL association. This two cases, lead us to believe that sirenomelia and the VACTERL association are probably different manifestations of a pathogenetic process leading to disorders of blastogenesis at different levels during embryonic development.
KEY WORDS: VACTERL association; VACTERL-H; Sirenomelia; Embryonic development; Genetic study; Congenital malformation.