title: High risk for major nonlimb anomalies associated with lower-limb deficiency: a population-based study.
abstract: BACKGROUND
  The aims of this study were to determine the prevalence of congenital lower-limb reduction defects and associated mortality, to evaluate lower-limb deficiencies by type of reduction, and to identify patterns of associated anomalies.
  
  
  METHODS
  We conducted a population-based study with use of data from the Finnish Register of Congenital Malformations and Care Register for Health Care. All cases of lower-limb deficiency among live births, stillbirths, spontaneous abortions, and terminations of pregnancy due to fetal anomalies from 1993 to 2008 were included. We analyzed medical records and classified lower-limb reduction defects. Associated major anomalies were recorded, and perinatal mortality and infant mortality were calculated.
  
  
  RESULTS
  Two hundred and sixty-six cases with lower-limb deficiency were identified, with a total prevalence of 2.8 per 10,000 births, a birth prevalence of 2.2 per 10,000 births, and a live-birth prevalence of 2.1 per 10,000 live births. Terminal transverse limb reductions accounted for 44.7% of the cases; longitudinal reductions, 22.9%; intercalary reductions, 7.9%; multiple reductions, 8.3%; and split-foot malformations, 4.5%. In addition to lower-limb deficiency, 47.7% of the cases had other major anomalies; anomalies of internal organs were noted in 26.3% of the cases, anomalies of the axial skeleton in 13.5% of cases, and central nervous system anomalies in 12.8%. Upper-limb reductions were observed in 32.0% of the cases. The relative risk (RR) for associated major anomalies was 12.54 (95% confidence interval [CI], 11.06 to 14.23) compared with the general figures for major congenital anomalies in Finland. The RR for associated anomalies was higher (1.75; 95% CI, 1.20 to 2.53) for longitudinal preaxial lower-limb deficiencies than for the other types of lower-limb reductions. Perinatal mortality was seventy-eight per 1000 births. All infant deaths were associated with chromosomal abnormalities, other known syndromes, or additional congenital malformations.
  
  
  CONCLUSIONS
  Nearly half of the cases with lower-limb deficiencies were found to have other major anomalies. In cases of preaxial lower-limb deficiencies, the risk for associated major anomalies was highest.
authors.affiliation: Departments of Paediatric Orthopaedic Surgery (J.S., E.K., and I.H.) and Orthopaedic Surgery (J.S.), Turku University Central Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland. E-mail address for J. Syvänen: johanna.syvanen@fimnet.fi.
authors.forename: Johanna
authors.initials: J
authors.lastname: Syvänen
authors.affiliation: Department of Paediatric Orthopaedic Surgery, Helsinki University Central Hospital, Stenbäckinkatu 11, 00290 Helsinki, Finland.
authors.forename: Yrjänä
authors.initials: Y
authors.lastname: Nietosvaara
authors.affiliation: Finnish Register of Congenital Malformations, National Institute for Health and Welfare, PL 30, 00271Helsinki, Finland.
authors.forename: Annukka
authors.initials: A
authors.lastname: Ritvanen
authors.affiliation: Departments of Paediatric Orthopaedic Surgery (J.S., E.K., and I.H.) and Orthopaedic Surgery (J.S.), Turku University Central Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland. E-mail address for J. Syvänen: johanna.syvanen@fimnet.fi.
authors.forename: Eeva
authors.initials: E
authors.lastname: Koskimies
authors.affiliation: Biostatistics, University of Turku, Turku, Finland.
authors.forename: Tommi
authors.initials: T
authors.lastname: Kauko
authors.affiliation: Departments of Paediatric Orthopaedic Surgery (J.S., E.K., and I.H.) and Orthopaedic Surgery (J.S.), Turku University Central Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland. E-mail address for J. Syvänen: johanna.syvanen@fimnet.fi.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Helenius
mesh_terms: D000015:Abnormalities, Multiple / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D038061:Lower Extremity Deformities, Congenital / Q000453:epidemiology* / Q000401:mortality; D008297:Male; D054238:Perinatal Mortality; D015995:Prevalence; D012042:Registries; D012306:Risk