Join the 200th Anniversary Celebration

Original Article

A Clinical Trial of Active Management of Labor

Fredric D. Frigoletto, Jr., M.D., Ellice Lieberman, M.D., Dr.P.H., Janet M. Lang, Ph.D., Sc.D., Amy Cohen, B.A., Vanessa Barss, M.D., Steven Ringer, M.D., Ph.D., and Sanjay Datta, M.D.

N Engl J Med 1995; 333:745-750September 21, 1995

Abstract

Background

Active management of labor is a multifaceted program that, as implemented at the National Maternity Hospital in Dublin, is associated with a lower rate of cesarean delivery than the rate usually found in the United States. We conducted a randomized trial to evaluate the efficacy of this approach in lowering the rate of cesarean section among women delivering their first babies.

Methods

We randomly assigned 1934 nulliparous women at low risk of complications of pregnancy, before 30 weeks' gestation, to active management of labor or to a usual-care group. The components of active management were customized childbirth classes; strict criteria for the diagnosis of labor; standardized management of labor, including early amniotomy and treatment with high-dose oxytocin; and one-to-one nursing. A low-risk subgroup was defined as including women with full-term, uncomplicated pregnancies who spontaneously went into labor (the protocol-eligible subgroup). Women meeting these criteria who had been randomly assigned to the active-management group were admitted to a separate unit where their labor was managed by trained, certified nurse-midwives.

Results

There was no difference between groups in the rate of cesarean section either among all women (active management, 19.5 percent; usual care, 19.4 percent) or in the protocol-eligible subgroup (active management, 10.9 percent; usual care, 11.5 percent). In the protocol-eligible subgroup, the median duration of labor was shortened by 2.7 hours by active management (from 8.9 to 6.2 hours), and the rate of maternal fever was lower (7 percent vs. 11 percent, P = 0.007). The percentage of women in whom labor lasted longer than 12 hours was three times higher in the usual-care group than in the active-management group (26 percent vs. 9 percent, P<0.001).

Conclusions

Active management of labor did not reduce the rate of cesarean section in nulliparous women but was associated with a somewhat shorter duration of labor and less maternal fever.

Media in This Article

Table 1Criteria for Inclusion in the Protocol-Eligible Subgroup.
Table 2Frequency of Cesarean Section in the Study Groups, According to Indication.
Article

O'Driscoll and colleagues at the National Maternity Hospital in Dublin, Ireland, pioneered a multifaceted approach to the management of labor in nulliparous women that is now referred to as active management of labor.1 It was introduced to shorten labor at a time when the rate of cesarean section was under 5 percent. Active management of labor includes strict criteria for the diagnosis of labor, early rupture of the amniotic membranes, prompt intervention with high-dose oxytocin in the event of inefficient uterine action, and a commitment never to leave a woman unattended during labor.

As the rate of cesarean section rose in most industrialized countries during the 1970s and 1980s, the persistently low rate of cesarean delivery at the National Maternity Hospital led other obstetrical services to use active management of labor as a means to reduce rates of cesarean section. However, the efficacy and safety of this protocol were not universally accepted.2,3 We conducted a randomized trial to evaluate this strategy for lowering the rate of cesarean section in nulliparous women.

Methods

This study protocol was reviewed and approved by the human research committees of the participating institutions. The safety of the protocol and quality control were monitored by an external data-monitoring board.

Study Population and Randomization

We recruited women from 17 prenatal care sites. Participants were nulliparous, at least 18 years old, English-speaking, and planning to deliver their babies at Brigham and Women's Hospital in Boston between June 10, 1991, and October 17, 1993. Women with conditions associated with an increased risk of preterm or cesarean delivery — such as multiple pregnancy, diabetes, cervical incompetence, or pregnancy-induced hypertension — were ineligible.

Medically eligible women were randomly assigned to the active-management group or to a usual-care group before 30 weeks' gestation. The primary method of randomization (used for 97 percent of the women) was through telephone calls placed by recruiters to the coordinating center; sealed, numbered envelopes were issued to each recruiter for use if necessary. Group assignments, stratified according to site, were determined with the use of random numbers in permuted blocks of six and eight.

Prenatal Period

All women received prenatal care from their own health care providers. Women in the active-management group attended special childbirth classes designed to explain the active-management protocol. To ensure equal access to childbirth education, women in the usual-care group received payment to attend classes of their choice.

Management of Labor

Fetal monitoring was routinely used in both groups, and all women had similar access to pain relief, including epidural anesthesia.

Usual Care

The study placed no constraints on the management practices of physicians caring for the women in the usual-care group. Therefore, as in all institutions, there was variation in practice among providers. However, the usual practice at our hospital was to initiate treatment with oxytocin, if it was used, at a dose of 1 to 2 mU per minute and to increase the dose periodically by 1 to 2 mU per minute. It was not the usual practice to rupture the membranes on admission to the hospital for labor and delivery. Although providers were not required to practice in this way, most did, and the two treatment groups differed markedly with respect to the use of oxytocin and the timing and frequency of amniotomy. In the usual-care group, there was no standardized protocol for initiating or stopping oxytocin, nor was there a prescribed schedule for measuring dilatation of the cervix.

Women in the usual-care group had their labor managed in the hospital labor and delivery unit, staffed with one nurse for every two patients until a late stage of labor, when a single nurse provided care to each patient. Women were not identified as study participants in their prenatal or hospital records.

Active Management

The active-management protocol was administered in a physically separate unit staffed by certified nurse-midwives and registered nurses who worked exclusively for the study. To be eligible for active management of labor, women had to reach term without medical complications and have spontaneous onset of labor with a singleton fetus in a vertex presentation. Women in the active-management group who did not meet these criteria had their labor managed in the hospital labor and delivery unit by their regular care provider.

The labor protocol for the active-management group had three main components:

One-to-one nursing care. A nurse (who changed only with shifts) remained with the patient throughout labor.

Standardized criteria for the diagnosis of labor. The certified nurse-midwife in charge made the diagnosis of labor. The criteria were painful contractions accompanied by effacement of at least 80 percent, bloody show (not precipitated by vaginal examination), or spontaneous rupture of the membranes.

Management of labor. Amniotomy was performed within one hour of the diagnosis of labor (or as soon as clinically feasible) if the membranes were still intact. Cervical examinations were performed at least every two hours to ensure prompt detection of inefficient uterine action. Inefficient uterine action was diagnosed during the first stage of labor if the rate of cervical dilatation was less than 1 cm per hour and during the second stage of labor if the time between full dilatation and the fetus's head reaching the pelvic floor was greater than one hour. Inefficient uterine action was treated with oxytocin. Oxytocin could also be initiated if the time between the head's reaching the pelvic floor and the delivery of the baby was more than 30 minutes.

The oxytocin infusion was begun at a dose of 4 mU per minute and increased by 4 mU per minute every 15 minutes until the maximal dose of 40 mU per minute was reached, unless hyperstimulation or a nonreassuring fetal-heart pattern was noted (in both groups, the guidelines for a nonreassuring fetal-heart rate were those of the American College of Obstetricians and Gynecologists).4 Hyperstimulation was defined as more than seven contractions of at least 30 seconds' duration during a 15-minute period or a single contraction lasting more than 60 seconds. In the event of hyperstimulation, the dose of oxytocin was initially decreased by 8 mU per minute. If the hyperstimulation persisted or a nonreassuring fetal-heart pattern occurred, oxytocin was stopped for 15 minutes and started again at half the previous dose.

Failure to progress was diagnosed if, during the first stage of labor, normal progress of cervical dilatation (at least 1 cm per hour) did not resume within 1 hour of the establishment of efficient uterine action with oxytocin (five to seven contractions of good quality in 15 minutes) or if the second stage of labor was prolonged. Until March 11, 1993, a prolonged second stage was defined as one longer than two hours for all women treated in the active-management unit (the initial protocol). After that date, the definition was changed to three hours for women who had an epidural catheter in place (the final protocol). This change was consistent with the guidelines of the American College of Obstetricians and Gynecologists5 and was the practice in the usual-care group. To maximize the number of women treated under the final protocol, after the change was made two women were randomly assigned to the active-management group for every one woman assigned to usual care.

The women's regular care providers assumed responsibility for care in the event of the failure of labor to progress as defined by the protocol, fetal distress, heavy meconium staining, substantial bleeding, hypertension, maternal fever, or the need for operative vaginal delivery.

Data Analysis

An intention-to-treat analysis included all women categorized according to study group. A secondary analysis included only women in the active-management group who were medically eligible to receive treatment according to the protocol at the onset of labor and their counterparts among the women in the usual-care group, with this group designated the protocol-eligible subgroup. Table 1Table 1Criteria for Inclusion in the Protocol-Eligible Subgroup. shows the criteria for inclusion in the subgroup.

Crude rates of cesarean delivery, relative risks, and 95 percent confidence intervals were calculated. Logistic-regression analyses controlled for any imbalances in base-line characteristics. Since the frequency of use of epidural anesthesia was different in the two study groups, the odds ratios were adjusted to evaluate the effect of active management independent of the use of epidural anesthesia.

Vaginal deliveries were categorized as either spontaneous or operative, and cesarean sections were classified according to the stage of labor (first or second) during which they were performed. The difference between the initial and final protocols affected only the duration of the second stage of labor before failure to progress could be diagnosed. Therefore, in analyzing outcomes related to failure to progress during the second stage we took into account the change in the protocol. The change had no bearing on other outcomes, including measures of safety.

Management practices during labor in the two groups were compared. We evaluated safety by examining complications of labor, postpartum complications, and the outcomes of the infants.

Results

Recruitment and Study Population

From January 14, 1991, through July 31, 1993, we identified 3028 nulliparous women eligible for the study, of whom 1934 (64 percent) agreed to participate and were randomly assigned to the active-management group (n = 1017) or to the usual-care group (n = 917). The characteristics of the women in the two groups were balanced with regard to race, age, education, and smoking habits. Data on the deliveries of 19 women were missing (8 from the active-management group and 11 from the usual-care group), and these women were therefore excluded from further analyses.

Intention-to-Treat Analysis

Among the 1915 women for whom data on outcomes were available, the rate of cesarean section was virtually identical in both groups: 19.5 percent in the active-management group and 19.4 percent in the usual-care group (relative risk, 1.0; 95 percent confidence interval, 0.8 to 1.2) (Table 2Table 2Frequency of Cesarean Section in the Study Groups, According to Indication.). Adjusting for base-line characteristics and use of epidural anesthesia with logistic regression left the results unchanged. In both groups, cesarean sections were performed at a similar rate in response to the failure of labor to progress (active management, 7 percent; usual care, 8 percent).

The effects of active management were then studied in the protocol-eligible subgroup. Although this was not an intention-to-treat analysis, it provided the clearest information regarding the effect of the protocol on women who remained at low risk for complications of pregnancy at term.

Analysis of the Protocol-Eligible Subgroup

Between randomization and the onset of labor, medical complications developed in one third of the women or their labor was induced with oxytocin, making them ineligible for the labor protocol (active management, 33 percent; usual care, 35 percent) (Table 3Table 3Reason for Ineligibility for the Protocol, According to Study Group.). Induction of labor accounted for 56 percent of the ineligibility for the active-management labor unit. The protocol-eligible subgroup was composed of 1263 women who had uncomplicated term pregnancies and a spontaneous onset of labor (active management, 678; usual care, 585). Of the 678 women in the active-management group who were eligible for the protocol, 633 (93.4 percent) were treated according to the protocol. Among the 331 women in the active-management group who were ineligible, 18 (5.4 percent) were treated according to the protocol.

Base-Line Characteristics

The characteristics of these women did not differ in the two study groups and were similar to those of the overall study population (data not shown).

Status of Labor at Admission and Labor Practices

At hospital admission, the percentage of women whose membranes had ruptured was similar in the two study groups (active management, 37 percent; usual care, 34 percent), as was the mean cervical dilatation at first examination (active management, 3.3 cm; usual care, 3.6 cm) (Table 4Table 4Status of Labor at Admission and Labor Practices for Protocol-Eligible Participants with Spontaneous Labor, According to Study Group.).

Practices for the management of labor mandated by the protocol differed in the two groups (Table 4). Women in the active-management group had more frequent vaginal examinations (mean frequency, every 1.6 hours, as compared with every 2.5 hours in the usual-care group). Their membranes were artificially ruptured more often (61 percent vs. 51 percent) and earlier (within one hour of admission in 76 percent, as compared with 15 percent in the usual-care group).

More women in the active-management group received oxytocin (70 percent vs. 56 percent), and the time from admission to the administration of oxytocin was typically 2 hours shorter (3.7 vs. 6.0 hours). The mean maximal dose of oxytocin administered was higher in the active-management group (24.1 mU per minute, vs. 7.4 mU per minute in the usual-care group). Women in the active-management group requested epidural anesthesia less often (54 percent vs. 64 percent) and tended to receive epidural anesthesia somewhat later in labor (mean cervical dilatation at the administration of anesthesia, 5.9 vs. 5.4 cm).

Method of Delivery

Overall, the rates of cesarean section were similar — 10.9 percent in the active-management group and 11.5 percent in the usual-care group. The odds ratio for cesarean section (adjusted for the use of epidural anesthesia) was 0.9 (95 percent confidence interval, 0.4 to 1.9) for the women in the active-management group as compared with those in the usual-care group during the final protocol (in which women in the active-management group were allowed a maximum of three hours for the second stage of labor with epidural anesthesia); the odds ratio was 1.2 (95 percent confidence interval, 0.8 to 1.8) during the initial protocol (with a maximum of two hours allowed for the second stage of labor with epidural anesthesia). The small difference between these two estimates was due to a lower rate of cesarean section during the second stage of labor with the final protocol. The results were essentially unchanged when adjustment was made for base-line characteristics of the groups.

There was a small but consistent decrease in the rate of cesarean section during first-stage and second-stage labor, as well as in the rate of operative vaginal delivery in the active-management group (Table 5Table 5Method of Delivery for Protocol-Eligible Participants According to Study Group.). None of these differences were statistically significant. For both groups, the rate of cesarean section performed because of fetal distress was low (active management, 2.2 percent; usual care, 1.2 percent). Therefore, the overall cesarean-section rates in the protocol-eligible subgroup reflect cesarean sections performed because labor failed to progress.

The median length of labor was 6.2 hours in the active-management group and 8.9 hours in the usual-care group. Differences in the length of labor remained when the groups were stratified according to the extent of cervical dilatation at first examination.

Maternal Complications and Infants' Outcomes

The only maternal complication that differed significantly in frequency between the groups was fever, which had a lower incidence in the active-management group (relative risk, 0.6; 95 percent confidence interval, 0.4 to 0.9). There was no significant difference in the occurrence of a number of other complications, including fetal distress, placental abruption, shoulder dystocia, and vaginal lacerations.

Among the infants, we observed no significant differences between the two groups in the frequency of jaundice, seizures, treatment for sepsis, resuscitation at birth, or admission to the neonatal intensive care unit. Only two infants in each group had five-minute Apgar scores of 5 or lower. Although there were more clavicle fractures in the active-management group (five, as compared with one in the usual-care group) and more nerve injuries in the usual-care group (seven, as compared with two in the active-management group), these differences could have been the result of chance, since both of the events were rare.

Discussion

In this clinical trial we investigated whether the implementation of a protocol for active management of labor would safely lower the rate of cesarean section among nulliparous women. We included all the components of the National Maternity Hospital protocol for active management of labor: customized education, specific criteria for the diagnosis of labor, specific management steps, use of high-dose oxytocin, and one-to-one nursing. Active management was implemented by a separate staff to guard against the bias that could result if the same staff simultaneously cared for patients in labor under both the active-management and usual-care protocols. In addition, the active-management staff worked in a delivery unit that was physically separated from the main labor and delivery unit of the hospital, which minimized contact between the staff members assigned to the two groups.

The safety of the protocol, including the use of high-dose oxytocin and management of labor by midwives, was confirmed. Shorter labors and a decreased occurrence of maternal fever were also noted. However, the anticipated substantial decrease in the rate of cesarean section was not observed. The overall rate of cesarean section was virtually the same in the two groups. In the subgroup of women who were at low risk because they had a spontaneous onset of labor at term, the rate of both first-stage and second-stage cesarean section was slightly lower in the active-management group. This decrease was neither statistically significant nor clinically relevant, because the overall rate of cesarean section was not altered. Although there was a small difference between the groups in the use of epidural anesthesia, this difference could not be responsible for our results, since all analyses were adjusted for the use of epidural anesthesia.

In another large, randomized trial of active management of labor,6 the rate of cesarean section was reduced from 14.1 percent to 10.5 percent, and the difference reached statistical significance only after a number of factors were controlled for. The fact that in that trial the labor of women in both study groups was managed in the same labor and delivery unit by the same personnel could have introduced bias that accounted for differences of the order of magnitude of the observed results.

A possible explanation for our negative results could be the Hawthorne effect7 — that is, that because the study focused on rates of cesarean section, the rate in the usual-care group was lowered. To evaluate that possibility, we compared the routes of delivery and labor practices for women in the usual-care group who were protocol-eligible with those of all women at similarly low risk who delivered first babies during the six months before the trial began. The rates of cesarean section and operative vaginal delivery, as well as of the use of oxytocin, were similar in the two groups (Table 6Table 6Labor Practices and Outcomes with Active Management and Usual Care.).

Another reason for our negative results could be that rates of cesarean section at our institution are already lower than would be expected in similar populations elsewhere. We do not believe that this is the case. For all nulliparous women delivering during the six months before the study, the rate of cesarean deliveries was 23.8 percent. In our study population, which excluded women known to be at high risk for cesarean delivery before randomization, the rate of cesarean section was 19.4 percent. The rate of 11.5 percent reported here is the rate of cesarean deliveries for the very lowest risk group — women who went into labor spontaneously at term with the infant in the cephalic presentation and who had none of a number of complications of pregnancy. The slightly higher rate of cesarean section in the control group in the study of López-Zeno et al.6 (14 percent) could be due to the fact that women with medical conditions such as hypertension and diabetes were not excluded from their study.

A striking difference between the data on cesarean sections from the randomized trials of active management of labor and those from the National Maternity Hospital is the distribution of cesarean sections between the first and second stages of labor. The rates of first-stage cesarean section were similar in all three cases: 5.2 percent in this study, 7 percent in the trial of López-Zeno et al., and 4.8 percent at the National Maternity Hospital (Boylan P, Robson M: personal communication). In contrast, active management of labor resulted in markedly different rates of cesarean section during the second stage of labor: 4 percent in our study and 3 percent in the trial of López-Zeno et al., as compared with only 0.2 percent at the National Maternity Hospital (Boylan P, Robson M: personal communication). This difference suggests the need for a careful assessment of practices for the management of the second stage of labor in North America.

In this randomized trial, we did not find that the active-management protocol was effective in reducing the rate of cesarean section. On the basis of results of the previously reported randomized trial6 and observational data,1,8,9 some managed-care organizations are suggesting that active management be instituted as the standard of practice in order to reduce the rate of cesarean sections. Although the active-management protocol did have some benefits — such as shorter labor and a decreased occurrence of maternal fever — our data do not provide justification for that recommendation.

Supported by a grant (RO1-HD2681304) from the National Institute of Child Health and Human Development and by Brigham and Women's Hospital and the Harvard Community Health Foundation.

We are indebted to the following medical practices and physicians for generously providing us with access to their offices and patients: Harvard Community Health Plan, Brigham and Women's Hospital Ambulatory Clinic, General Medical Associates, OB-GYN Associates, Boston OB-GYN Associates, New England OB-GYN Associates, Drs. Jeffrey Katz, James Marquardt, Carl Lopkin, Beatrice Pitcher, and Rafik Mansour; to the members of our data-monitoring board: Drs. Elizabeth Brown, John Hobbins, Ann Koontz, Richard Monson, and Donald Rubin; to the registered nurses and certified nurse-midwives whose careful implementation of the protocol ensured the reliability of our study results: Sherrin Langeler, Valerie Sweeney, Janet Armstrong, Cynthia DeSteuben, Mary Eliot Jackson, Iris Mulholland, Pauline Ratta, Terry Westerlund, Kathleen Delaney, Barbara Graczyk, Mary Kania, Suzanne Pannabecker, and Barbara Wallace-Lash; to other members of our staff whose efforts ensured the success of the study: Kimberly Coleman, Julie Alvarado, Susan Axeworthy, Ellen Bender, Beverly Gallagher, Patricia Mitchell, Shelley Myerson, Susanne Paullin, Eleanor Ringer, Beth Ritchie Burke, Judith Server, Marjorie Sokoll, Evelyn Soto Cosme, Sharon Smith, Frances Stewart, and Amy Zolit; to Dr. Peter Boylan, Master of the National Maternity Hospital in Dublin, Ireland, for his assistance in helping us adapt the active-management protocol for use in the United States; to Dr. Michael Robson for discussions about the interpretation of our results; and to the women who enrolled in our study for their willingness to participate and their enthusiastic cooperation.

Source Information

From the Departments of Obstetrics and Gynecology (F.D.F., E.L., A.C.), Anesthesia (S.D.), and Newborn Medicine (S.R.), Brigham and Women's Hospital and Harvard Medical School; the Department of Obstetrics and Gynecology, Harvard Community Health Plan, Brigham and Women's Hospital (V.B.); and the Department of Epidemiology and Biostatistics, Boston University School of Public Health (J.M.L.) — all in Boston.

Address reprint requests to Dr. Frigoletto at the Department of Obstetrics and Gynecology, Massachusetts General Hospital, 32 Fruit St., Boston, MA 02114.

References

References

  1. 1

    O'Driscoll K, Meagher D, Boylan P. Active management of labor. 3rd ed. London: Mosby–Year Book, 1993.

  2. 2

    Leveno KJ, Cunningham FG, Pritchard JA. Cesarean section: an answer to the house of Horne. Am J Obstet Gynecol 1985;153:838-844
    Web of Science | Medline

  3. 3

    Leveno KJ, Cunningham FG, Pritchard JA. Cesarean section: the house of Horne revisited. Am J Obstet Gynecol 1989;160:78-79
    Web of Science | Medline

  4. 4

    Fetal heart rate patterns: monitoring, interpretation, and management. Technical bulletin. No. 207. Washington, D.C.: American College of Obstetricians and Gynecologists, 1995.

  5. 5

    Freeman RK, Poland RL, eds. Guidelines for perinatal care. 3rd ed. Evanston, Ill.: American Academy of Pediatrics, American College of Obstetricians and Gynecologists, 1992.

  6. 6

    Lopez-Zeno JA, Peaceman AM, Adashek JA, Socol ML. A controlled trial of a program for the active management of labor. N Engl J Med 1992;326:450-454
    Full Text | Web of Science | Medline

  7. 7

    Roethlisberger FJ, Dickenson WJ. Management and the worker: an account of a research program conducted by the Western Electric Company, Hawthorne works, Chicago. Cambridge, Mass.: Harvard University Press, 1939.

  8. 8

    Turner MJ, Brassil M, Gordon H. Active management of labor associated with a decrease in the cesarean section rate in nulliparas. Obstet Gynecol 1988;71:150-154
    Web of Science | Medline

  9. 9

    Akoury HA, Brodie G, Caddick R, McLaughin VD, Pugh PA. Active management of labor and operative delivery in nulliparous women. Am J Obstet Gynecol 1988;158:255-258
    Web of Science | Medline

Citing Articles (101)

Citing Articles

  1. 1

    Vanitha Janakiraman, Jane Lazar, Karen E. Joynt, Ashish K. Jha. (2011) Hospital Volume, Provider Volume, and Complications After Childbirth in U.S. Hospitals. Obstetrics & Gynecology 118:3, 521-527
    CrossRef

  2. 2

    George J Bugg, Farah Siddiqui, Jim G Thornton, George J Bugg. 2011. Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour. .
    CrossRef

  3. 3

    Tekoa L. King. (2011) Can a Vaginal Birth After Cesarean Delivery be a Normal Labor and Birth? Lessons from Midwifery Applied to Trial of Labor After a Previous Cesarean Delivery. Clinics in Perinatology 38:2, 247-263
    CrossRef

  4. 4

    Kathleen Rice Simpson. (2011) Clinicians’ Guide to the Use of Oxytocin for Labor Induction and Augmentation. Journal of Midwifery & Women's Health 56:3, 214-221
    CrossRef

  5. 5

    Shu-Qin Wei, Zhong-Cheng Luo, Hui-Ping Qi, Hairong Xu, William D. Fraser. (2010) High-dose vs low-dose oxytocin for labor augmentation: a systematic review. American Journal of Obstetrics and Gynecology 203:4, 296-304
    CrossRef

  6. 6

    Munir`deen A. Ijaiya, Kike T. Adesina, Hadijat O. Raji, Abiodun P. Aboyeji, AbdulWaheed O. Olatinwo, Abiodun S. Adeniran, Idowu O. Adebara, Salamat Isiaka-Law. (2010) Duration of Labour with Spontaneous Onset at the University of Ilorin Teaching Hospital, Ilorin, Nigeria. Research Journal of Medical Sciences 4:3, 195-198
    CrossRef

  7. 7

    Denis Walsh. 2010. Labour Rhythms. , 63-80.
    CrossRef

  8. 8

    Shu-Qin Wei, Zhong-Cheng Luo, Hairong Xu, William D. Fraser. (2009) The Effect of Early Oxytocin Augmentation in Labor. Obstetrics & Gynecology 114:3, 641-649
    CrossRef

  9. 9

    Lawrence D. Devoe. (2009) The future of intrapartum care: navigating the perfect storm—an obstetrician's odyssey. American Journal of Obstetrics and Gynecology 201:1, 100-104
    CrossRef

  10. 10

    Shuqin Wei, Bi Lan Wo, Hairong Xu, Zhong-Cheng Luo, Chantal Roy, William D Fraser, William D Fraser. 2009. Early amniotomy and early oxytocin for prevention of, or therapy for, delay in first stage spontaneous labour compared with routine care. .
    CrossRef

  11. 11

    A Dencker, M Berg, L Bergqvist, L Ladfors, LS Thorsén, H Lilja. (2009) Early versus delayed oxytocin augmentation in nulliparous women with prolonged labour-a randomised controlled trial. BJOG: An International Journal of Obstetrics & Gynaecology 116:4, 530-536
    CrossRef

  12. 12

    Rainer Lenhardt, Martin Grady, Andrea Kurz. (2008) Hyperthermia during anaesthesia and intensive care unit stay. Best Practice & Research Clinical Anaesthesiology 22:4, 669-694
    CrossRef

  13. 13

    Vincenzo Berghella, Jason K. Baxter, Suneet P. Chauhan. (2008) Evidence-based labor and delivery management. American Journal of Obstetrics and Gynecology 199:5, 445-454
    CrossRef

  14. 14

    Heather C Brown, Shantini Paranjothy, Therese Dowswell, Jane Thomas, Heather C Brown. 2008. Package of care for active management in labour for reducing caesarean section rates in low-risk women. .
    CrossRef

  15. 15

    Julie Brown, Anne Lethaby, Heather Maxwell, Andrew J Wawrzyniak, Martin H Prins, Julie Brown. 2008. Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery. .
    CrossRef

  16. 16

    K Hinshaw, S Simpson, S Cummings, A Hildreth, J Thornton. (2008) A randomised controlled trial of early versus delayed oxytocin augmentation to treat primary dysfunctional labour in nulliparous women. BJOG: An International Journal of Obstetrics & Gynaecology 115:10, 1289-1296
    CrossRef

  17. 17

    Astrid Nystedt, Ulf Hgberg, Berit Lundman. (2008) Womens experiences of becoming a mother after prolonged labour. Journal of Advanced Nursing 63:3, 250-258
    CrossRef

  18. 18

    Anna Stålhammar, Barbro Boström. (2008) Policies for labour management – existence and content. Scandinavian Journal of Caring Sciences 22:2, 259-264
    CrossRef

  19. 19

    Edward J. Hayes, Louis Weinstein. (2008) Improving patient safety and uniformity of care by a standardized regimen for the use of oxytocin. American Journal of Obstetrics and Gynecology 198:6, 622.e1-622.e7
    CrossRef

  20. 20

    Shmuel Evron, Tiberiu Ezri, Michael Protianov, Gleb Muzikant, Oscar Sadan, Amir Herman, Peter Szmuk. (2008) The effects of remifentanil or acetaminophen with epidural ropivacaine on body temperature during labor. Journal of Anesthesia 22:2, 105-111
    CrossRef

  21. 21

    LA Samuels, L Christie, B Roberts-Gittens, H Fletcher, J Frederick. (2007) The effect of hyoscine butylbromide on the first stage of labour in term pregnancies. BJOG: An International Journal of Obstetrics & Gynaecology 114:12, 1542-1546
    CrossRef

  22. 22

    Emin Ustunyurt, Mustafa Ugur, Basak Ozlem Ustunyurt, Tekin Can Iskender, Ovgu Ozkan, Leyla Mollamahmutoglu. (2007) Prospective randomized study of oxytocin discontinuation after the active stage of labor is established. Journal of Obstetrics and Gynaecology Research 33:6, 799-803
    CrossRef

  23. 23

    Rebecca MD Smyth, S Kate Alldred, Carolyn Markham, Rebecca MD Smyth. 2007. Amniotomy for shortening spontaneous labour. .
    CrossRef

  24. 24

    Camille Le Ray, Pauline Serres, Thomas Schmitz, Dominique Cabrol, François Goffinet. (2007) Manual Rotation in Occiput Posterior or Transverse Positions. Obstetrics & Gynecology 110:4, 873-879
    CrossRef

  25. 25

    Kathleen R. Beebe, Kathryn A. Lee, Virginia Carrieri-Kohlman, Janice Humphreys. (2007) The Effects of Childbirth Self-Efficacy and Anxiety During Pregnancy on Prehospitalization Labor. Journal of Obstetric, Gynecologic, & Neonatal Nursing 36:5, 410-418
    CrossRef

  26. 26

    Gregory D. Berg, Sandeep Wadhwa. (2007) Health Services Outcomes for a Diabetes Disease Management Program for the Elderly. Disease Management 10:4, 226-234
    CrossRef

  27. 27

    Vincenzo Berghella. 2007. Before labor and first stage of labor. , 51-57.
    CrossRef

  28. 28

    Shmuel Evron, Reshmi Parameswaran, Dov Zipori, Tiberiu Ezri, Oscar Sadan, Rumelia Koren. (2007) Activin βA in term placenta and its correlation with placental inflammation in parturients having epidural or systemic meperidine analgesia: a randomized study. Journal of Clinical Anesthesia 19:3, 168-174
    CrossRef

  29. 29

    Nils Chaillet, Alexandre Dumont. (2007) Evidence-Based Strategies for Reducing Cesarean Section Rates: A Meta-Analysis. Birth 34:1, 53-64
    CrossRef

  30. 30

    Karin Svärdby, Lennart Nordström, Eva Sellström. (2007) Primiparas with or without oxytocin augmentation: a prospective descriptive study. Journal of Clinical Nursing 16:1, 179-184
    CrossRef

  31. 31

    Karin Svärdby, Lennart Nordström, Eva Sellström. (2006) Primiparas with or without oxytocin augmentation: a prospective descriptive study. Journal of Clinical Nursing 0:0, 061206015237004-???
    CrossRef

  32. 32

    Nils Chaillet, Eric Dubé, Marylène Dugas, François Audibert, Caroline Tourigny, William D. Fraser, Alexandre Dumont. (2006) Evidence-Based Strategies for Implementing Guidelines in Obstetrics. Obstetrics & Gynecology 108:5, 1234-1245
    CrossRef

  33. 33

    Tina Lavender, Zarko Alfirevic, Stephen Walkinshaw. (2006) Effect of Different Partogram Action Lines on Birth Outcomes. Obstetrics & Gynecology 108:2, 295-302
    CrossRef

  34. 34

    Helen Cheyne, Dawn W. Dowding, Vanora Hundley. (2006) Making the diagnosis of labour: midwives' diagnostic judgement and management decisions. Journal of Advanced Nursing 53:6, 625-635
    CrossRef

  35. 35

    Andrew J. Kotaska, Michael C. Klein, Robert M. Liston. (2006) Epidural analgesia associated with low-dose oxytocin augmentation increases cesarean births: A critical look at the external validity of randomized trials. American Journal of Obstetrics and Gynecology 194:3, 809-814
    CrossRef

  36. 36

    George J. Bugg, Eleanor Stanley, Philip N Baker, Michael J Taggart, Tracey A Johnston. (2006) Outcomes of labours augmented with oxytocin. European Journal of Obstetrics & Gynecology and Reproductive Biology 124:1, 37-41
    CrossRef

  37. 37

    Alan Johnson, Gregory Berg, Edward Fleegler, Marilyn Sauerbrun. (2005) A Matched-Cohort Study of Selected Clinical and Utilization Outcomes for an Asthma Care Support Program. Disease Management 8:3, 144-154
    CrossRef

  38. 38

    A NESS, J GOLDBERG, V BERGHELLA. (2005) Abnormalities of the First and Second Stages of Labor. Obstetrics and Gynecology Clinics of North America 32:2, 201-220
    CrossRef

  39. 39

    J PATES, A SATIN. (2005) Active Management of Labor. Obstetrics and Gynecology Clinics of North America 32:2, 221-230
    CrossRef

  40. 40

    Gregory D. Berg, Edward Fleegler, Catherine J. vanVonno, Eileen Thomas. (2005) A Matched-Cohort Study of Health Services Utilization Outcomes for a Heart Failure Disease Management Program. Disease Management 8:1, 35-41
    CrossRef

  41. 41

    S. Chhabra, P. Sukanya, M. Duryodhan. (2005) Trends of caesarean sections for failure to progress: Indian rural experience. Journal of Obstetrics & Gynaecology 25:6, 575-578
    CrossRef

  42. 42

    Alan Johnson, Gregory Berg, Edward Fleegler, Jeanne Lehn. (2005) Clinical and Utilization Outcomes for a Heart Failure Care Support Program. Disease Management & Health Outcomes 13:5, 327-335
    CrossRef

  43. 43

    Gregory D. Berg, Sandeep Wadhwa, Alan E. Johnson. (2004) A Matched-Cohort Study of Health Services Utilization and Financial Outcomes for a Heart Failure Disease-Management Program in Elderly Patients. Journal of the American Geriatrics Society 52:10, 1655-1661
    CrossRef

  44. 44

    Michael E. Foley, May Alarab, Leslie Daly, Declan Keane, Ann Rath, Colm O'Herlihy. (2004) The continuing effectiveness of active management of first labor, despite a doubling in overall nulliparous cesarean delivery. American Journal of Obstetrics and Gynecology 191:3, 891-895
    CrossRef

  45. 45

    Jay M Bolnick, Maria D Velazquez, Jose L Gonzalez, Valerie J Rappaport, Gena McIlwain-Dunivan, William F Rayburn. (2004) Randomized trial between two active labor management protocols in the presence of an unfavorable cervix. American Journal of Obstetrics and Gynecology 190:1, 124-128
    CrossRef

  46. 46

    St??phane Frenea, Christine Chirossel, Rapha??l Rodriguez, Jean-Philippe Baguet, Claude Racinet, Jean-Francois Payen. (2004) The Effects of Prolonged Ambulation on Labor with Epidural Analgesia. Anesthesia & Analgesia224-229
    CrossRef

  47. 47

    S. M. Rane, R. R. Guirgis, B. Higgins, K. H. Nicolaides. (2003) Pre-induction sonographic measurement of cervical length in prolonged pregnancy: the effect of parity in the prediction of the need for Cesarean section. Ultrasound in Obstetrics and Gynecology 22:1, 45-48
    CrossRef

  48. 48

    Gregory D Berg, Alan Johnson, Edward Fleegler. (2003) Clinical and Utilization Outcomes for a Pediatric and Adolescent Telephonic Asthma Care Support Program. Disease Management & Health Outcomes 11:11, 737-743
    CrossRef

  49. 49

    T BREEN. (2003) Databases and obstetric anesthesia research: opportunity and limitations. International Journal of Obstetric Anesthesia 12:1, 1-3
    CrossRef

  50. 50

    Jeffrey B. Gross, Amy P. Cohen, Janet M. Lang, Fredric D. Frigoletto, Ellice S. Lieberman. (2002) Differences in Systemic Opioid Use Do Not Explain Increased Fever Incidence in Parturients Receiving Epidural Analgesia. Anesthesiology 97:1, 157-161
    CrossRef

  51. 51

    Mureena A. Turnquest Wells. (2002) A Guest Editorial: Safely Reducing the Cesarean Delivery Rate. Obstetrical & Gynecological Survey 57:7, 409-412
    CrossRef

  52. 52

    J Martin Bland, Janet L Peacock. (2002) Interpreting statistics with confidence. The Obstetrician & Gynaecologist 4:3, 176-180
    CrossRef

  53. 53

    Wolfgang Janni, Barbara Schiessl, Ursula Peschers, Sandra Huber, Barbara Strobl, Peer Hantschmann, Natalie Uhlmann, Thomas Dimpfl, Gerhard Rammel, Franz Kainer. (2002) The prognostic impact of a prolonged second stage of labor on maternal and fetal outcome. Acta Obstetricia et Gynecologica Scandinavica 81:3, 214-221
    CrossRef

  54. 54

    Shiv K. Sharma, James M. Alexander, Gary Messick, Steven L. Bloom, Donald D. McIntire, Jackie Wiley, Kenneth J. Leveno. (2002) Cesarean Delivery. Anesthesiology 96:3, 546-551
    CrossRef

  55. 55

    D. A. Sacks, A. Sacks. (2002) Induction of labor versus conservative management of pregnant diabetic women. Journal of Maternal-Fetal and Neonatal Medicine 12:6, 438-441
    CrossRef

  56. 56

    Jennifer L. Bailit, Stephen M. Downs, John M. Thorp. (2002) Reducing the caesarean delivery risk in elective inductions of labour: a decision analysis. Paediatric and Perinatal Epidemiology 16:1, 90-96
    CrossRef

  57. 57

    Lynn C. Sadler, Tracey Davison, Lesley M.E. McCowan. (2001) Maternal Satisfaction with Active Management of Labor: A Randomized Controlled Trial. Birth 28:4, 225-235
    CrossRef

  58. 58

    Sue Taylor, Jim Thornton. (2001) The management of normal labour. The Obstetrician & Gynaecologist 3:2, 69-73
    CrossRef

  59. 59

    Chiharu Negishi, Rainer Lenhardt, Makoto Ozaki, Katharine Ettinger, Hiva Bastanmehr, Andrew R. Bjorksten, Daniel I. Sessler. (2001) Opioids Inhibit Febrile Responses in Humans, Whereas Epidural Analgesia Does Not. Anesthesiology 94:2, 218-222
    CrossRef

  60. 60

    Edward R Newton. (2000) Epidural Analgesia, Intrapartum Fever, and Neonatal Outcomes. Birth 27:3, 206-208
    CrossRef

  61. 61

    Y. Beilin, F. Friedman, L. A. Andres, S. Hossain, C. A. Bodian. (2000) The effect of the obstetrician group and epidural analgesia on the risk for cesarean delivery in nulliparous women. Acta Anaesthesiologica Scandinavica 44:8, 959-964
    CrossRef

  62. 62

    Christopher M. Viscomi, Theodore Manullang. (2000) Maternal Fever, Neonatal Sepsis Evaluation, and Epidural Labor Analgesia. Regional Anesthesia and Pain Medicine 25:5, 549-553
    CrossRef

  63. 63

    L. C. Sadler, T. Davison, L. M. E. McCowan. (2000) A randomised controlled trial and meta-analysis of active management of labour. BJOG: An International Journal of Obstetrics and Gynaecology 107:7, 909-915
    CrossRef

  64. 64

    Lawrence C. Tsen, Scott Segal. (2000) Another Explanation. Anesthesiology 93:1, 300-301
    CrossRef

  65. 65

    SUELLEN CLAYWORTH. (2000) The Nurse's Role During Oxytocin Administration. MCN, The American Journal of Maternal/Child Nursing 25:2, 80-85
    CrossRef

  66. 66

    Lawrence Impey, Kathryn MacQuillan, Michael Robson. (2000) Epidural analgesia need not increase operative delivery rates. American Journal of Obstetrics and Gynecology 182:2, 358-363
    CrossRef

  67. 67

    N. Arnott, A. J. Harrold, Pauline Lync. (2000) Variations in oxytocin regimes in Scottish labour wards in 1998. Journal of Obstetrics & Gynaecology 20:3, 235-238
    CrossRef

  68. 68

    JAMES A. THORP. (1999) Epidural Analgesia During Labor. Clinical Obstetrics and Gynecology 42:4, 785
    CrossRef

  69. 69

    J. Christopher Glantz, Thomas J. McNanley. (1999) Active Management of Labor: A Meta-Analysis of Cesarean Delivery Rates for Dystocia in Nulliparas. Obstetrical & Gynecological Survey 54:Supplement, 87-95
    CrossRef

  70. 70

    Tina Lavender, Akhtar H Wallymahmed, Stephen A Walkinshaw. (1999) Managing Labor Using Partograms with Different Action Lines: A Prospective Study of Women's Views. Birth 26:2, 89-96
    CrossRef

  71. 71

    M SOCOL, A PEACEMAN. (1999) ACTIVE MANAGEMENT OF LABOR. Obstetrics and Gynecology Clinics of North America 26:2, 287-294
    CrossRef

  72. 72

    KATHLEEN RICE SIMPSON, G. ERIC KNOX. (1999) STRATEGIES for Developing an Evidence-Based Approach to Perinatal Care. MCN, The American Journal of Maternal/Child Nursing 24:3, 122-131
    CrossRef

  73. 73

    William Camann. (1999) Intrapartum Epidural Analgesia and Neonatal Sepsis Evaluations. Anesthesiology 90:5, 1250-1252
    CrossRef

  74. 74

    Lawrence Impey, Peter Boylan. (1999) Active management of labour revisited. BJOG: An International Journal of Obstetrics and Gynaecology 106:3, 183-187
    CrossRef

  75. 75

    Lois H Thomas, Nicky A Cullum, Elaine McColl, Nikki Rousseau, Jennifer Soutter, Nick Steen, Lois H Thomas. 1999. Guidelines in professions allied to medicine. .
    CrossRef

  76. 76

    Sachs, Benjamin P., Kobelin, Cindy, , Castro, Mary Ames, Frigoletto, Fredric, . (1999) The Risks of Lowering the Cesarean-Delivery Rate. New England Journal of Medicine 340:1, 54-57
    Full Text

  77. 77

    Tina Lavender, Zarko Alfirevic, Stephen Walkinshaw. (1998) Partogram action line study: a randomised trial. BJOG: An International Journal of Obstetrics and Gynaecology 105:9, 976-980
    CrossRef

  78. 78

    Nicholas Kadar. (1998) Quasi-randomized trials. Gynaecological Endoscopy 7:4, 219-219
    CrossRef

  79. 79

    Marie-Louise Berg-Lekås, Ulf Högberg, Anna Winkvist. (1998) Familial occurrence of dystocia. American Journal of Obstetrics and Gynecology 179:1, 117-121
    CrossRef

  80. 80

    JAMES A. THORP. (1998) Epidural Analgesia for Labor: Effect on the Cesarean Birth Rate. Clinical Obstetrics and Gynecology 41:2, 449-460
    CrossRef

  81. 81

    Theodore G. Cheek, Edward T. McGonigal. (1998) Epidural anesthesia and the progress of labor. Current Opinion in Anaesthesiology 11:3, 265-269
    CrossRef

  82. 82

    C. R. Leitch, J. J. Walker. (1998) The rise in caesarean section rate: the same indications but a lower threshold. BJOG: An International Journal of Obstetrics and Gynaecology 105:6, 621-626
    CrossRef

  83. 83

    William Fraser, Francoise Vendittelli, Isabelle Krauss, +Gerard Breart. (1998) Effects of early augmentation of labour with amniotomy and oxytocin in nulliparous women: a meta-analysis. BJOG: An International Journal of Obstetrics and Gynaecology 105:2, 189-194
    CrossRef

  84. 84

    Nageotte, Michael P., Larson, David, Rumney, Pamela J., Sidhu, Mohan, Hollenbach, Katherine, . (1997) Epidural Analgesia Compared with Combined Spinal–Epidural Analgesia during Labor in Nulliparous Women. New England Journal of Medicine 337:24, 1715-1719
    Full Text

  85. 85

    JOSÉ A. LOPÉZ-ZENO. (1997) Active Management of Labor: The American Experience. Clinical Obstetrics and Gynecology 40:3, 510-515
    CrossRef

  86. 86

    Rebecca Rogers, George J. Gilson, Anthony C. Miller, Luis E. Izquierdo, Luis B. Curet, Clifford R. Qualls. (1997) Active management of labor: Does it make a difference?. American Journal of Obstetrics and Gynecology 177:3, 599-605
    CrossRef

  87. 87

    J. Christopher Glantz, Thomas J. McNanley. (1997) Active Management of Labor. Obstetrical & Gynecological Survey 52:8, 497-505
    CrossRef

  88. 88

    (1997) The whole duty of obstetricians. BJOG: An International Journal of Obstetrics and Gynaecology 104:4, 387-392
    CrossRef

  89. 89

    Ellice Lieberman, Janet M. Lang, Amy P. Cohen, Fredric D. Frigoletto, David Acker, Rajni Rao. (1997) The association of fetal sex with the rate of cesarean section. American Journal of Obstetrics and Gynecology 176:3, 667-671
    CrossRef

  90. 90

    N. Manassiev. (1997) The active mismanagement of labour. BJOG: An International Journal of Obstetrics and Gynaecology 104:2, 272-272
    CrossRef

  91. 91

    T. H. Bloomfield. (1997) The active mismanagement of labour. BJOG: An International Journal of Obstetrics and Gynaecology 104:2, 271-272
    CrossRef

  92. 92

    Patricia Crowley. (1996) 4 Using an overview. Baillière's Clinical Obstetrics and Gynaecology 10:4, 585-597
    CrossRef

  93. 93

    Paul, Richard H., . (1996) Toward Fewer Cesarean Sections — The Role of a Trial of Labor. New England Journal of Medicine 335:10, 735-736
    Full Text

  94. 94

    Elizabeth Shearer. (1996) Once a Cesarean, Always a Scar. Birth 23:3, 172-175
    CrossRef

  95. 95

    Richard P. Porreco, James A. Thorp. (1996) The cesarean birth epidemic: Trends, causes, and solutions. American Journal of Obstetrics and Gynecology 175:2, 369-374
    CrossRef

  96. 96

    Alan M. Peaceman, Michael L. Socol. (1996) Active management of labor. American Journal of Obstetrics and Gynecology 175:2, 363-368
    CrossRef

  97. 97

    Karl S. Olaih, Harry Gee. (1996) The active mismanagement of labour. BJOG: An International Journal of Obstetrics and Gynaecology 103:8, 729-731
    CrossRef

  98. 98

    James A. Thorp, Ginger Breedlove. (1996) Epidural Analgesia in Labor: An Evaluation of Risks and Benefits. Birth 23:2, 63-83
    CrossRef

  99. 99

    (1996) Amniotomy with Oxytocin to Induce and Augment Labour-Be Selective. BJOG: An International Journal of Obstetrics and Gynaecology 103:4, vii-viii
    CrossRef

  100. 100

    (1996) A Clinical Trial of Active Management of Labor. New England Journal of Medicine 334:12, 797-799
    Full Text

  101. 101

    James A Thorp, Peter E Nielsen. (1996) The effect of epidural analgesia on labour progress and mode of delivery. Fetal and Maternal Medicine Review 8:01, 29
    CrossRef