Table 1.

25 Studies included in systematic review

Trial	N	Trial Type	Inclusion/Exclusion Criteriaa	Qualifying Groups/Sub-groups
Fraser et al, Canada & US, 1993 22	925	Prospective, randomized	Inclusion: Intact membranes; normal fetal heart rate. Exclusion: Suspected IUGR; severe pre-eclampsia; IDDM; ≥ 6 cm at admission; maternal distress too great to permit informed consent.	Routine early amniotomy v conservative membrane management after admission at ≥ 3cm e
Cammu et al, Belgium, 1994 23	110	Prospective, randomized	Inclusion: Low-risk; 3–5 cm at admission; ruptured membranes with clear fluid; no dystocia at inclusion	Bathing v non-bathing with AML
Cammu et al, Belgium, 1994 24	1000	Prospective, observational	Inclusion: No contraindications for labor; maternal height ≥ 150 cm; one or more antenatal care visits	Unaugmented v augmented labor with AML but without epidurale
Albers et al, US, 1996 15	347 b	Retrospective, record review	Inclusion: Low-risk; non-Hispanic white, Hispanic, or American Indian; ≤ 4 cm at admission (for active phase analyses). Exclusion: Medical problems (e.g., hypertension, gestational diabetes, asthma, membranes ruptured > 24 hrs); oxytocin augmentation; epidural analgesia; operative delivery.	No treatment
Cammu et al, Belgium, 1996 25	306	Prospective, randomized	Inclusion: Normal cardiotocogram and clear amniotic fluid at admission; maternal height ≥ 150 cm; one or more antenatal outpatient clinic visits.	AML v selective intervention
Bofill et al, US, 1997 26	100	Prospective, randomized	Inclusion: Healthy. Exclusion: Medical problems (e.g., IDDM, medicated chronic hypertension, PIH).	Epidural v narcotics for labor pain relief
Dickinson et al, Australia, 1997 18	497	Prospective, observational	Inclusion: Low-risk.	Epidural v non-epidural with modified AML
Alexander et al, US, 1998 27	199	Retrospective analysis of randomized trial	Inclusion: Normal pregnancy; augmented with oxytocin; non-operative vaginal delivery. Exclusion: Pregnancy complication; > 5 cm at admission.	Epidural v meperidine (IV) for labor pain relief
Clark et al, US, 1998 28	318	Prospective, randomized	Exclusion: Contraindication to labor; thrombocytopenia or coagulation disorder precluding epidural placement.	Epidural v meperidine (IV) during AML for labor pain relief
Thompson et al, US, 1998 29	641	Retrospective, chart review	Inclusion: Low-risk; 18–35 yrs old; prenatal care provided by study institution; black or Caucasian race. Exclusion: Drug or alcohol abuse; smoking; pre- eclampsia; hypertension; diabetes; > 7 cm at admission; pre-pregnancy weight > 100 kg; chronic medical condition; history of pelvic injury or major abdominal surgery; hospitalization during pregnancy; uterine myoma; active genital herpes; oligo- or polyhydramnios; incomplete medical record.	No epidural (no analgesia or parenteral opioids only) v low- dose epidural v high-dose epidural
Albers, US, 1999 16	806 b	Prospective, observational	Inclusion: Low-risk; ≤ 4 cm at admission; membranes ruptured < 24 hrs. Exclusion: Medical problems (hypertension, gestational diabetes, asthma, drug use); oxytocin augmentation; epidural analgesia; operative delivery (cesarean, forceps, vacuum).	No treatment
Fontaine et al, US, 2000 30	100 b	Retrospective, chart review	Inclusion: < 6 cm at admission. Exclusion: Epidural use; other undefined reasons.	ITN v no ITN (IV narcotics or no analgesia)
Garite et al, US, 2000 31	195	Prospective, randomized	Inclusion: Uncomplicated pregnancy; 2–5 cm with or without ruptured membranes. Exclusion: Pre-eclampsia; cardiac or renal disease; chorioamnionitis, pyelonephritis, or febrile illness before randomization.	Isotonic IV fluids at 125 ml/hr v 250 ml/hr during labor
Sadler et al, New Zealand, 2000 32	651	Prospective, randomized	Exclusion: Evidence of fetal distress at admission; severe cardiac disease; uterine scar; contracted pelvis; elective cesarean.	AML v routine labor management
Sharma et al, India, 2001 33	150	Prospective, randomized	Inclusion: Healthy; 18–30 yrs old; intact membranes; dilatation of 4 cm with partially effaced cervix; established contractions. Exclusion: Medical, surgical, or obstetric complications (e.g., pre-eclampsia, antepartum hemorrhage); dilatation > 5 cm.	Drotaverine hydrochloride (IM) v valethamate bromide (IM) v unmedicated group
Zhang et al, US, 2001 34	1088	Retrospective, chart review	Inclusion: < 7 cm at admission; admission to delivery duration ≥ 3 hrs; 18–34 yrs old; birth weight of 2.5–4 kg.	Before v after ‘on-demand’ epidural analgesia
Gurewitsch et al, US & Israel, 2002 35	908 b	Retrospective, comparative	Inclusion: Uncomplicated pregnancy; ≥ 3 first-stage cervical exams. Exclusion: Contraindication to labor; uterine scars; hydramnios; fetal anomaly.	No treatment
Jones et al, US, 2003 17	120 b	Retrospective, comparative	Inclusion: Hispanic; 15–44 yrs old; spontaneous vaginal birth. Exclusion: Cephalopelvic disproportion; prolonged membrane rupture; social or medical problems (substance abuse, hypertension, diabetes, asthma); oxytocin augmentation; regional anesthesia.	No treatment
Kaul et al, US, 2004 36	1671	Retrospective, comparative	Inclusion: Healthy; epidural during labor; oxytocin augmentation during labor as subgroup; elective IOL as subgroup. Exclusion: Past medical problems; complicated pregnancy; cesareans for fetal distress.	Oxytocin augmentation group e
Somprasit et al, Thailand, 2005 37	960	Prospective, randomized	Inclusion: Low-risk. Exclusion: Medical or surgical complications; contraindications to vaginal delivery or oxytocin use; fetal distress at admission; diabetes; PIH.	AML v conventional labor management
Vahratian et al, US, 2005 38	2200	Retrospective, chart review	Inclusion: Low-risk; elective IOL as sub-group. Exclusion: Diabetes; hypertension; prior infectious cardiovascular, pulmonary, renal, mental, or thyroid disorders; IUGR; uterine bleeding; oligohydramnios.	Spontaneous labor onset group e
Eslamian et al, Iran, 2006 19	300	Prospective, randomized	Inclusion: Uncomplicated pregnancy; 3–5 cm; intact membranes. Exclusion: Chorioamnionitis; febrile illness or pyelonephritis; pre-eclampsia; history of cardiac or renal disease.	Isotonic IV fluids at 125 ml/hr v 250 ml/hr during labor
Mikki et al, Israel, 2007 39	157 b	Prospective, randomized	Inclusion: Low-risk; intact membranes at admission; normal fetal heart rate. Exclusion: Advanced labor; IUGR; suspected macrosomia (> 4.5 kg); pre- clampsia; IDDM; antepartum hemorrhage.	Early amniotomy v intent to conserve membranes
Miquelutti et al, Brazil, 2007 20	107	Prospective, randomized	Inclusion c: Low-risk; 3–5 cm at admission; 16–40 yrs old. Exclusion: Elective cesarean; contraindications to upright positions.	Upright position v no particular position encouraged (control group)
Svärdby et al, Sweden, 2007 21	164	Prospective, observational	Inclusion d: Uncomplicated pregnancy.	No augmentation v active phase v second stage augmentation

AML = active management of labor; IDDM = insulin-dependent diabetes mellitus; IM = intramuscular; IOL = induction of labor; ITN = intrathecally-injected narcotics; IUGR = intrauterine growth restriction; IV = intravenous; PIH = pregnancy-induced hypertension.

^aAll studies included nulliparae carrying live, singleton, cephalic presenting fetuses at a minimum of 36 wks gestation with spontaneous labor onset. Mean, median, or absolute dilatation between 3–5 cm at study enrollment or randomization must have been identified

^bValue represents nulliparous women only although this study also included primiparous and/or multiparous groups / sub-groups.

^cThrough contact with author, it was clarified that all labors had a spontaneous onset.

^dThrough contact with author, it was clarified that ‘primigravid’ rather than ‘primiparous’ women were included in the study.

^eStudy also included nulliparous sub-group(s) not qualifying for systematic review because dilatation at ‘active’ phase onset was < 3 cm, unknown, or labor was induced.