title: A method for estimating gestational age of fetal remains based on long bone lengths.
abstract: The estimation of gestational age (GA) in fetal human remains is important in forensic settings, particularly to assess fetal viability, in addition to often being the only biological profile parameter that can be assessed with some accuracy for non-adults. The length of long bone diaphysis is one of the most frequently used methods for fetal age estimation. The main objective of this study was to present a simple and objective method for estimating GA based on the measurements of the diaphysis of the femur, tibia, fibula, humerus, ulna, and radius. Conventional least squares regression equations (classical and inverse calibration approaches) and quick reference tables were generated. A supplementary objective was to compare the performance of the new formulae against previously published models. The sample comprised 257 fetuses (136 females and 121 males) with known GA (between 12 and 40 weeks) and was selected based on clinical and pathological information. All measurements were performed on radiographic images acquired in anonymous clinical autopsy records from spontaneous and therapeutic abortions in two Portuguese hospitals. The proposed technique is straightforward and reproducible. The models for the GA estimation are exceedingly accurate and unbiased. Comparisons between inverse and classical calibration show that both perform exceptionally well, with high accuracy and low bias. Also, the newly developed equations generally outperform earlier methods of GA estimation in forensic contexts. Quick reference tables for each long bone are now available. The obtained models for the estimation of gestational age are of great applicability in forensic contexts.
authors.affiliation: Garcia de Orta Hospital, EPE, Almada, Portugal. cristianacarneiro@sapo.pt.|Lisbon School of Health Technology, Polytechnic Institute of Lisbon, Lisbon, Portugal. cristianacarneiro@sapo.pt.|Laboratory of Forensic Anthropology, Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal. cristianacarneiro@sapo.pt.|Research Centre for Anthropology and Health, Department of Life Sciences, University of Coimbra, Coimbra, Portugal. cristianacarneiro@sapo.pt.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Carneiro
authors.affiliation: Laboratory of Forensic Anthropology, Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal.|Research Centre for Anthropology and Health, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.|Interdisciplinary Center for Archaeology and Evolution of Human Behavior, University of Algarve, Faro, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Curate
authors.affiliation: Laboratory of Forensic Anthropology, Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal.|Research Centre for Anthropology and Health, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
authors.forename: Eugénia
authors.initials: E
authors.lastname: Cunha
mesh_terms: D000365:Age Determination by Skeleton / Q000379:methods*; D050280:Arm Bones / Q000000981:diagnostic imaging / Q000254:growth & development*; D015331:Cohort Studies; D018483:Diaphyses / Q000000981:diagnostic imaging / Q000254:growth & development; D005260:Female; D005333:Fetus; D018732:Forensic Anthropology; D005865:Gestational Age; D006801:Humans; D016018:Least-Squares Analysis; D007867:Leg Bones / Q000000981:diagnostic imaging / Q000254:growth & development*; D008297:Male; D012189:Retrospective Studies
keywords: Age estimation; Fetus; Long bones; Radiography; Regression equations