Materials and Methods
We conducted a multicenter, retrospective and prospective, descriptive,
longitudinal study between 2016 and 2020.
Data
collection
Our study focused on three periods:
- Before 2016 : to assess the use of LVOT images before the
CNEOF update (introduction of the LVOT assessment).
- In 2017 : to assess practices after release of the update
- In the first quarter of 2020: to assess practices after
the introduction of, and guidance regarding quality criteria for LVOT
examination in the second half of 2019.
Our database consists of information from two tertiary centers (the
Saint Joseph Hospital in Marseille and the Groupe Hospitalier Sud
Réunion de Saint Pierre [GHSR]) and one primary center (an
ultrasound center in the Var). Images were retrieved from records via
the following:
- The Saint Joseph Hospital in Marseille: three doctors (one senior
expert and two senior experienced obstetricians), and one midwife
sonographer.
- The GHSR: three doctors (one senior expert, one senior experienced,
and one junior obstetricians), and one midwife sonographer.
- The Var screening centre: one experienced senior radiologist and one
midwife sonographer.
For each operator, we extracted, from the respective databases, images
relating to the LVOT corresponding to 15 examinations in the second and
third trimester, for all three periods. For each file that was randomly
examined, there were either no images, or one or more images. For the
latter, the best image for LVOT examination was selected.
The person responsible for retrieving these images referred to the
operators as A (senior expert), B (senior experienced obstetrician), C
(senior experienced obstetrician) and D (midwife) for the Saint Joseph
hospital; A (senior expert), B (senior experienced obstetrician), C
(young obstetrician) and D (midwife) for the GHSR; and A (senior
experienced radiologist) and B (midwife) for the Var center. Three files
(before 2016, in 2017, and in 2020) were thus created and contained data
on the practitioners’ examinations.
For each practitioner, there were 30 files, numbered T2-1 to T2-15 for
the 15 examinations in the second trimester and T3-1 to T3-15 for the 15
examinations in the third trimester for each of the three periods.
Data processing
Data were based on seven LVOT quality criteria proposed by Dr. E.
Quarello (EQ) in 2019 (11), defined by visualization of the
ANNEX 1 .
From the very start of our data collection, we asked all practitioners
to carefully read the information and explanatory sheets on the proposed
quality criteria (ANNEX 1 ). Three months later, we
evaluated the possible implementation of these criteria in their daily
practice through the study of images relating to examination of the LVOT
from 15 examinations in the second trimester and 15 examinations in the
third trimester, for these same sonographers during the first quarter of
2020.
Over the three periods, each image from the 10 practitioners’
examinations was rated for each of the seven quality criteria. The
ratings chosen were 0 or 1 depending on the absence or presence of the
quality criteria, respectively. The rating was carried out by a resident
specialising in gynaecology-obstetrics with a focus on foetal medicine,
Maud Regouin (MR). Thus, each image was scored out of seven points.
For all the images from each period, we attempted to identify the
position of the back of the foetus according to the following
classification (Figure 1 ):
- Position 1: foetal back between 12 o’clock and 3 o’clock
- Position 2: foetal back between 3 o’clock and 6 o’clock
- Position 3: foetal back between 6 o’clock and 9 o’clock
- Position 4: foetal back between 9 o’clock and 12 o’clock
To analyze inter-operator variability, 30 images were then arbitrarily
selected from the image bank and an expert (EQ) was asked to grade each
of them. These scores were compared to the scores from the trainee
doctor (MR) for the same set of images. To analyze intra-operative
variability of the junior doctor and expert (EQ), the 30 images were
analyzed again after more than 24 hours by the same respective doctors
and the scores were compared for the same set of images.
Data protection
All images were collected anonymously in each database. Only data that
was strictly necessary and relevant to the research objectives was
collected. All images were anonymised by the practitioners by removing
first and last names. Access to this database was confidential and
restricted to the direct users of the data.
Ethical and regulatory considerations
As this was non-interventional retrospective and prospective research
involving non-human data from a study in the health field, a simplified
MR004 procedure was granted with an agreement to comply with the
National Commission for Information Technology and Civil Liberties
(CNIL) (CNIL Reference 2219789 v 0) and registration of the project on
the Register of studies without CNIL authorization. Patients were
informed individually and in writing that ultrasound data from their
records could be used. Each patient was given the possibility of
declining the use of their data, by any means possible. In the event of
no reply, compliance was assumed.