GE Healthcare 6960-MON, 6961-MON Operators Guide

100-PT-056 rev1

A Guide to Monitoring Contractions with Monica Devices

Monica detects the electrical activity of the myometrium to monitor uterine contractions
(UC). Uterine electrical activity, consisting of infrequent and low amplitude EHG
(electrohysterography) bursts which occur throughout most of pregnancy, but do not
generally result in contractions that are perceived by the patient. In late pregnancy, these
bursts often correspond to periods of perceived contractility by the patient (Braxton Hicks
contractions). During both term labour and preterm labour, bursts of EHG activity are
frequent, of large amplitude, and are correlated with large changes in intrauterine pressure
and pain sensationi.

Monica reliably identifies UC during active labour. Currently it is not able to determine
contraction strengthii. In established labour, Monica EHG technology is more reliable and
has higher sensitivity than tocodynamometry
on occasion from various sources;

1. Low-level or uncoordinated EHG activity not associated with an increase in
intrauterine pressure appear as small irregular deflections from the baseline. These
are easily identified during labour among the larger more regular ‘true’ contractions.

2. Maternal activity or vigorous fetal movement can change maternal abdominal surface
contours and produce what appears on the trace to be a UC. This is caused by small
changes in the electrode positions in relation to each other and to the underlying skin.
This may create confusion particularly during antepartum and early induction
monitoring, when regular true contractions are not present.

iii iv

. Nevertheless false positive UC can occur

Before any definitive clinical interpretation of UC information generated by Monica is made,
ensure, if possible that the patient is not moving and is in a comfortable and relaxed
position. If there is concern about false positive contractions during early labour or
induction, it can be helpful to have the patient use the event marker either on the AN24 or
Doppler CTG monitor to indicate when she feels a contraction and/or the fetus move.

Irregular high amplitude ‘ragged’ looking contractions that are coincidental with fetal or
maternal movements with no other clinical indication of UC should be discounted. They are
unlikely to be real contractions. As such, they should not influence medical intervention
unless corroborated by another device.

Using Monica UC provides a wireless and beltless solution that is more comfortable for the
patient than tocodynamometry (TOCO). Once the electrodes are on the abdomen they do
not need to be readjusted. This is different from TOCO which often requires adjustment of
transducer position and belt tension. The belts themselves can be uncomfortable for the
patient. In addition, in obese patients tocodynamometry can be very difficult and Monica
can offer a solution in monitoring this cohort of womenv. TOCO does not provide an
accurate measurement of the intensity and duration of the uterine contractionsvi

vii viii ix x

.

When using either TOCO or Monica, interpretation of the UC pattern should be done in the
clinical context of the patient. It is always good practice to use manual palpation, maternal
perception of UC and observation in conjunction with any UC monitoring device.xi

xii

Monica Healthcare Ltd. Unit 8, Interchange 25 Business Park, Bostocks Lane, Nottingham, NG10 5QG, UK

www.monicahealthcare.com

Monica provides information on the:

- Frequency of contractions

Peak

Monica cannot be used to assess:

- Resting tone

Monica VS

Monica UC, FHR and MHR are all

5 seconds before

Monica UC cannot be used to coach patients to commence contraction pain coping strategies or

2. Flat baseline and smooth UA waveform:

Monica UC has a baseline that is flat and has a relatively smooth contraction waveform even when the

l wall may
occasionally produce a trace similar to a UC. Clinical assessment will distinguish these movement
artefacts from real contractions.

Monica VS

Monica VS

If the AN24 is moved (maternal movement) and

the UC trace as a change in colour (black to grey).
This indicates that caution in making clinical

- Timing of the contraction

- Duration of Contractions

- Intensity of the contraction

Important Features of Monica UC

1. Time delay:

Monica Novii (IF24)

The displayed
synchronised. However, to extract the UC waveform
there is delay of approximately 2
the UC is seen.

Note: These delays are not significant – thermal printers of fetal monitors can add delays of up to 30 seconds and

central viewing stations can vary up to 1 minute.

To extract the FHR, MHR and UC waveform
all signals are delayed equally by 10 (15)
seconds.

actively push in the second stage of labour. Its value lies in providing an accurate picture of the pattern
of uterine contractions over time. It is not of value in making instant real time assessment.

patient is actively pushing. Active fetal or maternal movements that shift the abdomina

3. UC trace markings when used with:

Monica Novii/IF24

None

An ‘M’ at the beginning of the recording and a
small vertical spike appears every 5 minutes on
the UC trace indicates that Monica is being used.

4. Maternal movement indicator when used with:
Monica Novii/IF24

If the Novii POD or AN24 is in motion for

lasts for longer than 20 seconds it is highlighted on

more than 20 seconds due to maternal
movement a dark zig-zag line will appear on

interpretation of the UC and FHR is required.

the UC tracing. This indicates that caution
in making clinical interpretation of the UC
and FHR during the 20 seconds prior to &

Monica Healthcare Ltd. Unit 8, Interchange 25 Business Park, Bostocks Lane, Nottingham, NG10 5QG, UK

www.monicahealthcare.com

during the dark line is required