Table 1.

Sonographic criteria for diagnosis of Caesarean section ectopic pregnancy

	Caesarean section ectopic	Cervical ectopic	Missed miscarriage
History of previous Caesarean section	Yes	N/A – but slight increased risk	N/A
Gestation sac location	Anterior lower uterine wall	Endocervical canal	May be in cervical canal
Colour Doppler appearances	Circumferential vascularity demonstrated	Circumferential vascularity demonstrated	No vascularity identified
Evidence of ‘sliding sign’	Fixed gestation sac	Fixed gestation sac	Mobility of gestation sac with gentle pressure