Description

Emerson et al listed criteria for various types of early gestation as seen on endovaginal sonography (EVS). The authors are from the University of Tennessee.


 

Categories of early gestation:

(1) viable and intrauterine

(2) failed and intrauterine

(3) ectopic

(4) indeterminate

 

Structure

Size

Features

Diagnosis

intrauterine gestational sac

NA

double sac sign or embryonic structure

viable

intrauterine gestational sac

>= 1 cm

no yolk sac

failed

intrauterine gestational sac

> 1.5 cm

no fetal pole

failed

intrauterine gestational sac

> 1.5 cm

no cardiac activity

failed

intrauterine gestational sac

< 1 cm

neither double sac sign nor embryonic structures

indeterminate

intrauterine sac abnormally low in the uterus

NA

NA

failed

extrauterine gestational sac

NA

with or without embryonic structures

ectopic

NA

NA

large amount of pelvic fluid

ectopic

adnexal mass

NA

separate from uterus and ovary

ectopic

adnexal mass

NA

originating from ovary

indeterminate

nothing

NA

NA

indeterminate

 

where:

• An ectopic gestation should have either an empty uterus or abnormal endometrial fluid.

• Nothing = empty uterus AND no adnexal gestational sac AND no adnexal mass.

• In the implementation the combination of intrauterine gestational sac, diameter > 1.5 cm, and cardiac activity was added as evidence of a viable pregnancy. This was to balance criteria for a failed gestation.

 


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