To validate spectral analysis of the fHRV as a new method for fetal monitoring. To determine the exact influence on fHRV of several commonly used medicines in obstetric care; namely tocolytic drugs, corticosteroids, antihypertensive agents,…
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Source
Brief title
Condition
- Maternal complications of pregnancy
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Measurements are performed using ten self-adhesive electrodes, placed in a
fixed configuration on the maternal abdomen. A non-invasive electrophysiologic
monitor for obstetrics (NEMO), is used to record and store the electrical
activity on the maternal abdomen. The collected data will be analysed off-line.
The maternal electrocardiogram (ECG) is removed, without affecting the present
fECG-complexes. Sympathetic and parasympathetic activity are determined by
calculating the power in the low frequency (LF; 0.04-0.15 Hz) and high
frequency (HF; 0.4-1.5 Hz) spectral band, respectively. This energy can be
expressed in absolute units (LF and HF) or normalised units (LFn and HFn); for
more information; see protocol page 9.
We will conduct a baseline measurement (*0-measurement*), before administration
of the medicine or, when this is not feasible, after the effects of the
medicine is vanished. This will be determined by the half-life of the specific
medicine (for more information, see protocol chapter 3, page 11). Measurements
will be repeated at established time intervals, depending on the
pharmacokinetics of the specific medicine.
The primary study parameters are the differences in LF, LFn, HF, HFn and
LF/HF-ratio, that manifest in the measurements before and after administration
of the medicine. The expected changes are different for every used medicine,
and because of the lack of prior studies it is hard to predict these changes.
Because the measurements take 30-45 minutes, it is unlikely that these
differences are solely caused by fetal behavioural stages, fetal body movements
or compression of the umbilical cord.
Secondary outcome
As secondary analysis, we will conduct measurements of the maternal
electrohysterogram. This will be extracted from a electrode patch, placed on
the maternal abdomen. We will analyse the effect of the medication on the
uterine activity.
Postpartum, general information regarding the delivery will be obtained from
the obstetric caregiver at the time of delivery. This will be noted on a
separate *follow-up postpartum* file and constitutes the inclusion number of
the patient, date of birth of the child, gestational age at birth, birth
weight, sex, Apgar score (1, 5 and 10 minute score), postpartum events and
cardiac problems postpartum.
Background summary
Cardiotocography (CTG), the current method for fetal monitoring worldwide, has
a poor predictive value with regard to the detection of neonatal asphyxia.
There is an urgent need for a fetal surveillance method that provides reliable
information on fetal wellbeing, to prevent perinatal morbidity and mortality.
This method should obtain data non-invasively, so it can be applied antepartum
as well as durante partu and in fetuses in breech presentation. Especially in
(high risk) fetuses at risk for premature birth, the CTG is often indecisive
and reliable information on fetal wellbeing is important.
Recent research showed that additional information on fetal wellbeing can be
obtained by using spectral analysis of fetal beat-to-beat heart rate
variability (fHRV), calculated from non-invasive fetal electrocardiogram (fECG)
recordings. Hypoxia activates the autonomic nervous system, which modulates the
fetal heart rate (FHR). The low-frequency (LF)-component is both
sympathetically and parasympathetically mediated. The high-frequency
(HF)-component is solely parasympathetically mediated. The ratio LF/HF-power
provides a marker of the sympatho-vagal balance in the control of heart rate,
and can be used to monitor autonomic nervous system activity.
Spectral analysis of the fHRV seems to be a promising new field in antenatal
monitoring, but needs to be validated properly before its introduction in
clinical practice. An important aspect is the influence on fHRV of commonly
used medicines in obstetric care; amongst others tocolytic drugs,
corticosteroids, antihypertensive agents, medication used for sedation and pain
relief during labour.
Study objective
To validate spectral analysis of the fHRV as a new method for fetal monitoring.
To determine the exact influence on fHRV of several commonly used medicines in
obstetric care; namely tocolytic drugs, corticosteroids, antihypertensive
agents, medication used for sedation and pain relief during labour.
Study design
At first, this study will be performed as an observational pilot study, because
there is very little former research regarding the influence of tocolytic
drugs, corticosteroids, antihypertensive agents, medication used for sedation
or pain relief during labour on the spectral analysis of the fHRV. Later on, a
prospective longitudinal study will be designed.
Study burden and risks
There are no physical risks or side effects to the mother, fetus or third
parties. Allergy or irritation from the used electrodes is the only conceivable
problem as this is the only contact of the subject with the equipment. All of
the used equipment is approved by the Medical Technical Service Department of
the MMC in safety tests. In pregnant women, one must always bear in mind the
risk of aortocaval compression. From midpregnancy onwards, the enlarged uterus
compresses both the inferior vena cava ant the lower aorta when the patient is
lying in supine position(34). To prevent this from happening, the patient will
be placed in a semi-recumbent position or left lateral tilt position during the
measurements.
Sometimes patients are discharged from the Máxima Medical Center before
completion of the total study period (5 days in case of corticosteroid
administration). We will ask these patients if they want to participate in
performing the remainder of the measurements at their home or the hospital they
are referred to, in order to complete the study period.
De Run 4600
Veldhoven 5504 DB
NL
De Run 4600
Veldhoven 5504 DB
NL
Listed location countries
Age
Inclusion criteria
Pregnant women, carrying a healthy, singleton fetus with a gestational age between 20 and 42 weeks, receiving one or more of the following medicines; tocolytic drugs, corticosteroids, antihypertensive agents or medication for sedation or pain relief during labour. Patients receiving both tocolytic drugs and corticosteroids at the same time can participate in this study, since this is standard care nowadays. Also patients receiving antihypertensive agents and corticosteroids simultaneously can be included in this study. In this way, we will get information that is applicable in daily clinical practice.
Exclusion criteria
Women under the age of 18 years old, using other medicines than examined in this study, multiple pregnancies, women carrying a fetus with a known congenital malformation and fetuses with an intra-uterine growth restriction are excluded (defined as a fetal growth lower than p5 as estimated by echography). Fetal congenital malformations discovered after inclusion will be analysed separately.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL43294.015.13 |