Greater than 50% funneling before 25 weeks is associated with approximately 80% risk of preterm delivery.
Good scanning technique is essential, as excessive pressure with the probe, or presence of a distended bladder may artificially narrow the canal. Preferrably, a transvaginal scan is recommended for accurate assesment of cervical length and measurement of funneling.
- percentage funnelling: funnel length / ( functional cervical length + funnel length)
- shape of funneling: V-shaped or U-shaped. U-shaped funneling have higher risk of preterm delivery4
- depth and width of funnel: V-shaped funnel has a depth with no width; however, U-shaped funnel has width as important parameter
- 1. Hricak H, Chang YC, Cann CE et-al. Cervical incompetence: preliminary evaluation with MR imaging. Radiology. 1990;174 (3): 821-6. Radiology (abstract) - Pubmed citation
- 2. Bowie JD, Andreotti RF, Rosenberg ER. Sonographic appearance of the uterine cervix in pregnancy: the vertical cervix. AJR Am J Roentgenol. 1983;140 (4): 737-40. AJR Am J Roentgenol (abstract) - Pubmed citation
- 3. Hassan S, Romero R, Hendler I et-al. A sonographic short cervix as the only clinical manifestation of intra-amniotic infection. J Perinat Med. 2006;34 (1): 13-9. doi:10.1515/JPM.2006.002 - Free text at pubmed - Pubmed citation
- 4. Berghella V, Owen J, Macpherson C et-al. Natural history of cervical funneling in women at high risk for spontaneous preterm birth. Obstet Gynecol. 2007;109 (4): 863-9. doi:10.1097/01.AOG.0000258276.64005.ce - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Funneling of the cervical os||✗|