Small gestational sac

A small gestational sac in early first trimester is considered a poor prognostic factor. Some authors use the mean sac diameter to crown rump length difference of 5 mm or greater to be normal 1.  

The smaller than expected sac diameter in pregnancies 36-42 days from the last menstrual period has been reported as a predictor of spontaneous miscarriage 2.

The difference between the two values should not be used in embryos older than 9 weeks 5.

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Article information

rID: 30066
System: Obstetrics
Synonyms or Alternate Spellings:
  • Small gestational sac size
  • First trimester oligohydramnios

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