Sirenomelia: A Review of European Prevalence Data and Epidemiological Analysis of 17 Cases Registered in Wales

BACKGROUND: Sirenomelia is a rare congenital condition most notably characterized by a single lower limb. Previous studies have suggested a prevalence of approximately 1 per 100,000 births. However, in Wales 17 cases were recorded between 1998 and 2016, suggesting a higher rate of sirenomelia in this country. OBJECTIVES: This study compared current prevalence of sirenomelia in Wales with European data. This study further reviewed detailed time, place, and person data on sirenomelia cases in Wales to investigate possible causal factors. METHOD: A retrospective cohort study from birth defect surveillance programs. Individual-level records for all welsh cases were examined for evidence of causal factors. Comparator data from other countries were obtained from EUROCAT (a European network of population-based registries for the epidemiological surveillance of congenital anomalies). RESULTS: European data from 24 national and regional registries of congenital anomalies included 97 cases of sirenomelia identified across 9.6 million births between 1998 and 2016, giving a prevalence rate of 1 per 100,000 (95% CI 0.83, 1.23). Five regions reported statistically significantly higher rates than that recorded across all registries, while one region reported a significantly lower rate. Small numbers of cases limit definitive statistical interpretation. Analysis of the Wales data did not identify common epidemiological factors between cases. CONCLUSIONS: The contemporary prevalence of sirenomelia across Europe is consistent with earlier studies at approximately 1 per 100,000 births (95% CI 0.83, 1.23). However, there is greater variation between regions than would be expected by chance. There remains no definitive evidence for causal environmental factors.

Authors

Institutions

Publication Details

Journal
Birth Defects Research
Published
2026-05-01
DOI
https://doi.org/10.1002/bdr2.70051
Primary Topic
Congenital gastrointestinal and neural anomalies
Type
article
Field-Weighted Citation Impact
0.00
Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Sirenomelia: A Review of European Prevalence Data and Epidemiological Analysis of 17 Cases Registered in Wales

Rhian Hughes, Carlos Matias Dias, Elizabeth S. Draper, Isabelle Perthus et al.
Birth Defects Research
Congenital gastrointestinal and neural anomalies
article

Sirenomelia: A Review of European Prevalence Data and Epidemiological Analysis of 17 Cases Registered in Wales

Rhian Hughes, Carlos Matias Dias, Elizabeth S. Draper, Isabelle Perthus, Florence Rouget, Jorieke E. H. Bergman, Annie Perraud, Joanna Sichitiu, Ingeborg Barišić, Elisa Ballardini, Isabelle Monier, Anna Latos‐Bieleńska, Elly Den Hond, Linda Bailey, Michele Santoro, Michael Olson, Clara Cavero Carbonell, David Tucker, Mary O'Mahony, Anke Rissmann, Sarah Stevens, Ciarán Humphreys, Diana Wellesley, Wladimir Wertelecki, Madalen Oribe Amores, Llion Davies, Robert Maddison, Judith Rankin, Martin Haeusler, Chris Emmerson, Ceri Williams
article en

Abstract

BACKGROUND: Sirenomelia is a rare congenital condition most notably characterized by a single lower limb. Previous studies have suggested a prevalence of approximately 1 per 100,000 births. However, in Wales 17 cases were recorded between 1998 and 2016, suggesting a higher rate of sirenomelia in this country. OBJECTIVES: This study compared current prevalence of sirenomelia in Wales with European data. This study further reviewed detailed time, place, and person data on sirenomelia cases in Wales to investigate possible causal factors. METHOD: A retrospective cohort study from birth defect surveillance programs. Individual-level records for all welsh cases were examined for evidence of causal factors. Comparator data from other countries were obtained from EUROCAT (a European network of population-based registries for the epidemiological surveillance of congenital anomalies). RESULTS: European data from 24 national and regional registries of congenital anomalies included 97 cases of sirenomelia identified across 9.6 million births between 1998 and 2016, giving a prevalence rate of 1 per 100,000 (95% CI 0.83, 1.23). Five regions reported statistically significantly higher rates than that recorded across all registries, while one region reported a significantly lower rate. Small numbers of cases limit definitive statistical interpretation. Analysis of the Wales data did not identify common epidemiological factors between cases. CONCLUSIONS: The contemporary prevalence of sirenomelia across Europe is consistent with earlier studies at approximately 1 per 100,000 births (95% CI 0.83, 1.23). However, there is greater variation between regions than would be expected by chance. There remains no definitive evidence for causal environmental factors.

Birth Defects ResearchVol. 118(5)
Poznan University of Medical Sciences (PL), University Medical Center Groningen (NL), University of Leicester (GB), Inserm (FR), University of Ferrara (IT), Medical University of Graz (AT), Université Paris Cité (FR), Ayuntamiento de Bilbao (ES), Singleton Hospital (GB), University Hospital of Wales (GB), Princess Anne Hospital (GB), Glangwili General Hospital (GB), Public Health England (GB), Public Health Wales (GB), Centre Technique des Industries Mécaniques (FR), Sorbonne Paris Cité (FR), Provincial Institute for Hygiene (BE), Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (ES), Azienda Unità Sanitaria Locale di Ferrara (IT), Istituto di Fisiologia Clinica (IT), Centro de Estudos para a Intervencao Social (PT), Institut de Recherche en Santé, Environnement et Travail (FR), International Wildlife Consultants (United Kingdom) (GB), Essex Cardiothoracic Centre (GB), Joint Research Centre (IT), Rivne State University of Humanities (UA), St. Finbarr's Hospital (IE), Mother Hospital (IN), Children's Hospital Zagreb (HR), Université de Rennes (FR), Cardiff Metropolitan University (GB), Newcastle University (GB), Otto-von-Guericke-Universität Magdeburg (DE), University of Wales (GB)
Good health and well-being
Openalex Percentile: Top 9%
Congenital gastrointestinal and neural anomalies
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.