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SMFM Fetal Anomalies Consult Series #2: Extremities

Published:September 18, 2019DOI:https://doi.org/10.1016/j.ajog.2019.09.019

      Introduction: Extremities

      This SMFM Consult Series focuses on the extremities. Malformations that involve the extremities are seen frequently on ultrasound images and can be isolated or associated with other anomalies. The fetal extremities are an integral part of the fetal anatomic survey, and detection of skeletal anomalies is a key component of prenatal diagnosis. The basic anatomic survey (CPT 76805) requires documentation only of the presence of arms and legs. A detailed anatomic survey (CPT 76811) requires documenting the number, architecture, and position of the arms, legs, hands, feet, and digits.
      • Wax J.
      • Minkoff H.
      • Johnson A.
      • et al.
      Consensus report on the detailed fetal anatomic ultrasound examination: indications, components, and qualifications.
      Systematic examination of the extremities should include a review of absence or hypoplasia of individual bones along with an assessment for bowing, fractures, abnormal ossification, or evidence of abnormal symmetry (eg, discrepant femur diaphysis lengths). If abnormalities of the extremities are suspected, these findings should be correlated with other anatomic structures or biometry (eg, spine, skull, thorax) for the possibility of skeletal dysplasia or specific genetic syndromes.
      The practice of medicine continues to evolve, and individual circumstances will vary. This opinion reflects information available at the time of its submission for publication and is neither designed nor intended to establish an exclusive standard of perinatal care. This presentation is not expected to reflect the opinions of all members of the Society for Maternal-Fetal Medicine (SMFM).
      Reprints will not be available.
      All authors and Committee members have filed a conflict of interest disclosure delineating personal, professional, and/or business interests that might be perceived as a real or potential conflict of interest in relation to this publication. Any conflicts have been resolved through a process approved by the Executive Board. The Society for Maternal-Fetal Medicine has neither solicited nor accepted any commercial involvement in the development of the content of this publication.
      This document has undergone an internal peer review through a multilevel committee process within SMFM. This review involves critique and feedback from the SMFM Publications and Document Review Committees and final approval by the SMFM Executive Committee. SMFM accepts sole responsibility for document content. SMFM publications do not undergo editorial and peer review by the American Journal of Obstetrics & Gynecology. The SMFM Publications Committee reviews publications every 18-24 months and issues updates as needed. Further details regarding SMFM Publications can be found at www.smfm.org/publications. All questions or comments regarding the document should be referred to the SMFM Publications Committee at [email protected] .
      The long bones should be examined in the sagittal view, and images should include bilateral views of the femur, humerus, radius, ulna, tibia, and fibula (Figure 1). The femur and humerus diaphysis lengths are measured optimally with the beam of insonation perpendicular to the shaft, excluding the distal epiphyses. Coronal views of the arms and legs, at the level of the hands and feet, should allow verification of hand/foot positions and their relationship to the long bones (ie, normal positioning of the ankle and wrist; Figure 2). If technically feasible, a plantar view of the feet should also be documented. Hand and foot digits should be counted, typically in a transverse (axial) or coronal view (Figure 3). Suspected abnormalities of joint movement should be documented, although the examiner should be cautious of any transient positions that could mimic a pathologic condition. Three-dimensional ultrasound imaging can sometimes be helpful in demonstrating anomalies of the extremities. Nomograms are available for various biometric measurements.
      • Altman D.G.
      • Chitty L.S.
      Charts of fetal size: 1. Methodology.
      ,
      • Buck Louis G.M.
      • Grewal J.
      • Albert P.S.
      • et al.
      Racial/ethnic standards for fetal growth: the NICHD Fetal Growth Studies.
      Figure thumbnail gr1
      Figure 1Long bones
      A, Left lower extremity, includes femur (left) and tibia and fibula (right). B, Right upper extremity, includes radius and ulna (left) and humerus (right).
      SMFM Fetal Anomalies Consult Series #2. Am J Obstet Gynecol 2019.
      Figure thumbnail gr2
      Figure 2Hand and foot positions
      A, Normal positioning of the wrist; B, normal positioning of the ankle.
      SMFM Fetal Anomalies Consult Series #2. Am J Obstet Gynecol 2019.
      Figure thumbnail gr3
      Figure 3Digits
      A, Normal hand; B, normal foot.
      SMFM Fetal Anomalies Consult Series #2. Am J Obstet Gynecol 2019.
      If a limb abnormality has been detected and a search for other abnormalities has been completed, the patient should be counseled about the clinical significance of the findings, prognosis, and other considerations for pregnancy management. Genetic counseling and options for diagnostic genetic testing should be offered. A multidisciplinary team should be convened to discuss postnatal surgery, genetic evaluation, and physical therapy support, if necessary.
      This series reviews the sonographic diagnosis, genetic evaluation, and potential treatment and outcome of the following abnormalities that affect the fetal extremities:
      • Amniotic band sequence
      • Arthrogryposis
      • Club foot
      • Polydactyly
      • Radial ray malformation

      Coding

      When coding for isolated fetal extremity abnormalities (for example, radial ray malformation, polydactyly, clubfoot) the SMFM Coding Committee recommends using the International Classification of Diseases–10 code series O35.8xx0–O35.8xx9 (non-central nervous system fetal malformation). When coding for fetal extremity abnormalities with higher suspicion for chromosomal or genetic syndromes, the International Classification of Diseases–10 code series O35.1xx0–O35.8xx9 may be used as well.

      Acknowledgments

      The authors wish to acknowledge Mary E. Norton, MD, Jeffrey A. Kuller, MD, and Angie C. Jelin, MD, for providing a review of the genetics content and Joseph Wax, MD, for providing a general review of the content of this Consult.

      References

        • Wax J.
        • Minkoff H.
        • Johnson A.
        • et al.
        Consensus report on the detailed fetal anatomic ultrasound examination: indications, components, and qualifications.
        J Ultrasound Med. 2014; 33: 189-195
        • Altman D.G.
        • Chitty L.S.
        Charts of fetal size: 1. Methodology.
        BJOG. 1994; 101: 29-34
        • Buck Louis G.M.
        • Grewal J.
        • Albert P.S.
        • et al.
        Racial/ethnic standards for fetal growth: the NICHD Fetal Growth Studies.
        Am J Obstet Gynecol. 2015; 213: 449.e1-449.e41

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