crown rump length


Summary: In utero measurement corresponding to the sitting height (crown to rump) of the fetus. Length is considered a more accurate criterion of the age of the fetus than is the weight. The average crown-rump length of the fetus at term is 36 cm. (From Williams Obstetrics, 18th ed, p91)

Top Publications

  1. Jou H, Wu S, Li T, Hsu H, Tzeng C, Hsieh F. Relationship between fetal nuchal translucency and crown-rump length in an Asian population. Ultrasound Obstet Gynecol. 2001;17:111-4 pubmed
  2. Aviram R, Shpan D, Markovitch O, Fishman A, Tepper R. Three-dimensional first trimester fetal volumetry: comparison with crown rump length. Early Hum Dev. 2004;80:1-5 pubmed
    ..the weekly increase of fetal volume during the first trimester of normal pregnancies compared to the crown rump length and creating a first trimester fetal volume nomogram...
  3. Rasmussen S, Kiserud T, Albrechtsen S. Foetal size and body proportion at 17-19 weeks of gestation and neonatal size, proportion, and outcome. Early Hum Dev. 2006;82:683-90 pubmed
    ..Symmetric and particularly asymmetric small foetuses at 17-19 weeks of gestation were generally lighter, shorter, and thinner at birth and had more often adverse perinatal outcome. ..
  4. Johnsen S, Rasmussen S, Sollien R, Kiserud T. Fetal age assessment based on femur length at 10-25 weeks of gestation, and reference ranges for femur length to head circumference ratios. Acta Obstet Gynecol Scand. 2005;84:725-33 pubmed
    ..Fetal age assessment based on FL is an equally robust method as using HC. FL/HC is a more robust ratio to characterize fetal proportions than is FL/BPD. ..
  5. Altay M, Yaz H, Haberal A. The assessment of the gestational sac diameter, crown-rump length, progesterone and fetal heart rate measurements at the 10th gestational week to predict the spontaneous abortion risk. J Obstet Gynaecol Res. 2009;35:287-92 pubmed
    ..MGSD-CRL and P could predict patients with low abortion risk. However, at the 10th week of pregnancy, FHR > or =175 beats/min should be evaluated for this purpose by future studies with larger sample sizes. ..
  6. Frost H, Krohn W, Bezembluk E, Lott R, Wallace C. Prenatal development in fishers (Martes pennanti). Theriogenology. 2005;63:1440-53 pubmed
    ..001). Biparietal and body diameters were also linearly related to gestational age (P < 0.001) and correctly predicted parturition dates within 1-2 d. ..
  7. Khan T, Hastie P, Beck N, Khalid M. hCG treatment on day of mating improves embryo viability and fertility in ewe lambs. Anim Reprod Sci. 2003;76:81-9 pubmed
    ..10) in hCG-treated animals compared to the controls. In conclusion, these data suggest that treatment of ewe lambs with hCG at the time of mating improves conceptus growth, placentation and number of lambs born. ..
  8. Matias A, Montenegro N, Loureiro T, Cunha M, Duarte S, Freitas D, et al. Screening for twin-twin transfusion syndrome at 11-14 weeks of pregnancy: the key role of ductus venosus blood flow assessment. Ultrasound Obstet Gynecol. 2010;35:142-8 pubmed publisher
    ..In these pregnancies, in addition to NT measurement at 11-14 weeks, the Doppler assessment of DV blood flow significantly increases the performance of screening for those at risk of developing TTTS. ..
  9. Law L, Leung T, Sahota D, Chan L, Fung T, Lau T. Which ultrasound or biochemical markers are independent predictors of small-for-gestational age?. Ultrasound Obstet Gynecol. 2009;34:283-7 pubmed publisher
    ..Combining them did not significantly improve prediction of SGA. Among the various known ultrasound and biochemical markers, only the first-trimester PlaV and the second-trimester PlaV plus UtA-PI are independent predictors for SGA. ..

More Information


  1. Salpou D, Kiserud T, Rasmussen S, Johnsen S. Fetal age assessment based on 2nd trimester ultrasound in Africa and the effect of ethnicity. BMC Pregnancy Childbirth. 2008;8:48 pubmed publisher
    ..The results support the recommendation that ultrasound in practical health care can be used to assess gestational age in various populations with little risk of error due to ethnic variation. ..
  2. Rolo L, Nardozza L, Araujo Júnior E, Nowak P, Moron A. Yolk sac volume assessed by three-dimensional ultrasonography using the VOCAL method. Acta Obstet Gynecol Scand. 2008;87:499-502 pubmed publisher
    ..063 cm(3) (95% CI: 0.047; 0.080) at 7 weeks to 0.164 cm3 (95% CI 0.095; 0.232) at 10 weeks. Reference limits were generated for first trimester YSV using 3D-US. There was a poor correlation between YSV and GA or CRL. ..
  3. Vlajkovic S, Dakovic Bjelakovic M, Cukuranovic R, Popović J. Evaluation of absolute volume of human fetal kidney's cortex and medulla during gestation. Vojnosanit Pregl. 2005;62:107-11 pubmed
    ..This study was an effort to provide some parameters which would help in the future investigations of the development of human fetal kidney. ..
  4. Martini V, Mandarim de Lacerda C. Offspring myocardium alteration from dams submitted to nitric oxide synthesis inhibition during pregnancy. Int J Cardiol. 2005;100:377-82 pubmed
    ..Furthermore, the prenatal NOS inhibition apparently stimulates the cardiomyocyte proliferation that can be observed until the end of lactation, which is when the number of cardiomyocytes nuclei profiles seems to become stable. ..
  5. Xu D, Chen Y, Zhao L, Wang H, Wei W. Reactive oxygen species are involved in lipopolysaccharide-induced intrauterine growth restriction and skeletal development retardation in mice. Am J Obstet Gynecol. 2006;195:1707-14 pubmed
    ..Reactive oxygen species might be, at least in part, involved in lipopolysaccharide-induced intrauterine fetal growth restriction and skeletal development retardation. ..
  6. Auerbach A. Long live generalism. Hospital medicine and the Journal of General Internal Medicine. J Gen Intern Med. 2005;20:208-9 pubmed
  7. Maymon R, Jauniaux E, Cohen O, Dreazen E, Weinraub Z, Herman A. Pregnancy outcome and infant follow-up of fetuses with abnormally increased first trimester nuchal translucency. Hum Reprod. 2000;15:2023-7 pubmed
    ..02). These findings suggest that the long-term prognosis of the euploid fetuses with large NT (<5 mm) is reassuring in younger women. ..
  8. Lombardi C, Bellotti M, Fesslova V, Cappellini A. Fetal echocardiography at the time of the nuchal translucency scan. Ultrasound Obstet Gynecol. 2007;29:249-57 pubmed
    ..A trained operator can perform a fetal heart study during the NT screening test using transabdominal high-resolution transducers in an acceptable length of time. ..
  9. Loncar D, Varjacic M, Novakovic T, Milovanovic D, Jankovic S. Correlation between serum biochemical markers and early amniocentesis in diagnosis of congenital fetal anomalies. Bosn J Basic Med Sci. 2010;10:9-14 pubmed
    ..The combined test, as a method of prenatal screening in the first trimester of pregnancy, if used at 11 - 13+6 weeks' gestation and for CRL of 45-84 mm, has a great importance in the detection of congenital foetal anomalies. ..
  10. Salomon L, Bernard J, Ville Y. Quality control at first trimester: is there something new?. Am J Obstet Gynecol. 2008;198:345-6; author reply 346 pubmed publisher
  11. Haggarty P, Campbell D, Bendomir A, Gray E, Abramovich D. Ponderal index is a poor predictor of in utero growth retardation. BJOG. 2004;111:113-9 pubmed
    ..The inclusion of a length term generally reduced the predictive ability with the highest powers resulting in the poorest prediction. ..
  12. Souka A, Krampl E, Geerts L, Nicolaides K. Congenital lymphedema presenting with increased nuchal translucency at 13 weeks of gestation. Prenat Diagn. 2002;22:91-2 pubmed
    ..The locus of the gene has been identified in the long arm of chromosome 15. We report one case of congenital lymphedema presenting with increased nuchal translucency at 13 weeks of gestation. ..
  13. El Kateb A, Nasr B, Nassar M, Bernard J, Ville Y. First-trimester ultrasound examination and the outcome of monochorionic twin pregnancies. Prenat Diagn. 2007;27:922-5 pubmed
    ..02). Monochorionic twin gestations who ultimately develop TTTS may exhibit intertwin difference in growth as early as 11-14 weeks of gestation. The earlier the discordance the earlier the development of the disease. ..
  14. Zoppi M, Ibba R, Axiana C, Floris M, Manca F, Monni G. Absence of fetal nasal bone and aneuploidies at first-trimester nuchal translucency screening in unselected pregnancies. Prenat Diagn. 2003;23:496-500 pubmed
    ..The absence of NB at 11 to 14 weeks is more frequent in fetuses with trisomy 21 and other aneuploidies than in normal karyotype fetuses. ..
  15. Redondo E, Franco A, Masot A. Morphometric and immunohistochemical study of the omasum of red deer during prenatal development. J Anat. 2005;206:543-55 pubmed
    ..However, its prenatal development was later than that of the omasum in sheep, goat and cow...
  16. Nicolaides K, Wegrzyn P. [Sonographic features of chromosomal defects at 11(+0) to 13(+6) weeks of gestation]. Ginekol Pol. 2005;76:423-30 pubmed
    ..In triploidy, there is early onset asymmetrical fetal growth restriction, bradycardia, holoprosencephaly, exomphalos, posterior fossa cyst and molar changes in the placenta. ..
  17. Webb S, Kanani M, Anderson R, Richardson M, Brown N. Development of the human pulmonary vein and its incorporation in the morphologically left atrium. Cardiol Young. 2001;11:632-42 pubmed
    ..Failure of incorporation on the left side may provide the substrate for congenital division of the left atrium. ..
  18. Verwoerd Dikkeboom C, Koning A, van der Spek P, Exalto N, Steegers E. Embryonic staging using a 3D virtual reality system. Hum Reprod. 2008;23:1479-84 pubmed publisher
    ..e. mainly limb development). After staging, the crown rump length (CRL) was measured...
  19. Vahtiala S, Säkkinen H, Dahl E, Eloranta E, Beckers J, Ropstad E. Ultrasonography in early pregnancy diagnosis and measurements of fetal size in reindeer (Rangifer tarandus tarandus). Theriogenology. 2004;61:785-95 pubmed
    ..Transrectal ultrasonography is an efficient tool in early pregnancy diagnosis of reindeer. The fetal growth curves obtained by ultrasonography resembled those obtained in previous morphological studies. ..
  20. Hackmon R, Le Scale K, Horani J, Ferber A, Divon M. Is severe macrosomia manifested at 11-14 weeks of gestation?. Ultrasound Obstet Gynecol. 2008;32:740-3 pubmed publisher
    ..47, P < 0.01 and r = 0.48, P < 0.01, respectively). Severe macrosomia apparently manifests as early as 11-14 weeks' gestation. ..
  21. Vimpelli T, Huhtala H, Acharya G. Fetal echocardiography during routine first-trimester screening: a feasibility study in an unselected population. Prenat Diagn. 2006;26:475-82 pubmed
    ..New reference ranges were established for fetal cardiac biometry at 11 + 0 to 13 + 6 weeks of gestation. ..
  22. Kato M, Niikura H, Yaegashi N, Murakami G, Tatsumi H, Matsubara A. Histotopography of the female cavernous nerve: a study using donated fetuses and adult cadavers. Int Urogynecol J Pelvic Floor Dysfunct. 2008;19:1687-95 pubmed publisher
    ..Because the female cavernous nerve and lateral vaginal wall are closely related, surgical treatment along the mid- and distal urethra should be conducted cautiously so as not to injure the perivaginal autonomic nerves. ..
  23. Osgerby J, Gadd T, Wathes D. The effects of maternal nutrition and body condition on placental and foetal growth in the ewe. Placenta. 2003;24:236-47 pubmed
    ..This study therefore demonstrates that body condition and ration can alter foetal and placental growth, perhaps by modifying systemic parameters and uterine IGF expression. ..
  24. Sacchini C, El Sheikhah A, Cicero S, Rembouskos G, Nicolaides K. Ear length in trisomy 21 fetuses at 11-14 weeks of gestation. Ultrasound Obstet Gynecol. 2003;22:460-3 pubmed
    ..014, P = 0.94). At 11-14 weeks of gestation the ear length in trisomy 21 fetuses is significantly reduced but the degree of deviation from normal is too small for this measurement to be useful in screening for trisomy 21. ..
  25. Sbarbati A, Marzola P, Simonati A, Nicolato E, Osculati F. High-field magnetic resonance imaging of the developing human brain from the 10th to the 16th week of gestational Age. Acta Anat (Basel). 1998;163:39-46 pubmed
    ..This technique can provide information about the morphology of the encephalic vesicles and their relations with the bone cavity that cannot be obtained with conventional methods and may be a useful adjunct to histological techniques. ..
  26. Ivanisevic M, Djelmis J, Jalsovec D, Bljajic D. Ultrasonic morphological characteristics of yolk sac in pregnancy complicated with type-1 diabetes mellitus. Gynecol Obstet Invest. 2006;61:80-6 pubmed
    ..A gross change in YS size may indicate or reflect significant dysfunction of the maternofetal transport system in early pregnancy which is complicated with type-1 DM. ..
  27. Verwoerd Dikkeboom C, Koning A, Hop W, Rousian M, van der Spek P, Exalto N, et al. Reliability of three-dimensional sonographic measurements in early pregnancy using virtual reality. Ultrasound Obstet Gynecol. 2008;32:910-6 pubmed publisher
    ..We have demonstrated that early pregnancy measurements in the I-Space are reliable. New areas of embryonic and fetal biometry can now be explored using this technique, which we tentatively name 'virtual embryoscopy'. ..
  28. Sullivan T, Micke G, Perkins N, Martin G, Wallace C, Gatford K, et al. Dietary protein during gestation affects maternal insulin-like growth factor, insulin-like growth factor binding protein, leptin concentrations, and fetal growth in heifers. J Anim Sci. 2009;87:3304-16 pubmed publisher
    ..02). These findings suggest that maternal dietary protein, age, and genotype influence plasma concentrations of metabolic hormones and fetal growth in Bos indicus-influenced heifers. ..
  29. Santolaya Forgas J, De Leon Luis J, Friel L, Wolf R. Application of Carnegie stages of development to unify human and baboon ultrasound findings early in pregnancy. Ultrasound Med Biol. 2007;33:1400-5 pubmed
    ..For this purpose, the gestational, amniotic and yolk sacs, embryonic crown rump length (CRL) and heart rate were measured ultrasonographically between 35 and 47 days from the mean day of a three-..
  30. Sherwood T, Mooney M, Sciote J, Smith T, Cooper G, Siegel M. Cranial base growth and morphology in second-trimester normal human fetuses and fetuses with cleft lip. Cleft Palate Craniofac J. 2001;38:587-96 pubmed
  31. Maslovitz S, Yaron Y, Fait G, Gull I, Wolman I, Jaffa A, et al. Feasibility of nuchal translucency in triplet pregnancies. J Ultrasound Med. 2004;23:501-4 pubmed
    ..Nuchal translucency values and distribution are the same in triplets and singletons, validating the utility of the cutoff values. ..
  32. Abaid L, As Sanie S, Wolfe H. Relationship between crown-rump length and early detection of cardiac activity. J Reprod Med. 2007;52:375-8 pubmed
    ..5 mm under ideal conditions. Vaginal bleeding increases the likelihood of demise, but does not alter test performance. Further investigation is warranted, as our data suggest a limit closer to 3 mm. ..
  33. van Oppenraaij R, Jauniaux E, Christiansen O, Horcajadas J, Farquharson R, Exalto N. Predicting adverse obstetric outcome after early pregnancy events and complications: a review. Hum Reprod Update. 2009;15:409-21 pubmed publisher
    ..Larger population-based controlled studies are needed to confirm these findings. Nevertheless, identification of these risks will improve obstetric care. ..
  34. Teixeira L, Leite J, Castro Viegas M, Faria M, Pires M, Teixeira H, et al. Non-influence of fetal gender on ductus venosus Doppler flow in the first trimester. Ultrasound Obstet Gynecol. 2008;32:12-4 pubmed publisher
    ..Our study suggests that fetal gender does not influence ductus venosus blood flow in the first trimester. ..
  35. Gottlieb A, Galan H. Nontraditional sonographic pearls in estimating gestational age. Semin Perinatol. 2008;32:154-60 pubmed publisher
  36. Farley D, Tejero M, Comuzzie A, Higgins P, Cox L, Werner S, et al. Feto-placental adaptations to maternal obesity in the baboon. Placenta. 2009;30:752-60 pubmed publisher
    ..In summary, these data demonstrate that in obese baboons in the absence of increased fetal weight, placental and fetal phenotype are consistent with those described for large-for-gestational age human fetuses. ..
  37. Maymon R, Levinsohn Tavor O, Cuckle H, Tovbin Y, Dreazen E, Wiener Y, et al. Correlation between nasal bone length and nuchal translucency thickness. Prenat Diagn. 2007;27:387 pubmed
  38. Prefumo F, Sairam S, Bhide A, Penna L, Hollis B, Thilaganathan B. Maternal ethnic origin and fetal nasal bones at 11-14 weeks of gestation. BJOG. 2004;111:109-12 pubmed
    ..This suggest that corrections for maternal ethnicity will be required to ensure equity of fetal nasal bone screening in multiracial populations. Whether corrections are required for the father's ethnic origin remains to be determined. ..
  39. Kutzler M, Yeager A, Mohammed H, Meyers Wallen V. Accuracy of canine parturition date prediction using fetal measurements obtained by ultrasonography. Theriogenology. 2003;60:1309-17 pubmed
    ..Parturition date predictions made after 39 days of gestation using only biparietal and BD fetal measurements were <50% accurate within +/-2 days. ..
  40. Hafner E, Metzenbauer M, Hofinger D, Stonek F, Schuchter K, Waldhor T, et al. Comparison between three-dimensional placental volume at 12 weeks and uterine artery impedance/notching at 22 weeks in screening for pregnancy-induced hypertension, pre-eclampsia and fetal growth restriction in a low-risk population. Ultrasound Obstet Gynecol. 2006;27:652-7 pubmed
    ..While both methods are insufficient for screening in a low-risk population, the PQ method has the potential advantage of being performed in the first trimester. ..
  41. Chavatte Palmer P, Laigre P, Simonoff E, Chesne P, Challah Jacques M, Renard J. In utero characterisation of fetal growth by ultrasound scanning in the rabbit. Theriogenology. 2008;69:859-69 pubmed publisher
    ..In late gestation, the fetuses that were transferred in limited numbers to the uterus of does were significantly larger than their natural breeding counterparts probably due to reduced litter size. ..
  42. Ranganathan S, Hoo A, Lum S, Goetz I, Castle R, Stocks J. Exploring the relationship between forced maximal flow at functional residual capacity and parameters of forced expiration from raised lung volume in healthy infants. Pediatr Pulmonol. 2002;33:419-28 pubmed
    ..3% and 8.9%, respectively).A more standardized protocol when analyzing data from the RVRTC would facilitate comparisons of results between centers in the future. ..
  43. Chen Y, Xu D, Zhao L, Wang H, Wang J, Wei W. Ascorbic acid protects against lipopolysaccharide-induced intra-uterine fetal death and intra-uterine growth retardation in mice. Toxicology. 2006;217:39-45 pubmed
  44. Davidson S. Birth weight and gestational age. Isr Med Assoc J. 2005;7:540-1; author reply 541 pubmed
  45. Ema M, Arima A, Fukunishi K, Matsumoto M, Hirata Koizumi M, Hirose A, et al. Developmental toxicity of dibutyltin dichloride given on three consecutive days during organogenesis in cynomolgus monkeys. Drug Chem Toxicol. 2009;32:150-7 pubmed publisher
    ..DBTCl did not affect the incidence of fetuses with skeletal variation or skeletal ossification of fetuses. These data confirm our previous findings that DBTCl was embryolethal, but not teratogenic, in cynomolgus monkeys. ..
  46. Tuxen A, Keeling J, Reintoft I, Fischer Hansen B, Nolting D, Kjaer I. A histological and radiological investigation of the nasal bone in fetuses with Down syndrome. Ultrasound Obstet Gynecol. 2003;22:22-6 pubmed
    ..The aim of this study was to investigate the presence and size of the nasal bones in postmortem Down syndrome fetuses by means of radiographs and histological examination...
  47. Chasen S, Sharma G, Kalish R, Chervenak F. First-trimester screening for aneuploidy with fetal nuchal translucency in a United States population. Ultrasound Obstet Gynecol. 2003;22:149-51 pubmed
    ..Using ultrasound techniques and risk algorithms from The FMF, the performance of the test in an American population is similar to that described in international populations. ..
  48. Metzenbauer M, Hafner E, Hoefinger D, Schuchter K, Stangl G, Ogris E, et al. Three-dimensional ultrasound measurement of the placental volume in early pregnancy: method and correlation with biochemical placenta parameters. Placenta. 2001;22:602-5 pubmed
    ..Future studies will be needed to evaluate the possible clinical use of first trimester placental volume measurements. ..
  49. Afshar M, Moallem S, Houshang Mohammadpour A, Shiravi A, Majid Jalalian S, Jafar Golalipour M. Teratogenic effects of carbamazepine on embryonic eye development in pregnant mice. Cutan Ocul Toxicol. 2010;29:10-5 pubmed publisher
    ..The implication of these results needs to be considered when carbamazepine is administered during human pregnancy. ..
  50. Plasencia W, Maiz N, Poon L, Yu C, Nicolaides K. Uterine artery Doppler at 11 + 0 to 13 + 6 weeks and 21 + 0 to 24 + 6 weeks in the prediction of pre-eclampsia. Ultrasound Obstet Gynecol. 2008;32:138-46 pubmed publisher
    ..Effective screening for pre-eclampsia can be achieved by the Doppler measurement of uterine artery PI at 11 + 0 to 13 + 6 weeks and the change in PI between 11 + 0 to 13 + 6 and 21 + 0 to 24 + 6 weeks. ..
  51. Herman A, Dreazen E, Herman A, Batukan C, Holzgreve W, Tercanli S. Bedside estimation of Down syndrome risk during first-trimester ultrasound screening. Ultrasound Obstet Gynecol. 2002;20:468-75 pubmed
    ..The results of the current study provide useful tables for simple and accurate 'bedside' estimation of Down syndrome risk without the need for computerized software or complicated calculations. ..
  52. Schuchter K, Hafner E, Stangl G, Metzenbauer M, Hofinger D, Philipp K. The first trimester 'combined test' for the detection of Down syndrome pregnancies in 4939 unselected pregnancies. Prenat Diagn. 2002;22:211-5 pubmed
    ..The DR for DS can be increased much more markedly using the 'combined test' with a FPR that still remains at the level as it was in the early 1970s. ..
  53. Smith G. Use of time to event analysis to estimate the normal duration of human pregnancy. Hum Reprod. 2001;16:1497-500 pubmed
    ..38; 95% CI 1.03-1.84). This study provides a basis for predicting the probability of labour at a given gestational age at term. ..