Apparatus for relief of fetal distress during labor

The present invention relates to an apparatus for simultaneously monitoring intrauterine pressure and delivering infusible fluids therein for relief of fetal distress during labor with ruptured membranes. The apparatus comprises a catheter assembly having a first and second catheter and a guide tube for providing passage of the catheter assembly therethrough into the uterus.

TECHNICAL FIELD 
The present invention relates to an apparatus for simultaneously monitoring 
intrauterine pressure and delivering infusible fluids therein for relief 
of fetal distress during labor. More particularly, this invention relates 
to an apparatus comprising a catheter assembly having a first and second 
catheter and a guide tube for introduction into a body cavity. 
BACKGROUND OF THE INVENTION 
During labor, it is sometimes necessary to monitor intrauterine pressure to 
more accurately assess contractions, and to aid in the detection of fetal 
distress so that appropriate remedial action can be taken. A condition 
that is frequently associated with fetal distress during labor is variable 
decelerations owing to a state of oligohydramnios, i.e., the presence of 
less than 300 milliliters amniotic fluid at term. 
Loss of amniotic fluid is particularly of serious concern when it brings on 
a state of oligohydramnios during the intrapartum period of advanced labor 
with ruptured membranes. Amniotic fluid provides constant lubrication 
between the fetus, umbilical cord, and membranes. It also protects the 
fetus from external trauma and pressure by equalizing forces applied to 
the intrauterine contents. 
Consequently, without adequate intrauterine fluid volume, fetal distress 
may occur. This distress may result from umbilical cord occlusion by 
entrapment between the fetus and the uterine wall, entanglement about the 
fetus, or from placental compression. 
It is desirable, therefore, to maintain an adequate amniotic fluid volume 
in order to prevent these complications. Remedial action by intrauterine 
saline amnioinfusion therapy has been found useful for relieving fetal 
distress by replenishing intrauterine fluid volume to overcome the effects 
of oligohydramnios. 
A discussion of amnioinfusion therapy can be found in Miyazaki et al., 
Amer. J. Obstet. Gynecol., 146, pages 670-678, 1983, (hereafter Miyazaki 
I); in Miyazaki et al., Amer. J. Obstet. Gynecol., 153, pages 301-306, 
1985 (hereafter Miyazaki II); and in Gabbe et al., Amer. J. Obstet. 
Gynecol., 126, pages 353-355, 1976; and in Nageotte et al., Amer. J. 
Obstet. Gynecol., 153, pages 557-562, 1985. 
A fluid filled intrauterine pressure catheter is typically used to 
effectively measure uterine contractions to avoid introducing air into the 
uterus and to measure the force of the intrauterine contractions 
transmitted through the uterine fluids and the liquid in the catheter to a 
pressure-measuring device, such as a strain gauge, a transducer, or the 
like. 
In practicing amnioinfusion therapy, however, there is a need to 
simultaneously infuse fluids into the uterus and constantly monitor 
intrauterine pressure. As will be appreciated, this need particularly 
arises under emergency conditions, such as sudden severe prolonged 
decelerations. 
In the past, attempts were made in Miyazaki I to infuse saline into the 
uterus by means of the fluid-filled pressure catheter by placing an 
extension tube leading to the saline in the line intermediate the 
transducer and the intrauterine catheter. However, this setup resulted in 
artificial pressure readings owing to resistance to outflow of the saline 
through the tip of the catheter, and a true reading could only be taken by 
shutting off the infusion flow. 
As can be appreciated, under emergency conditions of sudden severe 
prolonged decelerations, it is necessary to rapidly infuse the uterus. 
Prior attempts with the setup described in Miyazaki II required connecting 
the intrauterine saline delivery tubing directly to the intrauterine 
pressure catheter, thereby foregoing the monitoring of the pressure 
altogether during saline delivery. Such a disability is a serious one, 
because the period of saline delivery is a period of flux, and it is 
especially necessary to monitor pressure during a period of flux. 
There is a need, therefore, for an apparatus that allows for simultaneously 
monitoring intrauterine pressure during labor and delivering infusible 
fluid therein. To resolve the difficulty noted above, this invention 
relates to an apparatus that achieves the foregoing purpose. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, an apparatus is disclosed that 
provides for simultaneously monitoring intrauterine pressure in the body 
during labor and delivering infusible fluids therein to relieve fetal 
distress. Generally, the apparatus comprises a flexible catheter assembly 
comprised of a first and second catheter and a flexible guide tube 
providing for passage of the catheter assembly through the vaginal and 
cervical canal into the uterus. Also disclosed herein is a method for 
practicing amnioinfusion therapy for relieving fetal distress with an 
apparatus of this invention. 
In an embodiment of the present invention, the catheter assembly is 
comprised of a first catheter defining a first lumen being in fluid 
communication with a first body end opening and a first distal end opening 
adapted for connection to a transducer or like pressure monitoring device, 
and a second catheter defining a second lumen being in fluid communication 
with a second body end opening and a second distal end opening adapted for 
connection to an infusion bag containing an infusible fluid. 
The respective lumens of the first and second catheters are preferably 
substantially circular in circumference. The first and second catheters 
are preferably substantially coterminous at their respective body end 
openings, being in substantially contiguous spaced relationship with their 
respective lumens parallel and in close proximity to each other along a 
substantially major portion of their respective paths intermediate their 
respective body end opening and the distal end opening. The lumens are 
further readily separable to be non-contiguous in their respective paths 
beyond the contiguous portion of the catheter assembly. 
In accordance with one aspect of the invention, the guide tube is open at 
both ends with a rearward opening for ingress of the catheter assembly and 
a rounded forward end opening for egress of the catheter assembly. The 
guide tube is configured to define a path within the body cavity of the 
vaginal and cervical canal of a human. The guide tube is also preferably 
substantially circular in circumference and sized to receive the catheter 
assembly and permit passage of the coterminous body end opening of the 
first and second catheters via the vaginal and cervical canal into the 
uterus. 
The catheter assembly is longer and more flexible than the guide tube, and 
the guide tube has an inner diameter large enough to permit passage of the 
catheter assembly therethrough with substantially no friction. The guide 
tube is further configured to slide rearwardly along the catheter assembly 
for removal from the vaginal canal once the catheter assembly is 
appropriately positioned. 
In a preferred embodiment, the first body end opening of the first catheter 
has a plurality of perforations along an external wall portion of the tip 
of said catheter positioned in the uterus. In actual practice, as 
described hereinbelow, the first and second catheter, prior to introducing 
them in utero, are flushed with fluid, such as sterile water, retaining 
fluid therein to minimize the likelihood of introducing air into the 
uterus. Additionally, the first catheter is sometimes flushed to clean it 
of intrauterine matter during amnioinfusion therapy. Towards this end, 
therefore, provision is further made for including a syringe means having 
its leading edge in fluid connection intermediate the first distal end of 
the first catheter and the transducer, and an adapter therefor. 
In carrying out the invention, the catheter assembly is further provided by 
an indicia intermediate the respective body end openings and distal end 
openings and located along the substantially contiguous portions of the 
respective paths of the first and second catheter for sounding the depth 
of positioning in the uterus. 
In one form of the present invention, the respective lumens of the first 
and second catheters of the catheter assembly are bonded in substantially 
contiguously spaced relationship along a parallel portion of their 
respective paths rearwardly of the coterminous body end openings and the 
second distal end opening of the second catheter. In manufacturing the 
apparatus of this invention, the lumens of the first and second catheter 
can be bonded as by a membrane, adhesive, molding sprue, or the like. The 
contiguous portion of the catheter assembly should be desirably bonded so 
as not to be readily separable at or near the respective body end openings 
of the first and second catheter rearwardly of the coterminous body end 
openings and the indicia. The lumens can be bonded with a weakening point 
along said bonding intermediate the indicia and their respective first and 
second distal end openings so as to be separable and non-contiguous in 
their respective paths. In another aspect of the present invention, the 
respective lumens of the first and second catheters of the catheter 
assembly are divided from each other by a common internal wall along the 
contiguous spaced parallel portion of their respective paths. 
One benefit of the present invention is that intrauterine pressure can be 
continuously monitored simultaneously with the delivery of infusible 
fluids therein during the practice of amnioinfusion therapy. 
Another benefit is that the catheter assembly, the guide tube, and their 
associated adapter fitments can be made of disposable materials and 
packaged in sterile condition for one-time use, thereby eliminating costly 
cleaning and lessening the chance of infection. 
Numerous other advantages and features of the present invention will become 
readily apparent from the following detailed description, the accompanying 
drawings, and the appended claims.

DETAILED DESCRIPTION OF THE INVENTION 
While this invention is susceptible of embodiment in many different forms, 
there is shown in the drawings, and will herein be described in detail, a 
specific embodiment, with the understanding that the present disclosure is 
to be considered as an exemplification of the principles of the invention 
and is not intended to limit the invention to the embodiment illustrated. 
Referring first to FIG. 1, therein is illustrated the apparatus 10 
embodying the principles of this invention in operation for practicing 
amnioinfusion therapy for the intrauterine relief of fetal distress in the 
body during labor. In this illustrated embodiment, the apparatus 10 is 
shown with the catheter assembly 12 positioned so that the first body end 
opening 14 of the first lumen 16 of the first catheter 18 and the second 
body end opening 20 of the second lumen 22 of the second catheter 24 are 
in the uterus 66. 
In this illustration, the catheter assembly 12 has already been advanced 
through the guide tube 26 (not shown) through the vaginal and cervical 
canal (not shown), sounding the placement in the uterus by an indicia 46 
(not shown) intermediate their respective body end openings 14 and 20 and 
their non-contiguous respective paths 68 and 68'. The first catheter 18 
and the second catheter 24 of the catheter assembly 12 are shown in 
substantially contiguously spaced relationship 28 with their respective 
lumens 16 and 22 parallel and in close proximity to each other along a 
major portion of their respective paths rearward of their respective body 
end openings 14 and 20. 
The guide tube 26 being removed from the body cavity following introduction 
of the catheter assembly 12 is adapted to slide rearwardly along the 
length of the catheter assembly 12 to a point beyond the contiguous 
portion 28 of the first catheter 18 and second catheter 24. Thus, the 
guide tube 26 can be positioned, shown in phantom line, near the first 
distal end opening 30 of the first catheter 18 so as not to obstruct the 
connection of the second distal end opening 32 of the second catheter 24 
to the infusion bag 34 containing infusible fluid 35, such as normal 
saline, or like physiologically compatible fluid. 
Alternatively, the guide tube 26 can be removed completely from the 
catheter assembly 12 prior to connecting the first distal end opening 30 
of the first catheter 18 with a transducer 36 or like pressure monitoring 
device. Preferably, the guide tube 26 can be scored laterally along at 
least one lateral side to provide a weakening point to break away under 
relatively mild pressure, such as squeezing or twisting, for easy removal 
and disposal. 
In the illustrated embodiment of FIG. 1, the first catheter 18 is further 
provided with a first adapter 38, such as a needle-nose type adapter, for 
connection to a first fluid control valve means 40 intermediate the 
connection of the first distal end opening 30 and the transducer 36. For 
purposes of flushing the first catheter with a sterile fluid, such as 
water, a syringe 42 is provided with its leading edge 44 in fluid 
connection with the first fluid control valve means 40. 
The first and second catheter 18 and 24 are preferably flushed with sterile 
fluid, such as water, prior to inserting the catheter assembly 12 into the 
uterus to minimize introducing air into the uterus and to provide for 
transmitting the force of the intrauterine contractions through the fluid 
remaining in the first catheter 18 to the transducer 36. The syringe 42 
can also be used to flush the first catheter 18 in the event the 
perforated first body end opening 14 of the first catheter 18 accumulates 
intrauterine fluids during contractions. When the first catheter 18 is 
being so flushed or filled, the transducer 36 is vented, and for that 
purpose, a venting control valve means 48 is further provided. 
Turning now to FIG. 2, a lengthwise view of the catheter assembly 12 
portion of the apparatus 10 shown on FIG. 1 is illustrated. As best shown 
in FIG. 2, the catheter assembly 12 is comprised of a first catheter 18 
defining a first lumen 16 being in fluid communication with a first body 
end opening 14 and a first distal end opening 30 and a second catheter 24 
defining a second lumen 22 being in fluid communication with a second body 
end opening 20 and a second distal end opening 32. In a preferred 
embodiment illustrated in FIG. 2, the distal end opening of the first 
catheter 30 is substantially longer than that of the distal end opening of 
the second catheter 32. 
The body end opening 14 of the first catheter 18 is further provided with a 
plurality of perforations 50 (one indicated) along the external wall of 
the tip portion of the first body end opening 14. The perforations 50 are 
in fluid communication with the first lumen 16 of the first catheter 18, 
and are sufficient in number to permit the measure of intrauterine fluid 
pressure transmitted therethrough. Preferably, these perforations are 
located along a portion of the tip of the first catheter 18 of about 3 to 
about 7 centimeters, more preferably about 5 centimeters. The respective 
lumens 16 and 22 of the first catheter 18 and the second catheter 24 are 
substantially circular in circumference, and the first catheter 18 and 
second catheter 24 are substantially coterminous at their respective body 
end openings 14 and 20. 
The catheter assembly 12 is preferably manufactured and packaged so that 
the first catheter 18 and second catheter 24 are with their respective 
lumens 16 and 22 parallel and in close proximity to each other along a 
substantially major portion of their respective paths rearwardly of their 
respective body end openings 14 and 20 and the distal end openings 30 and 
32. The catheter assembly 12 is further provided by an indicia 46 
intermediate the body end openings 14 and 20 and the distal end openings 
30 and 32 of the substantially parallel portions of the respective paths 
of the first catheter 18 and second catheter 24 for sounding the depth of 
their respective body end openings 14 and 20 in the uterus. The indicia 46 
is preferably positioned at a point sufficient to mark a distance from the 
vaginal introitus (not shown) to the coterminous body end openings 14 and 
20 of the catheter assembly 12 when it is introduced into the uterus (not 
shown). A useful distance for positioning the indicia 46 is at about 18 to 
about 25 percent, preferably at about 20 to about 22 percent of the length 
of the first cathether 18, rearwardly of the first body end opening 14. 
The indicia can be a permanent marking, such as an indelible black marking 
or any like readily visible marker. 
In the embodiment illustrated in FIG. 2, the respective lumens 16 and 22 of 
the first and second catheter 18 and 24 are bonded in substantially 
contiguous spaced relationship 28 along a parallel portion of their 
respective paths rearwardly of their coterminous body end openings 14 and 
20 and the second distal end opening 32 of the second catheter 24. The 
respective lumens 16 and 22 of the first and second catheter 18 and 24 are 
preferably in contiguous spaced relationship so as not to be readily 
separable at or near the body end openings 14 and 20 rearwardly of the 
coterminous body end openings and the indicia 46. More preferably, the 
respective lumens 16 and 22 of the first and second catheters 18 and 24 
are in contiguous spaced relationship rearwardly of the indicia 46 to a 
location 52 beyond which the lumens 16 and 22 of the first and second 
catheters 18 and 24 are non-contiguous 68 and 68' (shown in phantom line) 
and are readily separable at their respective distal end openings 30 and 
32. For this purpose, the catheter assembly 12 can be provided with a 
readily disposable securing member 54 at or near the second distal end 
opening 32 of the second catheter 24 that can be readily removed and 
disposed of when the catheter assembly 12 is ready for use. 
In a particularly preferred embodiment of the type illustrated in FIG. 2, 
the first and second catheters 18 and 24 are in substantially contiguous 
spaced relationship along a major portion of their respective lengths 
representing about 40 to about 50 percent of the length of the catheter 
assembly 12 rearwardly of the first body end opening 14 of the first 
catheter 18, and the non-contiguous portion 52 of the catheter assembly 
12. The non-contiguous portion represents about 20 to about 25 percent of 
the length of the second catheter 24 forwardly from the distal end opening 
32. It will be appreciated that the portions of contiguous and 
non-contiguous lengths of the catheter assembly 12 can be determined on 
the basis of convenience and safety. 
In one embodiment that is particularly preferred, the path of the first 
lumen 16 of the first catheter 18 is about 1.5 to about 1.75 times longer 
than the path of the second lumen 22 of the second catheter 24, with a 
contiguous portion representing a path of about 75 to about 85 percent 
rearwardly of the respective coterminous body end openings of the first 
and second catheter 18 and 24 and the first distal end opening 30 of the 
first catheter 18. The catheter assembly 12 is preferably about 5 to about 
10 times the length of the guide tube (not shown). 
FIG. 3 is an enlarged lengthwise, sectional perspective view of the 
coterminous body end openings 14 and 20 of the first and second catheters 
18 and 24 shown in FIG. 2 received in the rounded forward end opening 27 
of the guide tube 26. The diameter of the guide tube 26 is large enough to 
permit passage of the catheter assembly therethrough, with substantially 
no friction therebetween. Preferably, the coterminous body end openings 14 
and 20 of the first and second catheters 18 and 24 are rounded to minimize 
adhering to tissue and to facilitate maneuverability within the uterus. 
FIG. 4 is an enlarged cross-sectional view of the coterminous body end 
openings 14 and 20 of the first and second catheters 18 and 24, taken 
substantially along the line 4--4 of FIG. 3. As can be seen in FIG. 4, the 
respective lumens 16 and 22 of the first and second catheters 18 and 24 
are substantially circular in circumference, and the guide tube 26 is 
configured in a substantially circular circumference for receiving the 
catheter assembly 12. In the embodiment illustrated in FIG. 4, the first 
and second catheters 18 and 24 define lumens 16 and 22 of equal internal 
cross-sectional diameter. A particularly preferred internal diameter is 
about 2 millimeters. In the embodiment shown in FIG. 4, the lumens 16 and 
22 are bonded at their contiguous portion 28 in the manner described 
previously. 
FIG. 5 is an enlarged cross-sectional view similar to FIG. 4, but 
illustrating a further embodiment of the respective body end openings 14 
and 20 of the catheter assembly 12 where the respective lumens 16 and 22 
of the first and second catheters 18 and 24 are divided from each other by 
a common internal wall 70 along the contiguous parallel portions of their 
respective paths. In this embodiment, the paths of the respective lumens 
16 and 22 of the first and second catheters 18 and 24 are separable beyond 
the contiguous portion by a separating juncture (not shown) located as 
shown in FIG. 2 at 52. The respective lumens 16 and 22 as shown are 
substantially semicircular, but can be circular in circumference. A 
particularly preferred embodiment has an exterior wall 58 and 58' 
thickness of about 0.4 millimeters and an internal wall 70 thickness of 
about 0.8 millimeters along the contiguous portion. 
It will be appreciated that the overall external circumferential diameter 
of the catheter assembly should be the smallest possible capable of 
practicing the principles of this invention so as to minimize interference 
with delivery of the fetus and to minimize the chance of perforating the 
uterus. A particularly desirable useful circumferential dimension for the 
catheter assembly is about 5.6 millimeters by 2.8 millimeters and for the 
guide tube of about 8 millimeters by 5 millimeters. A useful wall 
thickness for the first and second catheters is about 0.4 millimeters, and 
a useful wall thickness for the guide tube is about 1 millimeter. A useful 
internal dimension for the guide tube is about 6 millimeters by 3 
millimeters, and a useful path length for the guide tube is about 20 to 
about 26 centimeters. Preferably, the guide tube is arcuate in 
configuration at its forward end opening portion. 
The apparatus of this invention is preferably made of disposable, flexible, 
substantially translucent polymeric material. It will be appreciated that 
the materials used in manufacturing the apparatus of this invention and 
fitments operatively associated therewith are non-toxic and 
physiologically compatible with body fluids and tissues, such as 
polypropylene or polyethylene, and are packaged in sterile condition for a 
one-time use. 
While the respective body end openings of the first and second catheters 
are illustrated as being substantially coterminous, it is recognized that 
they could be in stepped relationship to each other. However, a stepped 
relationship is not a preferred embodiment because it increases the risk 
of perforating the uterus and causing infection. 
The apparatus of this invention has certain conventional fitments, the 
details of which, though not fully illustrated or described, will be 
apparent to those having skill in the art and an understanding of the 
necessary function of such fitments. 
Briefly described, a method aspect for practicing amnioinfusion therapy 
with an apparatus of this invention comprises the steps of 
providing an apparatus of this invention comprised of a catheter assembly 
and a guide tube as described herein before; 
providing a fluid-filled catheter assembly thereof by flushing the 
respective first and second catheters of the catheter assembly with a 
sterile fluid to retain fluid therein; 
receiving the coterminous body end openings of the fluid-filled catheter 
assembly in the guide tube within the body cavity of the vaginal canal 
through the cervical canal; 
introducing the fluid-filled catheter assembly into the uterus by advancing 
the catheter assembly through the forward end opening of the guide tube; 
removing the guide tube; 
separating the second distal end opening of the second catheter from the 
path of the first distal end opening of the first catheter; 
adapting the first distal end opening of the first catheter in operative 
association with a transducer; 
adapting the second distal end opening of the second catheter in sterile 
operative association with an infusion bag containing a sterile infusible 
fluid; and 
monitoring intrauterine fluid pressure transmitted through the first lumen 
of the first catheter and delivering the infusible fluid through the 
second lumen of the second catheter of the catheter assembly. 
In practicing the above method, the guide tube can be removed in the 
removing step by sliding the guide tube rearwardly from the coterminous 
end openings of the catheter assembly to a point beyond the second distal 
end opening of the second catheter. Alternatively, the guide tube can be 
provided with a weakening point along a lateral wall, such as by a scored 
line. In this instance, the guide tube can be removed in the removing step 
by sliding it rearwardly from the coterminous body end openings of the 
catheter assembly to a point beyond the body cavity and then removing the 
guide tube from the catheter assembly by applying relatively mild pressure 
at the weakening point. 
A particularly preferred method aspect for relieving fetal distress during 
the intrapartum period of advanced labor with ruptured membranes in a 
human body comprises the steps of: 
providing an apparatus of this invention comprising 
(1) a flexible catheter assembly comprised of a first catheter and a second 
catheter with their respective first and second lumens parallel and in 
close proximity to each other along a contiguous portion of about 40 to 
about 50 percent of their coterminous respective paths rearward of their 
respective first and second body end opening and first and second distal 
end opening, the respective distal end openings of the first catheter and 
second catheter being readily separable in their non-contiguous spaced 
position, the catheter assembly being further provided with an indicia at 
a distance of about 18 to about 25 percent of the length of the first 
catheter rearwardly of its body end opening, and 
(2) a flexible guide tube open at both ends having a rearward end opening 
for ingress of the catheter assembly and a rounded end opening for egress 
of the catheter assembly; 
providing a fluid-filled catheter assembly thereof by flushing the first 
catheter with sterile water through its first distal end opening, flushing 
the second catheter with sterile water through its second distal end 
opening; 
sealing the second distal end opening of the resulting fluid-filled second 
catheter with a temporary cap to maintain sterility until use; 
receiving the coterminous body end openings of the first and second 
catheters of the fluid-filled catheter assembly in the guide tube 
intermediate the rearward end opening and the forward end opening of the 
guide tube; 
advancing the fluid-filled catheter assembly and guide tube within the body 
cavity of the vaginal canal through the cervical canal; 
introducing the coterminous body end opening of the first and second 
catheters of the catheter assembly via the vaginal and cervical canal into 
the uterus by advancing the catheter assembly through the forward end 
opening of the guide tube until the egress of the catheter assembly 
therethrough brings the indicia to the vaginal introitus; 
removing the guide tube from the vaginal canal; 
sliding the guide tube rearwardly along the catheter assembly to a point 
beyond the contiguous portion of the catheter assembly; 
securing the catheter assembly to a portion of the human body, such as the 
thigh or abdomen, intermediate the indicia and the guide tube; 
sliding the guide tube rearwardly beyond the second distal end opening of 
the second catheter; 
separating the second distal end opening of the second catheter from the 
path of the first distal end opening of the first catheter; 
adapting the first distal end opening of the first catheter for connection 
in operative association with a transducer and providing a syringe having 
its leading edge in fluid communication with a first fluid control valve 
means intermediate the first distal end opening of the first catheter and 
the transducer; 
removing the temporary cap from the distal end opening of the second 
catheter; 
adapting the second distal end opening of the second catheter for 
connection in operative association with an infusion bag containing an 
infusible fluid by providing a sterile second fluid control valve 
intermediate the distal end opening of the second catheter and the 
infusion bag; 
monitoring intrauterine pressure transmitted through the first lumen of the 
first catheter operatively associated with the transducer; and 
delivering infusible fluid to the uterus through the second lumen of the 
second catheter operatively associated with the infusion bag when 
necessary to replenish the intrauterine fluid. 
The practice of the method of this invention can also include the further 
steps of providing the transducer with a venting control valve means, 
venting the transducer for a period sufficient to flush the first catheter 
with a sterile fluid, preferably water, by means of the syringe, to clear 
the first catheter in the event that the intrauterine fluids accumulate 
therein during the monitoring step, and resuming monitoring immediately 
thereafter. Thus, intrauterine pressure can be monitored throughout the 
labor in a virtually substantially uninterrupted manner. 
From the foregoing, it will be observed that numerous modifications and 
variations can be effected without departing from the true spirit and 
scope of the concept of the present invention. It is to be understood that 
no limitation with respect to the specific embodiments disclosed herein is 
intended or should be inferred. It is, of course, intended to cover, by 
the appended claims, all such modifications as fall within the scope of 
the claims.