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Sirenomelia in a twelve weeks abortus
Early Human Development, 15 (1987) 217-220 Elsevier Scientific Publishers Ireland Ltd.
217
EHD 00821
Sirenomelia
in a twelve weeks abortus
G. Malinger”, 0. Treschanb, N. Rosenb and H. Zakut” “Department ofObstetrics and Gynecology, bDepartmenr of Parhology, The Sackler Faculty of Medicine, Tel-Aviv
University, The Edith Wolfson Medical Center, Holon, Israel
Accepted for publication
19 October 1986
Summary
The anatomical findings of sirenomelia in a 12-weeks aborted embryo are reported. The occurrence of sirenomelia in material from spontaneous abortions is discussed. sirenomelia;
pregnancy
Introduction
Sirenomelia is a fetal malformation defined by the partial or total fusion of the lower limbs. The terms mermaid, fetus synpus and symelia are used as synonyms. This characteristic feature is usually combined with various genitourinary and intestinal malformations. It is a rare malformation incompatible with life. The majority of cases reported in the literature were delivered during the third trimester of pregnancy. This report describes the case of a sirenomelic embryo of 12 weeks gestational age, with the usual associated malformations.
Case Report
A 29-year-old woman, gravida 6 para 5 presented with spontaneous abortion at 12 weeks of pregnancy. Past history and physical examination were normal. Neither drug use nor smoking were reported. Her five siblings were healthy.
Address for correspondence: H. Zakut, Department of Obstetrics and Gynecology, The Edith Wolfson Medical Center, P.O. Box 5, Holon (58100), Israel. 0378-3782/87/$03.50
@ 1987 Elsevier Scientific Publishers Ireland Ltd. Published and Printed in Ireland
d Fig.
I.
-
-
Dorsal aspect of sirenomelic
big toes appearing
e ‘i
t*
embryo showing the fused lower limb, a normal number of toes, the
on the other side of the foot.
Curettage yielded a macerated sirenomehc embryo, 14 g in weight. with its single leg bent anteriorly. Its length was: CH-8 cm; CR-b.9 cm consistent with 12 weeks gestational age. The arms were of normal shape but the left arm, which was thinner, was wrapped together with the umbilical cord around the neck. The head and trunk were normal but the anus and external genitalia were absent. The lower
~. Fig. 1. The ovaries.
exposed
posterior
On the inner anterior
wall of the abdominal abdominal
cavity
_
showing
wall surface one umbilical
large
artery
oval adrenals
is seen.
and both
219
Fig. 3. X-ray (of the abortus) showing two separate skeletal axes of the fused limb. No evidence of fibules.
extremities were fused as far as the toes, which were ten in number, the big toes appearing on the lateral side of the foot (Fig. 1). The fused soles were directed anteriorly. Despite autolysis the anatomical shape of internal organs were preserved. The lungs, heart, diaphragm, and liver were of normal appearance. The gastrointestinal tract ended in a blind pouch above the pelvis and was filled with secretion. Absence of both kidneys, ureters, urinary bladder, urethra and left umbilical artery was observed. Both adrenal and ovaries were present, but the tubes and uterus were absent (Fig. 2). X-ray showed a normal body skeleton, the limb presenting two femora and two tibiae without fibulae (Fig. 3). The placenta weighed 16 g and the amniotic cavity was of normal size. A yolk sac was present. On histological examination no pathological findings in the placenta and the chorion were found.
Discussion
Fusion of the lower extremities is the characteristic feature of sirenomelia. This anomaly is usually combined with various malformations of the urogenital and gastrointestinal systems included in the ‘caudal regression syndrome’ which consists of the following major categories of malformations: lower extremities defects, anomalies of body skeleton, imperforated anus and visceral anomalies, agenesis or dysgenesis of urinary system and agenesis and dysmorphia of the reproductive system. Most theories on the pathogenesis of the sirenomelic syn-
220
drome tend to place the origin of the malformation in a primary defect in the caudal region of the developing embryo which occurs before the fifteenth week
I141. Sirenomelia
is a rare and severe anomaly incompatible
with life. It represents
I % of all fetal monsters and occurs once in 60 000 pregnancies, the male/female ratio being 2.7: 1. There are no known chromosomal anomalies in sirenomelia.
Most pathological data of the sirenomelic malformation is gathered from fetuses of late pregnancy and newborn periods. Their incidence is higher in twin pregnancies ISI. There are only isolated data of its occurrence in early abortion without pathological description of the anomalies. David et al. [l] reported one case delivered at 1X weeks. Poland et al. [3] in a study of 2020 abortus from less than 20 weeks mentioned one sirenomelic embryo of 8.5 cm CR length without further details about associated malformations. Fantel [2] in a comparative study of the occurrence of severe anomalies in spontaneous abortuses, therapeutic abortuses and newborns stressed the fact that their incidence was higher in spontaneous abortuses as compared with the other groups. Sirenomelia was present in spontaneous abortion (4/l 000 specimens) and absent in the others. In a list of severe anomalies in spontaneous abortuses divided by gestational age he documented two cases of sirenomelia in the age group of X weeks among 390 specimens, and one case in the age group of 19 weeks among 1 1X specimens. The estimated gestational age of our case was 12 weeks of pregnancy. We propose to do pathological study of all the aborted material in order to find the real incidence of sirenomelia.
References 1 David, M.P. and Fein, A. (1974): Sirenomelia. Report of a case with thoughts on the teratogenetic mechanism. Obstet. Gynecol., 43. 91-97. 2 Fantel, A.G. et al. (1980): Embryonic and fetal phenotypes. Prevalence and other associated factors. In: A large Study of Spontaneous Abortions in Human Embryonic and Fetal Death, Editors: LH. Parter and E.B. Hook. Academic Press. 3 Poland, B.J., Miller. J.R.. Harris, M. et al. (1981): Spontaneous abortion. A study of 1961 women and their conceptuses. Acta Obstet. Gynecol. Stand. Suppl., 101. 5. 4 Wolffe, E. (1936): Les bases de la teratogenese experimentale des vcrtebres ammotes. d’apres les resultats de methodes directes. Arch. Anat. (Strassbourg).. 22, I. 5 Wright, J.L.Y. and Christopher, C.R. (1982): Sirenomelia, Potter’s syndrome and their relationship to monozygotic twinning. A case report and discussion. J. Reprod. Med.. 27. 29 I
217
EHD 00821
Sirenomelia
in a twelve weeks abortus
G. Malinger”, 0. Treschanb, N. Rosenb and H. Zakut” “Department ofObstetrics and Gynecology, bDepartmenr of Parhology, The Sackler Faculty of Medicine, Tel-Aviv
University, The Edith Wolfson Medical Center, Holon, Israel
Accepted for publication
19 October 1986
Summary
The anatomical findings of sirenomelia in a 12-weeks aborted embryo are reported. The occurrence of sirenomelia in material from spontaneous abortions is discussed. sirenomelia;
pregnancy
Introduction
Sirenomelia is a fetal malformation defined by the partial or total fusion of the lower limbs. The terms mermaid, fetus synpus and symelia are used as synonyms. This characteristic feature is usually combined with various genitourinary and intestinal malformations. It is a rare malformation incompatible with life. The majority of cases reported in the literature were delivered during the third trimester of pregnancy. This report describes the case of a sirenomelic embryo of 12 weeks gestational age, with the usual associated malformations.
Case Report
A 29-year-old woman, gravida 6 para 5 presented with spontaneous abortion at 12 weeks of pregnancy. Past history and physical examination were normal. Neither drug use nor smoking were reported. Her five siblings were healthy.
Address for correspondence: H. Zakut, Department of Obstetrics and Gynecology, The Edith Wolfson Medical Center, P.O. Box 5, Holon (58100), Israel. 0378-3782/87/$03.50
@ 1987 Elsevier Scientific Publishers Ireland Ltd. Published and Printed in Ireland
d Fig.
I.
-
-
Dorsal aspect of sirenomelic
big toes appearing
e ‘i
t*
embryo showing the fused lower limb, a normal number of toes, the
on the other side of the foot.
Curettage yielded a macerated sirenomehc embryo, 14 g in weight. with its single leg bent anteriorly. Its length was: CH-8 cm; CR-b.9 cm consistent with 12 weeks gestational age. The arms were of normal shape but the left arm, which was thinner, was wrapped together with the umbilical cord around the neck. The head and trunk were normal but the anus and external genitalia were absent. The lower
~. Fig. 1. The ovaries.
exposed
posterior
On the inner anterior
wall of the abdominal abdominal
cavity
_
showing
wall surface one umbilical
large
artery
oval adrenals
is seen.
and both
219
Fig. 3. X-ray (of the abortus) showing two separate skeletal axes of the fused limb. No evidence of fibules.
extremities were fused as far as the toes, which were ten in number, the big toes appearing on the lateral side of the foot (Fig. 1). The fused soles were directed anteriorly. Despite autolysis the anatomical shape of internal organs were preserved. The lungs, heart, diaphragm, and liver were of normal appearance. The gastrointestinal tract ended in a blind pouch above the pelvis and was filled with secretion. Absence of both kidneys, ureters, urinary bladder, urethra and left umbilical artery was observed. Both adrenal and ovaries were present, but the tubes and uterus were absent (Fig. 2). X-ray showed a normal body skeleton, the limb presenting two femora and two tibiae without fibulae (Fig. 3). The placenta weighed 16 g and the amniotic cavity was of normal size. A yolk sac was present. On histological examination no pathological findings in the placenta and the chorion were found.
Discussion
Fusion of the lower extremities is the characteristic feature of sirenomelia. This anomaly is usually combined with various malformations of the urogenital and gastrointestinal systems included in the ‘caudal regression syndrome’ which consists of the following major categories of malformations: lower extremities defects, anomalies of body skeleton, imperforated anus and visceral anomalies, agenesis or dysgenesis of urinary system and agenesis and dysmorphia of the reproductive system. Most theories on the pathogenesis of the sirenomelic syn-
220
drome tend to place the origin of the malformation in a primary defect in the caudal region of the developing embryo which occurs before the fifteenth week
I141. Sirenomelia
is a rare and severe anomaly incompatible
with life. It represents
I % of all fetal monsters and occurs once in 60 000 pregnancies, the male/female ratio being 2.7: 1. There are no known chromosomal anomalies in sirenomelia.
Most pathological data of the sirenomelic malformation is gathered from fetuses of late pregnancy and newborn periods. Their incidence is higher in twin pregnancies ISI. There are only isolated data of its occurrence in early abortion without pathological description of the anomalies. David et al. [l] reported one case delivered at 1X weeks. Poland et al. [3] in a study of 2020 abortus from less than 20 weeks mentioned one sirenomelic embryo of 8.5 cm CR length without further details about associated malformations. Fantel [2] in a comparative study of the occurrence of severe anomalies in spontaneous abortuses, therapeutic abortuses and newborns stressed the fact that their incidence was higher in spontaneous abortuses as compared with the other groups. Sirenomelia was present in spontaneous abortion (4/l 000 specimens) and absent in the others. In a list of severe anomalies in spontaneous abortuses divided by gestational age he documented two cases of sirenomelia in the age group of X weeks among 390 specimens, and one case in the age group of 19 weeks among 1 1X specimens. The estimated gestational age of our case was 12 weeks of pregnancy. We propose to do pathological study of all the aborted material in order to find the real incidence of sirenomelia.
References 1 David, M.P. and Fein, A. (1974): Sirenomelia. Report of a case with thoughts on the teratogenetic mechanism. Obstet. Gynecol., 43. 91-97. 2 Fantel, A.G. et al. (1980): Embryonic and fetal phenotypes. Prevalence and other associated factors. In: A large Study of Spontaneous Abortions in Human Embryonic and Fetal Death, Editors: LH. Parter and E.B. Hook. Academic Press. 3 Poland, B.J., Miller. J.R.. Harris, M. et al. (1981): Spontaneous abortion. A study of 1961 women and their conceptuses. Acta Obstet. Gynecol. Stand. Suppl., 101. 5. 4 Wolffe, E. (1936): Les bases de la teratogenese experimentale des vcrtebres ammotes. d’apres les resultats de methodes directes. Arch. Anat. (Strassbourg).. 22, I. 5 Wright, J.L.Y. and Christopher, C.R. (1982): Sirenomelia, Potter’s syndrome and their relationship to monozygotic twinning. A case report and discussion. J. Reprod. Med.. 27. 29 I