FEATURES

Length of Normal Laborin Women of Hispanic OriginMarcia Jones, CNM, ND, and Elaine Larson, RN, PhD

Emanuel Friedman in the 1950s established means and statistical guidelines for normal lengths of labor. Thechildbearing population in the United States has changed considerably since Friedman’s research wasconducted. This study documented the duration of labor in a cohort of 240 Hispanic women who had normalvaginal births of singleton term infants from January 1995 through December 1998 and compared theseresults with the mean duration of the first and second stages of labor as established by Friedman. The meanduration of the active phase first stage labor duration for nulliparous Hispanic women was 6.2 hours, and formultiparous Hispanic women was 4.4 hours, both significantly longer than Friedman’s group (P � .01). Themean duration of the second stage of labor in nulliparous Hispanic women was 54.2 minutes and formultiparous Hispanic women was 22.2 minutes, not significantly different from Friedman’s group (P � .5 andP � .09, respectively). J Midwifery Womens Health 2003;48:2–9 © 2003 by the American College ofNurse-Midwives.keywords: first stage labor, stage second labor, labor complications

INTRODUCTION

An understanding of the norms and limits of the lengths oflabor is helpful in assessing labor variations and influencingmanagement decisions for labor and delivery. Currentclinical practice guidelines recommend that any laborexceeding two standard deviations beyond the mean iden-tified in Friedman’s seminal study in the 1950s of the lengthof labor be labeled as dysfunctional labor. A review ofFriedman’s1–3 work revealed that he did not investigate therelationship between ethnicity and labor lengths, yet hisguidelines have been held as the benchmark against whichprogress in labor has been measured without regard toracial and ethnic characteristics.

The childbearing population in the United States haschanged considerably in its ethnic mix since Friedman firstestablished the guidelines for the lengths of labor. Accord-ing to the Census Bureau of the United States Departmentof Commerce,4 the Hispanic population in the United Statesin the 2000 census numbered 32.8 million or 12% of thetotal population, making the U.S. Hispanic population thefifth largest in the world.

Despite growing numbers and the high birth rates ofHispanic women, only a few studies have investigated theirlengths of labor.5–7 Albers et al.5 examined the labors ofHispanic women residing in New Mexico and Albers6

multicenter study examined the labors of Hispanic womenresiding in New Mexico, California, Washington, RhodeIsland, Minnesota, Pennsylvania, Vermont, and NewHampshire. They found that Hispanic women, regardless of

parity, have longer active phases in the first stage of laborthan the means established by Friedman. Diegmann et al.7

concluded that Hispanic nulliparous women have shortersecond-stage labors than those noted by Friedman. Limita-tions of this study, however, were that only Hispanics ofPuerto Rican origin were included, and they did not controlfor the size of the baby.

The purpose of this study was to examine the relationshipbetween ethnicity and the duration of labor in Hispanicimmigrant women from several Latin American and Carib-bean countries and to compare these results with the meanduration of the first and second stages of labor as estab-lished by Friedman.

BACKGROUND

Emanuel Friedman1 conceived a simple mathematicalschema to quantify labor. He studied in detail the laborpatterns of a convenience sample of 100 Caucasian Amer-ican nulliparous women who presented in spontaneouslabor at Sloane Hospital for Women, Columbia Presbyte-rian Medical Center, New York. As described by Friedman,a square-ruled graph paper was used with 10 divisionsalong the ordinate to represent the cervical dilatation incentimeters; each corresponding division along the abscissadenoted time in hours. The readings were entered andjoined to the preceding notation by a straight line (p. 1570).A typical S-shaped or sigmoid curve for each individual’slabor was noted. The curve was divided into two stages.The first stage was further subdivided into phases. Fried-man analyzed the different sections of the labor curvemathematically and calculated (graphicostatistical analysis)normal limits of each phase for each stage of labor. Thisapproach to documenting labor gave clinicians a simple,

Address correspondence to Marcia Jones, CNM, ND, Columbia UniversitySchool of Nursing, 630 West 168 Street, New York NY 10032.

2 Volume 48, No. 1, January/February 2003© 2003 by the American College of Nurse-Midwives 1526-9523/03/$30.00• doi:10.1016/S1526-9523(02)00367-7Issued by Elsevier

graphic, objective, and scientific way in which they couldquantify and evaluate individual progress in labor.

Subsequently, Friedman2 studied the labor patterns of500 white American nulliparous women at the same hos-pital. There were 202 patients who had normal spontaneousvaginal deliveries. Low forceps were used in 256 patients,and mid-forceps were used in 19 patients. There were 14breech deliveries, 4 twin births, 69 pitocin inductions, andcaudal anesthesia was used in 42 labors. Cervical dilationwas assessed by rectal and vaginal examinations; findingswere entered on square-ruled graph paper by using anordinate of cervical dilatation in centimeters and an ab-scissa of time in hours. A sigmoid curve was again noted.Friedman examined the separate phases of the 500 curvesand calculated values for each phase to establish the meanand statistical limits (2 SDs � mean). For nulliparouswomen, he found that the mean for the active phase of laborwas 4.9 hours (�SD � 3.4), statistical limit 11.7 hours (i.e.,2 SD � mean), and the mean for the second stage of laborwas 0.95 hours (�57 minutes), statistical limit 54 minutes.Cephalic-pelvic disproportion, malposition, early rupturedmembranes, high levels of narcotic medication, and con-duction anesthesia were identified as possible etiologicfactors that prolonged labors.

In 1956, Friedman3 turned the focus of his research tomultiparous women. Again, he based his study on a sampleof 500 white American women who delivered at the samehospital. The age range for his sample was 17 to 43 years,with 254 birthing for the second time; 126 paras birthing forthe third time; 71 having a fourth birth; 30 with their fifth;and 19 grand multiparas with six and greater births. Hissample included 373 patients with spontaneous deliveries;12-assisted breech births; 101 low forceps; nine mid-forceps; including version and extraction in one woman.Only five cases resulted in cesarean birth; 75 women werenoted to have a fetus in the occipito-posterior position; 56were given pitocin; 53 had caudal anesthesia. In thispopulation, 26 infants weighed less than 2.5 kg and 29weighed more than 4 kg. Friedman3 calculated the mean forthe active phase of labor as 2.2 hours (�SD � 1.5),statistical limit 5.2 hours. The mean for the second stage oflabor was 18 minutes (�SD 18), statistical limit 54 min-utes. In his later work, Friedman8 and Friedman andKroll9,10 managed to amass a large data pool. He studiedmore than 10,000 women from 12 different sites, enablinghim to draw compelling conclusions. The statistical guide-lines reported by Friedman in the 1950s were so similar tothe findings of his later studies that the means and statisticalvalues of his 1955 and 1956 works continued to be used as

the norm for comparison with other groups. Based on theresults of these studies, Friedman recommended that clini-cians use the mean � 2 SDs to designate the upper limits ofnormal duration of labor.

In some practice settings, labors extending beyond Fried-man’s limits are considered dysfunctional and practiceguidelines recommend intervention for prolonged labor.Prolonged labors are presumed to cause fetal intolerance oflabor, maternal infection, and excessive blood loss. Tradi-tionally, obstetric providers have responded by attemptingto abbreviate these labors with procedures such as am-niotomy, administering drugs such as oxytocin, or perform-ing instrumental or operative deliveries.

Because there are increasing numbers of Hispanicwomen birthing in the United States and because only a fewstudies have investigated their lengths of labor in Hispanicwomen, this study investigated the relationship betweenHispanic ethnicity and labor lengths and compared themwith the mean duration of the first and second stages oflabor as established by Friedman.

METHODS

Research Design

This retrospective, comparative study documented thelengths of the first and second stages of labor for a randomsample of Hispanic women who had normal spontaneous,uncomplicated vaginal births of singleton term infants fromJanuary 1995 through December 1998 in New York. Datawere compiled on the lengths of labors of 240 Hispanicnulliparous and multiparous women who immigrated to theUnited States from Mexico, Ecuador, Guatemala, Peru, TheDominican Republic, Columbia, El Salvador, Paraguay,Uruguay, Chile, Honduras, and Bolivia. The results werecompared with the statistical guidelines for labors asreported by Emanuel Friedman.2,3

Human Subject Approval and Informed Consent

Human subject approval was obtained from Case WesternReserve University’s Institutional Review Board and fromthe study hospital. The study was conducted at PhelpsMemorial Hospital Center in Westchester County, NewYork. This community hospital’s obstetric service predom-inantly cares for women with low-risk pregnancies. Thereare about 750 births a year in this setting of whichmidwives do approximately 50%. Ninety percent of thewomen have the same midwife in attendance during theirentire labors.

The sample included normal uncomplicated labors of His-panic nulliparous and multiparous women, aged 15 to 44, whohad a spontaneous labor at term (37–42 weeks’ completedgestation) and gave birth to a singleton baby in the vertexpresentation. Multiple pregnancies and malpresentation wereexcluded because of the known relationship to labor compli-cations. Labors complicated by cephalopelvic disproportion,

Marcia Jones, CNM, ND, is a midwife and assistant clinical professor in theGraduate Nurse-Midwifery Program at Columbia University, New York, NY.

Elaine Larson, RN, PhD, FAAN, CIC, is Professor of Therapeutic andPharmaceutical Research, Columbia University School of Nursing and Pro-fessor of Epidemiology, Columbia School of Public Health, New York, NY.

Journal of Midwifery & Women’s Health • www.jmwh.org 3

forceps, vacuum, cesarean birth, prematurity, prolonged rup-tured membranes, and those labors complicated by social andmedical problems (substance abuse, hypertension, diabetes,and asthma) were excluded. Women with labors that wereinduced or augmented with oxytocin and those involvingregional anesthesia were also excluded. Sample size wascalculated at an alpha level of .05 and assumption of a mediumeffect size of .50 and a one-tail directional test of significance.A sample of 120 nulliparous and 120 multiparous women wasdetermined to have 95% power to detect a 50% difference inlength of labor.

All women who self-identified themselves as Hispanicand were registered in the nurse-midwifery service receivedprenatal care in one of four clinics located in the greaterWhite Plains area of Westchester and presented in labor atthe study hospital were eligible for the study. Demographicand obstetric data were collected as a part of the usualhistory on all women attending prenatal clinics. After eachbirth, the demographic, obstetric, and intrapartum data foreach woman were recorded in birth logs, kept on the laborand delivery unit.

The Hispanic ethnic group was defined as any woman whoidentified herself during the prenatal period as Hispanic andwho was born outside of the United States. The length of theactive phase first stage of labor was measured in hours andminutes from the time the cervix was first documented to be 4cm dilated to the time that the cervix was first documented tobe completely dilated. The length of the second stage of laborwas measured in hours and minutes from the time the cervixwas first documented to be completely dilated to the timewhen the infant was born. Vaginal examinations were per-formed on average every 3 hours.

Using Cohen’s11 table of random numbers, 600 birthrecords for the time period of January 1995 throughDecember 1998 were identified for review. Preliminarydata were collected from the birth logs. Demographic andobstetric data for country of origin age, parity, gestationalage, time of birth, Apgar scores, type of episiotomy,laceration, blood loss, and sex of the infant were initiallyobtained from the birth logs and then compared with thebirth records for accuracy. The birth records were consid-ered primary sources of data. The birth records wereorganized in a consistent and uniformed way with certainstandardized forms that had preset places for providers tochart specific demographic and obstetric and intrapartuminformation. Charting was usually performed soon afterevents or actions were taken, and as such, the birth recordswere accepted as reflecting the clinical situation withminimum recall bias.

Because the initial starting point of active phase first-stage labor was defined as 4-cm dilation to be included inthe study as the first stage of labor, the birth records had tohave a documented time for the cervix being exactly 4 cm.If the cervical dilatation was recorded as a range (e.g., 3–4cm or 4–5 cm), or if the initial cervical dilation onadmission was documented to be beyond 4 cm, these caseswere eliminated from the study. One hundred two birthrecords were eliminated because initial cervical dilation onadmission was beyond 4 cm. The investigators also cross-checked the entries of the nurse-midwives and the nurses toverify that the recorded data for time and measurement ofcervical dilation were consistent. Twelve birth records werefound to have discrepancies on cervical dilatation, andthese birth records were eliminated from the sample pool.In total, 194 birth records (33%) were eliminated secondaryto not meeting the inclusion criteria or because of incom-plete or contradictory data. The birth records of 120nulliparous and 120 multiparous women were then ran-domly selected for from the remaining 406 birth records.

Data were analyzed by using SPSS software.12 Meansand SDs and statistical limits of 2 SDs from the mean werecalculated for the length of the active phase first stage oflabor and second stage labor in nulliparous and multiparouswomen. The Student’s t-test and a Cochran Cox t-test (amodified t test) were used to compare mean length of laborin the study population with those of Friedman. Multivar-iate regression analyses were used to identify predictors of

Table 1. Hispanic Country of Origin by Parity

Country of Origin Nulliparas Multiparas Total (%)

Mexico 45 37 82 (34.2)Ecuador 19 28 47 (19.6)Guatemala 13 13 26 (10.8)Peru 15 11 26 (10.8)Dominican Republic 10 7 17 (7.1)El Salvador 3 12 15 (6.2)Columbia 8 6 14 (5.9)Paraguay 2 2 4 (1.7)Honduras 1 3 4 (1.7)Bolivia 2 2 1 3 (1.3)Chile 1 0 1 (0.4)Uruguay 1 0 1 (0.4)Total 120 120 240 (100)

Table 2. Demographic and Intrapartum Variables

Variable

Nulliparas(%)

(n � 120)

Multiparas(%)

(n � 120)

Total(%)

(n � 240)

Maternal age (y)�20 21.7 3.3 12.520–25 47.5 44.2 45.825–30 21.7 28.3 25.030–35 3.3 18.3 10.8�35 5.8 5.8 5.8

Birth weight (kg)�2.5 4.2 0.8 2.52.5–3.0 23.3 25.0 24.23.0–3.5 35.8 35.8 35.83.5–4.0 34.2 30.0 32.1�4 2.5 8.3 5.4

4 Volume 48, No. 1, January/February 2003

length of first and second stages of labor. Variables exam-ined in the model were maternal age, parity, and gestationalage, infant birthright, and country of origin. For additionalanalyses, parity, maternal age, and infant weight werestratified into groups, and country of origin was dividedinto two regions: Central and South America.

RESULTS

The normal uncomplicated labors of 240 Hispanic womenwere analyzed. Hispanic women originated from 12 coun-

tries (Table 1). The majority of the women originated fromMexico, Ecuador, Peru, and Guatemala, 60% of the His-panic women originated from Central America, and 40%were from South America.

Table 2 shows frequency distribution for demographicand intrapartum variables by parity for maternal age andinfant birth weights. The maternal age ranged from 16 to 43years with an average age of 25.7 years. Gestational ageranged from 37 to 42 weeks, with an average gestation ageof 39.5 weeks. Approximately 7% of the women received

Table 3. Nulliparous Length of Active Phase First-Stage and Second-Stage Labor

Variable

Active First-Stage Labor (h) Second Stage (min)

N Mean (SD) Stat Limit* Mean (SD) Stat Limit*

Total 120 6.2 (3.6) 13.4 54.2 (42.8) 139.8Maternal age (y)

�20 26 5.8 (2.9) 11.6 53.7 (46.7) 147.120–25 57 5.8 (3.7) 13.2 52.8 (40.9) 134.625–30 26 6.8 (3.8) 14.4 53.6 (38.6) 130.8�30 11 7.3 (4.3) 15.9 64.3 (56.3) 176.9

Birth weight (kg)�2.5 5 5.4 (2.2) 6.8 43.6 (19.3) 82.22.5–3.0 28 6.1 (3.1) 12.3 35.8 (32.4) 100.63.0–3.5 43 6.2 (3.6) 13.4 51.8 (43.3) 138.43.5–4.0 41 6.2 (4.0) 14.2 65.6 (44.2) 154.0�4 3 9.2 (6.3) 21.8 123.0 (19.0) 161.0

Regional originCentral American 72 6.1 (3.4) 12.9 47.3 (36.1) 119.5South American 48 6.3 (4.0) 14.3 64.5 (49.8) 164.1

*Stat. Limit � 2 SD � mean.

Table 4. Multiparous Length of Active Phase First-Stage and Second-Stage Labor

Variable

Active First-Stage Labor (h) Second stage (min)

N Mean (SD) Stat. Limit* Mean (SD) Stat. Limit*

Total 120 4.4 (3.4) 11.6 22.2 (27.5) 76.5Parity

1 84 4.4 (3.2) 0.8 24.8 (31.2) 87.22 30 5.4 (3.6) 12.6 16.9 (12.7) 42.33 6 3.6 (4.9) 13.4 6.0 (3.2) 12.4

Maternal age (y)�20 4 2.8 (1.3) 5.4 10.5 (7.9) 26.320–25 53 4.4 (3.4) 11.2 19.8 (22.8) 65.425–30 34 4.8 (4.0) 12.8 22.1 (24.4) 70.9�30 29 49 (3.2) 11.3 27.2 (37.9) 103.0

Birth weight (kg)�2.5 1 0.75 0.75 10.0 10.02.5–3.0 30 4.2 (3.4) 11.0 20.4 (32.7) 85.83.0–3.5 43 4.4 (3.5) 11.4 16.6 (31.7) 80.03.5–4.0 36 4.9 (3.1) 11.1 28.9 (31.7) 92.3�4 10 5.9 (4.5) 14.9 26.0 (35.0) 96.0

Region of originCentral American 72 4.7 (3.6) 11.9 19.0 (20.6) 60.2South American 48 4.5 (3.2) 10.9 26.5 (34.9) 96.3

*Stat. Limit � 2 SD � mean.

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pain medication during labor (Stadol 2 mg or Demerol 50mg with Phenergan 25 mg). Thirty-eight percent of thewomen had intact perineum, 42% had first-degree lacera-tions, 19% had second-degree lacerations, and 1% hadmidline episiotomies. Blood loss ranged from 50 to 800mL, with an average blood loss of 300 mL. Only threewomen had blood loss greater than 500 mL. Six infants hadbirth weights less than 2.5 kg. These six infants werefull-term infants without documentation of intrauterinegrowth restriction. Thirteen infants weighed more than 4kg; none of the infants over 4 kg had any documentation oftrauma or shoulder dystocia. Two infants had Apgar scoresless than 5 at 1 minute, and all infants had Apgar scoresgreater than 8 at 5 minutes. All infants had a normaloutcome, no infants were admitted to the neonatal intensivecare unit, and all 240 women and their infants weredischarged home within 48 hours in good health.

Parity, maternal age, and infant weight were stratifiedinto groups. Country of origin was divided into Central andSouth America regions. The mean length and statisticallimits for length of the active phase and second stages oflabor for the nulliparous group and multiparous groups,respectively, are shown in Tables 3 and 4. As parity

increased, the length of labor decreased, but as maternal ageand birth weight increased, the mean length of the activephase and second stages of labor increased in both thenulliparous and multiparous groups. South American His-panic women were also noted to have longer labors thanwomen from Central America.

Table 5 shows the length of the active-phase and secondstages of labor by parity compared with Friedman’s stud-ies.2,3 The mean duration of the active phase of labor was6.2 hours in nulliparas and 4.4 hours in multiparas. His-panic women had significantly longer active phases thanFriedman’s group (P � .01). The mean duration of thesecond stage of labor was 54.2 minutes in nulliparas and22.2 minutes for multiparas. Hispanic women did not havesignificantly longer second-stage labors than Friedman’sgroup (P � .5 for nulliparas and .09 for multiparas).

Variables related to prolonged active phase first-stageand second-stage labor according to parity were assessedvia logistic regression (Table 6). In the nulliparous group,there was a significant association between prolongedsecond stage and infant weight at birth (P � .01). In themultiparous group, increasing parity was associated withshortening of the second stage of labor (P � 0.05).

Table 5. Mean Length of Active-Phase First Stage and Second Stage of Labor by Parity

Friedman2,3 Current Study

Mean (� SD) Statistical Limit Mean (� SD) Statistical Limit *P Value

NulliparousActive phase first stage (h) 4.9 (3.4) 11.7 6.2 (3.6) 13.4 0.00Second stage (min) 57 (48) 153 54.2 (42.8) 139.8 0.5

MultiparousActive phase first stage (h) 2.2 (1.5) 5.2 4.4 (3.4) 11.6 0.00Second stage (min) 18 (18) 54 22.2 (27.5) 76.5 0.09

*T test comparing current study with Friedman; P � .05, significant difference in mean.

Table 6. Factors Associated with Length of Length of Labor

Active-Phase First-Stage Labor Second-Stage Labor

*OR (95% CI) P Value *OR (95% CI) P Value

NulliparasMaternal age 4.0 (�3.3, 11.5) 0.27 0.4 (�1.0, 1.7) 0.59Gestationalage

25.6 (�14.4, 65.7) 0.20 �0.97 (�8.4, 6.5) 0.78

Birth weight 1.1 (�46.4, 48.7) 0.96 15.26 (6.4, 24.1) 0.01Multiparas

Parity 14.4 (�52.7, 81.5) 0.67 �9.2 (�17.8, �0.5) 0.04Maternal age 3.8 (�4.2, 11.8) 0.35 0.5 (�0.48, 1.6) 0.29Gestationalage

17.7 (�17.2, 52.5) 0.31 �00.7 (�17.8, �0.5) 0.99

Birth weight 28.1 (�60.6, 116.8) 0.53 5.8 (�5.6, 17.3) 0.32

OR, odds ratio; CI, confidence interval; P � .05, significant difference in mean.

6 Volume 48, No. 1, January/February 2003

Maternal age and gestational age were not significantlyassociated with prolonged active phase first-stage or sec-ond-stage labor.

DISCUSSION

A retrospective sample of 240 healthy Hispanic womenwith normal spontaneous uncomplicated vaginal deliveriesof singleton term infants revealed significant differences inthe mean lengths of the active phase of labor, but nosignificant differences were found in the second stage oflabor compared with Friedman’s norms.2,3 The measure-ment of the active phase of the first stage of labor started at4 cm in the current study. It is possible that there weremeasurement differences between the study sample andFriedman’s sample. Friedman2,3 plotted cervical dilationagainst time and developed a graphic representation of asigmoid curve for normal labor. The upswing of the graphor the point at which the curve changed was designated asthe start of active phase of first-stage labor. On Friedman’sgraph, this starting point was depicted as 3 cm. In thecurrent study, 4 cm was used as the starting point, anddespite this fact, the results showed significantly longerlabors than Friedman.

In the analysis of labor lengths, Friedman2,3 explored theeffects of heavy sedation, pictocin use, cephalopelvic dis-proportion, occiput-posterior position, different types ofdelivery, childbirth preparation, time of ruptured mem-branes, parity, maternal age, and infant weight. Friedmanidentified cephalic-pelvic disproportion, malposition, earlyrupture of membranes, high levels of narcotic medication,and conduction anesthesia as possible etiologic factors thatprolonged labors. Because the sample in the current studywas selected to exclude many of these factors, only thevariables of parity, maternal age, and infant weight werecompared in detail.

Friedman3 found that as parity increased, the length ofthe active phase and second stage of labor both decreased.The current study supports these findings; Hispanic nullip-arous women had the longest lengths of labors, and mul-tiparous women had the shortest lengths of labors. Inparticular within the multiparous group, as parity increasedfrom a parity of 1 to 3, the mean length of the active phaseof labor decreased by approximately 1 hour, whereas thesecond stage decreased by approximately 8 to 10 minutes.

Friedman2 found that the duration of the active phase oflabor increased in nulliparas as infant weight increased. Inthe current study, a similar trend was noted: as infantweight increased, the length of the labor also increased.This finding was statistically significant for the secondstage of labor in the nulliparous group (P � .01). In themultiparous group, Friedman3 found no correlation be-tween infant weight and length of the first or second stagesof labor. Similarly, in the current study, infant weight wasnot a significant factor affecting length of labor in themultiparous group. A possible explanation for this is thatthe increase in parity may have countered the effect ofinfant weight on labor length.

Friedman2,3 found no significant correlation betweenmaternal age and length of labor. Maternal age did notsignificantly affect the length of active phase first-stage orsecond-stage labor in either the nulliparous or multiparousgroup in the current study. Diegmann et al.7 also reportedthat age was not a factor in the length of second stage laborfor Puerto Rican women. In contrast, Albers6 found thatmaternal age over 30 years was associated with prolongedsecond stage, particularly in nulliparas.

The current study did not control for insurance status,continuous fetal monitoring, amniotomy, positionalchanges, and emotional support, all of which are thought toinfluence length of labor. Albers6 found that that ambula-tion was positively associated with prolonged active phasefirst-stage labor only, whereas continuous fetal monitoringwas positively associated with the prolongation of both theactive phase first stage and second stages of labors regard-less of parity.

This research focused exclusively on a single health carefacility in New York State, leaving questions about regionalvariations across the United States. When the current studywas compared with the studies that have investigatedlengths of labor in Hispanic women,5–7 some similaritiesand a few differences were noted. Comparative results ofthe current study and the research of Albers, Diegmann, andFriedman2,3,5,7 are displayed in Table 7.

The mean length of the active phase of labor in nulliparouswomen in the studies by Albers et al.5 and Albers6 wasconsistently 2.1 hours longer than the findings of the currentstudy, and the mean length of the active phase of labor in

Table 7. Comparison of Length of Labor Between Hispanics and Friedman

Current Study Friedman2,3 Albers5 Albers6 Diegmann7

NulliparousActive phase first stage in hours (� SD) 6.2 (3.6) 4.9 (3.4) 8.3 (6.8) 8.3 (5.4) —Second stage in minutes (� SD) 54.2 (42.8) 57 (48) 54 (40.8) 51 (39) 43.8 (0.33)

MultiparousActive phase first stage in hours (� SD) 4.4 (3.4) 2.2 (1.5) 5.3 (3.6) 6.2 (4.4) —Second stage in minutes (� SD) 22.2 (27.5) 18 (18) 17 (18.6) 16 (18.6) —

Journal of Midwifery & Women’s Health • www.jmwh.org 7

multiparous women ranged from 0.6 to 0.9 hours longer thannoted in the current study. There were no notable differencesbetween the current study and Albers5,6 in the mean length ofthe second stages of labor in either nulliparous or multiparouswomen.

The reasons for the significant difference in the meanlength of the active phase of labor in the nulliparous groupis unclear. The sample populations in Albers’ studies weremainly from practices in New Mexico and California. TheHispanic population residing in New Mexico and Californiaare primarily Mexican American. It is possible that theHispanics in the studies by Albers were more homoge-neous. Similarly, the longer length of second-stage laborreported by Diegmann et al.7 may be due to the homoge-neity of the group, in that the Hispanics in that group wereall of Puerto Rican origin.

The current study reflected a diverse group of Hispanicwomen who originated from 12 countries, and the differencein results may in part be a result of the larger diversity in thesubgroups of Hispanics in the current study. Although thecurrent study identified Hispanic women from different na-tionalities, the sample population for each country was toosmall for comparative analysis. However, when the samplewas divided into regions, a trend was noted. The women fromregions in South America had longer second-stage labors thanthe Central American group, although not statistically signif-icant. Research comparing larger numbers from each countrymay reveal if country of origin is a factor that affects the lengthof labor.

This current study also did not factor the length of U.S.residency into consideration, so a woman living in theUnited States for 6 months was considered comparable to awoman who had lived here for 10 years. Future researchmay consider whether length of residency changes the laborpatterns for this population

IMPLICATIONS FOR PRACTICE

Differences among racial and ethnic groups in the UnitedStates must be understood to develop accurate guidelinesfor clinical practice. In view of the significant increase ofHispanic births in the United States, maternity providersand childbirth attendants need to reevaluate the appropri-ateness of Friedman’s guidelines as the criteria for theduration of normal labor in the Hispanic population. Manyobstetric providers have embraced and accepted Friedman’sguidelines for length of labor and have applied obstetricpractices that enable women in labor to comply with theaccepted time frames. This is evident in the proliferation ofnational, professional, and site-specific clinical practiceguidelines. Obstetric providers are increasingly expected tocomply with standard-of-care guidelines that limit thelength of time a woman is allowed to labor withoutobstetric intervention.

These research findings add to a growing body of

evidence that normal uncomplicated active phase of laborin Hispanic women are appreciably longer than those ofFriedman’s original sample.5,6 Therefore, clinicians areurged to be more tolerant of longer labors. Greater patienceis needed with the labor process, and clinicians are encour-aged to develop skills to support women whose laborprogress are naturally longer than the accepted norm.Practices that support labor may decrease the number ofprocedures, restrictions, discomforts, and costs associatedwith unnecessary obstetric interventions. Labor manage-ment should be based on evidence and includes carefulclinical observations, detailed documentation, and a sup-portive presence.

The current research contributes important data for theprovision of appropriate evidence-based care to the grow-ing number of Hispanic women in the United States. Morebroadly, the work argues that there is a critical need forclinical research addressing the expanding demographicgroup of Hispanic Americans in the United States to betterserve this population during the childbirth experience.

This publication is based on a doctoral thesis at Case Western ReserveUniversity, Cleveland, Ohio. The investigators thank the thesis committee, Dr.Claire Andrews, Dr. Carol Musil, Dr. Theresa Standing, and Gretchen Mettlerfor their guidance and advice. They acknowledge financial support from TheNational Association of University Women and The American Association ofUniversity Women. Sincere thanks are extended to Dr. Betty Watts Carrington,CNM, Patricia Loftman, CNM, Julie Rousseau, CNM, Irene Rose, CNM, Rev.Leroy Richards, Wayne Robotham, Howard Hale, Etta Jones, and ColumbiaUniversity School of Nursing Nurse-Midwifery faculty and support staff fortheir editorial help and/or moral support.

REFERENCES

1. Friedman EA. The graphic analysis of labor. Am J ObstetGynecol 1954;68:1568–75.

2. Friedman EA. Privigavid labor: a graphicostatistical analysis.Am Acad Obstet Gynecol 1955;6:567–89.

3. Friedman EA. Labor in multipara: a graphicostatistical analy-sis. Obstet Gynecol 1956;8:691–703.

4. Therrien M, Ramirez RR, Tuck SM, Cardozo LD, Studd JW,Gibb DM. The Hispanic population in the United States: March 2000(Current Population Reports No P20-535). Washington (DC): 5.U.S.Census Bureau, 2000.

5. Albers LL, Schiff M, Gorwoda JG. The length of active laborin normal pregnancies. Obstet Gynecol 1996;87:355–9.

6. Albers LL. The duration of labor in healthy women. J Perinatol1999;19:114–9.

7. Diegmann EK, Andrews CM, Niemczura CA. The length of thesecond stage of labor in uncomplicated, nulliparous African Ameri-can and Puerto Rican women. J Midwifery Womens Health 2000;45:67–71.

8. Friedman EA. Labor: clinical evaluation and management, 2nd

ed. New York: Appleton, 1978.

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9. Friedman EA, Kroll BH. Computer analysis of labour progres-sion. J Obstet Gynaecol Br Commonwealth 1969;76:1075–6.

10. Friedman EA, Kroll BH. Computer analysis of labor progres-sion. Distribution of data and limits of normal. J Reprod Med 1971a;6:1, 20–25.

11. Cohen J. Statistical power analysis for the behavioral sciences,2nd ed. Hillsdale (NJ): Lawrence Erlbaum Associates Publishers,1988.

12. SPSS for Windows 10.0.7. (2000). Chicago (IL): SPSS Inc.,2000.

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