Amniotic sac sign in the diagnosis of miscarriage: a prospective study
Research type
Research Study
Full title
The amniotic sac sign in the diagnosis of miscarriage: A prospective multi-centre evaluation of the predictive value of the presence of an amniotic sac without an embryonic heartbeat in the diagnosis of early embryonic demise - a student study
IRAS ID
295658
Contact name
Davor Jurkovic
Contact email
Sponsor organisation
University College London
Clinicaltrials.gov Identifier
Z6364106/2022/03/80, UCLH Data protection number
Duration of Study in the UK
0 years, 9 months, 1 days
Research summary
Miscarriage is a common complication of pregnancy. It has been reported that 8.3% to 22% of clinically recognised pregnancies fail during the first trimester. When biochemical pregnancies were also taken into consideration the miscarriage rate was as high as 30%. Even that is likely to be an underestimate as many early pregnancy losses occur in the community and are not reported.
Ultrasound is the mainstay of diagnosing a miscarriage and is widely available and safe to use. NICE have adopted ultrasound criteria which include a high safety margin for the diagnosis of miscarriage. While helping to reduce the risk of misdiagnosis of miscarriage, this protocol requires women to return for at least one and often for multiple follow-up visits until the final diagnosis is reached. This can be a period of prolonged distress and anxiety for many women and emphasises the importance of acquiring a more accurate and faster test to diagnose miscarriage.
In a recent large study, Dooley et al showed that all pregnancies with visible amniotic sac and no live embryo were diagnosed with early embryonic demise on follow up scans. They concluded that this ‘amniotic sac sign’ test had 100% specificity and overall 88.20% accuracy for the detection of early pregnancy failure at the initial visit. This reduced the number of follow-up scans for pregnancies of uncertain viability by 14.4%, accounting for 11% of all follow-up scans during their study period.
Our aim is to externally validate the potential impact of the amniotic sac sign on reducing the follow-up rates in women presenting to EPUs with suspected early pregnancy complications, as part of a multi-centre evaluation. In addition, we will re-examine the accuracy of the amniotic sac sign for the diagnosis of miscarriage.
REC name
London - Harrow Research Ethics Committee
REC reference
22/LO/0346
Date of REC Opinion
16 May 2022
REC opinion
Favourable Opinion