How accurate is ultrasound in diagnosing molar pregnancy?

Alex Rourke, Nottingham University Hospitals


Diagnosing molar pregnancy with ultrasound is challenging. The project aim was to assess the accuracy of Trust A’s ultrasound service in diagnosing molar pregnancy.

The objectives were to

Find how many histologically proven cases of molar pregnancy were suspected after ultrasound examination.

Analyse the data collected to determine whether current practice at Trust A needs to be adapted.


This project is a retrospective single-centre study with a descriptive design. A literature review, including critical appraisal of literature, demonstrated the relevant previous research and provided a clear rationale for the project.

Data were collected from 1 January 2015 to 31 December 2021. All cases of histologically diagnosed molar pregnancy at Trust A were found. The ultrasound report for these cases was accessed to determine if a molar pregnancy was suspected after ultrasound examination.

An image review was performed to assess whether pre-determined sonographic features of molar pregnancy were demonstrated in cases of partial molar pregnancy (PMP) where a molar pregnancy was not diagnosed on ultrasound examination.


Data collection found 108 participants with a histologically proven molar pregnancy. 34% were complete molar pregnancy (CMP) while 66% were PMP. 92% of CMP were diagnosed at the ultrasound examination while 27% of PMP were detected on ultrasound.

The image review found that 84% of the cases where a PMP was undiagnosed by ultrasound had sonographic features of the condition.


The results showed that Trust A’s ultrasound detection rates are consistent with the studies found in the literature. However, the diagnoses of PMP were at the lower end of the range when compared to previous research. This suggests that diagnosing a PMP with ultrasound could be operator dependent, an argument supported by the image review, and that practice at Trust A could be adapted to improve detection rates.

View poster