The effect of gestational age on trial of labor after Cesarean section.

OBJECTIVES: To evaluate the effect of gestational age on the rate of successful vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior Cesarean delivery. STUDY DESIGN: This was a cohort study including patients with a live singleton fetus undergoing a TOL after a previous low transverse Cesarean delivery between 1988 and 2002. Patients were divided into three groups according to gestational age: 24-36 weeks 6 days, 37-40 weeks 6 days and > or = 41 weeks. Obstetric outcomes, including the rates of successful vaginal delivery and symptomatic uterine rupture, were compared between the groups. Multivariate logistic regression analysis was performed to adjust for potential confounding factors. RESULTS: There were 253, 1911 and 329 patients in each group, respectively. In patients with advanced gestational age (> or = 41 weeks) the rate of uterine rupture was significantly higher (0% vs. 1.0% vs. 2.7%, p = 0.006) and the rate of successful vaginal deliveries was significantly lower (83% vs. 76.9% vs. 62.6%, p < 0.001). After adjusting for confounding variables, advanced gestational age was associated with a lower rate of successful vaginal delivery (odds ratio 0.68, 95% CI 0.51-0.89), and a higher rate of uterine rupture (odds ratio 2.85, 95% CI 1.27-6.42) when compared to 37-40 weeks 6 days. CONCLUSION: Advanced gestational age is associated with higher rates of failed TOL and uterine rupture.

Should we allow a trial of labor after a previous cesarean for dystocia in the second stage of labor?

OBJECTIVE: To estimate the rate of successful vaginal birth including operative vaginal delivery in patients with a previous cesarean for cephalopelvic disproportion in the second stage of labor. METHODS: Data from all patients who underwent trial of labor after a previous cesarean between 1990 and 2000 at our tertiary care institution were analyzed. Medical records were reviewed and data collected for the following variables: indication for the previous cesarean, birth weight and cervical dilatation at previous cesarean delivery, as well as the mode of delivery (spontaneous, vacuum, forceps, cesarean) and the birth weight for the subsequent pregnancy. Pearson's chi(2) test and one-way analysis of variance were used for statistical analyses. RESULTS: There were 2002 patients included in the study. Two hundred fourteen (11%) had their previous cesarean for dystocia in the second stage of labor, 654 (33%) for dystocia in the first stage of labor, and 1134 (57%) for other indications. The vaginal birth after cesarean success rate was 75.2% (P = .015 vs other indications), 65.6% (P < .001 vs other indications), and 82.5%, respectively. The rate of operative vaginal delivery was 15%, 12%, and 10% (P = .109). CONCLUSION: A trial of labor is reasonable in women whose previous cesarean was for dystocia in the second stage of labor. In this series, patients who underwent a trial of labor after a previous cesarean for dystocia in the second stage had 75.2% (95% confidence interval 69.5, 81.0) chance of achieving vaginal delivery.

A randomized clinical trial of care for women with preterm labour: home management versus hospital management.

BACKGROUND: Preterm labour occurs in about 10% of all pregnancies and is the most important cause of premature birth. Women with preterm labour are admitted to hospital to have the contractions stopped. Thereafter, many women remain in hospital until delivery. We conducted a randomized clinical trial to compare hospital care with home care of women who had been admitted to hospital for preterm labour. METHODS: After they had received treatment for an acute episode of premature labour, women at 2 regional perinatal centres associated with teaching hospitals were randomly assigned to home care or hospital care. Eligible women (n = 250) were aged 18 years or older, lived within 50 km of the hospital, had a gestational age between 20 and 35 weeks, had no prior preterm delivery and were experiencing their first episode of preterm labour and first admission to hospital for preterm labour. Analysis was by intention to treat. RESULTS: There were no significant differences between the 2 groups in mean gestational age at delivery (home: 37.52 weeks, hospital: 37.50 weeks) or in mean birth weight (home: 2974 g, hospital: 3020 g). There were no significant differences between the 2 groups with respect to the proportions of babies born before term or the mean duration of neonatal hospital stay, neonatal intensive care unit stay and intermediate care nursery stay. The mean duration of the first stay in hospital for the women in the home group (3.8 days) was significantly shorter than the mean duration for women in the hospital group (6.1 days). In addition, the mean duration of all maternal stays in hospital was significantly shorter for the women in the home group (3.7 days) than in the hospital group (5.0 days). INTERPRETATION: Home care management is an efficient and acceptable alternative to hospital care for women experiencing preterm labour.

A controlled clinical trial of home care management versus hospital care management for preterm labour.

Prenatal hospitalisation has not been shown to reduce perinatal morbidity and mortality, yet it is still the treatment of choice for women who experience preterm labour. Home care management may be an alternative means of delivering safe, efficacious and care for these women. The objectives of this controlled clinical trial were to examine differences in neonate's gestational age and birthweight, and antenatal stress, social support satisfaction, and family functioning among pregnant women receiving home care and those receiving hospital care management. Pregnant women experiencing preterm labour (N=250) were randomly assigned to home care management (the experimental group [EG]) or hospital care management (the control group [CG]). A Perinatal Information Form was used to collect data on sociodemographic and pregnancy variables. The High-Risk Pregnancy Stress Scale, Brown's Social Behaviors Inventory, and the Family Assessment Measure III Dyadic Relationships Scale were administered to the women at randomisation (T1) and at 1-week (T2) and 2-weeks (T3) after randomisation. Gestational age and birthweight were similar in the two groups of neonates. Women in the EG reported that antenatal stress was significantly lower at T3 than at T1 and T2, while for those in the CG, antenatal stress was significantly lower at T3 than at T1, and significantly lower at T2 than at T1. Women in the EG were more satisfied with support from the male partner at T3 than women in the CG. There was no significant difference between the two groups in family functioning at T1, T2 and T3. These findings indicate that home care management is a safe and efficacious mode of health care delivery for women experiencing preterm labour.

Physicians' beliefs and behaviour during a randomized controlled trial of episiotomy: consequences for women in their care.

OBJECTIVE: To evaluate whether physicians' beliefs concerning episiotomy are related to their use of procedures and to differential outcomes in childbirth. DESIGN: Post-hoc cohort analysis of physicians and patients involved in a randomized controlled trial of episiotomy. SETTING: Two tertiary care hospitals and one community hospital in Montreal. PARTICIPANTS: Of the 703 women at low risk of medical or obstetric problems enrolled in the trial we studied 447 women (226 primiparous and 221 multiparous) attended by 43 physicians. Subjects attended by residents or nurses were excluded. PATIENTS: intact perineum v. perineal trauma, length of labour, procedures used (instrumental delivery, oxytocin augmentation of labour, cesarean section and episiotomy), position for birth, rate of and reasons for not assigning women to a study arm, postpartum perineal pain and satisfaction with the birth experience, physicians: beliefs concerning episiotomy. RESULTS: Women attended by physicians who viewed episiotomy very unfavorably were more likely than women attended by the other physicians to have an intact perineum (23% v. 11% to 13%, p < 0.05) and to experience less perineal trauma. The first stage of labour was 2.3 to 3.5 hours shorter for women attended by physicians who viewed episiotomy favourably than for women attended by physicians who viewed episiotomy very unfavorably (p < 0.05 to < 0.01), and the former physicians were more likely to use oxytocin augmentation of labour. Physicians who viewed episiotomy more favourably failed more often than those who viewed the procedure very unfavourably to assign patients to a study arm late in labour (odds ratio [OR] 1.88, p < 0.05), both overall and because they felt that "fetal distress" or cesarean section necessitated exclusion of the subject. They used the lithotomy position for birth more often (OR 3.94 to 4.55, p < 0.001), had difficulty limiting episiotomy in the restricted-use arm of the trial and diagnosed fetal distress and perineal inadequacy more often than the comparison groups. The patients of physicians who viewed episiotomy very favourably experienced more perineal pain (p < 0.01), and of those who viewed episiotomy favourably and very favourably experienced less satisfaction with the birth experience (p < 0.01) than the patients of physicians who viewed the procedure very unfavourably. CONCLUSIONS: Physicians with favourably views of episiotomy were more likely to use techniques to expedite labour, and their patients were more likely to have perineal trauma and to be less satisfied with the birth experience. This evidence that physician beliefs can influence patient outcomes has both clinical and research implications.

Relationship of episiotomy to perineal trauma and morbidity, sexual dysfunction, and pelvic floor relaxation.

OBJECTIVE: Our purpose was to compare consequences for women of receiving versus not receiving median episiotomy early and 3 months post partum on the outcomes perineal pain, urinary and pelvic floor functioning by electromyography, and sexual functioning and to analyze the relationship between episiotomy and third- and fourth-degree tears. STUDY DESIGN: A secondary cohort analysis was performed of participants within a randomized clinical trial, analyzed by type of perineal trauma and pain, pelvic floor, and sexual consequences of such trauma, while controlling for trial arm. The study was conducted in three university or community hospitals; 356 primiparous and 341 multiparous women were studied. RESULTS: Early and 3-month-postpartum perineal pain was least for women who gave birth with an intact perineum. Spontaneous perineal tears were less painful than episiotomy. Sexual functioning was best for women with an intact perineum or perineal tears. Postpartum urinary and pelvic floor symptoms were similar in all perineal groups. At 3 months post partum those delivered with an intact perineum had the strongest pelvic floor musculature, those with episiotomy the weakest. Among primiparous women third- and fourth-degree tears were associated with median episiotomy (46/47). After forceps births were removed and 21 other variables potentially associated within such tears were controlled for, episiotomy was strongly associated with third- and fourth-degree tears (odds ratio +22.08, 95% confidence interval 2.84 to 171.53). Physicians using episiotomy at high rates also used other procedures, including cesarean section, more frequently. CONCLUSION: Perineal and pelvic floor morbidity was greatest among women receiving median episiotomy versus those remaining intact or sustaining spontaneous perineal tears. Median episiotomy was causally related to third- and fourth-degree tears. Those using episiotomy at the highest rates were more likely use other interventions as well. Episiotomy use should be restricted to specified fetal-maternal indications.

Does episiotomy prevent perineal trauma and pelvic floor relaxation?

OBJECTIVE: To compare the outcomes of the current practice of liberally or routinely employing episiotomy to prevent perineal tears and pelvic floor relaxation (control group) to a policy of restricting episiotomy use to specific fetal and maternal indications (experimental group). DESIGN: A randomized controlled trial (RCT). SETTING: Three university hospitals in Montreal. SUBJECTS: Seven hundred three low-risk women enrolled at 30 to 34 weeks of gestation were randomized late in labor to the designated trial arm, by parity, and followed up to 3 months postpartum. MAIN OUTCOME MEASURES: Antepartum and postpartum information on perineal trauma and pain, pelvic floor symptoms (urinary incontinence), and sexual activity was collected through the use of standard questionnaires; pelvic floor function was measured by electromyographic (EMG) perineometry. RESULTS: Restricting episiotomy use in primiparous women was associated with similar sutured perineal trauma to the liberal or routine approach. Multiparous women in the restricted episiotomy group more often gave birth with an intact perineum (31% compared with 19%, odds ratio (OR) = 1.85, 95% confidence interval (CI) = 1.09 to 3.16). All but one 3rd/4th-degree perineal tear was associated with median episiotomy (46 of 47 in primiparous women and 6 of 6 among multiparous women). No difference between trial groups was found in postpartum perineal pain, antepartum and 3-month postpartum EMG perineometry, and urinary and pelvic floor symptoms. CONCLUSIONS: We found no evidence that liberal or routine use of episiotomy prevents perineal trauma or pelvic floor relaxation. Virtually all severe perineal trauma was associated with median episiotomy. Restriction of episiotomy use among multiparous women resulted in significantly more intact perineums and less perineal suturing.

The reproducibility of intrapartum cardiotocogram assessments.

Five obstetrician-gynecologists experienced in fetal monitoring assessed 150 intrapartum cardiotocograms obtained with an external transducer. There were three successive blind readings, the first two without any clinical data apart from gestational age. The reviewers indicated whether the tracings showed definite, possible or no abnormalities. The interpretations given by each reviewer for any one tracing were fairly consistent, but they varied markedly from one reviewer to another. The proportion of tracings interpreted as normal ranged from 39% to 74%, and the proportion assessed as abnormal ranged from 3% to 43%. All five observers agreed on the interpretation of 29% of the tracings. Inter-reviewer reproducibility scarcely changed when clinical data were provided. These findings emphasize the need to evaluate all methods of fetal monitoring before they become widespread.

Estriol in pregnancy. VII. Unconjugated plasma estriol in prolonged gestation.

This study was undertaken to determine the course of unconjugated plasma estriol (E3) concentrations after 40 weeks' gestation and to assess whether the latter may be used as a first-line test in the management of term pregnancies with poor dates and prolonged gestation. Plasma E3 was measured twice weekly in 134 women with well-dated pregnancies of 40 weeks or more and in 213 women with pregnancies of unverified age but believed to be in excess of 40 weeks from the last menstrual period. The obstetric management was based upon twice weekly determinations of urinary E3 and antepartum heart rate testing, but not all patients complied. Plasma E3 levels were not availabe for management of the patients. The results indicate that unconjugated plasma E3 levels are highest at 40 weeks' gestation and decline thereafter by 12% each week. Because of this slow decline, biweekly assays suffice. Increasing and plateauing serial plasma E3 levels reveal that a patient approaches term or has reached 39 to 41 weeks' gestation, respectively, whereas decreasing E3 concentrations indicate that the patient is well beyond 40 weeks, and that her fetus may be about to or has become postmature. Only seven of the 347 patients studied were delivered of a postmature infant. Their last plasma E3 levels ranged from 3.8 to 8.0 ng/ml, i.e., were below the 95% confidence limits established for normal term pregnancies. It was found that 73% of the 347 patients had plasma E3 levels of 12 ng/ml or more, and that all their pregnancies ended normally, except for three instances of presumed intrapartum fetal distress. However, in 19 (20%) of the other 27% of the 347 patients who had plasma E2 levels of less than 12 ng/ml, abnormal outcome was encountered: postmaturity (seven), fetal death (four), intrauterine growth retardation (three), malformations (two), or intrapartum fetal distress (three). These results allow the conclusion that twice weekly assays of unconjugated plasma E2 may be used as a first-line test in the management of prolonged gestation.

Clinical fetal monitoring. The usage and relationship to trends in cesarean delivery and perinatal mortality.

During the six years 1970--1975, 62,266 deliveries occurred at Women's Hospital, Los Angeles Country--University of Southern California Medical Center. Of these patients, 18,106 (29 per cent) were monitored, with an incidence of 18 per cent in 1970 which rose to 35 per cent in 1975. The patients were divided into monitored and unmonitored groups for comparison of cesarean section rates and various aspects of perinatal mortality. The overall cesarean section rate was 9.6 per cent with 2,830 cesareans performed in monitored patients (16 per cent) and 3,124 in those unmonitored, a 7 per cent incidence including repeat cesarean. The cesarean rate remained remarkably stable over the 6-year study period even though the monitoring incidence nearly doubled. From 1970 to 1975, the intrapartum death rate fell progressively in contrast to the incidence of antepartum fetal deaths, which remained unchanged. Overall, 50 per cent survival rate was achieved in the birth weight range of 1,200 grams. A particular group of perinatal patients who apparently benefited from intrapartum monitoring were those liveborns with birth weights of 1,500 grams or less. Over the study period, the neonatal mortality in monitored patients declined, whereas mortality in the neonates which were not monitored during labor remained high.

Antepartum fetal heart rate testing. I. Evolution of the nonstress test.

On May 1, 1975, at Women's Hospital, Los Angeles County--University of Southern California Medical Center, a new antepartum fetal heart rate (AFHRT) protocol was put into clinical use. This included the widely used contraction stress test (CST) and a new concept of nonstress testing (NST). The NST was based on FHR response associated with fetal movements and was categorized as reactive (normal) or nonreactive (abnormal). The nonreactive fetus was then evaluated with a CST if not contraindicated. During the 24 months, May 1, 1975 to April 30, 1977, a total of 2,422 NST's were done in 1,169 patients with 1,547 (64 per cent) reactive and 829 (35 per cent) nonreactive. CST was done 939 times, with 851 (90.6 per cent) negative, 29 (3 per cent) positive, 13 (1.4 per cent) equivocal, and 46 (5.0 per cent) unsatisfactory. There were ten (3.3 per cent) perinatal deaths within one week of a negative CST, five (1.0 per cent) within one week of a reactive NST, and two (8.7 per cent) with a positive CST. A reactive NST was as predictive of good outcome as was a negative CST. Analysis of the nonreactive NST showed that two or more accelerations were not associated with abnormal CST's. Also, some nonreactive fetuses became reactive with oxytocin and had good outcome. These observations were utilized in the development of a newer, shorter NST which allows for fetal stimulation in an attempt to further define fetal well-being.

Antepartum fetal heart rate testing. II. Intrapartum fetal heart rate observation and newborn outcome following a positive contraction stress test.

The positive contraction stress test (CST) has been looked upon as a predictor of fetal compromise. On this basis, some reports advise routine cesarean delivery on the assumption that the compromised fetus should not tolerate labor. Other authors advocate selective cesarean delivery, based on obstetrical factors such as the inducibility of the cervix and the practicality of fetal monitoring. Finally, an attempted trial of labor may be allowed on the basis of occurrence of fetal heart rate acceleration with fetal movement, or "reactivity." The occurrence of "false positive" tests is not infrequent (20 to 45 per cent). The definition of such is unclear and little quantitative information regarding intrapartum performance is available. In this series of 27 patients, a trial of labor was undertaken in 20. Vaginal delivery occurred in 11 (55 per cent) and cesarean section in nine (45 per cent). Fetal heart rate abnormalities thought to indicate "distress" occurred in five patients (25 per cent). The "positive" window or repetitive late deceleration as equivalent to the positive CST was seen in only three patients during labor. A trial of labor should be attempted in the face of a positive CST whenever obstetric factors are favorable and careful intrapartum monitoring can be performed.

Fetal demise following negative contraction stress tests.

The contraction stress test (CST) has become widely used to assess antepartum fetal well-being over the past 5 years. A summary of 14 reports in the literature revealed seven fetal deaths in 1739 patients within 1 week of a negative CST, an incidence of 0.4%. This prompted an investigation of our results for comparison. During the period January 1, 1975, to February 28, 1977, 746 patients underwent 1119 CSTs. Seven fetal deaths occurred in 680 patients within 1 week of a negative CST, an incidence of 1.0%. Although maternal conditions associated with fetal demise within 1 week of a negative CST include diabetes mellitus, prolonged pregnancy, chronic hypertension, and pre-eclampsia, fetal death in most instances resulted from factors other than uteroplacental insufficiency (UPI). Conditions commonly associated with fetal demise following a negative CST were umbilical cord accidents, severe congenital anomalies, and abruptio placentae. The low incidence of fetal death after a negative CST supports continued use of the CST in evaluation of high-risk pregnancies.