Biomedical subjects

Donald D McIntire

Publications and source records attributed to Donald D McIntire.

At least 37 records · Page 2Linked to original sources

PubMed2005

Magnetic resonance imaging pelvimetry and the prediction of labor dystocia.

OBJECTIVE: To study whether magnetic resonance imaging (MRI) pelvimetry has the ability to identify those women who require cesarean delivery for labor dystocia. METHODS: From July 2003 to April 2004, nulliparous women scheduled for a labor induction for prolonged pregnancy (42 weeks) were asked to participate in a pelvimetry study. Those who consented underwent fast-acquisition MRI that included two 90-second acquisitions to evaluate fetal biometry and volumetry and maternal pelvimetry, including novel measurements of pelvic bony and soft tissue volumes as determined by MRI. Information about each patient's pregnancy, labor course, and neonatal outcome was prospectively collected. Pelvimetry results for those women undergoing operative delivery for labor dystocia were compared with those who did not. Single fetal and maternal pelvic measurements, as well as ratios of both, were analyzed. In addition, previously described radiographic pelvimetry techniques and formulas to predict dystocia were used. RESULTS: One hundred one women underwent MRI, and 22 of these underwent cesarean delivery for dystocia. No single fetal measurement was statistically associated with dystocia. Several maternal pelvic measures, fetal-to-maternal ratios, and previously reported pelvimetric techniques were significantly associated with dystocia. The ratio of magnetic resonance (MR) fetal head volume to pelvic soft tissue volume had statistical significance (P = .04). Receiver operator characteristic curves were developed for the different measurements, ratios, and formulas studied to assess whether any of the techniques could accurately predict labor dystocia requiring operative delivery. The area under the curve values ranged from 0.6 to 0.8, with the ratio of MR head volume to pelvic soft tissue being 0.7. These values suggest that MRI can identify those women at greatest risk for dystocia, but it cannot with accuracy predict which ones will require a cesarean. CONCLUSION: We found significant associations with MRI pelvimetry and labor dystocia, but MRI was not a significant improvement over previously described pelvimetric techniques. LEVEL OF EVIDENCE: II-3.

Adult↗

PubMed2004

A hospital-sponsored quality improvement study of pain management after cesarean delivery.

OBJECTIVE: We undertook this study to systematically assess prevailing pain management regimes used at our hospital in women after cesarean delivery. STUDY DESIGN: Between August 1999 and July 2000, all women delivered by cesarean section at Parkland Hospital were assigned to 1 of 4 different pain management strategies: (1). intramuscular (IM) meperidine, (2). patient-controlled analgesia (PCA) meperidine, (3). IM morphine sulfate, and (4). PCA morphine sulfate. A combination of methods were used to compare these different pain management strategies. A survey questionnaire, using Likert scale responses, was administered to evaluate maternal satisfaction with pain control. Visual Analog Scale (VAS) scores and information regarding breastfeeding and rooming-in were also collected. RESULTS: A total of 1256 women were allocated to the 4 analgesia study groups. The median meperidine dosages for the IM and PCA groups were 350 mg and 600 mg, respectively (P <or=.01). Conversely, the median IM morphine dose (65 mg) was significantly higher than that for the PCA group (60 mg). The percentage of women reporting moderate or worse pain (VAS scores 4 or more) was significantly lower in those women who received PCA meperidine compared with IM meperidine. Women who received morphine reported less severe pain compared with meperidine, regardless of route of administration. The patients' subjective report of satisfaction with pain management was not related to the method or drug used for pain control (P=.13). Fewer women assigned to morphine therapy stopped breastfeeding (P=.02) and more roomed-in with their infants (P <.01). CONCLUSION: Pain relief was superior with the morphine regimens used and was positively associated with breastfeeding and infant rooming-in.

Adolescent↗

PubMed2004

Correlation of measured amnionic fluid volume to sonographic and magnetic resonance predictions.

OBJECTIVE: The purpose of this study was to compare the relationship between the actual amnionic fluid volume that was measured at delivery and magnetic resonance amnionic fluid volume determination, largest vertical pocket, and amnionic fluid index. STUDY DESIGN: Three hours before cesarean delivery, 80 women had sonographic measurement of the amnionic fluid index and the largest vertical pocket. Magnetic resonance imaging was then completed, and the magnetic resonance amnionic fluid volume was determined. At surgery, the amnionic fluid was collected. Pearson correlations were determined. Receiver operating characteristic curves were developed for each method as a measure of predictability for oligohydramnios. RESULTS: The correlations for the magnetic resonance amnionic fluid volume, amnionic fluid index, and largest vertical pocket to amnionic fluid volume was 0.84, 0.77, and 0.71, respectively. Magnetic resonance amnionic fluid volume has a statistically higher correlation than the largest vertical pocket ( P = .046). The 3 methods, however, are statistically comparable for identifying oligohydramnios. CONCLUSION: Magnetic resonance imaging is comparable with ultrasound evaluation for the prediction of oligohydramnios. Correlations to actual amnionic fluid volume are also comparable.

Adult↗

PubMed2004

Morbidity that is associated with curettage for the management of spontaneous and induced abortion in women who are infected with HIV.

OBJECTIVE: The purpose of this study was to determine the morbidity that is associated with curettage for the management of abortions in women who were infected with human immunodeficiency virus compared with women who were not infected with human immunodeficiency virus. STUDY DESIGN: Women who were infected with human immunodeficiency virus (cases) and who underwent curettage for the management of scheduled and unscheduled abortions in the first half of pregnancy between January 1, 1993, and December 31, 2002, were identified. Women who were not infected with human immunodeficiency virus (control subjects) were matched 3:1 to cases for gestational age, type of abortion, and year of procedure. Medical records were reviewed to obtain demographic characteristics, gestational age, abortion characteristics, and procedure-related complications. Chi-squared test, Student t test, and Wilcoxon rank-sum test were used to determine statistical significance. RESULTS: Seventy-one women who were infected with human immunodeficiency virus (cases) and 213 women who were not infected with human immunodeficiency virus (control subjects) who underwent curettage during the study period were evaluated. Forty-eight cases (68%) and 146 control subjects (69%) underwent a scheduled curettage. Twenty-three cases (32%) and 66 control subjects (31%) underwent an unscheduled curettage for spontaneous or incomplete abortion. No significant differences were seen in age, gravidity, or parity. There were significantly more black women in the HIV-infected cohort (P < .001), which was representative of our human immunodeficiency virus population. The mean gestational age in the cases was greater than in the control subjects (10.9 +/- 4.2 weeks of gestation vs 9.2 +/- 3.1 weeks of gestation; P = .004). Procedure-related complications occurred in 10 of the women (14%) who were infected with human immunodeficiency virus who underwent curettage, compared with 9 of the women (4%) who were not infected with human immunodeficiency virus (P = .004). With the use of logistic regression, complication rates were unaffected by the difference in gestational age. Infectious complications did not differ between the 2 groups (P = .435). CONCLUSION: There was a higher rate of procedure-related complications among women who were infected with human immunodeficiency virus and who underwent curettage for management of spontaneous and induced abortions. There was no increase in infectious morbidity in the women who were infected with human immunodeficiency virus.

Abortion, Induced↗

PubMed2004

The significance of antiphospholipid antibodies in pregnant women with chronic hypertension.

The objective of this study was to perform antiphospholipid antibody screening in women with chronic hypertension to assess whether the presence of such antibodies is associated with adverse pregnancy outcome. Serum for anticardiolipin antibodies and lupus anticoagulant was obtained in pregnant women with chronic hypertension who had no other indications for such testing. The primary outcomes of interest were the development of superimposed preeclampsia, preterm delivery, and fetal growth restriction. Only 8 (9%) of the 87 women enrolled tested positive (> 95th percentile) for anticardiolipin immunoglobulin G. None tested positive for lupus anticoagulant. The presence of antiphospholipid antibodies was not associated with adverse pregnancy outcome. We were unable to demonstrate that screening for antiphospholipid antibodies is a useful clinical practice in women whose only pregnancy complication was chronic hypertension. The significance of such antibodies in this particular group of patients can only be resolved with a large multicenter study.

Adult↗

PubMed2004

Labor analgesia and cesarean delivery: an individual patient meta-analysis of nulliparous women.

BACKGROUND: The authors performed an individual patient meta-analysis of 2,703 nulliparous women who were randomized to either epidural analgesia or intravenous opioids for pain relief during labor from five trials conducted at their hospital. The primary purpose in this meta-analysis was to evaluate the effects of epidural analgesia during labor on the rate of cesarean delivery. METHODS: Between November 1, 1993, and November 3, 2000, 2,703 nulliparous women (2,188 healthy parturients and 515 women with pregnancy-induced hypertension) in spontaneous labor at term were randomized to receive either epidural analgesia or intravenous opioid analgesia in the five studies. Epidural analgesia was initiated with either epidural bupivacaine or intrathecal sufentanil and was maintained with a low-dose (0.0625% or 0.125%) mixture of bupivacaine with fentanyl. Intravenous opioid analgesia was initiated with 50 mg meperidine and 25 mg promethazine hydrochloride and was maintained with intravenous boluses of meperidine as needed. RESULTS: A total of 1,339 nulliparous women were randomized to receive epidural analgesia, and 1,364 women were randomized to receive intravenous meperidine analgesia. There was no difference in the rate of cesarean deliveries between the two analgesia groups (epidural analgesia, 10.5% [140 of 1,339] vs. intravenous meperidine analgesia, 10.3% [141 of 1,364]; adjusted odds ratio, 1.04; 95% confidence interval, 0.81-1.34; P = 0.920). Significantly more women randomized to epidural analgesia had forceps deliveries compared to meperidine analgesia (13% [172 of 1,339] vs. 7% [101 of 1,364]; adjusted odds ratio, 1.86; 95% confidence interval, 1.43-2.40; P < 0.001). Epidural women had longer first and second stages of labor. Women who received epidural analgesia reported lower pain scores during labor and delivery compared to women who received intravenous meperidine analgesia. CONCLUSION: Epidural analgesia compared to intravenous meperidine analgesia during labor does not increase the number of cesarean deliveries.

Adult↗

PubMed2004

Timing of birth after spontaneous onset of labor.

OBJECTIVE: To describe naturally occurring birth patterns in low-risk women with singleton gestations and spontaneous onset of labor at term. MATERIALS AND METHODS: The timing of birth of women who delivered in the low-risk labor unit at Parkland Hospital, Dallas, Texas, between January 1, 2000, to December 31, 2000, was analyzed. Women admitted to this unit were between 36(0/7) and 41(6/7) weeks of gestation, were in spontaneous labor, and had a singleton gestation. Women with contraindications to labor, significant medical problems, a known fetal anomaly, and stillbirths were excluded from analysis. The frequency of birth was analyzed in relation to the time of day, day of week, and month of the year. RESULTS: Low-risk women (n = 6608) met the study criteria and were included in the analysis. No association was found between the day of the week and the frequency of births (P =.31). Births were most common between the hours of 1 to 2 pm and least common between the hours of 10:00 to 12:00 hours (Central Standard Time, P =.04). Births were more common in the fall, September through November, and least common in the winter, December through February. Daylight Saving Time did not affect these results. CONCLUSION: Birth after the spontaneous onset of labor is most common in the early afternoon, and most births occur in the fall. There is no natural association between spontaneous birth in low-risk women and the day of the week. LEVEL OF EVIDENCE: II-2

Adolescent↗

PubMed2003

A randomized, placebo-controlled trial of corticosteroids for hyperemesis due to pregnancy.

OBJECTIVE: Hyperemesis gravidarum, a severe form of nausea and vomiting due to pregnancy for which there is no proven pharmacological treatment, is the third leading cause for hospitalization during pregnancy. Corticosteroids are commonly used for the treatment of nausea and vomiting due to cancer chemotherapy-induced emesis and might prove useful in hyperemesis gravidarum. METHODS: A randomized, double-blind, placebo-controlled trial was conducted in 126 women who previously had not responded to outpatient therapy for hyperemesis gravidarum during the first half of pregnancy. Intravenous methylprednisolone (125 mg) was followed by an oral prednisone taper (40 mg for 1 day, 20 mg for 3 days, 10 mg for 3 days, 5 mg for 7 days) versus an identical-appearing placebo regimen. All women also received promethazine 25 mg and metoclopramide 10 mg intravenously every 6 hours for 24 hours, followed by the same regimen administered orally as needed until discharge. The primary study outcome was the number of women requiring rehospitalization for hyperemesis gravidarum. RESULTS: A total of 110 women delivered at our hospital and had pregnancy outcomes available for analysis; 56 were randomized to corticosteroids and 54 were administered placebo. Nineteen women in each study group required rehospitalization (34% versus 35%, P =.89, for corticosteroids versus placebo, respectively). CONCLUSION: The addition of parenteral and oral corticosteroids to the treatment of women with hyperemesis gravidarum did not reduce the need for rehospitalization later in pregnancy.

Adolescent↗

PubMed2003

Inhibin-A and superimposed preeclampsia in women with chronic hypertension.

OBJECTIVE: To determine if maternal serum inhibin-A can be used as a marker for subsequent development of superimposed preeclampsia in women with chronic hypertension. METHODS: Serum for measurement of inhibin-A was obtained at monthly intervals in women with chronic hypertension requiring antihypertensive medications. Superimposed preeclampsia, the primary outcome of interest, was diagnosed when hypertensive women developed proteinuria (at least 300 mg per 24-hour urine specimen). Serum inhibin-A was considered abnormally elevated when the value exceeded the mean plus two standard deviations of the log for chronically hypertensive women who did not develop preeclampsia. RESULTS: A total of 61 women were enrolled in this study, and 21 (34%) developed superimposed preeclampsia. Inhibin-A levels increased with advancing gestational age. Ten women had abnormally increased inhibin-A levels; eight (80%) developed superimposed preeclampsia, compared with 13 of 51 (26%) women with normal inhibin-A levels (P <.001). Sensitivity and specificity were 38% and 95%, respectively, whereas the positive and negative predictive values were 80% and 75%, respectively. CONCLUSION: Although inhibin-A was abnormally increased an average of 3 weeks before the clinical onset of superimposed preeclampsia, the sensitivity of the test as a screen was too limited to be clinically useful.

Adult↗

PubMed2003

Ruptured membranes at term: randomized, double-blind trial of oral misoprostol for labor induction.

OBJECTIVE: To determine if oral misoprostol can replace oxytocin for labor stimulation in women with ruptured membranes at term and without evidence of labor. METHODS: Nulliparous women at 36 to 41 weeks with a singleton, cephalic-presenting fetus and ruptured membranes without evidence of labor were randomized to receive oral misoprostol (100 microg) or a placebo every 4 hours for a maximum of two doses. Intravenous oxytocin was initiated if active labor had not ensued within 8 hours of the initial study drug dose. RESULTS: Fifty-one women were randomized to oral misoprostol and 51 women to the placebo. Misoprostol reduced the use of oxytocin stimulation of labor from 90% to 37% (P <.001) and was associated with approximately a 7-hour shorter elapsed time in the labor unit. Uterine hyperactivity, defined as six or more contractions in 10 minutes without fetal heart rate decelerations, occurred in 25% of women randomized to misoprostol. However, uterine hyperactivity associated with fetal heart rate decelerations occurred in only three (6%) women, none of whom required emergency cesarean delivery. Route of delivery and infant outcomes were not related to misoprostol use. CONCLUSION: Oral misoprostol (100 microg) given in a maximum of two doses 4 hours apart significantly reduced the use of oxytocin in the management of women with ruptured membranes without labor at term.

Administration, Oral↗

PubMed2003

Recurrence of mild malformations and dysplasias.

OBJECTIVE: To estimate whether women delivering infants with mild malformations are at increased risk to have a subsequent infant with a mild malformation. METHODS: Both severe and mild malformations detected at birth were cataloged prospectively for 33,701 women with two consecutive singleton births of infants weighing 500 g or more at a tertiary care hospital. Records from a total of 67,402 infants were analyzed from January 1, 1988, through December 31, 2000. Mild malformations and dysplasias were defined to include skin lesions (eg, café au lait spots, nevi, and hemangiomas), extra nipples, and abnormalities involving digits. Pearson and McNemar chi(2) statistics and analysis of variance were used for statistical analysis. Estimation of recurrence risks was accomplished using standard methods for rates and proportions. RESULTS: Of the study women, 2.7% delivered infants with mild malformations in their index pregnancy. Mild malformations recurred in 7% of women whose index infant had a mild malformation (2.7% versus 7%, P <.001). Mild malformations involving the skin or digits also significantly increased in the next delivery (2% versus 5%, P <.001; 0.5% versus 8%, P <.001; recurrence of skin and digit anomalies, respectively). CONCLUSION: Women delivering infants with mild malformations involving the skin and digits of the infant are at increased risk for recurrence during their next pregnancy.

Congenital Abnormalities↗

PubMed2003

A comparison of the effects of epidural and meperidine analgesia during labor on fetal heart rate.

OBJECTIVE: To estimate the effects of initiation of epidural analgesia on fetal heart rate (FHR) patterns compared with intravenous meperidine analgesia. METHODS: Fetal heart rate patterns in 200 nulliparous women with term pregnancies randomized to epidural analgesia with 0.25% bupivacaine were compared with those of 156 similar women given intravenous meperidine. Fetal heart rate patterns occurring within 40 minutes of initiation of labor analgesia were retrospectively read by three maternal-fetal medicine specialists who were blind to clinical events, including type of labor analgesia. RESULTS: Meperidine, compared with epidural analgesia, was associated with statistically significantly less beat-to-beat variability (absent or less than 5 beats per minute) of the FHR (30% versus 7% of fetuses, P <.001) in the first 40 minutes after initiation of analgesia, as well as with fewer FHR accelerations (88% versus 62% of fetuses, P <.001). Neither the incidence of FHR decelerations nor the type of deceleration were significantly different between methods of labor analgesia. Specifically, 41% of women given meperidine exhibited FHR decelerations within 40 minutes, compared with 34% given epidural analgesia (P =.353). CONCLUSION: Epidural analgesia does not have deleterious effects on FHR.

Adult↗

PubMed2003

Homocysteine plasma concentration levels for the prediction of preeclampsia in women with chronic hypertension.

OBJECTIVE: The purpose of this study was to evaluate prospectively midtrimester homocysteine concentration levels for the prediction of superimposed preeclampsia in women with chronic hypertension. STUDY DESIGN: Between March 1, 2000, and February 1, 2002, pregnancies that were complicated by chronic hypertension that required medication had homocysteine, vitamin B(12), and folate concentrations measured between 16 and 20 weeks of gestation. All women received folate supplementation. An upper limit threshold for increased homocysteine was defined as the mean value plus 2 SDs. RESULTS: Fifty-seven women were enrolled. Mean homocysteine concentration levels were 5.1+/-1.7 micromo/L for the 16 women who had preeclampsia compared with 4.7+/-1.3 micromo/L for the 41 women without preeclampsia (P=.56). Two of 16 women with preeclampsia (13%) had concentration levels that exceeded the 95th percentile (6.9 micromo/L) compared with 2 of 41 women (5%) without preeclampsia (P=.31). The sensitivity and specificity were 13% (95% CI, 1.6-38.3) and 95.1% (95% CI, 83.5-99.4), respectively. CONCLUSION: Second-trimester homocysteine concentration levels were not helpful in the prediction of preeclampsia in chronically hypertensive women.

Adult↗

PubMed2003

Feasibility of the fetal anatomic and maternal pelvic survey by magnetic resonance imaging at term.

OBJECTIVE: This study was undertaken to determine which nonbiometric components of the American College of Obstetricians and Gynecologists recommended ultrasound fetal anatomic and maternal pelvic survey can be evaluated by fast acquisition magnetic resonance (MR) imaging in the term fetus. STUDY DESIGN: Nonbiometric components of the fetal survey were retrospectively evaluated by fast acquisition MR images. Thirteen components were assessed, including fetal number, presentation, placental location, qualitative assessment of amniotic fluid, and the maternal pelvis (n=5). The fetal anatomy included bilateral cerebral ventricles, spine, bilateral kidneys, stomach, bladder, cord insertion, sex, and four-chamber view of the heart (n=8). Studies were performed before delivery and neonatal outcomes were reviewed. RESULTS: All 50 neonates were normal at follow-up. A total of 94% (702 of 750) of the components were assessed by MR imaging. CONCLUSION: Fetal MR imaging can assess 94% of the American College of Obstetricians and Gynecologists recommended ultrasound fetal and pelvic anatomic survey. If the heart is excluded, this increases to 99%.

Feasibility Studies↗

PubMed2003

Comparison of magnetic resonance imaging to ultrasound in the estimation of birth weight at term.

OBJECTIVE: This study was undertaken to compare magnetic resonance (MR) and ultrasound (US) fetal weight estimates obtained immediately before delivery with birth weight. STUDY DESIGN: Eighty women scheduled for a cesarean delivery underwent a fast acquisition MR and US for fetal weight estimation within 3 hours of delivery. Prospective MR calculation was based on the equation 0.12+1.031 g/mLxfetal volume (mL)=MR weight (g). US fetal weight estimation was calculated by the formula by Hadlock et al. Estimations were compared with birth weight. RESULTS: Correlation (95% CI) between birth weight and MR weight is 0.95 with a mean absolute error of 129 g (105-155) compared with the correlation between birth weight and US of 0.85 with a mean absolute error of 225 g (186-264). The correlation for birth weight and MR imaging is significantly greater than that of birth weight and US, P<.001. CONCLUSION: Birth weight estimation is more accurate by MR imaging than by US in term infants.

Birth Weight↗

PubMed2002

Effect of a resident-created study guide on examination scores.

OBJECTIVE: To evaluate the effect of a resident-created study guide on Council on Resident Education in Obstetrics and Gynecology (CREOG) In-Training and American Board of Obstetrics and Gynecology (ABOG) written examination scores. METHODS: In 1995, a group of residents at the University of Texas Southwestern Medical Center began creating an annual study guide based on the CREOG Test Item Summary Booklet. Individual, program, and national scores for 3 years before the intervention were compared with scores for 3 years after the intervention. A four-way analysis of variance was used to evaluate the effect of the intervention accounting for sex, Alpha Omega Alpha Medical Honor Society (AOA) status, and calendar year. A random effects model was also used to adjust for confounders. Categoric variables were compared using Mantel-Haenszel chi(2). Program failure rates for the ABOG written examination before and after the intervention were compared with relative risks. RESULTS: After introduction of the study guide, the annual difference between our program and the national percent correct increased significantly (2.1% versus 4.8%, P <.001), after adjustment for AOA status and calendar year. The improvement was distributed among resident levels 2-4 (all P <.02) and for non-AOA residents (P < or = .001). The relative risk of failure of the written ABOG examination before the study guide was 3.5 (95% confidence interval 0.77, 15.9). CONCLUSION: These findings demonstrate an important cooperative use of the Test Item Summary Booklet as an educational resource.

Adult↗

PubMed2002

Persistence of placenta previa according to gestational age at ultrasound detection.

OBJECTIVE: To evaluate gestational age at ultrasound detection of placenta previa as a predictor of previa persistence until delivery, and to estimate the effects of previa type, parity, and prior cesarean delivery on previa persistence. METHODS: This was a retrospective cohort study of pregnancies with placenta previa detected during transabdominal or endovaginal ultrasound examination. Previa was categorized as complete if the placenta completely covered the internal cervical os or incomplete if the inferior placental edge partially covered or reached the margin of the os. Gestational age was grouped into 4-week intervals from 15 to 36 weeks. The outcome was cesarean delivery for persistent previa. RESULTS: Previa was detected during 940 ultrasound examinations in 714 pregnancies. Of those with placenta previa at 15-19 weeks, 20-23 weeks, 24-27 weeks, 28-31 weeks, and 32-35 weeks, previa persisted until delivery in 12%, 34%, 49%, 62%, and 73%, respectively. At each interval, complete previa was more likely to persist than incomplete previa, all P <.001. Prior cesarean delivery was an independent risk factor for persistent previa among women diagnosed with previa in the second trimester, P <.05. However, parity was not an independent risk factor for persistence at any gestational age interval after adjusting for prior cesarean delivery. CONCLUSION: Gestational age at ultrasound detection of placenta previa may be used to predict likelihood of previa persistence. After midpregnancy, risk of persistence appears to be higher than previously reported. Type of placentation and prior cesarean delivery are important factors that modify the risk that previa will complicate delivery.

Cesarean Section↗

PubMed2002

Epidural analgesia lengthens the Friedman active phase of labor.

OBJECTIVE: To estimate the effect of epidural analgesia on the Friedman labor curve. METHODS: This study was a secondary analysis of a previously reported randomized trial of the effects of patient-controlled epidural analgesia during labor compared with patient-controlled meperidine on cesarean delivery rate. All subjects had a singleton, cephalic, nonanomalous fetus at or beyond 37 weeks' gestation. This secondary analysis was limited to women who had cervical dilatation commencing of at least 3 cm (ie, active phase of labor). RESULTS: A total of 459 women were randomized. Twenty-five women were excluded for a cervix less than 3 cm dilated, leaving 220 women allocated to patient-controlled epidural analgesia and 214 to patient-controlled intravenous meperidine available for analysis. There were no significant demographic differences between the two groups, including age, race, gestational age, and cervix on admission. The active phase of labor was 1 hour longer in the epidural-treated group (6.0 +/- 3.2 hours versus 5.0 +/- 3.2 hours, P <.001). The rate of cervical dilation was significantly less with epidural analgesia (1.4 cm/h versus 1.6 cm/h, P <.002). The duration of the second stage tended to be longer in the epidural group (1.1 +/- 1.5 hours versus 0.9 +/- 1.0 hours, P =.079). CONCLUSION: Epidural analgesia prolonged the active phase of labor by 1 hour compared with Friedman's original criteria.

Adolescent↗