The frequency and complication rates of hysterectomy accompanying cesarean delivery

OBJECTIVE

To estimate the frequency, indications, and complications of cesarean hysterectomy.

METHODS

This was a prospective, 2-year observational study at 13 academic medical centers conducted between January 1, 1999, and December 31, 2000, on all women who underwent a hysterectomy at the time of cesarean delivery. Data were abstracted from the medical record by study nurses. The outcomes included procedure frequency, indications, and complications.

RESULTS

A total of 186 cesarean hysterectomies (0.5%) were performed from a cohort of 39,244 women who underwent cesarean delivery. The leading indications for hysterectomy were placenta accreta (38%) and uterine atony (34%). Of the hysterectomy cases with a diagnosis recorded as accreta, 18% accompanied a primary cesarean delivery, and 82% had a prior procedure (P<.001). Of the hysterectomy cases with atony recorded as a diagnosis, 59% complicated primary cesarean delivery, whereas 41% had a prior cesarean (P<.001). Major maternal complications of cesarean hysterectomy included transfusion of red blood cells (84%) and other blood products (34%), fever (11%), subsequent laparotomy (4%), ureteral injury (3%), and death (1.6%). Accreta hysterectomy cases were more likely than atony hysterectomy cases to require ureteral stents (14% compared with 3%, P=.03) and to instill sterile milk into the bladder (23% compared with 8%, P=.02).

CONCLUSION

The rate of cesarean hysterectomy has declined modestly in the past decade. Despite the use of effective therapies and procedures to control hemorrhage at cesarean delivery, a small proportion of women continue to require hysterectomy to control hemorrhage from both uterine atony and placenta accreta.

LEVEL OF EVIDENCE

II.

Is there a seasonal variation in the diagnosis of oligohydramnios?

OBJECTIVE

We hypothesized that oligohydramnios would be diagnosed more frequently in the warm summer months when dehydration might be more common.

METHODS

The clinical diagnosis of oligohydramnios was extracted from the databases of four completed National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network protocols. These data were stratified by quarter of delivery and compared using Fisher's Exact Test.

RESULTS

The clinical diagnosis of oligohydramnios was made more frequently in deliveries occurring in the summer months of June, July and August as compared with the remainder of the calendar year (7.2% vs 5.9%, p=0.0178).

CONCLUSIONS

In these studies the diagnosis of oligohydramnios is made more frequently in those pregnancies delivered during the summer months. Although not proven by this association, maternal dehydration may contribute to this finding.

Timing of elective repeat cesarean delivery at term and neonatal outcomes

BACKGROUND

Because of increased rates of respiratory complications, elective cesarean delivery is discouraged before 39 weeks of gestation unless there is evidence of fetal lung maturity. We assessed associations between elective cesarean delivery at term (37 weeks of gestation or longer) but before 39 weeks of gestation and neonatal outcomes.

METHODS

We studied a cohort of consecutive patients undergoing repeat cesarean sections performed at 19 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network from 1999 through 2002. Women with viable singleton pregnancies delivered electively (i.e., before the onset of labor and without any recognized indications for delivery before 39 weeks of gestation) were included. The primary outcome was the composite of neonatal death and any of several adverse events, including respiratory complications, treated hypoglycemia, newborn sepsis, and admission to the neonatal intensive care unit (ICU).

RESULTS

Of 24,077 repeat cesarean deliveries at term, 13,258 were performed electively; of these, 35.8% were performed before 39 completed weeks of gestation (6.3% at 37 weeks and 29.5% at 38 weeks) and 49.1% at 39 weeks of gestation. One neonatal death occurred. As compared with births at 39 weeks, births at 37 weeks and at 38 weeks were associated with an increased risk of the primary outcome (adjusted odds ratio for births at 37 weeks, 2.1; 95% confidence interval [CI], 1.7 to 2.5; adjusted odds ratio for births at 38 weeks, 1.5; 95% CI, 1.3 to 1.7; P for trend <0.001). The rates of adverse respiratory outcomes, mechanical ventilation, newborn sepsis, hypoglycemia, admission to the neonatal ICU, and hospitalization for 5 days or more were increased by a factor of 1.8 to 4.2 for births at 37 weeks and 1.3 to 2.1 for births at 38 weeks.

CONCLUSIONS

Elective repeat cesarean delivery before 39 weeks of gestation is common and is associated with respiratory and other adverse neonatal outcomes.

Salivary progesterone and estriol among pregnant women treated with 17-alpha-hydroxyprogesterone caproate or placebo

OBJECTIVE

The objectives of the study was to determine whether salivary progesterone (P) or estriol (E3) concentration at 16-20 weeks' gestation predicts preterm birth or the response to 17alpha-hydroxyprogesterone caproate (17OHPC) and whether 17OHPC treatment affected the trajectory of salivary P and E3 as pregnancy progressed.

STUDY DESIGN

This was a secondary analysis of a clinical trial of 17OHPC to prevent preterm birth. Baseline saliva was assayed for P and E3. Weekly salivary samples were obtained from 40 women who received 17OHPC and 40 who received placebo in a multicenter randomized trial of 17OHPC to prevent recurrent preterm delivery.

RESULTS

Both low and high baseline saliva P and E3 were associated with a slightly increased risk of preterm birth. However, 17OHPC prevented preterm birth comparably, regardless of baseline salivary hormone concentrations. 17OHPC did not alter the trajectory of salivary P over pregnancy, but it significantly blunted the rise in salivary E3 as well as the rise in the E3/P ratio.

CONCLUSION

17OHPC flattened the trajectory of E3 in the second half of pregnancy, suggesting that the drug influences the fetoplacental unit.

Cesarean delivery for the second twin

OBJECTIVE

To examine maternal and infant outcomes after a vaginal delivery of twin A and a cesarean delivery of twin B, and to identify whether the second twin experienced increased short-term morbidity as part of a combined route of delivery.

METHODS

Between January 1, 1999, and December 31, 2000, a prospective cohort study of all cesarean deliveries was conducted at 13 university centers. This secondary analysis was limited to women with twin gestations who experienced labor and underwent cesarean delivery. We compared outcomes of the second twin in women who had vaginal delivery of the first twin and a cesarean delivery of the second twin to those who had cesarean delivery of both twins.

RESULTS

One thousand twenty-eight twin pregnancies experienced labor and underwent cesarean delivery; 179 (17%) had a combined vaginal/cesarean delivery. Gestational age at delivery was 34.6 weeks in both groups (P=.97). The rupture of membranes to delivery interval was longer in the combined group (3.2 compared with 2.3 hours, P<.001). Endometritis and culture-proven sepsis in the second twin were more common in the combined group, respectively (n=24, odds ratio 1.6, 95% confidence interval, 1.0-2.7; n=15, odds ratio 1.8, 95% confidence interval, 1.0-3.4). These differences were not significant after logistic regression analysis. There were no statistically significant differences in an arterial cord pH of less than 7.0, Apgar score less than or equal to 3 at 5 minutes, seizures, grade III or IV intraventricular hemorrhage, hypoxic ischemic encephalopathy, or neonatal death.

CONCLUSION

Combined twin delivery may be associated with endometritis and neonatal sepsis when compared with a twin delivery where both are delivered by cesarean in twin pregnancies experiencing labor. More serious neonatal sequelae, including hypoxic ischemic encephalopathy and death, were not affected by the route of delivery of the second twin.

A randomized, controlled trial of magnesium sulfate for the prevention of cerebral palsy

BACKGROUND

Research suggests that fetal exposure to magnesium sulfate before preterm birth might reduce the risk of cerebral palsy.

METHODS

In this multicenter, placebo-controlled, double-blind trial, we randomly assigned women at imminent risk for delivery between 24 and 31 weeks of gestation to receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour, or matching placebo. The primary outcome was the composite of stillbirth or infant death by 1 year of corrected age or moderate or severe cerebral palsy at or beyond 2 years of corrected age.

RESULTS

A total of 2241 women underwent randomization. The baseline characteristics were similar in the two groups. Follow-up was achieved for 95.6% of the children. The rate of the primary outcome was not significantly different in the magnesium sulfate group and the placebo group (11.3% and 11.7%, respectively; relative risk, 0.97; 95% confidence interval [CI], 0.77 to 1.23). However, in a prespecified secondary analysis, moderate or severe cerebral palsy occurred significantly less frequently in the magnesium sulfate group (1.9% vs. 3.5%; relative risk, 0.55; 95% CI, 0.32 to 0.95). The risk of death did not differ significantly between the groups (9.5% vs. 8.5%; relative risk, 1.12; 95% CI, 0.85 to 1.47). No woman had a life-threatening event.

CONCLUSIONS

Fetal exposure to magnesium sulfate before anticipated early preterm delivery did not reduce the combined risk of moderate or severe cerebral palsy or death, although the rate of cerebral palsy was reduced among survivors. (ClinicalTrials.gov number, NCT00014989.)

Prediction of uterine rupture associated with attempted vaginal birth after cesarean delivery

OBJECTIVE

The purpose of this study was to develop a model that predicts individual-specific risk of uterine rupture during an attempted vaginal birth after cesarean delivery.

STUDY DESIGN

Women with 1 previous low-transverse cesarean delivery who underwent a trial of labor with a term singleton were identified in a concurrently collected database of deliveries that occurred at 19 academic centers during a 4-year period. We analyzed different classification techniques in an effort to develop an accurate prediction model for uterine rupture.

RESULTS

Of the 11,855 women who were available for analysis, 83 women (0.7%) had had a uterine rupture. The optimal final prediction model, which was based on a logistic regression, included 2 variables: any previous vaginal delivery (odds ratio, 0.44; 95% CI, 0.27-0.71) and induction of labor (odds ratio, 1.73; 95% CI, 1.11-2.69). This model, with a c-statistic of 0.627, had poor discriminating ability and did not allow the determination of a clinically useful estimate of the probability of uterine rupture for an individual patient.

CONCLUSION

Factors that were available before or at admission for delivery cannot be used to predict accurately the relatively small proportion of women at term who will experience a uterine rupture during an attempted vaginal birth after cesarean delivery.

Bone metabolism in pregnant women exposed to single compared with multiple courses of corticosteroids

OBJECTIVE

To compare markers of maternal bone metabolism between women who received a single compared with multiple courses of antenatal corticosteroids.

METHODS

This is an analysis of serum samples from a previously reported randomized, placebo-controlled, multicenter trial. Women at risk for preterm delivery after an initial course of corticosteroids were randomly assigned to weekly courses of betamethasone (active) or placebo. Serum levels of carboxy terminal propeptide of type I procollagen (PICP) and cross-linked carboxy terminal telopeptide of type I collagen (ICTP) were measured to assess the rate of bone formation and resorption, respectively, at three time points. The placebo group (n=93) was compared with the active group, receiving four or more courses of betamethasone (n=112).

RESULTS

There were significant (P<.001) increases in PICP and ICTP between baseline and delivery in both groups. Cross-linked carboxy terminal telopeptide of type I collagen, but not PICP, was lower with corticosteroid exposure immediately before administration of the fourth study course (P<.001). No significant differences in PICP and ICTP were seen between groups at delivery.

CONCLUSION

Increasing levels of PICP and ICTP with advancing gestation are consistent with physiologic changes in maternal bone metabolism. Multiple courses of corticosteroids for fetal maturation are not associated with persistent or cumulative effects on maternal bone metabolism as measured by PICP and ICTP.

LEVEL OF EVIDENCE

II.

The effect of body mass index on therapeutic response to bacterial vaginosis in pregnancy

Our objective was to determine the effect of body mass index (BMI) on response to bacterial vaginosis (BV) treatment. A secondary analysis was conducted of two multicenter trials of therapy for BV and TRICHOMONAS VAGINALIS. Gravida were screened for BV between 8 and 22 weeks and randomized between 16 and 23 weeks to metronidazole or placebo. Of 1497 gravida with asymptomatic BV and preconceptional BMI, 738 were randomized to metronidazole; BMI was divided into categories: < 25, 25 to 29.9, and > or = 30. Rates of BV persistence at follow-up were compared using the Mantel-Haenszel chi square. Multiple logistic regression was used to evaluate the effect of BMI on BV persistence at follow-up, adjusting for potential confounders. No association was identified between BMI and BV rate at follow-up ( P = 0.21). BMI was associated with maternal age, smoking, marital status, and black race. Compared with women with BMI of < 25, adjusted odds ratio (OR) of BV at follow-up were BMI 25 to 29.9: OR, 0.66, 95% CI 0.43 to 1.02; BMI > or = 30: OR, 0.83, 95% CI 0.54 to 1.26. We concluded that the persistence of BV after treatment was not related to BMI.

Cervical length and the risk of spontaneous labor at term

OBJECTIVE

To investigate the relationship between cervical length (CL) at 37 to 40 weeks and delivery within 7 days and delivery by 41 weeks.

STUDY DESIGN

We performed transvaginal ultrasound to measure CL in women with singleton gestations at 37 to 40 weeks. We then used a receiver operating characteristic curve (ROC) to assess the relationship between CL and delivery within 7 days and delivery by 41 weeks.

RESULT

For the 120 women included in the analysis, the mean CL (+/-s.d.) was 25.3+/-9.8 mm. The logistic regression model to predict each of the outcomes includes gestational age at ultrasound (GA-US) and CL. Neither birthweight, nor parity seems to affect the probability of delivery within 7 days. The ROC curve was used to assess the probability of spontaneous labor within 7 days at each CL measurement. The likelihood ratio of delivery within 7 days when CL is < or = 10 mm is 12.

CONCLUSION

CL measurement at 37-40 weeks is an independent predictor of delivery within 7 days and delivery by 41 weeks regardless of GA-US. This information can be utilized when counseling patients regarding the management of term pregnancies.

Risk of Uterine Rupture and Adverse Perinatal Outcome at Term After Cesarean Delivery

OBJECTIVE

Current information on the risk of uterine rupture after cesarean delivery has generally compared the risk after trial of labor to that occurring with an elective cesarean delivery without labor. Because antepartum counseling cannot account for whether a woman will develop an indication requiring a repeat cesarean delivery or whether labor will occur before scheduled cesarean delivery, the purpose of this analysis was to provide clinically useful information regarding the risks of uterine rupture and adverse perinatal outcome for women at term with a history of prior cesarean delivery.

METHODS

Women with a term singleton gestation and prior cesarean delivery were studied over 4 years at 19 centers. For this analysis, outcomes from five groups were studied: trial of labor, elective repeat with no labor, elective repeat with labor (women presenting in early labor who subsequently underwent cesarean delivery), indicated repeat with labor, and indicated repeat without labor. All cases of uterine rupture were reviewed centrally to assure accuracy of diagnosis.

RESULTS

A total of 39,117 women were studied. In term pregnant women with a prior cesarean delivery, the overall risk for uterine rupture was 0.32% (125 of 39,117), and the overall risk for serious adverse perinatal outcome (stillbirth, hypoxic ischemic encephalopathy, neonatal death) was 106 of 39,049 (0.27%). The uterine rupture risk for indicated repeat cesarean delivery (labor or without labor) was 7 of 6,080 (0.12%); the risk for elective (no indication) repeat cesarean delivery (labor or without labor) was 4 of 17,714 (0.02%). Indicated repeat cesarean delivery increased the risk of uterine rupture by a factor of 5 (odds ratio 5.1, 95% confidence interval 1.49-17.44). In the absence of an indication, the presence of labor also increased the risk of uterine rupture (4 of 2,721 [0.15%] compared with 0 of 14,993, P<.01). The highest rate of uterine rupture occurred in women undergoing trial of labor (0.74%, 114 of 15,323).

CONCLUSION

At term, the risk of uterine rupture and adverse perinatal outcome for women with a singleton and prior cesarean delivery is low regardless of mode of delivery, occurring in 3 per 1,000 women. Maternal complications occurred in 3-8% of women within the five delivery groups.

Perioperative morbidity and mortality among human immunodeficiency virus infected women undergoing cesarean delivery

OBJECTIVE

To determine whether human immunodeficiency virus (HIV)-infected women have a higher rate of postcesarean morbidity and mortality compared with women without HIV infection.

METHODS

A secondary analysis was performed of women with singleton gestations undergoing cesarean delivery with known HIV status. Data were collected as part of a prospective 4-year (1999-2002) observational study and analyzed using logistic regression. Women were surveyed for a large number of intraoperative complications, common perioperative morbidities, and uncommon maternal complications.

RESULTS

There were 378 HIV-infected and 54,281 uninfected women who met criteria. Patients infected with HIV were more likely to have postpartum endometritis (11.6% compared with 5.8%, P<.001), require a postpartum blood transfusion (4.0% compared with 2.0%, P=.02), develop maternal sepsis (1.1% compared with 0.2%, P<.001), be treated for pneumonia (1.3% compared with 0.3%, P=.001), and to have a maternal death (0.8% compared with 0.1%, P<.001). After controlling for potential confounders, patients with HIV infection were more likely to have one or more postpartum morbidities (odds ratio 1.6, 95% confidence interval 1.2-2.2).

CONCLUSION

Women with HIV infection undergoing cesarean delivery are at increased risk for perioperative morbidity and maternal mortality.

LEVEL OF EVIDENCE

II.

The Effect of Multiple Reexcisions on the Risk of Local Recurrence After Breast Conserving Surgery

BACKGROUND

Guidelines for breast conserving surgery (BCS) advise mastectomy if negative margins cannot be obtained after reasonable surgical attempts. This study examined the effect of multiple reexcisions on local recurrence (LR) and identified factors predictive of the need for multiple reexcisions.

METHODS

2,770 patients undergoing BCS over 25 years were analyzed; 137 patients (group A) with two or more reexcisions, 1514 patients with one reexcision (group B), and 1119 patients who had no reexcision (group C). The median follow-up was 73 months.

RESULTS

The five and ten-year actuarial LR rates for groups A, B, and C were 5.5%, 1.9%, 2.5%, and 10%, 5.7%, and 5.6%, respectively. The number of reexcisions did not predict for LR on multivariate analysis. Women <40 years underwent reexcision more frequently than other age groups. Patients with tumors detected by palpation alone made up 14% of the reexcision group versus 8% of the no reexcision group (p < 0.001). Patients with ductal carcinoma in situ and lobular carcinoma were more likely to require reexcision than those with ductal carcinoma. On multivariate analysis, younger age, detection by physical exam only, lobular histology, smaller tumor size, and the presence of extensive intraductal component (EIC) were highly significant predictors of the need for reexcision.

CONCLUSIONS

Multiple reexcisions do not impact on LR rates if negative margins are ultimately obtained. Conversion to mastectomy based solely on the number of excisions performed is not indicated. Subsets of patients more likely to require reexcision, who may be candidates for a larger initial resection, can be identified.

Antimicrobial prophylaxis in otorhinolaryngology/head and neck surgery

Prophylactic antimicrobial therapy is defined as the administration of an antimicrobial agent prior to contamination of previously sterile tissues or fluids, in an attempt to reduce the microbial burden of intraoperative contamination. Prophylactic antimicrobial therapy should cover the anticipated floral contamination, with therapeutic levels from incision to closure. There is level I evidence to support the use of prophylaxis in clean-contaminated head and neck procedures and tonsillectomy, while level II evidence fails to support the use of prophylaxis in clean head and neck procedures. The aim of this study was to evaluate the use, timing and appropriateness of antimicrobial prophylaxis perioperatively, in otorhinolaryngological/head and neck procedures. A total of 34/51 (66%) patients were administered antimicrobial agents prophylactically. Six of 19 patients (42%) who ought to have received prophylaxis did not, while six of 13 (46%) of those who did not require it received it. Administration was unsuitably timed in 14 of 34 (41%) operations. This study demonstrates unnecessary administration of antimicrobial agents perioperatively, subclinical intraoperative antimicrobial levels for prophylaxis and inconsistent documentation regarding prophylaxis in otorhinolaryngological/head and neck procedures in a general ENT unit.

Comparison of Maternal and Infant Outcomes From Primary Cesarean Delivery During the Second Compared With First Stage of Labor

OBJECTIVE

To compare maternal and neonatal outcomes when primary cesarean delivery is performed in the second stage of labor compared with the first stage.

METHODS

Between January 1, 1999, and December 31, 2000, a prospective observational study of primary cesarean deliveries was conducted at 13 university centers comprising the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. The primary outcomes of interest included a maternal composite (composed of at least one of the following: endometritis, intraoperative surgical complication, blood transfusion, or wound complication) and neonatal composite (which included at least one of the following: Apgar score of 3 or less at 5 minutes, neonatal death, neonatal intensive care unit admission, seizure, delivery room intubation in the absence of meconium, or fetal injury).

RESULTS

A total of 11,981 cesarean deliveries were available for analysis: 9,265 were performed in the first stage and 2,716 in the second stage. Cesarean deliveries performed in the second stage were associated with longer operative times, epidural analgesia, chorioamnionitis, and higher birth weight (all P<.001). The maternal composite index was slightly increased in women undergoing cesarean delivery in the second stage of labor, primarily due to uterine atony, uterine incision extension, and incidental cystotomy. This difference was significant after multivariable analysis (odds ratio 1.21, 95% confidence interval 1.07-1.37). After multivariable analysis, the neonatal composite did not differ significantly between groups (odds ratio 0.96, 95% confidence interval 0.84-1.08).

CONCLUSION

Cesarean delivery in the second stage of labor is associated with slightly increased maternal but not neonatal composite morbidity.

LEVEL OF EVIDENCE

II.

Development of a Nomogram for Prediction of Vaginal Birth After Cesarean Delivery

OBJECTIVE

To develop a model based on factors available at the first prenatal visit that predicts chance of successful vaginal birth after cesarean delivery (VBAC) for individual patients who undergo a trial of labor.

METHODS

All women with one prior low transverse cesarean who underwent a trial of labor at term with a vertex singleton gestation were identified from a concurrently collected database of deliveries at 19 academic centers during a 4-year period. Using factors identifiable at the first prenatal visit, we analyzed different classification techniques in an effort to develop a meaningful prediction model for VBAC success. After development and cross-validation, this model was represented by a graphic nomogram.

RESULTS

Seven-thousand six hundred sixty women were available for analysis. The prediction model is based on a multivariable logistic regression, including the variables of maternal age, body mass index, ethnicity, prior vaginal delivery, the occurrence of a VBAC, and a potentially recurrent indication for the cesarean delivery. After analyzing the model with cross-validation techniques, it was found to be both accurate and discriminating.

CONCLUSION

A predictive nomogram, which incorporates six variables easily ascertainable at the first prenatal visit, has been developed that allows the determination of a patient-specific chance for successful VBAC for those women who undertake trial of labor.

LEVEL OF EVIDENCE

II.

Sentinel lymph node biopsy in elderly irish patients with malignant melanoma

In patients with malignant melanoma, Breslow depth increases with age. However, studies suggest that the frequency of sentinel lymph node metastases in malignant melanoma decreases with age. We investigated whether this applied to the cohort of patients undergoing sentinel lymph node biopsy (SLNB) in our institution. In a prospectively accrued database we identified 149 patients undergoing SLNB from 1997 to 2005. Tumour thickness as measured by Breslow depth was assessed in stratified age groups. We assessed the relationship between SLNB positivity and age using the Chi-square for trend. We directly examined the relationship between SLNB positivity in patients aged less than 65 and aged 65 years of age and over. Disease-free and overall survival in patients aged less than 65 and aged 65 years of age and over were also assessed. Comparing the age groups, there was no significant difference identified in Breslow depth (<65 years, median Breslow > or = 1.2 mm (range 0.2-9.7); > or =65 years, median Breslow > or = 1.4 mm (range 0.12-8.5); p > or = 0.06, Mann-Whitney U). Chi-square for trend identified no significant relationship between SLNB positivity and age. We found n=120 patients <65 had SLNB, of which 26 (21.7%) were positive. In patients =65, n=29 had SLNB of which 3 (10.3%) were positive. These differences were not statistically significant (Fisher's exact test, p > or = 0.2). There was no difference in disease-free or overall survival between patients aged <65 or > or =65 who had SLNB (median follow-up 37.5 months (range 5-70); disease-free survival, p > 0.08; overall survival, p > or = 0.3, Logrank test). We did not find that elderly patients with malignant melanoma had a demonstrable difference in tumour thickness when compared to younger patients. In those patients who underwent SLNB there was no significant difference in node positivity between the age groups. Disease-free and overall survival were not significantly different between the age groups. Further study and longer follow-up will help establish the relationship between age and SLNB positivity.

Outcomes of Induction of Labor After One Prior Cesarean

OBJECTIVE

To compare pregnancy outcomes in women with one prior low-transverse cesarean delivery after induction of labor with pregnancy outcomes after spontaneous labor.

METHODS

This study is an analysis of women with one prior low-transverse cesarean and a singleton gestation who underwent a trial of labor and who were enrolled in a 4-year prospective observational study. Pregnancy outcomes were evaluated according to whether a woman underwent spontaneous labor or labor induction.

RESULTS

Among the 11,778 women studied, vaginal delivery was less likely after induction of labor both in women without and with a prior vaginal delivery (51% versus 65%, P<.001; and 83% versus 88%, P<.001). An increased risk of uterine rupture after labor induction was found only in women with no prior vaginal delivery (1.5% versus 0.8%, P=.02; and 0.6% versus 0.4%, P=.42). Blood transfusion, venous thromboembolism, and hysterectomy were also more common with induction among women without a prior vaginal delivery. No measure of perinatal morbidity was associated with labor induction. An unfavorable cervix at labor induction was not associated with any adverse outcomes except an increased risk of cesarean delivery.

CONCLUSION

Induction of labor in the study population is associated with an increased risk of cesarean delivery in all women with an unfavorable cervix, a statistically significant, albeit clinically small, increase in maternal morbidity in women with no prior vaginal delivery, and no appreciable increase in perinatal morbidity.

LEVEL OF EVIDENCE

II.

Sample bias among women with retained DNA samples for future genetic studies

OBJECTIVE

To evaluate whether women who agree to future use of their biologic specimens for genetic studies reflect the larger study population from which they are derived.

METHODS

Women were questioned as to the future disposition of their maternal and fetal DNA samples upon enrollment in a multicenter, observational study originally designed to identify factor V Leiden mutation carriers and prospectively ascertain the estimated rate of pregnancy-related venous thromboembolism and adverse pregnancy outcome. Univariate and multivariate analyses was carried out on the 5,003 of 5,188 enrolled women who indicated their desire regarding future disposition of their DNA samples.

RESULTS

Among these 5,003 women, 20.1% desired that their samples be discarded and not available for future genetic studies. Multivariate analysis demonstrated that women who agreed to subsequent use of samples were less likely African-American (odds ratio [OR] 0.6, 95% confidence interval [CI] 0.4-0.7) or Hispanic (OR 0.4, 95% CI 0.3-0.5), and more likely to use tobacco (OR 1.2, 95% CI 1.0-1.6) than those who desired that their samples be discarded.

CONCLUSION

Genetic samples from women agreeing to their use in a sample repository may not be representative of the index study cohort. This should be considered in their subsequent interpretation and generalizability.

LEVEL OF EVIDENCE

III.

Fetal Injury Associated With Cesarean Delivery

OBJECTIVE

To describe the incidence and type of fetal injury identified in women undergoing cesarean delivery.

METHODS

Between January 1, 1999, and December 31, 2000, a prospective cohort study of all cesarean deliveries was conducted at 13 university centers. Information regarding maternal and infant outcomes was abstracted directly from hospital charts.

RESULTS

A total of 37,110 cesarean deliveries were included in the registry, and 418 (1.1%) had an identified fetal injury. The most common injury was skin laceration (n = 272, 0.7%). Other injuries included cephalohematoma (n = 88), clavicular fracture (n = 11), brachial plexus (n = 9), skull fracture (n = 6), and facial nerve palsy (n = 11). Among primary cesarean deliveries, deliveries with a failed forceps or vacuum attempt had the highest rate of injuries (6.9%). In women with a prior cesarean delivery, the highest rate of injury also occurred in the unsuccessful trial of forceps or vacuum (1.7%), and the lowest rate occurred in the elective repeat cesarean group (0.5%). The type of uterine incision was associated with fetal injury, 3.4% "T" or "J" incision, 1.4% for vertical incision, and 1.1% for a low transverse (P = .003), as was a skin incision-to-delivery time of 3 minutes or less. Fetal injury did not vary in frequency with the type of skin incision, preterm delivery, maternal body mass index, or infant birth weight greater than 4,000 g.

CONCLUSION

Fetal injuries complicate 1.1% of cesarean deliveries. The frequency of fetal injury at cesarean delivery varies with the indication for surgery as well as with the duration of the skin incision-to-delivery interval and the type of uterine incision.

LEVEL OF EVIDENCE

II-3.

The MFMU Cesarean Registry: impact of time of day on cesarean complications

OBJECTIVE

Studies suggest that sleep deprivation adversely affects performance. We hypothesized that cesarean delivery complications would be more frequent during the night shift (11 pm-7 am), and evaluated morbidities by delivery shift.

STUDY DESIGN

Eighteen thousand nine hundred and thirty-nine term women undergoing an unscheduled cesarean delivery in 13 centers from 1999 to 2000 within a prospective observational study were included. Maternal/neonatal morbidities and time from decision to cesarean delivery were evaluated by time of delivery (7 am-3 pm, 3 pm-11 pm, 11 pm-7 am). A composite of maternal morbidities was evaluated by logistic regression controlling for potentially confounding factors.

RESULTS

Controlling for age, race, insurance, cardiac disease, preeclampsia, diabetes, previous incision type, and prenatal care, shift of delivery had no impact on maternal morbidity (11 pm-7 am OR 0.9 [95% CI 0.81-1.0]). NICU admissions were slightly increased at night but neonatal complications were not.

CONCLUSION

Maternal and neonatal complications of cesarean delivery do not increase with delivery during the night shift.

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.

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.