The MFMU Cesarean Registry: impact of fetal size on trial of labor success for patients with previous cesarean for dystocia

OBJECTIVE

The purpose of this study was to determine the influence of change in infant birth weight between pregnancies on the outcome of a trial of labor for women whose first cesarean delivery was performed for dystocia.

STUDY DESIGN

Secondary analysis of 7081 patients with 1 previous cesarean delivery and no other deliveries after 20 weeks' gestation, undergoing a trial of labor with a singleton gestation. Cases were classified as dystocia if the listed indication for the cesarean delivery in the first pregnancy was failed induction, cephalo-pelvic disproportion, failure to progress, or failed forceps or vacuum. Outcomes of the trial of labor were correlated with fetal size relative to birth weight in the initial pregnancy for those women whose initial cesarean delivery was for dystocia and those with other indications.

RESULTS

For the cohort being studied (n = 7081), dystocia was the indication for the first cesarean delivery for 3182 (44.9%). Trial of labor resulted in vaginal delivery for 54% of patients whose first cesarean delivery was performed for dystocia, compared with 67% for those with other indications (P < .01). For those whose first cesarean delivery was for dystocia, trial of labor success was correlated with birth weight differences between the pregnancies, with only 38% delivering vaginally if the trial of labor birth weight exceeded the initial pregnancy birth weight by more than 500 g. Using logistic regression and adjusting for other potential confounding factors, the odds of success decreased by 3.8% for each increase of 100 g in birth weight in the trial of labor relative to the first birth weight.

CONCLUSION

For women with previous cesarean delivery for dystocia, increasing birth weight in the subsequent trial of labor relative to the first birth weight diminishes the chances of successful vaginal delivery.

The Maternal-Fetal Medicine Units Cesarean Registry: safety and efficacy of a trial of labor in preterm pregnancy after a prior cesarean delivery

OBJECTIVE

This study was undertaken to compare success rates of vaginal birth after cesarean (VBAC) delivery, and uterine rupture as well as maternal/perinatal outcomes between women with preterm and term pregnancies undergoing trial of labor (TOL), and to compare maternal and neonatal morbidities in those women with preterm pregnancies undergoing a TOL versus repeat cesarean delivery without labor (RCD).

STUDY DESIGN

Prospective 4-year observational study of women with a singleton gestation and a prior cesarean delivery at 19 academic centers. Clinical characteristics, maternal complications and VBAC delivery success for those with a preterm (24(0)-36(6) weeks) TOL, preterm RCD and term TOL (> or = 37 weeks) were analyzed.

RESULTS

Among 3119 preterm pregnancies with prior cesarean delivery, 2338 (75%) underwent a TOL. 15,331 women undergoing TOL at term were also analyzed as a control group. TOL success rates for preterm and term pregnancies were similar (72.8% vs 73.3%, P = .64). Rates of uterine rupture (0.34% vs 0.74%, P = .03) and dehiscence (0.26% vs 0.67%, P = .02) were lower in preterm compared with term TOL. Thromboembolic disease, coagulopathy and transfusion were more common in women undergoing a preterm TOL than those at term. Among women undergoing a preterm TOL, rates of uterine dehiscence, coagulopathy, transfusion, and endometritis were similar to those having a preterm RCD. After controlling for gestational age at delivery and race, neonatal outcomes such as Neonatal Intensive Care Unit (NICU) admission, intraventricular hemorrhage, sepsis, and ventilatory support were similar in both groups except for a higher rate of respiratory distress syndrome in those delivered after a TOL.

CONCLUSION

The likelihood of VBAC success after TOL in preterm pregnancies is comparable to term gestations, with a lower risk of uterine rupture. Perinatal outcomes are similar with preterm TOL and RCD. TOL should be considered as an option for women undergoing preterm delivery with a history of prior cesarean delivery.

Single versus weekly courses of antenatal corticosteroids: evaluation of safety and efficacy

OBJECTIVE

The purpose of this study was to determine if weekly corticosteroids improve neonatal outcome without undue harm.

STUDY DESIGN

Women 23 to 32 weeks receiving 1 course of corticosteroids 7 to 10 days prior were randomized to weekly betamethasone or placebo.

RESULTS

The study was terminated by the independent data and safety monitoring committee with 495 of the anticipated 2400 patients enrolled. There was no significant reduction in the composite primary morbidity outcome (8.0% vs 9.1%, P = .67). Repeated courses significantly reduced neonatal surfactant administration (P = .02), mechanical ventilation (P = .004), CPAP (P = .05), pneumothoraces (P = .03). There was no significant difference in mean birth weight or head circumference. The repeat group had a reduction in multiples of the birth weight median by gestational age (0.88 vs 0.91) (P = .01) and more neonates weighing less than the 10th percentile (23.7 vs 15.3%, P = .02). Significant weight reductions occurred for the group receiving > or = 4 courses.

CONCLUSION

Repeat antenatal corticosteroids significantly reduce specific neonatal morbidities but do not improve composite neonatal outcome. This is accompanied by reduction in birth weight and increase in small for gestational age infants.

Maternal morbidity associated with multiple repeat cesarean deliveries

OBJECTIVE

Although repeat cesarean deliveries often are associated with serious morbidity, they account for only a portion of abdominal deliveries and are overlooked when evaluating morbidity. Our objective was to estimate the magnitude of increased maternal morbidity associated with increasing number of cesarean deliveries.

METHODS

Prospective observational cohort of 30,132 women who had cesarean delivery without labor in 19 academic centers over 4 years (1999-2002).

RESULTS

There were 6,201 first (primary), 15,808 second, 6,324 third, 1,452 fourth, 258 fifth, and 89 sixth or more cesarean deliveries. The risks of placenta accreta, cystotomy, bowel injury, ureteral injury, and ileus, the need for postoperative ventilation, intensive care unit admission, hysterectomy, and blood transfusion requiring 4 or more units, and the duration of operative time and hospital stay significantly increased with increasing number of cesarean deliveries. Placenta accreta was present in 15 (0.24%), 49 (0.31%), 36 (0.57%), 31 (2.13%), 6 (2.33%), and 6 (6.74%) women undergoing their first, second, third, fourth, fifth, and sixth or more cesarean deliveries, respectively. Hysterectomy was required in 40 (0.65%) first, 67 (0.42%) second, 57 (0.90%) third, 35 (2.41%) fourth, 9 (3.49%) fifth, and 8 (8.99%) sixth or more cesarean deliveries. In the 723 women with previa, the risk for placenta accreta was 3%, 11%, 40%, 61%, and 67% for first, second, third, fourth, and fifth or more repeat cesarean deliveries, respectively.

CONCLUSION

Because serious maternal morbidity increases progressively with increasing number of cesarean deliveries, the number of intended pregnancies should be considered during counseling regarding elective repeat cesarean operation versus a trial of labor and when debating the merits of elective primary cesarean delivery.

LEVEL OF EVIDENCE

II-2.

Trial of Labor or Repeat Cesarean Delivery in Women With Morbid Obesity and Previous Cesarean Delivery

OBJECTIVE

Assess effects of body mass index (BMI) on trial of labor after previous cesarean delivery and determine whether morbidly obese women have greater maternal and perinatal morbidity with trial of labor compared with elective repeat cesarean delivery.

METHODS

Secondary analysis from a prospective observational study included all term singletons undergoing trial of labor after previous cesarean delivery. Body mass index groups were as follows: normal 18.5-24.9, overweight 25.0-29.9, obese 30.0-39.9, morbidly obese 40.0 kg/m2 or greater, and were compared for failure and maternal and neonatal morbidities. The morbidly obese trial of labor and elective repeat cesarean delivery were compared for maternal and neonatal morbidities. Multivariable logistic regression analysis controlled for confounding variables.

RESULTS

There were 14,142 trial of labor participants and 14,304 elective repeat cesarean delivery participants. Increasing BMI was directly associated with failed trial of labor after previous cesarean delivery: from 15.2% in normal weight (1,344) to 39.3% in morbidly obese (1,638), with combined risk of rupture/dehiscence increasing from 0.9% to 2.1% in morbidly obese women. Among morbidly obese women, trial of labor carried greater than five-fold risk of uterine rupture/dehiscence (2.1% versus 0.4%), almost a two-fold increase in composite maternal morbidity (7.2% versus 3.8%) and five-fold risk of neonatal injury (1.1% versus 0.2%) (fractures, brachial plexus injuries, and lacerations), but no neonatal encephalopathy. Morbidly obese women failing a trial of labor had six-fold greater composite maternal morbidity than those undergoing a successful trial of labor (14.2% versus 2.6%).

CONCLUSION

Body mass index correlates with outcomes in trial of labor after previous cesarean delivery. Morbidly obese women undergoing a trial of labor were at increased risk for failure. Increased BMI was associated with greater composite morbidity and neonatal injury compared with elective repeat cesarean delivery, but absolute morbidities were small. Increased risks should be considered before trial of labor after previous cesarean delivery.

LEVEL OF EVIDENCE

II-2.

Risk of Uterine Rupture With a Trial of Labor in Women With Multiple and Single Prior Cesarean Delivery

OBJECTIVE

To determine whether the risk for uterine rupture is increased in women attempting vaginal birth after multiple cesarean deliveries.

METHODS

We conducted a prospective multicenter observational study of women with prior cesarean delivery undergoing trial of labor and elective repeat operation. Maternal and perinatal outcomes were compared among women attempting vaginal birth after multiple cesarean deliveries and those with a single prior cesarean delivery. We also compared outcomes for women with multiple prior cesarean deliveries undergoing trial of labor with those electing repeat cesarean delivery.

RESULTS

Uterine rupture occurred in 9 of 975 (0.9%) women with multiple prior cesarean compared with 115 of 16,915 (0.7%) women with a single prior operation (P = .37). Multivariable analysis confirmed that multiple prior cesarean delivery was not associated with an increased risk for uterine rupture. The rates of hysterectomy (0.6% versus 0.2%, P = .023) and transfusion (3.2% versus 1.6%, P < .001) were increased in women with multiple prior cesarean deliveries compared with women with a single prior cesarean delivery attempting trial of labor. Similarly, a composite of maternal morbidity was increased in women with multiple prior cesarean deliveries undergoing trial of labor compared with those having elective repeat cesarean delivery (odds ratio 1.41, 95% confidence interval 1.02-1.93).

CONCLUSION

A history of multiple cesarean deliveries is not associated with an increased rate of uterine rupture in women attempting vaginal birth compared with those with a single prior operation. Maternal morbidity is increased with trial of labor after multiple cesarean deliveries, compared with elective repeat cesarean delivery, but the absolute risk for complications is small. Vaginal birth after multiple cesarean deliveries should remain an option for eligible women.

LEVEL OF EVIDENCE

II-2.

The incidence of Sheehan's syndrome after obstetric hemorrhage

OBJECTIVE

To estimate the incidence of Sheehan's syndrome in a well-described cohort of patients with obstetric hemorrhage.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care center.

PATIENT(S)

Two hundred patients.

INTERVENTION(S)

Questionnaires were sent to study and comparison patients asking about menstrual dysfunction, lactation difficulty, cold intolerance, fatigue, axillary and pubic hair loss, and secondary infertility.

MAIN OUTCOME MEASURE(S)

Women who experienced two or more symptoms were referred for hormone testing of insulin-like growth factor 1 (IGF-1), T4, PRL, and early morning cortisol (F) levels.

RESULT(S)

A total of 109 patients responded to the survey, a 55% response rate. Fourteen of 55 (25%) patients in the hemorrhage group identified themselves as suffering from two or more symptoms on the questionnaire. Eight of the 14 patients were tested, but none had hormonal evidence of hypopituitarism. Four of 54 (7%) comparison patients also identified themselves as suffering from two or more symptoms, but neither of the two tested had hormonal evidence of hypopituitarism.

CONCLUSION(S)

Among women with postpartum hemorrhage, subsequent development of clinical symptoms does not correlate well with laboratory evidence of hypopituitarism. Clinically significant Sheehan syndrome is an uncommon consequence of obstetric hemorrhage in today's environment.

The MFMU Cesarean Registry: factors affecting the success of trial of labor after previous cesarean delivery

OBJECTIVE

The purpose of this study was to determine which factors influence the likelihood of successful trial of labor (TOL) after 1 previous cesarean delivery (CD).

STUDY DESIGN

We performed a multicenter 4-year prospective observational study (1999-2002) of all women with previous CD undergoing TOL. Women with term singleton pregnancies with 1 previous low transverse CD or unknown incision were included for analysis.

RESULTS

Fourteen thousand five hundred twenty-nine women underwent TOL, with 10,690 (73.6%) achieving successful VBAC. Women with previous vaginal birth had an 86.6% success rate compared with 60.9% in women without such a history (odds ratio [OR] 4.2; 95% CI 3.8-4.5; P < .001). TOL success rates were affected by previous indication for CD, need for induction or augmentation, cervical dilation on admission, birth weight, race, and maternal body mass index. Multivariate logistic regression analysis identified as predictive of TOL success: previous vaginal delivery (OR 3.9; 95% CI 3.6-4.3), previous indication not being dystocia (CPD/FTP) (OR 1.7; 95% CI 1.5-1.8), spontaneous labor (OR 1.6; 95% CI 1.5-1.8), birth weight <4000 g (OR 2.0; 95% CI 1.8-2.3), and Caucasian race (OR 1.8, 95% CI 1.6-1.9) (all P < .001). The overall TOL success rate in obese women (BMI > or = 30) was lower (68.4%) than in nonobese women (79.6%) (P < .001), and when combined with induction and lack of previous vaginal delivery, successful VBAC occurred in only 44.2% of cases.

CONCLUSION

Previous vaginal delivery including previous VBAC is the greatest predictor for successful TOL. Previous indication as dystocia, need for labor induction, or a maternal BMI > or = 30 significantly lowers success rates.

The interval between a single course of antenatal steroids and delivery and its association with neonatal outcomes

OBJECTIVE

This study was undertaken to determine whether the benefits of a single course of antenatal steroid treatment for neonatal respiratory morbidity diminish beyond 7 days.

STUDY DESIGN

A retrospective chart review was performed of all deliveries less than 34 weeks' gestation where delivery occurred after completing a single course of antenatal steroids (dexamethasone or betamethasone). Maternal and neonatal charts were reviewed, treatment course was confirmed, and neonatal morbidities were collected.

RESULTS

Of 197 neonates whose mothers received a full course of antenatal steroids, 98 delivered within 7 days and 99 delivered more than 7 days after the initial dose. The 2 groups were similar in gestational age at delivery (30 weeks 0 days vs 30 weeks 4 days). The groups were also similar in maternal age, race, payor status, type of steroid given, route of delivery, gender, and birth weight. Overall, infants delivering within 7 days had a lower incidence of receiving respiratory support for more than 24 hours (62% vs 81%, P < .01), but there were no significant differences between the groups in surfactant treatment (39% vs 47%), use of mechanical ventilation (49% vs 59%), necrotizing enterocolitis (6% vs 4%), intraventricular hemorrhage (15% vs 20%), oxygen dependence at 28 days (24% vs 23%) or at 36 weeks estimated gestational age (13% vs 12%), length of stay (34 days vs 38 days), or mortality (2 vs 0). These results were no different when evaluating only infants delivered before 30 weeks.

CONCLUSION

Among infants exposed to a single course of antenatal steroids, delivering more than 7 days after initiation of treatment was associated with an increased need for short-term respiratory support, but not other measures of neonatal morbidity. These data challenge the concept of diminishing efficacy of steroids after 7 days, and question the need for considering a rescue course.

Does Progesterone Treatment Influence Risk Factors for Recurrent Preterm Delivery?

OBJECTIVE

To examine how demographic and pregnancy characteristics can affect the risk of recurrent preterm delivery and the how the effectiveness of progesterone treatment for prevention alters these relationships.

METHODS

This was a secondary analysis of a randomized trial of 17alpha-hydroxyprogesterone caproate to prevent recurrent preterm delivery in women at risk. Associations of risk factors for preterm delivery (less than 37 completed weeks of gestation) were examined separately for the women in the 17alpha-hydroxyprogesterone caproate (n = 310) and placebo (n = 153) groups.

RESULTS

Univariate analysis found that the number of previous preterm deliveries and whether the penultimate delivery was preterm were significant risk factors for preterm delivery in both the placebo and progesterone groups. High body mass index was protective of preterm birth in the placebo group. Multivariate analysis found progesterone treatment to cancel the risk of more than 1 previous preterm delivery, but not the risk associated with the penultimate pregnancy delivered preterm. Obesity was associated with lower risk for preterm delivery in the placebo group but not in the women treated with progesterone.

CONCLUSION

The use of 17alpha-hydroxyprogesterone caproate in women with a previous preterm delivery reduces the overall risk of preterm delivery and changes the epidemiology of risk factors for recurrent preterm delivery. In particular, these data suggest that 17alpha-hydroxyprogesterone caproate reduces the risk of a history of more than 1 preterm delivery.

LEVEL OF EVIDENCE

I.

Progesterone for prevention of recurrent preterm birth: impact of gestational age at previous delivery

OBJECTIVE

Preterm birth occurs in 1 of 8 pregnancies and may result in significant morbidity and mortality. 17-alpha hydroxyprogesterone caproate (17-OHP caproate) has been found to be efficacious in reducing the risk of subsequent preterm delivery in women who have had a previous spontaneous preterm birth (sPTB). This analysis was undertaken to evaluate if 17-OHP caproate therapy works preferentially depending on the gestational age at previous spontaneous delivery. We hypothesized that treatment with 17-OHP caproate is more effective in prolonging pregnancy depending on the gestational age of the earliest previous preterm birth (20-27.9, 28-33.9 vs 34-36.9 weeks).

STUDY DESIGN

This was a secondary analysis of 459 women with a previous sPTB enrolled in a randomized controlled trial evaluating 17-OHP caproate versus placebo. Effectiveness of 17-OHP caproate for pregnancy prolongation was evaluated based on gestational age at earliest previous delivery according to clinically relevant groupings (20-27.9, 28-33.9, and 34-36.9 weeks). Statistical analysis included the chi-square, Fisher exact, and Kruskal-Wallis tests, logistic regression, and survival analysis using proportional hazards.

RESULTS

Gestational age at earliest previous delivery was similar between women treated with 17-OHP caproate or placebo (P = .1). Women with earliest delivery at 20 to 27.9 weeks and at 28 to 33.9 weeks delivered at significantly more advanced gestational age if treated with 17-OHP caproate than with placebo (median 37.3 vs 35.4 weeks, P = .046 and 38.0 vs 36.7 weeks, P = .004, respectively) and were less likely to deliver <37 weeks (42% vs 63%, P = .026 and 34% vs 56%, P = .005, respectively). Those with earliest delivery at 34 to 36.9 weeks were not significantly different between 17-OHP caproate or control.

CONCLUSION

17-OHP caproate therapy given to prevent recurrent PTB is associated with a prolongation of pregnancy overall, and especially for women with a previous spontaneous PTB at <34 weeks.

Plasma CRH measurement at 16 to 20 weeks' gestation does not predict preterm delivery in women at high-risk for preterm delivery

OBJECTIVE

The purpose of this study was to examine the utility of a single second-trimester plasma corticotropin-releasing hormone measurement as a marker for preterm delivery in women at high risk for preterm delivery.

STUDY DESIGN

This is an analysis of data from a multicenter placebo-controlled trial designed to evaluate the role of 17 alpha hydroxyprogesterone caproate (17P) in the prevention of recurrent preterm birth. Women with a documented history of a previous spontaneous preterm birth at <37 weeks were enrolled (16-20 wks) and randomly assigned in a 2 to 1 ratio to weekly injections of 17P or matching placebo. Blood was collected before treatment in 170 patients (113 assigned 17P and 57 placebo) who were enrolled at 11 of the 19 centers. Plasma levels of corticotropin-releasing hormone were compared between those who delivered preterm and those delivering at term. Data were analyzed using the Wilcoxon rank-sum test.

RESULTS

The overall rates of preterm birth in this cohort of 170 patients were 35.9% at <37 weeks (31.9% progesterone, 43.9% placebo), and 19.4% at <35 weeks (18.6% vs 21.1%). The median levels of corticotropin-releasing hormone were similar between those delivering at <37 weeks and those delivering > or = 37 weeks (0.39 ng/mL vs 0.37 ng/mL, P = .08). In addition, there were no differences in corticotropin-releasing hormone levels among those who delivered at <35 weeks or > or = 35 weeks (0.36 vs 0.38, P = .90). Moreover, there were no differences in corticotropin-releasing hormone levels among those in the placebo group who delivered at <37 or > or = 37 weeks (0.40 vs 0.41, P = .72) and at <35 or > or = 35 weeks (P = .64).

CONCLUSION

A single measurement of corticotropin-releasing hormone at 16 to 20 weeks' gestation is not a good biomarker for recurrent preterm delivery in patients at high risk for this complication.

The risk of cesarean delivery with neuraxial analgesia given early versus late in labor

BACKGROUND

Epidural analgesia initiated early in labor (when the cervix is less than 4.0 cm dilated) has been associated with an increased risk of cesarean delivery. It is unclear, however, whether this increase in risk is due to the analgesia or is attributable to other factors.

METHODS

We conducted a randomized trial of 750 nulliparous women at term who were in spontaneous labor or had spontaneous rupture of the membranes and who had a cervical dilatation of less than 4.0 cm. Women were randomly assigned to receive intrathecal fentanyl or systemic hydromorphone at the first request for analgesia. Epidural analgesia was initiated in the intrathecal group at the second request for analgesia and in the systemic group at a cervical dilatation of 4.0 cm or greater or at the third request for analgesia. The primary outcome was the rate of cesarean delivery.

RESULTS

The rate of cesarean delivery was not significantly different between the groups (17.8 percent after intrathecal analgesia vs. 20.7 percent after systemic analgesia; 95 percent confidence interval for the difference, -9.0 to 3.0 percentage points; P=0.31). The median time from the initiation of analgesia to complete dilatation was significantly shorter after intrathecal analgesia than after systemic analgesia (295 minutes vs. 385 minutes, P<0.001), as was the time to vaginal delivery (398 minutes vs. 479 minutes, P<0.001). Pain scores after the first intervention were significantly lower after intrathecal analgesia than after systemic analgesia (2 vs. 6 on a 0-to-10 scale, P<0.001). The incidence of one-minute Apgar scores below 7 was significantly higher after systemic analgesia (24.0 percent vs. 16.7 percent, P=0.01).

CONCLUSIONS

Neuraxial analgesia in early labor did not increase the rate of cesarean delivery, and it provided better analgesia and resulted in a shorter duration of labor than systemic analgesia.

Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery

BACKGROUND

The proportion of women who attempt vaginal delivery after prior cesarean delivery has decreased largely because of concern about safety. The absolute and relative risks associated with a trial of labor in women with a history of cesarean delivery, as compared with elective repeated cesarean delivery without labor, are uncertain.

METHODS

We conducted a prospective four-year observational study of all women with a singleton gestation and a prior cesarean delivery at 19 academic medical centers. Maternal and perinatal outcomes were compared between women who underwent a trial of labor and women who had an elective repeated cesarean delivery without labor.

RESULTS

Vaginal delivery was attempted by 17,898 women, and 15,801 women underwent elective repeated cesarean delivery without labor. Symptomatic uterine rupture occurred in 124 women who underwent a trial of labor (0.7 percent). Hypoxic-ischemic encephalopathy occurred in no infants whose mothers underwent elective repeated cesarean delivery and in 12 infants born at term whose mothers underwent a trial of labor (P<0.001). Seven of these cases of hypoxic-ischemic encephalopathy followed uterine rupture (absolute risk, 0.46 per 1000 women at term undergoing a trial of labor), including two neonatal deaths. The rate of endometritis was higher in women undergoing a trial of labor than in women undergoing repeated elective cesarean delivery (2.9 percent vs. 1.8 percent), as was the rate of blood transfusion (1.7 percent vs. 1.0 percent). The frequency of hysterectomy and of maternal death did not differ significantly between groups (0.2 percent vs. 0.3 percent, and 0.02 percent vs. 0.04 percent, respectively).

CONCLUSIONS

A trial of labor after prior cesarean delivery is associated with a greater perinatal risk than is elective repeated cesarean delivery without labor, although absolute risks are low. This information is relevant for counseling women about their choices after a cesarean section.

Efficacy and side effect profile of varying doses of intrathecal fentanyl added to bupivacaine for labor analgesia

The purpose of this randomized, double blinded and controlled study was to determine the optimal dose of intrathecal fentanyl when combined with bupivacaine 2.5 mg for initiation of labor analgesia. Parous parturients with cervical dilation between 3 and 5 cm were randomized to receive intrathecal fentanyl 0 (control), 5, 10, 15, 20 or 25 micrograms, combined with bupivacaine 2.5 mg, followed by a lidocaine/epinephrine epidural test dose. Visual analog pain scores (VAPS) and the presence of side effects were determined every 15 min until the parturient requested additional analgesia. Fetal heart rate (FHR) tracings were compared between groups. All parturients who received fentanyl >/= 15 micrograms had VAPS < 20 mm and duration of analgesia > 15 min, but this was not true for all parturients with fentanyl doses < 15 micrograms. Duration of analgesia was shorter for fentanyl groups 0, 5 and 10 micrograms, compared to groups 15, 20 and 25 micrograms, but there was no difference between the 15, 20 and 25 micrograms groups. There was no difference in the incidence of nausea and vomiting, or in FHR tracing changes. The incidence of pruritus was greater in all fentanyl groups compared to control. These data suggest that, when combined with intrathecal bupivacaine 2.5 mg, fentanyl 15 micrograms provides satisfactory analgesia to all parturients. Higher fentanyl doses produced no additional benefit in duration or quality of analgesia.

Management of the second stage of labor in nulliparas with continuous epidural analgesia

OBJECTIVE

To determine if waiting for a strong urge to push in nulliparas with continuous low-concentration epidural analgesia shortens the pushing duration in the second stage.

METHODS

Nulliparas with standardized patient-controlled epidural analgesia (0.0625% bupivacaine with fentanyl 2 microg/mL) were randomly assigned to pushing immediately upon complete cervical dilatation (n = 85) or waiting for a strong urge to push (n = 117). Urge to push and patient satisfaction were quantified on 100-mm visual analogue scales. Duration of pushing and total duration of the second stage were analyzed as survival time data.

RESULTS

Women who delayed pushing and those who pushed immediately were similar with respect to maternal characteristics. Women who delayed pushing had a stronger urge to push (P <.01) and a longer second stage (P <.05) than women who pushed immediately. There was no significant difference in the time spent pushing (median 57 versus 62 minutes, respectively) or the median level of patient satisfaction (80 mm for both groups). There were no significant differences in the overall rates of cesarean delivery (6% versus 12%, respectively), cesarean delivery during the second stage (2% in each group), spontaneous vaginal delivery (70% versus 69%, respectively), or neonatal or maternal morbidity.

CONCLUSION

In nulliparas with continuous low-concentration epidural analgesia, delaying pushing until a strong urge is felt does not reduce the duration of pushing in the second stage of labor.

Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate

BACKGROUND

Women who have had a spontaneous preterm delivery are at greatly increased risk for preterm delivery in subsequent pregnancies. The results of several small trials have suggested that 17 alpha-hydroxyprogesterone caproate (17P) may reduce the risk of preterm delivery.

METHODS

We conducted a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery. Women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation and randomly assigned by a central data center, in a 2:1 ratio, to receive either weekly injections of 250 mg of 17P or weekly injections of an inert oil placebo; injections were continued until delivery or to 36 weeks of gestation. The primary outcome was preterm delivery before 37 weeks of gestation. Analysis was performed according to the intention-to-treat principle.

RESULTS

Base-line characteristics of the 310 women in the progesterone group and the 153 women in the placebo group were similar. Treatment with 17P significantly reduced the risk of delivery at less than 37 weeks of gestation (incidence, 36.3 percent in the progesterone group vs. 54.9 percent in the placebo group; relative risk, 0.66 [95 percent confidence interval, 0.54 to 0.81]), delivery at less than 35 weeks of gestation (incidence, 20.6 percent vs. 30.7 percent; relative risk, 0.67 [95 percent confidence interval, 0.48 to 0.93]), and delivery at less than 32 weeks of gestation (11.4 percent vs. 19.6 percent; relative risk, 0.58 [95 percent confidence interval, 0.37 to 0.91]). Infants of women treated with 17P had significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen.

CONCLUSIONS

Weekly injections of 17P resulted in a substantial reduction in the rate of recurrent preterm delivery among women who were at particularly high risk for preterm delivery and reduced the likelihood of several complications in their infants.

Prematurity in multiple gestations: identification of patients who are at low risk

OBJECTIVE

The purpose of this study was to evaluate a strategy for the identification of patients with multiple gestations who are at low risk for preterm delivery.

STUDY DESIGN

A prospective observational study among patients with twin and triplet gestations. At 20 and 24 weeks of gestation, screening for bacterial vaginosis and fetal fibronectin was performed, followed by digital and sonographic assessment of the cervix. The treating physicians were blinded to test results.

RESULTS

At the 24-week examination, specificities for delivery at >32 weeks of gestation for digital examination (92.9%), fetal fibronectin level (93.9%), cervical length on sonographic scan (85.1%), and combined fetal fibronectin level and cervical length (81.3%) did not differ statistically. Negative predictive values for these tests were >or=95%. All tests performed better at 24 weeks of gestation than at 20 weeks of gestation.

CONCLUSION

At 24 weeks of gestation, a normal digital examination, a negative fetal fibronectin level, a normal cervical length on sonographic scan, or the combination of a negative fetal fibronectin level and a normal cervical length each confer a similarly high likelihood of delivery at >32 weeks of gestation in women with multiple gestations.

Risk-adjustment of cesarean delivery rates: a practical method for use in quality improvement

Risk-adjustment of cesarean birthrates has been hampered by inadequacies in the existing secondary data sources or by the need for extensive chart review. This study presents an efficient risk-adjustment model for cesarean birth, based on easily retrievable ICD-9 codes and clinical risk factors least influenced by physician practice style. Data are presented for mothers undergoing 7322 deliveries from 1997-1998 at a large academic medical center with a cesarean birth rate of 15.9%. Multiple logistic regression was used to predict the likelihood of cesarean delivery controlled for maternal age, 10 risk factors identified through ICD-9 coding, and 3 additional clinical variables (nulliparity, birth weight, and gestational age) derived from a perinatal (birth certificate) database. All risk factors were significant predictors of cesarean birth, producing an area under the receiver-operating characteristic curve of 0.86 and a 60-fold increase in cesarean delivery from highest to lowest deciles of predicted risk. This methodology can be used widely for quality improvement without the need for extensive chart review.

The dose-response of intrathecal sufentanil added to bupivacaine for labor analgesia

BACKGROUND

Regional analgesia for labor often is initiated with an intrathecal injection of a local anesthetic and opioid. The purpose of this prospective, randomized, blinded study was to determine the optimal dose of intrathecal sufentanil when combined with 2.5 mg bupivacaine for labor analgesia.

METHODS

One hundred seventy parous parturients with cervical dilation between 3-5 cm were randomized to receive intrathecal 0 (control), 2.5, 5.0, 7.5, or 10.0 microg sufentanil combined with 2.5 mg bupivacaine, followed by a lidocaine epidural test dose, for initiation of analgesia (34 patients in each group). Visual analog scores and the presence of nausea, vomiting, and pruritus were determined every 15 min until the patient requested additional analgesia. Fetal heart rate tracings were compared between groups.

RESULTS

Groups were similar for age, height, weight, oxytocin dose, duration of labor, and baseline visual analog scores. Duration of action was significantly shorter for control patients (39 +/- 25 min [mean +/- SD]) compared with those administered sufentanil, all doses (93 +/- 32, 93 +/- 47, 94 +/- 33, 97 +/- 39 min), but was not different among groups administered 2.5, 5.0, 7.5, or 10.0 microg sufentanil. More patients who received 10 microg sufentanil reported nausea and vomiting than did control patients. The severity of pruritus increased with administration of 7.5 and 10.0 microg sufentanil. There was no difference in fetal heart rate changes among groups.

CONCLUSIONS

Intrathecal bupivacaine (2.5 mg) without sufentanil did not provide satisfactory analgesia for parous patients. However, bupivacaine combined with 2.5 microg sufentanil provided analgesia comparable to higher doses, with a lower incidence of nausea and vomiting and less severe pruritus.

Cost-effectiveness of elective cesarean delivery after one prior low transverse cesarean

OBJECTIVE

This analysis was undertaken to better understand the costs and health consequences of a trial of labor after cesarean when compared with a policy of routine elective repeat cesarean delivery.

METHODS

A decision-tree model incorporating a Markov analysis was used to examine the reproductive life of a hypothetical cohort of 100,000 pregnant women whose only prior pregnancy was delivered through a low transverse cesarean incision. Using this model, the policy of performing routine elective cesarean delivery was compared with a policy of allowing a trial of labor. Main outcome measures were maternal and neonatal morbidity and mortality, total costs to the health care system, and cost per major neonatal complication avoided (death or permanent neurologic sequelae).

RESULTS

The consequences of routine elective cesarean delivery for a second birth are significant, with an additional 117,748 cesarean deliveries, 5500 maternal morbid events, and $179 million incurred during the reproductive life of 100,000 women. The prevention of one major adverse neonatal outcome requires 1591 cesarean deliveries and $2.4 million. Sensitivity analysis confirms the robustness of the analysis.

CONCLUSION

Routine elective cesarean for a second delivery for women with a prior low transverse cesarean incision results in an excess of maternal morbidity and mortality and a high cost to the medical system.

A multicenter, placebo-controlled pilot study of intravenous immune globulin treatment of antiphospholipid syndrome during pregnancy. The Pregnancy Loss Study Group

OBJECTIVE

Treatment with heparin and low-dose aspirin improves fetal survival among women with antiphospholipid syndrome. Despite treatment, however, these pregnancies are frequently complicated by preeclampsia, fetal growth restriction, and placental insufficiency, often with the result of preterm birth. Small case series suggest that intravenous immune globulin may reduce the rates of these obstetric complications, but the efficacy of this treatment remains unproven. This pilot study was undertaken to determine the feasibility of a multicenter trial of intravenous immune globulin and to assess the impact on obstetric and neonatal outcomes among women with antiphospholipid syndrome of the addition of intravenous immune globulin to a heparin and low-dose aspirin regimen.

STUDY DESIGN

This multicenter, randomized, double-blind pilot study compared treatment with heparin and low-dose aspirin plus intravenous immune globulin with heparin and low-dose aspirin plus placebo in a group of women who met strict criteria for antiphospholipid syndrome. All patients had lupus anticoagulant, medium to high levels of immunoglobulin G anticardiolipin antibodies, or both. Patients with a single live intrauterine fetus at </=12 weeks' gestation were randomly assigned to receive either intravenous immune globulin (1 g/kg body weight) or an identical-appearing placebo for 2 consecutive days each month until 36 weeks' gestation in addition to a heparin and low-dose aspirin regimen. Maternal characteristics, obstetric complications, and neonatal outcomes were compared with the Student t test and the Fisher exact test as appropriate.

RESULTS

Sixteen women were enrolled during a 2-year period; 7 received intravenous immune globulin and 9 were given placebo. The groups were similar with respect to age, gravidity, number of previous pregnancy losses, and gestational age at the initiation of treatment. Obstetric outcomes were excellent in both groups, with all women being delivered of live-born infants after 32 weeks' gestation. The rates of antepartum complications such as preeclampsia, fetal growth restriction, and placental insufficiency (as manifested by fetal growth restriction or fetal distress) were similar between the 2 groups. Gestational age at delivery (intravenous immune globulin group, 34.6 +/- 1.1 weeks; placebo group, 36.7 +/- 2.1 weeks) and birth weights (intravenous immune globulin group, 2249.7 +/- 186.1 g; placebo group; 2604.4 +/- 868.9 g) were similar between the 2 groups. There were fewer cases of fetal growth restriction (intravenous immune globulin group, 0%; placebo group, 33%) and neonatal intensive care unit admission (intravenous immune globulin group, 20%; placebo group, 44%) among the infants in the intravenous immune globulin group than those in the placebo group, but these differences were not significant.

CONCLUSION

A multicenter treatment trial of intravenous immune globulin is feasible. In this pilot study intravenous immune globulin did not improve obstetric or neonatal outcomes beyond those achieved with a heparin and low-dose aspirin regimen. Although not statistically significant, the findings of fewer cases of fetal growth restriction and neonatal intensive care unit admissions among the intravenous immune globulin-treated pregnancies may warrant expansion of the study.

Tumor necrosis factor-alpha is decreased in the umbilical cord plasma of patients with severe preeclampsia

We investigated the role of the fetal immune system in pregnancies complicated by preeclampsia by assessing umbilical cord plasma levels of the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta). Nineteen nulliparous patients with severe preeclampsia composed the study group (group A). A comparison group was comprised of 19 healthy nulliparous patients with uneventful pregnancies (group B). Mixed umbilical cord blood was collected immediately after delivery. Plasma was prepared and all samples were assayed for TNF-alpha and IL-1beta by specific enzyme-linked immunoassays (ELISAs). Data are presented as the median with range of values. The length of labor was similar in both groups. TNF-alpha was detected less frequently in the umbilical cord plasma of preeclamptic patients than in the umbilical cord plasma of control patients (57.9 vs. 89.5%, p < 0.05), and the concentrations of TNF-alpha were significantly lower in the umbilical cord plasma of the preeclamptic patients [20 pg/ml (0-80 pg/mL) vs. 50 pg/mL (0-310 pg/mL), p < 0.05]. Umbilical cord plasma IL-1beta detection rates and concentrations from the preeclamptic and control patients were similar, [15.8 vs. 5.3%, 0 pg/mL (0-40 pg/mL) vs 0 pg/mL (0-10 pg/mL)]. The lower concentrations of TNF-alpha in umbilical cord plasma of patients with severe preeclampsia suggest that release of TNF-alpha by the fetus and mother are independent and may reflect adaptation of the fetus to reduced placental perfusion in preeclampsia.

Active management of labor

The active management of labor may be one approach to achieving lower rates of intervention. Numerous institutions have reported lower CS rates since initiating this labor management scheme, and concurrent decreases in the length of labor and infectious morbidity have been demonstrated. Sufficient data now exist to conclude that such programs can be instituted without deleterious effects on neonatal outcomes. Nevertheless, success in decreasing CS rates has not been uniform and may be confined to certain settings. Other approaches to labor management may be as good or better at achieving low rates of intervention with minimum morbidity. Any approach that emphasizes advocacy for vaginal birth is likely to produce some success and should receive support.

Vaginal birth after cesarean: an appraisal of fetal risk

OBJECTIVE

To expand on prior investigations and further evaluate the fetal risk associated with vaginal birth after cesarean (VBAC) by examining the incidence not only of a depressed Apgar score at 5 minutes but also of fetal acidemia.

METHODS

Between January 1, 1991, and December 31, 1996, the following groups of patients who delivered a singleton fetus with birth weight greater than 750 g were identified: 2082 patients with one or more prior cesarean deliveries who were allowed a trial of labor, 1677 of whom delivered vaginally and 405 of whom delivered by repeat cesarean; 920 patients delivered by elective repeat cesarean; 22,863 patients without a prior cesarean who delivered vaginally; and 2432 patients delivered by primary cesarean after laboring. Umbilical cord arterial blood gases were obtained in 88.3% of these deliveries. Comparisons of Apgar scores at 5 minutes and umbilical cord arterial pH measurements were made between groups with chi2 or Fisher exact test, and odds ratios (ORs) were calculated.

RESULTS

The only significant differences were noted between those patients who delivered vaginally after a prior cesarean and those patients who delivered vaginally without a prior cesarean. Neonates in the successful VBAC group were more likely to have an Apgar score at 5 minutes less than 7 (OR 1.52) or an umbilical arterial pH less than 7.1 (OR 1.69). Those neonates, however, were not at greater risk for an Apgar score less than 4 or a pH less than 7.0.

CONCLUSION

Our experience suggests that VBAC poses a low level of fetal risk, although a much larger sample size would be required to exclude a two-fold increase in potentially damaging fetal acidemia.

Risk factors for cesarean delivery in twin gestations near term

OBJECTIVE

We evaluated the risk factors associated with cesarean delivery in laboring twin gestations at least 36 completed weeks.

METHODS

We reviewed the records of 134 women with twin gestations who underwent a trial of labor between 1993 and 1995. Women who delivered by cesarean were compared with women who delivered vaginally. The factors associated with an increased risk for cesarean were determined using univariate analysis. Logistic regression was used to determine which of those factors was most strongly associated with cesarean delivery.

RESULTS

Of 134 laboring twin gestations, 25 (18.7%) delivered by cesarean and 109 (81.3%) delivered vaginally. Univariate analysis revealed that women who delivered by cesarean were more likely to be nulliparous, have a less advanced cervix at both admission and epidural placement, a higher mean oxytocin infusion rate for induction or augmentation of labor, a combined fetal weight greater than 5500 g, and received magnesium for seizure prophylaxis. Multivariate analysis identified that nulliparity and timing of epidural administration were the factors most strongly associated with cesarean delivery.

CONCLUSION

The timing of epidural analgesia is a modifiable risk factor strongly associated with cesarean delivery in term and near-term laboring twin gestations.

Neonatal outcomes in triplet gestations after a trial of labor

OBJECTIVE

This study aimed to compare neonatal outcomes in a cohort of triplet gestations undergoing a trial of labor with those of a similar cohort delivered by elective cesarean delivery.

STUDY DESIGN

Thirty-three women with triplet gestations who underwent a trial of labor were compared with a matched cohort of 33 women with triplet gestations who were delivered of their infants by elective cesarean delivery. Neonatal outcomes assessed included respiratory distress syndrome, retinopathy of prematurity, necrotizing enterocolitis, intraventricular hemorrhage, Apgar scores, and birth trauma.

RESULTS

Twenty-nine of 33 women (87.9%) who underwent a trial of labor had a successful vaginal delivery of all 3 neonates. One patient was delivered of her first triplet vaginally but then required a cesarean delivery for abruptio placentae; 3 other patients were delivered of their infants by cesarean section for active-phase arrest of labor. There were no differences in neonatal outcomes between the 2 groups, although triplet neonates delivered by elective cesarean section demonstrated a trend toward a greater incidence of respiratory distress syndrome (P = .09).

CONCLUSION

Our experience suggests that offering vaginal delivery is an acceptable management plan for triplet gestations.

Maternal hospital charges associated with trial of labor versus elective repeat cesarean section

BACKGROUND

Although cesarean section is known to be associated with higher hospital charges than vaginal delivery, cost comparisons require further investigation. This study compared maternal hospital charges of women with one previous cesarean section undergoing a trial of labor with the charges of women who underwent an elective repeat cesarean section. Hospital charges for the trial of labor group were also compared with charges of women with a previous vaginal delivery but no previous cesarean section.

METHODS

A retrospective analysis of three primiparous privately insured patient groups who gave birth from July 1992 to October 1993 was conducted. Hospital charges for 50 primiparas with previous cesarean births who underwent a trial of labor were compared with those of 50 contemporaneous primiparas who underwent elective repeat cesarean section, and with those of 50 primiparas without a past history of cesarean birth.

RESULTS

Trial of labor was associated with a mean maternal hospital charge of $5820 +/- $1609 compared with $6785 +/- $771 for elective repeat cesarean section (p < 0.001). Trial of labor was also associated with a decreased length of stay when compared with elective cesarean section (2.48 +/- 0.88 days vs 3.62 +/- 0.57 days, p < 0.001). The difference in charges between these two groups was primarily due to charges associated with length of stay and the operating room, but was partly offset by charges associated with labor. The group of women without a past history of cesarean birth had a mean maternal hospital charge of $4685 +/- $966 and a mean length of stay of 1.96 +/- 0.63 days.

CONCLUSIONS

Trial of labor is associated with an overall 14 percent reduction in maternal hospital charges and a 31 percent reduction in length of stay compared with elective repeat cesarean section.

Fetal fibronectin as a predictor of preterm birth in patients with symptoms: a multicenter trial

OBJECTIVE

Our aim was to determine whether the presence of fetal fibronectin in vaginal secretions of patients with symptoms suggestive of preterm labor predicts preterm delivery.

STUDY DESIGN

Patients who were examined at the hospital between 24 weeks' and 34 weeks 6 days' gestation with intact membranes, no prior tocolysis, symptoms suggestive of preterm labor, and cervical dilation < 3 cm were recruited at 10 sites. Swabs of the posterior fornix were assayed for the presence of fetal fibronectin by monoclonal antibody assay, with a positive result defined as > or = 50 ng/ml. Results were not available to the managing physicians. Tocolysis was used when clinically indicated after specimen collection.

RESULTS

A total of 763 patients had fetal fibronectin results and pregnancy outcome data available for analysis. Fetal fibronectin was detected in specimens from 150 (20%) patients. Compared with patients who had negative results, patients who had positive results for fetal fibronectin were more likely to be delivered within 7 days (relative risk 25.9 [95% confidence interval 7.8 to 86]), within 14 days (relative risk 20.4 [95% confidence interval 8.0 to 53]), and before 37 completed weeks (relative risk 2.9 [95% confidence interval 2.2 to 3.7]). The negative predictive values for delivery within 7 days, within 14 days, and at < 37 weeks were 99.5%, 99.2%, and 84.5%, respectively. When we used multiple logistic regression analysis to control for potential confounding variables among singleton pregnancies, only the presence of fetal fibronectin (odds ratio 48.8, 95% confidence interval 7.4 to 320), prior preterm birth (odds ratio 8.3, 95% confidence interval 1.5 to 46.6), and tocolysis (odds ratio 4.1, 95% confidence interval 1.0 to 16.0) were associated with birth within 7 days; fetal fibronectin (odds ratio 3.6, 95% confidence interval 2.2 to 5.9), prior preterm birth (odds ratio 2.5, 95% confidence interval 1.4 to 4.4), cervical dilatation > 1 cm (odds ratio 2.9, 95% confidence interval 1.6 to 5.2), and tocolysis (odds ratio 4.5, 95% confidence interval 2.8 to 7.2) were all independently associated with delivery before 37 weeks.

CONCLUSION

In a population of patients with symptoms, the presence of fetal fibronectin in vaginal secretions best defines a subgroup at increased risk for delivery within 7 days; the high negative predictive value of fetal fibronectin sampling supports less intervention for patients with this result.

Soluble tumor necrosis factor receptors and interleukin-6 levels in patients with severe preeclampsia

OBJECTIVE

To investigate whether serum and amniotic fluid (AF) levels of soluble tumor necrosis factor receptors and interleukin-6, markers of immune activation and endothelial dysfunction, are altered in patients with severe preeclampsia.

METHODS

Plasma was collected before induction of labor, at delivery, and postpartum from 19 patients with severe preeclampsia. Amniotic fluid was also obtained in early labor from these patients. Similar samples were obtained from an antepartum control group matched for gestational age and a term control group without preeclampsia. All plasma and AF samples were assayed for p55 and p75 soluble tumor necrosis factor receptors and for interleukin-6 by specific enzyme-linked immunoassays. Levels in preeclamptic patients and the control groups were compared.

RESULTS

Levels of both receptors were significantly elevated in AF and all maternal plasma samples except those collected 24 hours postpartum for patients with preeclampsia relative to levels in controls. Interleukin-6 was detected more frequently and in higher concentrations in the plasma collected before labor for preeclamptic patients compared with controls, but no difference was noted in interleukin-6 detection rates or plasma concentrations at delivery. Conversely, AF concentrations of interleukin-6 were significantly reduced in patients with preeclampsia.

CONCLUSION

The increased levels of soluble tumor necrosis factor receptors found in patients with severe preeclampsia may represent a protective response to increased tumor necrosis factor activity and be a marker for immune activation. Increased interleukin-6 concentrations in maternal plasma before labor suggest the involvement of this cytokine as well in the altered immune response and its contribution to endothelial cell dysfunction.

Active management of labor

Active management of labor was first instituted as a program to shorten the length of nulliparous labor. Numerous institutions have found that implementation of this program decreased rates of cesarean section. Two randomized trials have evaluated this program, with both showing that labor was shortened by approximately 2 hours and maternal infectious morbidity was decreased by approximately 50%. Although one trial demonstrated a significant reduction in the rate of cesarean birth, the other did not. No users have reported any increase in neonatal morbidity. For some institutions implementation of active management of labor principles may be one approach to decrease operative deliveries for dystocia.

The effect of aspirin and indomethacin on prostacyclin and thromboxane production by placental tissue incubated with immunoglobulin G fractions from patients with lupus anticoagulant

OBJECTIVE

We investigated the hypothesis that nonsteroidal antiinflammatory agents can influence the abnormal prostanoid production associated with antiphospholipid antibodies. We specifically assessed whether aspirin or indomethacin could eliminate the increased placental thromboxane production previously observed with immunoglobulin G fractions from patients with lupus anticoagulant without adversely affecting prostacyclin production.

STUDY DESIGN

Immunoglobulin G fractions were prepared from the plasma of eight nonpregnant patients with antiphospholipid antibody syndrome and demonstrable lupus anticoagulant. Samples from each patient were then placed in incubation wells containing explants from normal term pregnancies and 10(-4) mol/L aspirin, 10(-7) mol/L indomethacin, or no added drug. Aliquots were removed at intervals up to 48 hours of incubation and assessed for placental prostacyclin and thromboxane production by radioimmunoassay of the stable metabolites prostaglandin F1 alpha and thromboxane B2.

RESULTS

The addition of aspirin to wells containing immunoglobulin G from patients with lupus anticoagulant was associated with a significant decrease in thromboxane production compared with wells without added drug, but prostacyclin production was unaffected. In contrast, the addition of indomethacin also decreased thromboxane production significantly, but prostacyclin production was also diminished, so the ratio of thromboxane to prostacyclin was unaffected.

CONCLUSION

These results support a role for the use of aspirin for antiphospholipid antibody-related pregnancy loss through a mechanism similar to that postulated for preeclampsia, namely, selective inhibition of thromboxane production.

Soluble tumor necrosis factor receptors in maternal plasma and second-trimester amniotic fluid

OBJECTIVES

We assessed maternal plasma and second-trimester amniotic fluid for levels of the p55 and p75 soluble tumor necrosis factor receptors.

STUDY DESIGN

Blood was drawn from 61 healthy pregnant women (group A) before second-trimester genetic amniocentesis, and an aliquot of amniotic fluid was also obtained for this study. An additional blood sample was obtained from 13 of these patients at 36 to 40 weeks' gestation. Twenty-three healthy, nonpregnant women of reproductive age donated blood as a control group (group B). All plasma and amniotic fluid specimens were collectively assayed for the p55 and p75 soluble tumor necrosis factor receptors by specific enzyme-linked immunoassays. Additionally, tumor necrosis factor-alpha concentrations were measured in second-trimester plasma and amniotic fluid of 22 patients in group A and in all 23 of the nonpregnant women.

RESULTS

The p55 and p75 soluble tumor necrosis factor receptors were detectable in all plasma samples from both groups of patients. The concentrations of both soluble receptors were significantly higher in second-trimester plasma compared with nonpregnant measurements (p < 0.01), and the plasma concentrations of both soluble receptors increased significantly from the second to third trimester (p < 0.01). The p55 and p75 soluble tumor necrosis factor receptors were also detectable in all amniotic fluid samples. Tumor necrosis factor-alpha was detected in the plasma of 15 of 22 patients in the second trimester but in none of the amniotic fluid samples and in none of the plasma samples from the nonpregnant cohort.

CONCLUSIONS

Both the p55 and p75 soluble tumor necrosis factor receptors are physiologic constituents of second-trimester maternal plasma and amniotic fluid. Concentrations are elevated in pregnancy and further increase from the second to third trimester.

Understanding prostaglandin metabolites and platelet-activating factor in the pathophysiology and treatment of the antiphospholipid syndrome

As clinicians include an immunologic evaluation in their assessment of recurrent fetal loss among otherwise asymptomatic women, the diagnosis of PAPS will be uncovered with greater frequency. Our understanding of the underlying pathophysiology of PAPS is critical if we are to propose safe and rational therapies for these patients. It appears as though prostaglandin metabolites are implicated directly in the processes that culminate in this unique, localized vasculopathy; and research is actively progressing with this focus in mind. For the present, we should look critically at the available treatments to be sure that the rationale for use is consistent with current evidence and that the margin of fetal and maternal safety justifies their use. To date, only low-dose aspirin appears to alter prostaglandin metabolites favorably and is thus, emerging as our safest and most efficacious treatment.

Fetal fibronectin levels are elevated in maternal plasma and amniotic fluid of patients with severe preeclampsia

OBJECTIVE

Our purpose was to investigate levels of fetal fibronectin in maternal plasma, amniotic fluid, and umbilical cord plasma from patients with severe preeclampsia.

STUDY DESIGN

The study group comprised 20 patients with severe preeclampsia (group A). An antepartum comparison group was composed of 20 healthy patients matched for gestational age (group B). An intrapartum control group consisted of 20 term normotensive patients (group C). Maternal plasma samples were collected before labor (groups A and B), then immediately after delivery, and again at 20 to 24 hours post partum (groups A and C). Amniotic fluid was also collected in early labor, and umbilical cord blood was collected at delivery (groups A and C). Samples were assayed for fetal fibronectin by a specific enzyme-linked immunoassay.

RESULTS

Before labor maternal plasma levels of fetal fibronectin were significantly elevated in preeclamptic patients compared with patients in group B (p < 0.0001). Plasma levels of fetal fibronectin were also increased in preeclamptic patients compared with patients in group C at delivery (p < 0.0001) and post partum (p < 0.05). Additionally, amniotic fluid levels of fetal fibronectin in the preeclamptic patients were significantly increased (p < 0.05). In contrast, umbilical cord plasma fetal fibronectin concentrations from the preeclamptic and control patients were similar.

CONCLUSIONS

Fetal fibronectin is elevated in the maternal plasma and amniotic fluid, but not umbilical cord plasma, of patients with severe preeclampsia. These findings suggest an increase in production of fetal fibronectin from chorionic trophoblast in patients with preeclampsia or an abnormal interaction between chorionic trophoblast and decidua with resultant increased leakage into the maternal circulation and amniotic fluid.

Immunoreactive tumor necrosis factor-alpha is elevated in maternal plasma but undetected in amniotic fluid in the second trimester

OBJECTIVE

We investigated the participation of the cellular arm of the immune system in adaptation to pregnancy by assessing plasma and amniotic fluid levels of the cytokine tumor necrosis factor-alpha.

STUDY DESIGN

Fifty-five healthy pregnant women who underwent second-trimester genetic amniocentesis at a mean gestational age of 17.0 +/- 1.4 weeks composed study group A. Blood was drawn from each patient before amniocentesis, and an aliquot of amniotic fluid was obtained for this study. Twenty-one healthy patients at a mean gestational age of 35.5 +/- 4.8 weeks composed study group B, and blood was obtained from each patient at an outpatient prenatal visit. Twenty-two healthy, nonpregnant women of reproductive age composed the control group (C). All specimens were stored at -70 degrees C and collectively assayed for tumor necrosis factor-alpha by a specific enzyme-linked immunoassay.

RESULTS

All patients in group A had a normal karyotype and all patients in groups A and B had uneventful pregnancies. Tumor necrosis factor-alpha was detected in the plasma of 43 of 55 (78.2%) patients in group A compared with 7 of 21 (33.3%) patients in group B (p < 0.001); tumor necrosis factor-alpha was not detected in any of the 22 women in group C. The median plasma tumor necrosis factor-alpha level for group A was 135 pg/ml (range 0 to 625 pg/ml) compared with 0 pg/ml (range 0 to 110 pg/ml) in group B (p < 0.001). Tumor necrosis factor-alpha was not detected in any of the amniotic fluid specimens studied.

CONCLUSIONS

Levels of tumor necrosis factor-alpha were elevated in the plasma but not detected in the amniotic fluid of normal pregnant patients in the second trimester. These findings suggest involvement of the cellular branch of the immune system and its products, the cytokines, in the normal adaptation of the mother to the fetal allograft, with a possible role in regulating trophoblast growth and invasion.

Tumor necrosis factor-alpha is elevated in plasma and amniotic fluid of patients with severe preeclampsia

OBJECTIVE

Our purpose was to investigate whether markers for activation of the immune system are present in patients with preeclampsia by assessing maternal plasma and amniotic fluid for tumor necrosis factor-alpha and interleukin-1 beta.

STUDY DESIGN

Twenty-one patients with severe preeclampsia composed the study group (group A). An antepartum comparison group was composed of healthy nulliparous patients not in labor and matched for gestational age (group B). Another control group consisted of term nulliparous patients in labor with uneventful pregnancies (group C). Maternal plasma samples were collected from all patients at recruitment and from patients in groups A and C immediately after delivery and again 20 to 24 hours post partum. Amniotic fluid was also collected from patients in groups A and C during labor. All samples were collectively assayed for tumor necrosis factor-alpha and interleukin-1 beta by specific enzyme-linked immunoassays.

RESULTS

Before labor tumor necrosis factor-alpha was detected more frequently in the plasma of preeclamptic patients than in the plasma of patients in group B (12/16 vs 5/16, p < 0.05) and in higher concentrations (median 35 pg/ml vs median 0 pg/ml, p < 0.05). Although tumor necrosis factor-alpha was frequently detected in the plasma of patients in group C in early labor (16/20), concentrations were higher in the four preeclamptic patients first sampled in early labor (210 pg/ml vs 65 pg/ml, p < 0.05). Similarly, amniotic fluid levels of tumor necrosis factor-alpha were increased in preeclamptic patients compared with control patients. At delivery tumor necrosis factor-alpha was more likely to be identified in the plasma of preeclamptic patients and was found in higher concentrations, but by 20 to 24 hours post partum measurements in the preeclamptic and control patients were similar. There were no differences in the frequency with which interleukin-1 beta was detected or the concentration of interleukin-1 beta in any of the samples.

CONCLUSIONS

Tumor necrosis factor-alpha is increased in the plasma and amniotic fluid of patients with severe preeclampsia. These data are suggestive of a role for abnormal immune activation in the pathophysiologic mechanisms of preeclampsia.

Severe postpartum pulmonary, cardiac, and renal syndrome associated with antiphospholipid antibodies

BACKGROUND

The antiphospholipid antibody syndrome has been associated with thromboembolic events, thrombocytopenia, fetal death, fetal growth retardation, and early-onset severe preeclampsia.

CASE

A postpartum woman developed fever, pulmonary infiltrates, cardiac conduction defects, and renal insufficiency following severe preeclampsia. She tested positive for lupus anticoagulant and anticardiolipin antibody, and responded to steroid therapy and plasmapheresis.

CONCLUSION

The postpartum multi-system involvement suggests that a variety of clinical presentations may be associated with antiphospholipid antibodies. Treatment with plasmapheresis or corticosteroids may be of value in similar cases.

The effect of immunoglobulin G fractions from patients with lupus anticoagulant on placental prostacyclin and thromboxane production

OBJECTIVE

We evaluated whether the production of prostacyclin and thromboxane by normal human placental tissue is consistently altered by incubation with immunoglobulin G fractions prepared from plasma of patients with lupus anticoagulant.

STUDY DESIGN

The immunoglobulin G fractions were prepared from eight patients with lupus anticoagulant and eight control patients. Doses of these fractions (3 mg, 7.5 mg, and 12 mg) were incubated with placental explants obtained from normal pregnancies, and prostacyclin and thromboxane production was assessed over 48 hours.

RESULTS

Prostacyclin production was similar for placental tissue incubated with immunoglobulin fractions from control and lupus anticoagulant patients at all of the doses tested. Placental production of thromboxane was significantly increased with immunoglobulin fractions from lupus anticoagulant patients for all three doses (p = 0.02).

CONCLUSIONS

The immunoglobulin G fraction from patients with lupus anticoagulant consistently alters placental thromboxane production without affecting prostacyclin production. Increases in placental thromboxane production may contribute to antiphospholipid antibody-mediated pregnancy loss.

Factors that influence route of delivery--active versus traditional labor management

OBJECTIVE

Our purpose was to compare maternal and fetal factors that influence the route of delivery with active management of labor and a traditional labor management protocol.

STUDY DESIGN

Data were collected prospectively on 346 consecutive patients receiving active management of labor and 354 patients who were managed traditionally. Within each group demographic and labor characteristics of patients undergoing cesarean section were compared with those of patients having vaginal deliveries by means of the Student t test, chi 2 analysis, and stepwise logistic regression.

RESULTS

With both active management of labor and traditional labor management success in achieving vaginal delivery was related to the station of the fetal vertex at admission, the need for oxytocin augmentation of labor, the uterine response to oxytocin, the use of epidural anesthesia, and the development of chorioamnionitis. By means of multiple logistic regression analysis maternal age, height, payor status, and birth weight were also identified as risk factors for cesarean section with traditional labor management but not with active management of labor.

CONCLUSIONS

Differences were identified in risk factors for cesarean section between active management and traditional labor management. Active management of labor may diminish or eliminate some patient characteristics as risk factors for cesarean birth.

Factors contributing to the increased cesarean birth rate in older parturient women

OBJECTIVE

Our purpose was to determine factors contributing to the increased use of cesarean section in patients > or = 35 years old.

STUDY DESIGN

Data were collected prospectively on nulliparous patients in spontaneous labor with term, singleton pregnancies and vertex presentations. Criteria for the diagnosis of labor were standardized: regular, painful uterine contractions at least once every 5 minutes in the presence of either complete cervical effacement or spontaneous rupture of membranes. The labors of women > or = 35 years old (n = 74) were compared with those of women 20 to 29 years old (n = 275).

RESULTS

The cesarean section rate was significantly greater for patients > or = 35 years old (21.6% vs 10.2%, odds ratio 2.4, 95% confidence interval 1.2 to 5.1). Mean birth weights were similar in the two groups, but when birth weight was > or = 3600 gm patients > or = 35 years old were more likely to be delivered by cesarean section (36.7% vs 12.2%, odds ratio 4.0, 95% confidence interval 1.4 to 11.9). There were no differences between the two age groups in physician factors that could explain the disparate rates of cesarean delivery. Indeed, of patients delivered vaginally the older parturients received oxytocin for longer duration (6.4 +/- 2.6 vs 5.0 +/- 3.1 hours, p < 0.05) and at higher maximum doses (12.4 +/- 6.1 vs 9.8 +/- 6.2 mU, p < 0.05). After controlling for potentially confounding variables with multiple logistic regression analysis, maternal age (R = 0.125, p < 0.005), birth weight (R = 0.196, p < 0.001), the need for oxytocin (R = 0.210, p < 0.001), and epidural anesthesia (R = 0.195, p < 0.001) were found to be independently associated with the increased rate of cesarean section.

CONCLUSION

We could not identify any controllable physician factors affecting the rate of cesarean section in patients > or = 35 years old. The increased oxytocin requirements and the incidence of dystocia with birth weight > or = 3600 gm suggest that maternal and fetal characteristics contribute to the increased frequency of cesarean section in older parturients.

Reducing cesarean births at a primarily private university hospital

OBJECTIVE

The rise in cesarean birth at Northwestern Memorial Hospital in 1986 to 27.3% prompted implementation of three initiatives to reverse the escalating cesarean section rate.

STUDY DESIGN

First, vaginal birth after cesarean section was more strongly encouraged. Second, after the 1988 calendar year the cesarean section rate of every obstetrician was circulated annually to each attending physician. Third, on completion of a prospective, randomized trial of the active management of labor in early 1991, this protocol was recommended as the preferred method of labor management for term nulliparous patients.

RESULTS

The total, primary, and repeat cesarean section rates declined from 27.3%, 18.2%, and 9.1% in 1986 to 16.9%, 10.6%, and 6.4%, respectively, in 1991. At the same time the perinatal mortality dropped from 19.5 to 10.3. Significant reductions in abdominal deliveries occurred for both private patients (30.3% to 19.1%, p < 0.0001) and clinic patients (20.8% to 11.5%, p < 0.0001). A decline in operative deliveries for dystocia and an increase in vaginal birth after prior cesarean section were the principal factors contributing to the lower cesarean section rates. However, in 1991 individual private physicians still had wide variations in primary cesarean section rates (4.6% to 21.1%) and use of vaginal birth after prior cesarean section (5.3% to 90%).

CONCLUSION

The cesarean section rate has been significantly reduced for both private and clinic patients. Differences in population demographics and individual physician practice patterns contributed to a higher incidence of cesarean birth on the private service.

The immunoglobulin G fraction from plasma containing antiphospholipid antibodies causes increased placental thromboxane production

OBJECTIVE

Our objective was to evaluate whether the immunoglobulin G fraction from plasma containing high levels of antiphospholipid antibodies alters the production of prostacyclin or thromboxane when incubated with normal human placental tissue.

STUDY DESIGN

The immunoglobulin G fraction was prepared from the pooled plasma of five volunteers with normal obstetric histories and no antiphospholipid antibodies. The immunoglobulin G fraction was prepared similarly from a patient with the antiphospholipid antibody syndrome. Doses of these immunoglobulin G fractions ranging from 0.3 to 3.0 mg were incubated with placental explants obtained from eight normal pregnancies, and prostacyclin and thromboxane production was assessed over 48 hours.

RESULTS

Placental prostacyclin production was unaltered by incubation with either immunoglobulin G fraction at any of the doses tested. Placental thromboxane production tripled by 32 hours with the addition of 0.6, 1.5, and 3.0 mg of the antiphospholipid antibody fraction (p < 0.05) compared with baseline production but was unaltered by the addition of the normal pooled plasma fraction at any dose. The increase in thromboxane production with antiphospholipid antibody immunoglobulin G appeared to be dose related.

CONCLUSION

The immunoglobulin G fraction prepared from plasma containing antiphospholipid antibodies caused increased placental thromboxane production without altering prostacyclin production.

Antepartum management of triplet gestations

OBJECTIVE

We evaluated an alternative approach to the management of triplet gestations that did not include home uterine monitoring, prophylactic tocolysis, or routine antepartum hospitalization.

STUDY DESIGN

Fifteen patients were managed over a 42-month period by an antepartum protocol that emphasized patient education regarding signs and symptoms of preterm labor, weekly prenatal visits after 24 weeks' gestation with cervical examination, and increased rest in an outpatient setting. Tocolytic therapy was only used for regular uterine contractions when cervical change was documented.

RESULTS

Nine of 15 (60%) patients with management in this uniform manner were delivered at > or = 35 weeks' gestation, and six patients (40%) completed 37 weeks of pregnancy. Only five patients (33%) received tocolytic therapy. The mean birth weight was 1957 +/- 488 gm, and only 19 of 45 neonates (42%) were admitted to the intensive care nursery.

CONCLUSION

This management scheme was effective in reducing preterm delivery and thereby optimizing perinatal outcome.