Irregular yolk sac
Citation, DOI, disclosures and article data
Citation:
Radswiki T, Jones J, Di Muzio B, et al. Irregular yolk sac. Reference article, Radiopaedia.org (Accessed on 28 Mar 2025) https://doi.org/10.53347/rID-14835
rID:
14835
Article created:
30 Aug 2011,
The Radswiki ◉
Disclosures:
At the time the article was created The Radswiki had no recorded disclosures.
View The Radswiki's current disclosures
Last revised:
Disclosures:
At the time the article was last revised Jeremy Jones had no recorded disclosures.
View Jeremy Jones's current disclosures
Revisions:
3 times, by
3 contributors -
see full revision history and disclosures
Systems:
Synonyms:
- Irregular yolk sac shape
- Irregularly shaped yolk sac
- Abnormal yolk sac shape
An irregular yolk sac or an abnormally shaped yolk sac is an imaging feature that can be observed in early pregnancy scanning. It may be seen in up to 17% of early pregnancy scans 1. In contrast to an irregular gestational sac, the observation of an irregular yolk sac in not thought to correlate with pregnancy failure - low sensitivity but high specificity 2.
Practical points
- indeterminate abnormal yolk sac abnormality that should not be considered alone for the diagnosis of failed early pregnancy
- follow-up ultrasonography at 7-14 days to assess the pregnancy for viability is generally appropriate
References
- 1. Tan S, İpek A, Pektas MK et-al. Irregular yolk sac shape: is it really associated with an increased risk of spontaneous abortion? J Ultrasound Med. 2011;30 (1): 31-6. J Ultrasound Med (full text) - Pubmed citation
- 2.Küçük T, Duru NK, Yenen MC et-al. Yolk sac size and shape as predictors of poor pregnancy outcome. J Perinat Med. 1999;27 (4): 316-20. doi:10.1515/JPM.1999.045 - Pubmed citation
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