Active management of labor: Does it make a difference?

Rebecca Rogers, MD, * George J. Gilson, MD, ~ Anthony C. Miller, MD, b Luis E. Izquierdo, MD,"

Luis B. Curet, MD," and Clifford R. Quails, PhD ~

Albuquerqz~e, New Mexico

OBJECTIVE: Our goal was to evaluate whether active management of labor lowers cesarean section rates, shortens the length of labor, and overcomes any negative effects of epidural analgesia on nulliparous labor. STUDY DESIGN: We randomly assigned 405 low-risk term nulliparous patients to either an active management of labor (n = 200) or our usual care control protocol (n = 205). Patients who were undergoing active management of labor were diagnosed as being in labor on the basis of having painful palpable contractions accompanied by 80% cervical effacement, underwent early amniotomy, and were treated with high-dose oxytocin for failure to progress adequately in labor. RESULTS: The cesarean section rate in the active management of labor group was lower than that of controls but not significantly so (active management, 7.5%; controls, 11,7%; p = 0.36). The length of labor in the active management group was shortened by 1,7 hours (from 11.4 to 9.7 hours, p = 0.001). Fifty-five percent of patients received epidural analgesics; a reduction in length of labor persisted despite the use of epidural analgesics (active management 11.2 hours vs control 13.3 hours, p = 0.001). A significantly greater proportion of active management patients were delivered by 12 hours compared with controls (75% vs 58%, p = 0.01); this difference also persisted despite the use of epidural analgesics (66% vs 51%, p = 0.03). CONCLUSIONS: Patients undergoing active management had shortened labors and were more likely to be delivered within 12 hours, differences that pe{sisted despite the use of epidural analgesics. There was a trend toward a reduced rate of cesarean section. (Am J Obstet Gynecol 1997;177:599-605.)

Key words: Active management of labor, cesarean section

During the past 20 years of obstetric practice in the

United States there has been an alarming increase in the

rate of cesarean deliveries. The 1970 cesarean section rate

in the United States of 5.5% more than quadrupled over

the last two decades without an appreciable change in the

perinatal mortality rate. 1 The majority of this increase has

been in the number of cesarean sections performed on

nulliparous patients for dystocia and as repeat cesarean

sections in multiparous women. Any intervention aimed at reducing the first indication would, by definition, lead to a

reduction in the second. With the assumption that ineN-

cient uterine action is largely responsible tbr dystocia, augmentation of labor is an appropriate intervention. Ac-

tive management of labor, introduced in Ireland by

O'Driscoll et aI., 2 is associated with a low rate of abdominal

From the Division of Maternal-Fetal Medicine, Department of Obstetr&s and Gynecology, ~ the Department of Anesthesiology and Critical Care Medicine/' and the Department of Mathematics, ~ University of New Mexico Health Sciences Center. Supported in part by National Center for Research Resources-General Clinical Research Center grant 3 MO1-RRO0997 from the National Institutes of Health. Received for publication October 14, 1996," revised April 1, 1997; accepted April 16, 1997. Reprint requests: George J. Gilson, MD, 221l Lomaa NE, 4-ACC, Albuquerque, NM 87131. Copyright © 1997 by Mosby-Year Book, hze. 0002-9378/97 $5.00 + 0 6/1/82779

delivery in low-risk nulliparous patients. Unlike the use of

low-dose oxytocin proposed by Seitchik and Castillo ~ and

recommended by The American College of Obstetricians

and Gynecologists, 4 active management of labor uses a

relatively high dose of oxTtocin and also espouses the use of

early amniotomy once the diagnosis of labor is established. These interventions have been shown not to compromise

neonatal outcome, 5 while maintaining the cesarean section

rate at a much lower level than at comparable institutions in this country. 6

Prospective randomized contro]led investigations of

the efficacy of active management of labor in the United States 7, s demonstrate reductions in the lengths

of labor and a trend toward a reduct ion in cesarean

section rates in patients undergoing active manage-

ment compared with patients in usual care protocols.

We designed a prospective randomized trim to evalu-

ate the efficacy of early amniotomy and of high-dose

oxytocin in lowering cesarean section rates in nutlipa-

rous women in a university hospital setting. Our populat ion 's high epidural use reflects the analgesia preferences of many laboring patients in this country,

We evaluated whether active management of labor would shorten labor, lower cesarean section rates, and

overcome any negative effects epidural analgesia might have on labor in null iparous women.

599

600 Fto9ers et al. September 1997 Am J Obstet Gynecol

Material and methods

This randomized prospective study was carried out at

the University of New Mexico Hospital, a tertiary care

facility that serves a largely indigent population of His-

panic, white, and Native American patients. The smdy

period extended from August 1992 to April 1996. Eligi-

ble patients included nulliparous women at term preg- nancy who were examined in the antenatal testing unit

and who had painful, palpable uterine contractions <--5

minutes apart , with cervical effacement of at least 80%.

After informed consent was obtained, sealed opaque

envelopes with the patient's randomization to either the

active management of labor group or our current proto-

col were opened in the antepartum testing unit. Ran-

domization was based on a computer-generated list of

random numbers. Inclusion criteria included gestational

age ->37 weeks, cephalic presentation, no known mater-

nal medical complications, and no known fetal anoma-

lies. Patients were excluded if they had placenta previa or

abruptio placentae, twin gestations, prior uterine sur-

gery, or any other obstetric or any medical complication

of pregnancy. Resident physicians in training, under the

direct supervision of the authors, provided care to all

patients in both arms of the study. The active management of labor protocol was based

on a stritt diagnosis of labor, defined as the presence of

regular painful uterine contractions occurring every 2 to

5 minutes in a patient having attained at least 80%

cervical effacement, regardless of cervical dilatation. The

onset of labor, starting the clock on length of labor, was

established when the diagnosis of true labor was made. Amniotomy was performed within 2 hours of admission,

and augmentation of labor with oxytocin was instituted if

cervical dilatation of 1 cm/h r in the first stage of labor or

descent of 1 cm/h r in the second stage failed to occur.

Cervical examinations every 2 hours documented labor

progression. If augmentation was necessary, oxytocin

infusions were started at 6 m U / m i n and increased every

15 minutes, titrating to seven contractions in 15 minutes

or appropriate cervical change. The maximum dose of

oxytocin was 36 mU/min . Internal uterine pressure transducers were used as clinically indicated. Electronic

fetal heart rate monitoring, external or internal, was routinely used. One labor and delivery nurse was as-

signed to two laboring patients at any one time. The control protocol consisted of admission to the

labor suite at 3 to 4 cm of cervical dilatation, regardless of

effacement, in conjunction with regular painful contrac- üons every 2 to 5 minutes. If adequate progression in labor was not made, defined as cervical ehange of 1.25

cm/h r once the patient was in the active phase of labor, an oxytocin infusion was begun at 1 m U / m i n and was increased by 1 m U / m i n every 30 to 40 minutes to achieve and maintain adequate uterine activity as defined here. The decision to rupture membranes was made at the

discretion of the attending physician. The maximal dose

of oxytocin and the indications for the use of internal

uterine monitoring or electronic fetal heart rate moni-

toring, as weil as the nurse-to-patient ratio, were identical

to those in the investigational arm. Dystocia was defined as failure to progress in labor

either because of arrest of dilatation in the first stage of

labor or because of arrest of descent in the second stage of labor. M1 patients who were assigned the diagnosis of

dystocia attained at least 5 cm of cervical dilatation. Fetal intolerante of labor was defined as either repetitive late

decelerations or repetitive severe variable decelerations

of the fetal heart rate (defined as decelerations lasting

>60 seconds, dropping >60 beats /min below the base-

line heart rate or dropping below a rate of 60 beats/min)

or >5 minutes of bradycardia. A diagnosis of fetal

intolerance of labor was made only after attempts at

correction of the fetal heart rate pattern with hydration, uterine displaeement, oxygen administration, and ephe-

drine administration if indicated for epidural-associated maternal hypotension had failed. Fetal scalp pH deter-

minations were used in 10.3% of cases to confirm the

diagnosis of fetal intolerance of labor suggested by the tracings. Meconium staining of the amniotic fluid at the

time of membrane rupture was subjectively quantified by

the attendant as either thick or thin. Uterine hyperstimu-

lation was defined as the occurrence of uterine contrac-

tions every <-1 minute or of >2 minutes' duration. Epidural analgesics were administered at the. discre-

tion of the attending obstetrician and attending anesthe-

siologist on the request of the patient. Parturients re-

ceived continuous infusions of 0.08% bupivacaine plus 1 p~g/ml fentanyl after an initial bolus of 0.125% bupiva- caine plus 50 Ixg fentanyl. Infusions were titrated to

maintain a T8-10 sensory level. Epidural analgesia was continued throughout the second stage of labor until

delivery. The study was approved by the University of New

Mexico Hospital Human Research Review Committee

before its commencement. Statistical analysis was carried

out with independent t tests for the continuous variables and X 2 analysis for the frequency data. Fisher's exact test

was used where the cell size was small. Bivariate analysis of variance was also used where appropriate to compare

subgroups. Significance was set at a p value of <0.05. A power smdy indicated that 390 patients would be neces- sary to demonstrate with 80% power a reduction of the cesarean section rate from 14.5% in our institution in the

year before the study to the 5.5% rate reported by

O'Driscoll et al. 2

Results Between August 1992 and April 1996, 407 women were

enrolled in the study. Two women, both multiparous, were not included in the final analysis because they were

Volume 177, Number 3 Rogers e t al. 601 Am J Obstet GynecoI

Table I. Patient demographics

Characteristic Active management (n = 200) [ Control (n = 205) [ Sigrfifican«e

Age (}T) 20.7 -+ 4.2 20.5 + 3.7 NS Gestation (wk) 39.4 ± 1.0 39.6 ± 1.0 NS Ethnicity (%) NS Hispanic (No.) 132 (66%) 140 (68%) Non-Hispanic wbite (No.) 58 (29%) 51 (25%) Other (No.) 10 (5%) 14 (7%)

Table II. Labor characteristics

l ' Active management (n = 200) Control (n = 205) ] Significance

Augmentation (No.) Oxytocin dose (mU/min) AdmissiorJ dilatation (cm) Admission effacement (%) Spontaneous rupture of membranes (No.) Thick meconium (No.) Epidural analgesia (No.) Internal fetal monitors (No.)

112 (56%) t05 (51%) NS 13 ± 9 6 ± 5 p = o.ool

2.8 - 1.0 2.9 ± 1.I NS 90 (80oi00) 90 (80-100) NS 28 (14%) 41 (20%) NS 20 (10%) 16 (8%) NS

118 (59%) 105 (51%) NS 138 (69%) 137 (67%) NS

Table III. Length of labor (hours)

All patients Patients with epidural analgesia

Active management ] (n = 200) Controls (n = 205) Signißca~zce

Active management (n = 1 2 6 ) Cont~~ls (n = 131) Significance

Total length of labor (hr) 9.7 -+ 4.9 11.4 + 5.4 p = 0.002 11.2 + 4.6 13.3 + 5,2 p < 0.001 First stage 8.5 -+ 4.5 10.1 ± 5,9 p = 0.001 9.7 _+ 4.4 11.7 ± 4.8 p < 0.00I Second stage 1.0 -+ 1.0 1.1 ± 1ù4 NS 1.3 + 1.0 1.4 + 1.7 NS Third stage 0.15 ± 0.13 0.14 ± 0.13 NS 0.14 ± 0.13 0.14 ± 0.14 NS

en te red into the study in error. The results r epor t ed hefe

include 200 women in the active m a n a g e m e n t o f labor

arm and 205 in the cur ren t pro tocol control arm. Table

I presents the demograph ic feamres and Table II dem-

onstrates the labor characteristics of these patients. The

patients did not va W significantly with regard to age,

gestational age, or ethnicfly. At randomizat ion, active

m a n a g e m e n t of labor and control patients did no t va U

significantly in dilatation, effacement, inc idence of spo~»

taneous rupture of membranes , or distribution of thick

mecon ium. Patients on the active m a n a g e m e n t pro tocol

received a significantly h igher dose of oxytocin than

those enrol led in the current protocol (13 ± 9 m U / h r vs

6 + ä m U / h r , p = 0.001). Nevertheless, u ter ine hype>

st imulation was no t seen with any greater B'equency in

the active m a n a g e m e n t g roup compared with the control

group (11% versus 8%, p = 0.31). In both groups rnore

than half of the patients requ i red labor augmenta t ion

(active m a n a g e m e n t 56%, control 51%). Approximate ly

equal numbers of the patients in each group reques ted

and received epidural analgesics for pain control (59% and 51%, respectively).

Table III details the dura t ion o f labor in the various subgroups. The length of labor in the active manage-

m e n t group was reduced by 102 minutes when, compared

with controls (p = 0.001). Patients in e i ther group who

requi red oxytocin augmenta t ion had longer labors than

their n o n a u g m e n t e d counterparts , as did patients who

received epidnral analgesics. Patients in the active man-

agemen t group who received epidural analgesics bad the

first stage of labor significant]y shor tened by an average

of 2 hours as compared with the controts. This relation-

ship persisted in the active m a n a g m e n t patients with

epidural analgesia whe ther they also requ i red or did no t

requi re augmenta t ion of labor. The lengths o f the sec-

ond and third stages of labor were not significantly

different across subgroups. Finally, in the contro! group

of patients who were delivered vaginally, 41% labored

>12 hours. In the actively managed group only 25~

labored >12 hours. This difference was statisticatly sig-

nificant (p = 0.01) and persisted despite the use of

epidnal analgesia (active managemen t 51% vs contro!

66%, p = 0.03).

Table IV demonst ra tes that there was no s~gnificant

difference in the n u m b e r o f patients achieving spontane-

ous vaginal delivery between the two groups (81% in the

active m a n a g e m e n t group and 82% in controls) . T h e

rates of operat ive vaginal delivery ",vere comparab le in

602 F:logers et at. September 1997 .~n J Obstet Gynecol

Table IV. Mode of delivery

All patients

Active management (n = 200) 1 Control (n = 205) Signi ficance

Total vaginal deliveries (No.) 185 (92.5%) 181 (88.3%) NS Spontaneous 150 (81%) 148 (82%) NS Forceps or vacuum 35 (19%) 33 (18%) NS

Total cesarean sections (No.) 15 (7.5%) 24 (11.7%) NS Arrest of dilatation 9 (60%) 16 (67%) NS Arrest of descent 4 (27%) 5 (21%) NS Fetal intolerance 2 (13%) 3 (12%) NS

Table V. Outcomes in patients receiving either epidural analgesics or oxytocin augmentation, or both

] Length of (hr) section No. labor Cesarean

All patients receiving oxytocin augmentation (n = 217) Controls (n = 105) Active management (n = 112)

All patients receiving epidural analgesia (n = 230) Controls (n = 131) Active management (n = 126)

Epidural analgesia and augmentation (n = 145) Controls (n = 82) Active management (n = 86)

Epidural analgesia without augmentation (n = 85) Controls (n = 49) Active management (n = 40)

13.1 + 4.8* 20 (19%) 11.6 +-_ 4.7* 12 (10.7%)

13.3 Z 5.2t 20 (15.3%) 11.2 + 4.6 t 14 (11.1%)

14.1 + 4.6 + 16 (19.5%) 12.3 2 4.7 + 12 (14.0%)

12.1 +- 5.9§ 4 (8.2%) 8.8 -+ 3.4§ 2 (5.0%)

*p = 0.03.

tP = 0.001. +p = 0.02. §p = 0.002.

the two groups (19% and 18%, respectively). There were

15 cesarean sections in the active management group

(7.5%) and 24 in the control group (11.7%), a reduction

of 36% in the actively managed group, which was not

significant. The indications for either an operative vagi-

nal delivery or a cesarean secUon were not different

between groups, with 9 patients in the active manage-

ment group and 16 in the control group undergoing

eesarean section for arrest of dilatation in first-stage

labor, implying a trend toward the reduction of dystocia

in the active management patients. The rate of second-

stage cesarean secuons was 2.0% among active manage-

ment patients and 2.4% among usual care patients.

Among patients who received epidural analgesics, the

cesarean section rate was 11.1% among the patients

being actively managed and 15.3% in the control group.

Among those patients who did not receive epidural

analgesics, the overall rate of cesarean section was ex-

tremely low at 2.7%. Table V stratifies the data on length

of labor and mode of delivery by whether patients

received either epidural analgesics or augmentation, or

both. The patients who were augmented under the active

management protocol had a signifieantly shorter length

of labor (mean 90-minute reducüon, p = 0.03). Those

patients who had epidural analgesia and augmentation

according to the active management protocol, as well as

those with epidural analgesia in the active management

group who did not receive augmentation, also had

shorter lengths of labor (mean 108-minute reduetion,

p = 0.02, and mean 198-minute reduction, p = 0.002,

respectively). Thirty-four of the the 39 total cesarean

deliveries were carried out in patients who had reeeived

epidural analgesics. Delivery complications between the

two groups were equivalent. Four percent of active

management paäents and 7% of controls had postpar-

mm hemorrhage (defined as estimated blood loss >500

tal), and 14% and 13%, respectively, of the patients in

eaeh group experienced febrile episodes during labor

attributable to chorioamnionitis. Table VI details the

neonatal outcomes. Apgar scores, fetal weights, and

neonatal outcomes did not vary signifieantly between

groups.

Comment

For >25 years active management of labor has been

successfully used at the National Maternity Hospital in

Dublin according to the protocol instituted by O'Driscoll

et al. 2 The basis of active management rests on the tenets

of an accurate diagnosis of true labor, early amniotomy,

selective use of high-dose oxytocin, limitation of the total

Volume 177, Number 3 Flogers et aJ. 603 Am J Obstet Gynecol

Table VI. Neonatal outcomes

Active management (n = 200) Control (n = 205) 1 Significance

Infant weight (gm) 3300 +_ 405 3245 + 417 NS Apgar score <7 at 5 min 2 2 NS NICU admission 1 4 NS Cord pH <7.00 2 2 NS

duration of labor to 12 hours, supportive maternal intrapartum care, and antenatal education. In 1984

O'Driscoll et al. 6 investigated a group of 8742 women

who all underwent active management of labor, of whom

3106 were nulliparous and 5636 were multiparous. The

cesarean section rate was 5.5% for the nulliparous

women and 2.8% among the multiparous ones. They

ascribed the higher rate of dystocia in the nulliparous

patients to inadequate uterine activity and the need to

overcome the increased soft tissue resistance of the

untried birth canal. They touted oxytocin as the only

reasonable alternative to cesarean section.

Other investigators have further evaluated active man- agement of labor as described by O'Driscoll et al. Four of

these studies used historic controls and did not random- ize patients. 9~2 An analysis of these retrospective studies

reveals significant decreases in the cesarean section rates

and modest declines in the rates of operative vaginal

deliveries. Not all studies commented on lengths of

labor, but in those that did, patients in the active

management groups had shorter overall durations of

labor, most notably in first-stage labor. None of the

studies showed any increase in the incidence of poor neonatal outcome in the patients who received active

management. Satin et at. 13 noted that a given patient's

response to the dosage of o~,e/tocin was hig-hly variable and precluded prediction of the mode of delivery, im-

plying that other factors besides oxytocin may account

for the favorable outcomes noted in these studies.

Two prospective randomized controlled trials have

been published in the United States, those of Lopez- Zeno et al. 7 and of Frigoletto et al. s Both of these studies

used the same tenets espoused here, namely, early diag- nosis of true labor, early atnniotomy, amt high-dose

oxytocin. Lopez-Zeno et al. ~ randomly assigned 351

women to active management of labor and 354 to the

control g roup Length of labor in the active management

group was shortened by 1.7 hours, with a 15% decrease in the cesarean section rate, from 10.5% in the active management patients to 14.1% in the control group. Frigoletto et aL e randomly assigned 1017 women to

active management and 917 women to usual care in their

study. They reproduced all the tenets of the work of O'Driscoll et al., including antenatal education and one-on-one nursing. Length of labor was significantly shortened by 2.7 hours (6.2 vs 8.9 hours), and the cesarean section rate was reduced 18% in the active

management group compared with controIs (9.2% vs

11.3%, p not significant), confirming the findings of

Lopez-Zeno et al. The results of the current study show a 36% lower

cesarean section rate in the active management group

compared with the conventionally managed group, a

difference consistent with the aforementioned larger

studies and not significant. The overall cesarean section

rate for study participants was 9.6%, with a rate of 7.5%

in the actively managed patients and a rate of 11.7% in

the usual care group. The cesarean delivery rate in the

study patients was lower than the overall institutional rate

of 14.5% over the same study period but comparable to

our rate of 10.9% for nulliparous patients with uncom- plicated term gestations. It would have been preferable

for us to perform an initial power study that was based on

our institutional cesarean section rate for nutliparous

patients with uncomplicated term gestations of 10.9%.

More relevantly, a poststudy power analysis that was

based on our results demonstrated that it would have

required 765 subjects in each arm to achieve 80% power

for this end point. We believed it reasonable to stop with

the number of subjects we did recruit, but this explains

the low power we actually achieved for demonstrating a reduction in the cesarean section rate. A multicenter

collaborative trial or a metaanalysis of the existing ran-

domized controlled trials may better address this key

issue.

The current study did show a significant decrease in

the length of labor of the actively managed patients,

which persisted despite a high use of epidural analgesics

(Tables III and V). Finally, this study confirms that,

despite the use of high-dose ox-y.tocin, there was no

evidence of increased fetal intolerance of labor with this

method of labor management. There were two fetuses in

the actively managed group with fetal intolerance of

labor as the indication for abdominal delivery and three fetuses in the usual care group. There were no long-term

adverse neonatal outcomes in this sample. The incidence of a febrile episode during labor was 14% in tile active

management group and 13% in the control group. Factors hypothesized to be contributing to the increas-

ing rate of cesarean section in the United States include

the use of epidural analgesics, the lack of support of the

parturient patient during labor, and the fear oflitigati0n. The increasing use of epidural analgesics has been suggested by some to be a factor contributing signifi-

604 Roger8 et al. September 1997 ,~n J Obstet Gynecol

cantly to the increasing inc idence of cesarean delivery

for dystocia in nul l iparous w o m e n and has been a cause

of conce rn and controversy in the Uni ted States. Five

prospective studies 14-1s have looked at this issue and have

demons t ra ted that the respective cesarean section rates

be tween the no epidural and epidural groups were 7.1%

and 21.0% (p < 0.05). The a rgumen t has been advanced

that patients exper ienc ing longer, dysfunctional, and

more painful labors are more likely to choose epidural

analgesia, thus preselect ing themselves to be more likely

to unde rgo cesarean delivery and the reby biasing the

studies. It is then reasonable to investigate whe ther

augmenta t ion of desultory labor after the fashion of the

active m a n a g e m e n t protocols migh t be able to overcome

the apparen t deleter ious effect of epidural analgesia on

labor progress. The cur ren t study shows an overall cesar-

ean section rate of 9.6%. A m o n g all patients with epi-

dural analgesia the cesarean section rate was 13.6%,

lower than that observed in previous r andomized studies.

Within this group patients with augmenta t ion unde r the

active m a n a g e m e n t pro tocol had a rate of 11.1% and

controls had a rate of 15.3%, a nonsignif icant difference.

Nevertheless, the length of labor in these patients was

r educed a m e a n of 126 minutes (p = 0.001), which we

believe is clinically relevant. Finally, among those pa-

tients who did no t receive epidural analgesics, the overall

rate of cesarean section was extremely low at 2.7%. Thus

the vast majori ty of cesarean sections were pe r fo rmed on

patients with epidural analgesia p laced for rel ief of pain

dur ing first-stage labor, making the implicat ions of our

f indings regarding active m a n a g e m e n t o f labor and

epidural analgesia clinically very useful.

O h r study cont inues to suppor t previous observations

that actively managed labor leads to shorter labors re-

gardless of the need for augmenta t ion or epidural anal-

gesia. The benefi t o f this m o d e of labor m a n a g e m e n t

may be its ability to identify the onset of true labor and to

decrease the total length of labor. The onset of labor in

nul l iparous patients he re was based on effacement and

regular painful contractions, ra ther than on Fr iedman ' s

def ini t ion of dilatation and regular painful contrac-

tions. 19 The cur ren t study questions the s tandard d ic tum

that active labor does no t c o m m e n c e unti l the par tur ien t

reaches a cervical dilatation of 3 to 4 cm. Hefe , as weil as

in o ther studies, patients were admi t ted with less cervical

dilatation bu t with more advanced effacement and with a

decrease in the length of labor, as well as a decrease in

cesarean section rates.

Patients in the active m a n a g e m e n t arm of the current

study had m e m b r a n e s rup tu red on admission at an

average of 2.8 cm of cmwical dilatation. Recent studies of

early amnio tomy 2°-22 have shown the total dura t ion of

labor to be r educed by an average of only 92 minutes

with no reduc t ion in the cesarean section rate after

amnio tomy p e r f o r m e d before late-active-phase labor.

These studies involved a total of 2750 subjects; however,

they demons t ra ted very little difference between groups

as regards cervical dilatation at the t ime of amniotomy.

"One-on-one" parturient-midwife labor is also a critical

aspect of actively managed labor in Ireland, and its

benefits have been no ted by o t h e r s Y In this study nurses

were usually, assigned to two laboring patients at a time,

and certified nurse-midwives did no t participate in the

study, no t duplicat ing this aspect of the Dublin experi-

ence. In addit ion, there was no r igorous a t tempt at

antenatal educat ion, ano the r central tenet of active

m a n a g e m e n t as pract iced in Ireland.

In summary, active manageraen t of labor in nullipa-

rous women shortens the dura t ion of labor, increases the

l ikel ihood of delivery within 12 honrs, and overcomes

the delay in delivery associated with the use of epidural

analgesia. Whereas there was a t rend toward a lower

inc idence of cesarean section in the actively managed

group, this reduc t ion did no t reach statistical signifi-

cance compared wirb o u t institutional rate for low-risk

nulligravid women. Nevertheless, the degree of reduc-

tion achieved may be clinically significant, especially in

the paüents receiving epidural analgesics. Fur ther trials

of the efficacy and safety of active m a n a g e m e n t of labor

seem warranted as we cont inue our efforts to lower the

rate of abdomina l delivery in the Uni ted States. A

collaborative mul t icenter trial or fur ther combined indi-

vidual trials subjected to a metaanalysis will be necessary

to attain the power needed for a definitive s ta tement on

the efflcacy of this m o d e of labor m a n a g e m e n t as regards

lowering the cesarean section rate.

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7. Lopez-Zeno JAS, Peaceman AM, Adashek JA, Socol ML. A controlled trial of a program for the active management of labor. N EnglJ Med 1992;326:450-4.

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10. A~kom T AH, Brodie G, Caddick R, McLaughin VD, Pugh PA.

Volume 177, Number 3 Rogers et al. 605 Am J Obstet Gynecol

Active management of labor and operative delivery in nulliparous women. AmJ Obstet Gynecol 1988;158:255-9.

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16. Chestnut DH, Vincent RD, McGrath JM, Choi WW, Bates JN. Does early administration of epidural analgesia affect obstetric outcome in nulliparous women who are receiving intravenous oxytocin? Anesthesiology 1994:801193-200.

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22. The UKAmniotomy Group. A multicenter randomised triat of amniotomy in spontaneous first labor at term. BrJ Obstet Gynaecol 1994;101:307-9.

23. Sosa R, Kennell J, Klaus M, Robertson S, Urrutia J. The effect of a supportive companion on perinatal problems, length of labor, and mother-infant interaction. N Engl J Med 1980;303:597-600.

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