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Limb reduction defects in South America
Author(s) -
Castilla Eduardo E.,
Cavalcanti Denise P.,
Dutra Maria G.,
LopezCamelo Jorge S.,
Paz Joaquin E.,
Gadow Enrique C.
Publication year - 1995
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1995.tb11292.x
Subject(s) - medicine , congenital malformations , hypoplasia , population , lower limb , reduction (mathematics) , pregnancy , pediatrics , surgery , biology , genetics , geometry , environmental health , mathematics
Objective Limb reduction defects were considered as possible indicators of environmental teratogenesis; it was suggested that also invasive prenatal procedures could increase the risk for limb reduction defects. The purpose of this work is to give a baseline frequency for limb reduction defects, using data from a population not exposed to prenatal diagnosis procedures. Design Using data collected in the period 1967 to 1992 within the frame of the Latin American Collaborative Study of Congenital Malformations which clinically examined 2,917,074 newborn infants, a total of 1715 with limb reduction defects were found. All cases were classified and analysed in 25 categories. Geographic differences in recorded rates were tested by χ 2 for homogeneity. Secular trends were analysed using χ 2 test for linear trends. Results The overall birth prevalence rate of limb reduction defects among liveborn infants was 4.91 (per 10,000 births) (3.05 for isolated and 1.85 for associated cases). For stillbirths, the total prevalence was 2673/10,000 (553 for isolated and 21.20 for associated cases). The inclusion of the brachydactylies increased those figures to 5.55110,000 (3.39 for isolated and 2.16 for associated cases), and 27.42, respectively, (5.53 for isolated and 21.89 for associated cases). When isolated and associated cases were considered together, a geographic heterogeneity was found in pre‐axial limb reduction defects; there was also some heterogeneity for amputations. A maternal age effect was found for the isolated hypoplasias. Standardising by maternal age, the overall prevalence of limb reduction in liveborn infants was 5.66 per 10,000 ( 95% CI = 5.38–5.93 ). An increasing trend was suggested by the isolated form of distal amputations which involved hands, feet, or digits. Conclusions Our data suggest that clustering limb reduction defects in wide groups as transverse and longitudinal may lead to heterogeneous entities. When a possible association is suspected, it would be preferable to present and analyse data in the most discriminant form available. Due to the maternal age effect, it would be advisable to standardise the rates of transversal limb reduction defects by this variable.