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Fetal monitoring: Its effect on the perinatal mortality and cesarean section rates and its complications
Fetal monitoring: Its effect on the perinatal mortality and cesarean section rates and its complications GINO
TUTERA,
ROBERT
L.
h’ansas
City,
M.D. NEWMAN,
M.D.
Missouri
fcfui monitoring was employed in 608 patients, 96 per cent of whom were thought to bc at “hi,
0 N E 0 F T H E P R I M E objectives Of any practitioner of obstetrics is reduction of the perinatal mortality rattk. Evaluation of amniotic fluid, serial maternal estriol levels, and other laboratory and clinical paramc’ters have given us insight into the antepartum environment, as well as guidelines to follow to evaluate intrauterine development and well-being. With the advent of intrauterine fetal monitoring, the obstetrician now possesses the ability of direct measurement of the intrauterine environment. Direct measurement of the intrapartum environment consists of: ( I ) measurement of the intrauterine pressure (IUP) by catheter placement in the amniotic sac, and (2) continuous fetal heart rate (FHK) monitoring by a fetal scalp electrode. This method of monitoring allows the obstetrician the opportunity to watch the effect of the stresses of labor on the fetus and response of the fetus to those stresses. From
St. Luke’s
Supported Medical
Presented Noz,ember Rec&ed Revised Accepted
to the Kansas 15, 1973.
City
for publication
October
Material
Foundation
Gynecologic
August
and
methods
Fetal monitoring was accomplished with the use of two monitors.* Roth monitors were equipped with self-recording equipment. Intrauterine pressure was measured by placement of an intra-amniotic polyethylene catheter with the use of a sterile technique. Catheter application was done solely by the vaginal transcervical method. The catheter applications at first \zere done in the delivery suite with the patient in obstetric stirrups, but, with the increased experience of the house staff, the majority of the applications were done in the labor rooms with a sterile technique. The fetal electrocardiogram (FECG) and FHR are monitored by application of a fetal scalp electrode. The clamp electrode was used at first, but, with the development of the spiraltype electrode and its ease of application, th? clamptype electrode was abandoned. Fetal monitor strips were taken and interpreted by the patient’s physician and/or the house officer in attendance. The indications for monitoring and, assessment of the monitor
Hospital.
by St. Luke’s Hospital Education and Research.
October
The purpose of this paper is to report the direct fetal monitoring experience of a university-affiliated community hospital’s obstetric service. This report will disruss the effect of direct fetal monitoring on the perinatal mortality rate, cesarean section rate, and Apgar scores and the difficulties and complications encountered with its utilization.
for Society,
6, 1974.
17, 1974. 17, 1974.
Reprint requests: Dr. Gino Tutera, Medical Education and Research, St. Luke’s Hospital, Wornall Rd. at Forty-fourth, Kansas City, Missouri 641 I I.
*Models Inc., 2 necticut
750
101 Barnes 06492.
and 102, Industrial
Corometrics Park Rd.,
Medical Wallingford,
Systems, Con-
Volume Number
122 6
Fetal
NAME:
751
DATE:
P.F.
8
AGE:
ADDRESS: REASON FACTORS
COMPLICATION Premature Abruptio
Decreased Increased
OF PREGWNCY
METHOD
III.
II.
AFTER VALUE
-Electrode Electrode Catheter Specify Unable
Changes Compression Compression
-Cord -u.p.1. Acceleration Baseline Changes Tachycardia -Bradycardia
THE APGAR
OTHER
(SPECIFY)
(State)
MONITORING OF MONITOR
( Be Critical
Application Dislodged Malfunction Any Equipment to Interpret
BIRTH 1 Minute
SCORE:
Poor Progress; suspected CPD Prev C-section Uterine Anomaly Multiple Gestation Assess Oxytocin Augmentation Oxytocin Induction
)
PROBLEMS
TYPE DELIVERY SCORE:
FACTORS
Demonstrated Fetal Distress Avert C-section Decrease Anxiety of Obstetrician -Better Assessment of Labor No Value Misleading (State Why)
pressure
Normal
APGAR
Request Study
Special
IV.
Head
UTERINE
Demonstration
FHR OBSERVATIONS
Periodic
III.
VI.
-Patient
USED
External Technique -FECG, FHR, & I.U. FECG, FHR only z1.u. pressure only
COMPLICATIONS
-ELECTIVE
v-
COMPLETE I.
MATERNAL
Toxemia Diabetes Anemia Heart Disease Rh Isoimmunization Prev Perinatal Death -Elderly Primigravida Grandmultiparity
Rupture Membranes Placenta Placenta Previa Cord 3rd Trim. Bleeding
-Partial -Prolapsed Undeter. Amnionitis
FOR MONITORING
II.
Bradycardia Tachycardia Irregularity Meconium Passage -Fetal Activity Fetal Activity -Breech Presentation Prematurity Postmaturity Dx Fetal Viability IV.
WKS GEST
PHONE:
FETAL
I.
V.
monitoring
(X's) or Technical FHR Patterns
WT.
Problems
SEX 5 Minute
Higher Than As Anticipated Lower Than M.D.
Fig. 1. Fetal monitor history sheet.
pattern and the value of the particular monitoring experience were recorded on individual data sheets (Fig. 1 i .’ On the data sheets, the method of delivery, .\pgar rating (at one and five minutes), and sex and xveight of the infant were also included. In our study, monitored patients were from the private and house staff services. House staff services accounted for 25 per cent of the total volume: however, 75 per cent of the monitored patients were
from the house staff service. The duration of the study extended from May, 1969, until May, 1973. During this time, 6,787 patients were delivered of infants, and 608 patients were monitored, for an incidence of 9 per cent. The incidence of monitoring is low, but this is a report on our initial experience with direct fetal monitoring. Our most recent study showed that nearly 98 per cent of our patients are now monitored. With
7.52 ‘Peru
and
-_-_,.;_,..q-:
Newmcr
Am.
Table 1. Indications for monitoring (listed decreasing order of frequency per category)
in
Fetal factors
Unmonitored group (6,Z Perinatal (per 1,000 Neonatal (per 1,000 Fetal, before admission Fetal, after admission
Uterine factors Poor progress, suspected cephalopelvic disproportion Assess oxytocin induction Assess oxytocin augmentation Attempted vaginal delivery following previous cesarean section Multiple gestation Uterine anomaly Maternal complications Toxemia Diabetes Previous perinatal death Rh isoimmunization Sickle cell anemia Seizure disorder Elderly primigravida Miscellaneous-hyperthyroidism, collagen disease, drug addiction, etc. Complications of pregnancy Premature rupture of membranes Falling estriol levels Amnionitis Undetermined third-trimester bleeding Polyhydramnios
most common
in
morn
indications
Poor progress, suspected cephalopelvic Assess oxytocin usage Premature rupture of membranes Toxemia Prematurity Fetal bradycardia Meconium passage
for
disproportion
the exception of 27 patients monitored for demonstration purposes only on a purely elective basis, all other patients were considered at “high risk.” The indications for monitoring were separated into fetal factors, uterine factors, maternal complications, and complications of pregnancy (Table I). In over 95 per cent of the cases, at least two indications were noted on each individual data sheet. Table II demonstrates the most common indications for monitoring, all categories considered. In our series of 608 patients, 62 patients underwent primary cesarean section, for an incidence of 10.1 per cent. This is a significant increase over
: ( \ncc;l
torecl
Prir,ate house
Deaths
Postmaturity Prematurity Meconium passage Bradycardia Cardiac irregularity Diagnosis of fetal viability
Table II. The monitoring
rate
Table III. Perinatal mortality and unmonitored groups
J. Ohatr
and itaff
79 patients) births) births) (per 1,000 births) (per 1,000 births)
1!I il .i 6
Monitored group (608 patients) Perinatal (per 1,000 births) Neonatal (per 1,000 births) Fetal, before admission (per 1,000 births) Fetal, after admission (per 1,000 births)
8 0 6 2
Table
IV. Apgar
Apgar
scores
(live-born
infants) No.
score
One
minute l-3 4-6 7-10 Five minutes l-3 4-6 7-10
Table Birth
‘4 55 529 0 6 602
V. Results in monitored
weight (Cm.)
No. of infants
500-1,000 l,OOO-1,500
1 6
1,500~2,000 2,000-2,500 2 2,500
25 63 518
Total
613s
*Five
group Fetal/neonatal deaths 1 1 2 1
Fetal death in utero Neonatal death Fetal deaths in utero Fetal death in utero
sets of twins.
the primary cesarean section rate in the unmonitored group of 4.8 per cent, with the over-all cesarean section rate in the unmonitored group being 6.3 per cent. The over-all cesarean section rate in our institution over the past five years has been 5.1 per cent. Thirty-three of the cesarean sections in the study group were done for fetal distress (fetal distress is defined as patterns of late or variable deceleration with an FHR of 90 or below that were not corrected by change of position or nasal oxygen or both in 30 minutes) although there were 107 additional patients who were delivered vaginally despite monitor patterns indicating fetal distress. The 107 cesarean sections that were averted can be directly attributed to the employment of the fetal monitor.
Volume Numbpr
122 6
The physicians in attendance were able to detect and correct the types of distress patterns (variable and/or late deceleration) by employment of nasal oxygen and/or positional change. Fifty-one per cent of the primary cesarean sections in our study group were done for fetal distress. This differs from Paul’s’ study in which the primary indication for cesarean section was poor progress in labor with suspected cephalopelvic disproportion. The perinatal mortality rate for all deliveries in our institution over the last five years has been 19 per 1,000, including study yrars. During the period of this particular investigation, the mortality rate was unchanged in the unmonitored group. Table III demonstrates the breakdown of the perinatal mortality rate in the monitored and unmonitored groups. In the monitored groups, only one fetal death occurred after admission, giving a mortality rate of 2 per 1.000 live births. Four fetal deaths occurred before admission and are included in the statistics for the monitored group since the monitors were used to detect fetal viability and gauge uterine contractility during oxytocin usage. The low mortality rate and, specifically, the fact that only one fetal death occurred after admission speak well not only of fetal monitoring but also for the aggressive management of these high-risk patients by both the obstetricians and neonatologists. Apgar scores were recorded for the 608 live-born infants at one- and five-minute intervals (Table IV). Five hundred and twenty-nine infants had Apgar scores of 7 to 10 at one minute; 55 infants had one-minute Apgar scores of between 4 and 6; 24 live-born infants had Apgar scores between 1 and 3. Of the 79 infants with c\pgar scores of 6 or below, only six had five-minute Apgar scores of 6 or below. In 70 infants the Apgar scores were as anticipated; nine infants had Apgar scores lower than anticipated. In all 79 cases, evidence of fetal distress was present. The logical conclusion would be that fetal monitor patterns do give an estimate of frtal well-being and should alert the obstetrician to be ready for resuscitation of the distressed infant. In addition, the obstetrician now has the capability to reduce the number of distressed infants taken care of by the neonatologist. Table V gives a distribution of the monitored infants in relation to birth weight in grams. Of interest is that nearly one sixth of the patients were below 2,500 grams and that all fetal deaths occurred in infants below 2,000 grams. Obviously, a monitored infant, even in the premature weight
Fetal
monitoring
753
range, has a better chance of survival because monitoring affords the obstetrician the opportunity to eliminate or reduce stresses imposed upon an already high-risk fetus. Technical
ditlkulties
and
complications
The most common technical difficulties encountered were minor. The one found most often was malfunction of the intrauterine catheter which usually was caused by “plugging up” of the catheter by vernix or small blood clots. This usually required simple irrigation with sterile saline or bacteriostatic water to re-establish function of the catheter. If these efforts failed, catheter application was repeated. Problems with dislodgement of fetal scalp electrodes were nearly eradicated following the availability of the spiral-type electrode. This type of scalp electrode was surprisingly easy to apply, with no more discomfort to the patient than that from a routine vaginal examination. The additional advantage of this electrode is application by palpation, with only fingertip cervical dilatation necessary; in contrast, the clamp-type electrode necessitated direct visualization through a vaginal cone, causing increased vaginal discomfort to the patient. Patient discomfort with application of both the intrauterine catheter and fetal scalp electrode decreased markedly with increased experience pf catheter application by the house staff and by improvement of the equipment utilized. Patient discomfort resulted from producing inducement of uterine contractions, “labor pains.” This was primarily during the application of intrauterine catheters. Complications associated with the use of the fetal monitor are as follows: (1) uterine perforation by the uterine catheter, (2) cephalohematoma for2 mation secondary to scalp electrode application with or without resultant scalp abscess formation.” and (3) puerperal pyrexia.“, r, Uterine perforation occurred once in our series. The diagnosis was made when the catheter became palpable abdominally. Cesarean section was performed because of pre-existing fetal distress, and the perforation was found in the posterior portion of the lower uterine segment. A viable infant with a one-minute Apgar score of 6 was delivered, and intraperitoneal bleeding was estimated to be 25 to 50 C.C. The uterine perforation was closed easily with chromic suture; the patient’s postoperative course was uneventful. Cephalohematoma occurred after scalp electrode . . . application m two Infants, one of which resulted in abscess formation. The one infant with the cephalo-
hrmatoma did well with conservative therapy; the inf,ant with scalp abscess formation was treated with antibiotic therapy, surgical incision, and drainage and recovered uneventfully. These two complications occurred with the clamp-type electrode; with the employment of spiral electrodes, no further problems have occurred. No other fetal complications were encountered. In no instance was chorioamnionitis, amnionitis, or puerperal pyrexia exceeding 100.4’ F. after the first 24 hours post partum found to occur following intrauterine catheter placement that was not existing at the time of catheter placement. This is certainly indicative of the near absence of complications associated with fetal monitoring. Comment Reduction of the perinatal mortality rate is one of the most important goals in obstetrics. A significant reduction in fetal loss can be accomplished in the intrapartum period by the continuous monitoring of the fetal heart rate. The ability to monitor the effects of labor on the fetus will lead to delivery by the appropriate method of any “distressed fetus.” In this series the direct method of fetal monitoring significantly reduced the perinatal mortality rate in monitored high-risk patients. The impressive reduc-
tion of perinatal deaths has resulted in application of a fetal monitor to all patients who are admitted to our obstetric unit. This has been facilitated bv the acquisition of additional monitors equipprd w-ith ultrasound Doppler-type fetal heart rate detectors. These results certainly can only encourage The employment of fetal monitors in any hospital with an obstetric unit, especially in any center that deals with a large high-risk population. With the ability to detect the distressed fetus. the appropriate type of delivery can be chosen with objective evidence as to the status of fetal well-being at a particular stage of labor. This should reduce the number of unnecessary cesarean sections, but it should not imply that a reduction in the cesarean section rate will occur. On the contrary, a rise in the cesarean section rate should probably be expected. The future of fetal monitoring obviously is a bright one. The development of the new ultrasound external monitors will allow indirect monitoring of any patient, even prior to rupture of the amniotic membrane. With the widespread employment of fetal monitors, one of the goals of the obstetrician, i.e., reduction in the perinatal mortality rate, should be achieved.
REFERENCES
1. Data sheets utilized at the University of Southern California, Los Angeles County Hospital. 2. Paul, R. H.: Clinical fetal monitoring, AM. J. OBSTET. GYSECOL. 113: 573, 1972. 3. Cordero, L., Jr., and Hon, E. H.: Scalp abscess: A rare complication of fetal monitoring, J. Pediatr. 78: 533, 1971.
Note The
to Authors: Editors
and
Change Publisher
have
in Reference agreed
to add
4. 5.
Paul, R. H., and Hon, E. H.: A clinical fetal monitor, Obstet. Gynecol. 35: 161, 1970. Beard, R. W., Brudenell, J. M., Feroze, R. M., et al.: Intensive care of the high risk fetus in labour, J. Obstet. Gynaecol. Br. Commonw. 78: 882, 1971.
Style
the article title to references in the AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY. References will now conform to the style of the Cumulated Index Medicus, viz., name of author, title of article, name of periodical, volume, page, and year. Authors are always encouraged to limit references to sixteen for the following JOURNAL sections: Obstetrics, Gynecology, and Fetus, Placenta, and Newborn.
TUTERA,
ROBERT
L.
h’ansas
City,
M.D. NEWMAN,
M.D.
Missouri
fcfui monitoring was employed in 608 patients, 96 per cent of whom were thought to bc at “hi,
0 N E 0 F T H E P R I M E objectives Of any practitioner of obstetrics is reduction of the perinatal mortality rattk. Evaluation of amniotic fluid, serial maternal estriol levels, and other laboratory and clinical paramc’ters have given us insight into the antepartum environment, as well as guidelines to follow to evaluate intrauterine development and well-being. With the advent of intrauterine fetal monitoring, the obstetrician now possesses the ability of direct measurement of the intrauterine environment. Direct measurement of the intrapartum environment consists of: ( I ) measurement of the intrauterine pressure (IUP) by catheter placement in the amniotic sac, and (2) continuous fetal heart rate (FHK) monitoring by a fetal scalp electrode. This method of monitoring allows the obstetrician the opportunity to watch the effect of the stresses of labor on the fetus and response of the fetus to those stresses. From
St. Luke’s
Supported Medical
Presented Noz,ember Rec&ed Revised Accepted
to the Kansas 15, 1973.
City
for publication
October
Material
Foundation
Gynecologic
August
and
methods
Fetal monitoring was accomplished with the use of two monitors.* Roth monitors were equipped with self-recording equipment. Intrauterine pressure was measured by placement of an intra-amniotic polyethylene catheter with the use of a sterile technique. Catheter application was done solely by the vaginal transcervical method. The catheter applications at first \zere done in the delivery suite with the patient in obstetric stirrups, but, with the increased experience of the house staff, the majority of the applications were done in the labor rooms with a sterile technique. The fetal electrocardiogram (FECG) and FHR are monitored by application of a fetal scalp electrode. The clamp electrode was used at first, but, with the development of the spiraltype electrode and its ease of application, th? clamptype electrode was abandoned. Fetal monitor strips were taken and interpreted by the patient’s physician and/or the house officer in attendance. The indications for monitoring and, assessment of the monitor
Hospital.
by St. Luke’s Hospital Education and Research.
October
The purpose of this paper is to report the direct fetal monitoring experience of a university-affiliated community hospital’s obstetric service. This report will disruss the effect of direct fetal monitoring on the perinatal mortality rate, cesarean section rate, and Apgar scores and the difficulties and complications encountered with its utilization.
for Society,
6, 1974.
17, 1974. 17, 1974.
Reprint requests: Dr. Gino Tutera, Medical Education and Research, St. Luke’s Hospital, Wornall Rd. at Forty-fourth, Kansas City, Missouri 641 I I.
*Models Inc., 2 necticut
750
101 Barnes 06492.
and 102, Industrial
Corometrics Park Rd.,
Medical Wallingford,
Systems, Con-
Volume Number
122 6
Fetal
NAME:
751
DATE:
P.F.
8
AGE:
ADDRESS: REASON FACTORS
COMPLICATION Premature Abruptio
Decreased Increased
OF PREGWNCY
METHOD
III.
II.
AFTER VALUE
-Electrode Electrode Catheter Specify Unable
Changes Compression Compression
-Cord -u.p.1. Acceleration Baseline Changes Tachycardia -Bradycardia
THE APGAR
OTHER
(SPECIFY)
(State)
MONITORING OF MONITOR
( Be Critical
Application Dislodged Malfunction Any Equipment to Interpret
BIRTH 1 Minute
SCORE:
Poor Progress; suspected CPD Prev C-section Uterine Anomaly Multiple Gestation Assess Oxytocin Augmentation Oxytocin Induction
)
PROBLEMS
TYPE DELIVERY SCORE:
FACTORS
Demonstrated Fetal Distress Avert C-section Decrease Anxiety of Obstetrician -Better Assessment of Labor No Value Misleading (State Why)
pressure
Normal
APGAR
Request Study
Special
IV.
Head
UTERINE
Demonstration
FHR OBSERVATIONS
Periodic
III.
VI.
-Patient
USED
External Technique -FECG, FHR, & I.U. FECG, FHR only z1.u. pressure only
COMPLICATIONS
-ELECTIVE
v-
COMPLETE I.
MATERNAL
Toxemia Diabetes Anemia Heart Disease Rh Isoimmunization Prev Perinatal Death -Elderly Primigravida Grandmultiparity
Rupture Membranes Placenta Placenta Previa Cord 3rd Trim. Bleeding
-Partial -Prolapsed Undeter. Amnionitis
FOR MONITORING
II.
Bradycardia Tachycardia Irregularity Meconium Passage -Fetal Activity Fetal Activity -Breech Presentation Prematurity Postmaturity Dx Fetal Viability IV.
WKS GEST
PHONE:
FETAL
I.
V.
monitoring
(X's) or Technical FHR Patterns
WT.
Problems
SEX 5 Minute
Higher Than As Anticipated Lower Than M.D.
Fig. 1. Fetal monitor history sheet.
pattern and the value of the particular monitoring experience were recorded on individual data sheets (Fig. 1 i .’ On the data sheets, the method of delivery, .\pgar rating (at one and five minutes), and sex and xveight of the infant were also included. In our study, monitored patients were from the private and house staff services. House staff services accounted for 25 per cent of the total volume: however, 75 per cent of the monitored patients were
from the house staff service. The duration of the study extended from May, 1969, until May, 1973. During this time, 6,787 patients were delivered of infants, and 608 patients were monitored, for an incidence of 9 per cent. The incidence of monitoring is low, but this is a report on our initial experience with direct fetal monitoring. Our most recent study showed that nearly 98 per cent of our patients are now monitored. With
7.52 ‘Peru
and
-_-_,.;_,..q-:
Newmcr
Am.
Table 1. Indications for monitoring (listed decreasing order of frequency per category)
in
Fetal factors
Unmonitored group (6,Z Perinatal (per 1,000 Neonatal (per 1,000 Fetal, before admission Fetal, after admission
Uterine factors Poor progress, suspected cephalopelvic disproportion Assess oxytocin induction Assess oxytocin augmentation Attempted vaginal delivery following previous cesarean section Multiple gestation Uterine anomaly Maternal complications Toxemia Diabetes Previous perinatal death Rh isoimmunization Sickle cell anemia Seizure disorder Elderly primigravida Miscellaneous-hyperthyroidism, collagen disease, drug addiction, etc. Complications of pregnancy Premature rupture of membranes Falling estriol levels Amnionitis Undetermined third-trimester bleeding Polyhydramnios
most common
in
morn
indications
Poor progress, suspected cephalopelvic Assess oxytocin usage Premature rupture of membranes Toxemia Prematurity Fetal bradycardia Meconium passage
for
disproportion
the exception of 27 patients monitored for demonstration purposes only on a purely elective basis, all other patients were considered at “high risk.” The indications for monitoring were separated into fetal factors, uterine factors, maternal complications, and complications of pregnancy (Table I). In over 95 per cent of the cases, at least two indications were noted on each individual data sheet. Table II demonstrates the most common indications for monitoring, all categories considered. In our series of 608 patients, 62 patients underwent primary cesarean section, for an incidence of 10.1 per cent. This is a significant increase over
: ( \ncc;l
torecl
Prir,ate house
Deaths
Postmaturity Prematurity Meconium passage Bradycardia Cardiac irregularity Diagnosis of fetal viability
Table II. The monitoring
rate
Table III. Perinatal mortality and unmonitored groups
J. Ohatr
and itaff
79 patients) births) births) (per 1,000 births) (per 1,000 births)
1!I il .i 6
Monitored group (608 patients) Perinatal (per 1,000 births) Neonatal (per 1,000 births) Fetal, before admission (per 1,000 births) Fetal, after admission (per 1,000 births)
8 0 6 2
Table
IV. Apgar
Apgar
scores
(live-born
infants) No.
score
One
minute l-3 4-6 7-10 Five minutes l-3 4-6 7-10
Table Birth
‘4 55 529 0 6 602
V. Results in monitored
weight (Cm.)
No. of infants
500-1,000 l,OOO-1,500
1 6
1,500~2,000 2,000-2,500 2 2,500
25 63 518
Total
613s
*Five
group Fetal/neonatal deaths 1 1 2 1
Fetal death in utero Neonatal death Fetal deaths in utero Fetal death in utero
sets of twins.
the primary cesarean section rate in the unmonitored group of 4.8 per cent, with the over-all cesarean section rate in the unmonitored group being 6.3 per cent. The over-all cesarean section rate in our institution over the past five years has been 5.1 per cent. Thirty-three of the cesarean sections in the study group were done for fetal distress (fetal distress is defined as patterns of late or variable deceleration with an FHR of 90 or below that were not corrected by change of position or nasal oxygen or both in 30 minutes) although there were 107 additional patients who were delivered vaginally despite monitor patterns indicating fetal distress. The 107 cesarean sections that were averted can be directly attributed to the employment of the fetal monitor.
Volume Numbpr
122 6
The physicians in attendance were able to detect and correct the types of distress patterns (variable and/or late deceleration) by employment of nasal oxygen and/or positional change. Fifty-one per cent of the primary cesarean sections in our study group were done for fetal distress. This differs from Paul’s’ study in which the primary indication for cesarean section was poor progress in labor with suspected cephalopelvic disproportion. The perinatal mortality rate for all deliveries in our institution over the last five years has been 19 per 1,000, including study yrars. During the period of this particular investigation, the mortality rate was unchanged in the unmonitored group. Table III demonstrates the breakdown of the perinatal mortality rate in the monitored and unmonitored groups. In the monitored groups, only one fetal death occurred after admission, giving a mortality rate of 2 per 1.000 live births. Four fetal deaths occurred before admission and are included in the statistics for the monitored group since the monitors were used to detect fetal viability and gauge uterine contractility during oxytocin usage. The low mortality rate and, specifically, the fact that only one fetal death occurred after admission speak well not only of fetal monitoring but also for the aggressive management of these high-risk patients by both the obstetricians and neonatologists. Apgar scores were recorded for the 608 live-born infants at one- and five-minute intervals (Table IV). Five hundred and twenty-nine infants had Apgar scores of 7 to 10 at one minute; 55 infants had one-minute Apgar scores of between 4 and 6; 24 live-born infants had Apgar scores between 1 and 3. Of the 79 infants with c\pgar scores of 6 or below, only six had five-minute Apgar scores of 6 or below. In 70 infants the Apgar scores were as anticipated; nine infants had Apgar scores lower than anticipated. In all 79 cases, evidence of fetal distress was present. The logical conclusion would be that fetal monitor patterns do give an estimate of frtal well-being and should alert the obstetrician to be ready for resuscitation of the distressed infant. In addition, the obstetrician now has the capability to reduce the number of distressed infants taken care of by the neonatologist. Table V gives a distribution of the monitored infants in relation to birth weight in grams. Of interest is that nearly one sixth of the patients were below 2,500 grams and that all fetal deaths occurred in infants below 2,000 grams. Obviously, a monitored infant, even in the premature weight
Fetal
monitoring
753
range, has a better chance of survival because monitoring affords the obstetrician the opportunity to eliminate or reduce stresses imposed upon an already high-risk fetus. Technical
ditlkulties
and
complications
The most common technical difficulties encountered were minor. The one found most often was malfunction of the intrauterine catheter which usually was caused by “plugging up” of the catheter by vernix or small blood clots. This usually required simple irrigation with sterile saline or bacteriostatic water to re-establish function of the catheter. If these efforts failed, catheter application was repeated. Problems with dislodgement of fetal scalp electrodes were nearly eradicated following the availability of the spiral-type electrode. This type of scalp electrode was surprisingly easy to apply, with no more discomfort to the patient than that from a routine vaginal examination. The additional advantage of this electrode is application by palpation, with only fingertip cervical dilatation necessary; in contrast, the clamp-type electrode necessitated direct visualization through a vaginal cone, causing increased vaginal discomfort to the patient. Patient discomfort with application of both the intrauterine catheter and fetal scalp electrode decreased markedly with increased experience pf catheter application by the house staff and by improvement of the equipment utilized. Patient discomfort resulted from producing inducement of uterine contractions, “labor pains.” This was primarily during the application of intrauterine catheters. Complications associated with the use of the fetal monitor are as follows: (1) uterine perforation by the uterine catheter, (2) cephalohematoma for2 mation secondary to scalp electrode application with or without resultant scalp abscess formation.” and (3) puerperal pyrexia.“, r, Uterine perforation occurred once in our series. The diagnosis was made when the catheter became palpable abdominally. Cesarean section was performed because of pre-existing fetal distress, and the perforation was found in the posterior portion of the lower uterine segment. A viable infant with a one-minute Apgar score of 6 was delivered, and intraperitoneal bleeding was estimated to be 25 to 50 C.C. The uterine perforation was closed easily with chromic suture; the patient’s postoperative course was uneventful. Cephalohematoma occurred after scalp electrode . . . application m two Infants, one of which resulted in abscess formation. The one infant with the cephalo-
hrmatoma did well with conservative therapy; the inf,ant with scalp abscess formation was treated with antibiotic therapy, surgical incision, and drainage and recovered uneventfully. These two complications occurred with the clamp-type electrode; with the employment of spiral electrodes, no further problems have occurred. No other fetal complications were encountered. In no instance was chorioamnionitis, amnionitis, or puerperal pyrexia exceeding 100.4’ F. after the first 24 hours post partum found to occur following intrauterine catheter placement that was not existing at the time of catheter placement. This is certainly indicative of the near absence of complications associated with fetal monitoring. Comment Reduction of the perinatal mortality rate is one of the most important goals in obstetrics. A significant reduction in fetal loss can be accomplished in the intrapartum period by the continuous monitoring of the fetal heart rate. The ability to monitor the effects of labor on the fetus will lead to delivery by the appropriate method of any “distressed fetus.” In this series the direct method of fetal monitoring significantly reduced the perinatal mortality rate in monitored high-risk patients. The impressive reduc-
tion of perinatal deaths has resulted in application of a fetal monitor to all patients who are admitted to our obstetric unit. This has been facilitated bv the acquisition of additional monitors equipprd w-ith ultrasound Doppler-type fetal heart rate detectors. These results certainly can only encourage The employment of fetal monitors in any hospital with an obstetric unit, especially in any center that deals with a large high-risk population. With the ability to detect the distressed fetus. the appropriate type of delivery can be chosen with objective evidence as to the status of fetal well-being at a particular stage of labor. This should reduce the number of unnecessary cesarean sections, but it should not imply that a reduction in the cesarean section rate will occur. On the contrary, a rise in the cesarean section rate should probably be expected. The future of fetal monitoring obviously is a bright one. The development of the new ultrasound external monitors will allow indirect monitoring of any patient, even prior to rupture of the amniotic membrane. With the widespread employment of fetal monitors, one of the goals of the obstetrician, i.e., reduction in the perinatal mortality rate, should be achieved.
REFERENCES
1. Data sheets utilized at the University of Southern California, Los Angeles County Hospital. 2. Paul, R. H.: Clinical fetal monitoring, AM. J. OBSTET. GYSECOL. 113: 573, 1972. 3. Cordero, L., Jr., and Hon, E. H.: Scalp abscess: A rare complication of fetal monitoring, J. Pediatr. 78: 533, 1971.
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Paul, R. H., and Hon, E. H.: A clinical fetal monitor, Obstet. Gynecol. 35: 161, 1970. Beard, R. W., Brudenell, J. M., Feroze, R. M., et al.: Intensive care of the high risk fetus in labour, J. Obstet. Gynaecol. Br. Commonw. 78: 882, 1971.
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the article title to references in the AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY. References will now conform to the style of the Cumulated Index Medicus, viz., name of author, title of article, name of periodical, volume, page, and year. Authors are always encouraged to limit references to sixteen for the following JOURNAL sections: Obstetrics, Gynecology, and Fetus, Placenta, and Newborn.