The development of ultrasound techniques such as 3D and 4D and new reproducible and
increasingly accurate volumetric acquisition modalities shows promise for improving the
diagnosis of OASIS and the clinical management of OASIS and consequently the quality of
life of women.
With new, simpler techniques of 3D/4D volume analysis of the anal sphincter, the number
of operators able to objectively and accurately assess anal sphincter integrity, both in
the delivery room and postpartum, could increase. The application and dissemination of an
accurate and reproducible technique in the subjective assessment of the anal sphincter
could help operators improve and refine the technique of surgical correction of anal
sphincter injuries.
The primary objective of the study is to evaluate the reproducibility of novel 3D/4D
ultrasound volume analysis techniques, using curvilinear reconstruction of the coronal
plane of the anal sphincter combined with contrast enhancement technique (optic
OMNIVIEW), in the assessment of anal sphincter integrity and thickness, both in pregnancy
and immediate postpartum.
Secondary objectives include:
Evaluation of the feasibility of new off-line analysis techniques.
Evaluation of the correlation between thickness and ultrasound integrity of the anal
sphincter at the postpartum visit and women's symptomatology in the postpartum.
To reduce bias as much as possible, each operator during each assessment will be
"blinded" to the patient's history and all other measurements.
Clinicians who perform more than one measurement per volume will do so at least one month
apart between each measurement.
The patient will be treated according to common clinical practice ensuring the standard
of care. Patients will not undertake additional visits to those routinely performed. This
is an evaluation of new techniques for off-line (in the absence of the patient) analysis
of ultrasound volumes that are currently part of routine visits in both pre and
postpartum.