Shorted fetal femur is a morphological descriptor and is usually defined when the femoral length falls below the 5th centile for gestational age (some define it when it is under the 2.5th centile 5) or less than 0.91 predicted by the bi-parietal diameter. It can occur in isolated or in association with a number of other anomalies.
According to the former definition (e.g. using the 5th centile), the estimated incidence is at 5% of pregnancies.
Recognized associations include
- aneuploidic syndromic
- non-aneuploidic syndromic
If detected in the 2nd trimester, a careful search for any other fetal anomalies as well as a follows up scan later in the pregnancy6 is often recommended.
The prognosis can be variable depending on the presence of associated anomalies
- 1. Weisz B, David AL, Chitty L et-al. Association of isolated short femur in the mid-trimester fetus with perinatal outcome. Ultrasound Obstet Gynecol. 2008;31 (5): 512-6. doi:10.1002/uog.5349 - Pubmed citation
- 2. Todros T, Massarenti I, Gaglioti P et-al. Fetal short femur length in the second trimester and the outcome of pregnancy. BJOG. 2004;111 (1): 83-5. BJOG (link) - Pubmed citation
- 3. Twining P, Whalley DR, Lewin E et-al. Is a short femur length a useful ultrasound marker for Down's syndrome? Br J Radiol. 1991;64 (767): 990-2. doi:10.1259/0007-1285-64-767-990 - Pubmed citation
- 4. Papageorghiou AT, Fratelli N, Leslie K et-al. Outcome of fetuses with antenatally diagnosed short femur. Ultrasound Obstet Gynecol. 2008;31 (5): 507-11. doi:10.1002/uog.5265 - Pubmed citation
- 5. www.sogc.org/guidelines/public/162E-CPG-June2005.pdf
- 6. Avni EF, Avni FE. Perinatal imaging, from ultrasound to MR imaging. Springer Verlag. (2002) ISBN:354067327X. Read it at Google Books - Find it at Amazon
- 7. Entezami M, Albig M, Knoll U et-al. Ultrasound Diagnosis of Fetal Anomalies. Thieme. (2003) ISBN:1588902129. Read it at Google Books - Find it at Amazon