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Are we trending back to “once a cesarean birth, always a cesarean birth”?
SMFM Abstracts S139
Volume 189, Number 6 Am J Obstet Gynecol 280
281
ARE WE TRENDING BACK TO ‘‘ONCE A CESAREAN BIRTH, ALWAYS A CESAREAN BIRTH’’? SEAN TUCKER1, CAMILLE KANAAN1, MICHEAL PLEVYAK1, STEVE ROSS1, SCOTT DEXTER2, JEAN-CLAUDE VEILLE1, 1 Albany Medical College, Ob Gyn, Albany, NY 2Albany Medical Center, Obstetrics & Gynecology, Albany, NY OBJECTIVES: (1) To determine the occurrence of vaginal birth after a cesarean (VBAC) in the face of increasing uterine ruptures with induction/ augmentation of labor, (2) to determine if changes of VBAC practices in ‘‘smaller’’ obstetrical delivery services have occurred over the last 5 years. STUDY DESIGN: Since 1998, the Regional Perinatal Center for Northeastern New York (NENY) has traced perinatal outcome data and trends throughout the region. It encompasses 24 hospitals in 25 counties, for a total of 16,954 births in 2001. Hospitals are classified in 4 different cohorts: I = 2000+; II = 1000-1999; III = 500-999; IV = 0-499 deliveries per year. RESULTS: (1) Across the entire region, there has been a steady decrease in the ‘‘absolute’’ number of VBACs (1st column). (2) Cohorts 1 and 2 had the most significant decline over the last 4 years; cohorts 3 and 4 had no significant rate of decline during 1998 and 1999; cohorts 2 and 4 had the most significant decrease in 2001. CONCLUSION: (1) VBAC is on the decrease in our region; 2) this decreased occurred before the term immediate was recently introduced; 3) There was a sharp fall in cohorts 2 and 4 in 2001, which may reflect the recent findings of an increased number of uterine ruptures in VBAC patients. Speculation: If these trends continue for the year 2002, it is unlikely that the goals set by the Healthy People 2010 task force (45%) will occur.
FACTORS PREDICTIVE OF FAILED OPERATIVE VAGINAL DELIVERY SAMEER GOPALANI1, KENT BENNETT2, CATHY CRITCHLOW2, 1University of Washington, Maternal-Fetal Medicine, Seattle, WA 2University of Washington, Epidemiology, Seattle, WA OBJECTIVE: To determine which maternal, fetal, pregnancy, or providerrelated characteristics are associated with an increased likelihood of failed operative vaginal delivery (FOVD). STUDY DESIGN: We performed a case-control study using the Washington (WA) State Birth Certificate Database. All live-born, singleton births in WA State from 1992-2001 with both cesarean section and an OVD (forceps and/or vacuum) coded as the delivery method were selected as cases (n = 1750). Liveborn, singleton births with only forceps and/or vacuum coded as the delivery method were randomly selected as controls, with frequency matched to cases by year of birth in a 2:1 ratio (n = 3500). We measured the degree of association between FOVD and predictive factors of interest with adjusted odds ratios (ORs), estimated using the Mantel-Haenszel technique. All reported ORs were statistically significant (P < .05). RESULTS: Compared with women of normal weight, overweight (OR 1.6) and obese (OR 1.7) women were more likely to have an FOVD. Women aged 3039 (OR 1.5) and those $40 years (OR 2.7) were more likely to have an FOVD than women younger than 30. Gestational diabetes (OR 1.5), preexisting diabetes (OR 2.8), birthweight $4000 g (OR 2.1), and identification as African American (OR 2.5) independently increased the likelihood of FOVD. CONCLUSION: Maternal weight, age, diabetes, and race, as well as fetal birthweight, were found to be independently associated with FOVD. Identification of factors associated with FOVD will enable providers to better counsel patients as to the likelihood of FOVD and allow improved planning and allocation of surgical resources.
282
LABOR HAS NO EFFECT ON TOTAL COLLAGEN OR COLLAGEN CROSS-LINKS IN THE LOWER UTERINE SEGMENT (LUS) CATALIN BUHIMSCHI1, IRINA BUHIMSCHI1, J. DAN SHARER2, LYNETTE MACKAY3, MICHAEL DIAMOND4, CARL WEINER5, GEORGE SAADE6, ROBERT GARFIELD6, 1Yale University, Ob/Gyn, New Haven, CT 2Emory Univ, Biochem Genetics, Atlanta, GA 3Univ of Texas Medical Branch, Galveston, Ob/Gyn, Galveston, TX 4Wayne State University, Ob/Gyn, Detroit, MI 5 University of Maryland at Baltimore, Ob/Gyn, Baltimore, MD 6University of Texas Medical Branch at Galveston, Obstetrics and Gynecology, Galveston, TX OBJECTIVE: The complex collagen network embedded in the extracellular matrix determines the visco-elastic properties of LUS, the preferred site of cesarean section (LTCS). We hypothesized that labor induces modifications in collagen content or cross-linking in LUS. STUDY DESIGN: Myometrial strips were collected from 25 laboring women undergoing primary LTCS at term (39.4 ± 1.5wks) for active phase arrest and 10 non-laboring women undergoing primary elective LTCS (39.4 ± 1.3wks). Collagen cross-links (pyridinoline [Pyd] and deoxypyridinoline [dPyd]) were measured by reversed-phase HPLC. Collagen content was estimated by hydroxyproline (Hyp) and birefringence after staining biopsies with a polyazo dye Sirius red. A semi-quantitative estimate of collagen content was obtained by averaging luminosity from six fields on each biopsy. This birefringence is highly specific for mature collagen. RESULTS: Labor arrested at a median dilatation of 7 cm [range 4-10] and high pelvic station (median: ÿ2). Labor was unassociated with a change in Hyp (labor: 8.4 ± 2.4; non-labor: 10.1 ± 3.2 lg/mg total protein, P = 0.4) or crosslinks (Pyd: labor: 42.6 ± 12.3; non-labor: 33.2 ± 10.5 pmol/mg, P = 0.5; dPyd: labor: 3.0 ± 0.9; non-labor: 2.3 ± 0.7 pmol/mg, P = 0.3). Myometrial content of Pyd was 10-fold that of dPyd. The Pyd/dPyd ratio was unaffected by labor (labor: 13.6 ± 3.9; 15.7 ± 5.0 pmol/mg, P = 0.24). Examination of Sirius red-stained tissue sections through cross-polars showed large collagen fibers brilliant yelloworange on a black background similar in labor and non-labor (luminosity labor: 56.2% ± 3.7%; non-labor: 61.3% ± 2.6%, P = 0.16). There was a significant correlation between mean luminosity and Hyp (r = 0.46, P = 0.03). CONCLUSION: Sirius staining reflects collagen content and can be used to estimate the relative abundance of mature collagen in tissues. Labor at term per se has no effect on collagen content or collagen cross-links of LUS at cesarean site.
283
AN INNOVATIVE SCORING SYSTEM TO COUNSEL PATIENTS WITH A PRIOR CESAREAN DELIVERY: A STEP TOWARDS A SAFER AND MORE SUCCESSFUL TRIAL OF LABOR EMMANUEL BUJOLD1, ROBERT GAUTHIER2, 1Wayne State University, Obstetrics and Gynecology, Detroit, MI 2Sainte-Justine Hospital, Obstetrics and Gynecology, Montreal, Quebec, Canada OBJECTIVE: To develop and evaluate a single scoring system to predict the rate of successful vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior cesarean delivery. STUDY DESIGN: A scoring system was developed from factors associated with uterine rupture or successful VBAC (MEDLINE 1966-2003). Subsequently, the charts of patients who had a TOL after a previous LTCS between 1988 and 2002 in a tertiary care center were reviewed and a score was calculated for each patient. Patients were divided according to their score. The rates of successful VBAC and symptomatic uterine rupture were calculated. RESULTS: Twelve factors known to be associated with VBAC outcomes have been retained and a score from ÿ2 to 4 (based on published data) was attributed for each of them. Subsequently, out of 2493 patients included, 227 (9.1%) scored < 5; 572 (22.9%) scored from 5 to 7; 933 (37.4%) scored from 8 to 10; and 761 (30.5%) patients scored > 10. The difference between the rate of successful VBAC and the rate of uterine rupture was very significant between the groups (Figures). Patients with a score $8 represented 68% of the total number of patients and they had an overall rate of successful delivery of 81.2% (RR: 1.27, 95%CI: 1.20-.35) and a rate of uterine rupture of 0.4% (RR: 0.15, 95%CI: 0.06-0.35).
Rates of uterine rupture and successful VBAC CONCLUSION: We developed a novel scoring system, which identified more than 2/3 of the patients with a high rate of successful VBAC and a low rate of uterine rupture.
Volume 189, Number 6 Am J Obstet Gynecol 280
281
ARE WE TRENDING BACK TO ‘‘ONCE A CESAREAN BIRTH, ALWAYS A CESAREAN BIRTH’’? SEAN TUCKER1, CAMILLE KANAAN1, MICHEAL PLEVYAK1, STEVE ROSS1, SCOTT DEXTER2, JEAN-CLAUDE VEILLE1, 1 Albany Medical College, Ob Gyn, Albany, NY 2Albany Medical Center, Obstetrics & Gynecology, Albany, NY OBJECTIVES: (1) To determine the occurrence of vaginal birth after a cesarean (VBAC) in the face of increasing uterine ruptures with induction/ augmentation of labor, (2) to determine if changes of VBAC practices in ‘‘smaller’’ obstetrical delivery services have occurred over the last 5 years. STUDY DESIGN: Since 1998, the Regional Perinatal Center for Northeastern New York (NENY) has traced perinatal outcome data and trends throughout the region. It encompasses 24 hospitals in 25 counties, for a total of 16,954 births in 2001. Hospitals are classified in 4 different cohorts: I = 2000+; II = 1000-1999; III = 500-999; IV = 0-499 deliveries per year. RESULTS: (1) Across the entire region, there has been a steady decrease in the ‘‘absolute’’ number of VBACs (1st column). (2) Cohorts 1 and 2 had the most significant decline over the last 4 years; cohorts 3 and 4 had no significant rate of decline during 1998 and 1999; cohorts 2 and 4 had the most significant decrease in 2001. CONCLUSION: (1) VBAC is on the decrease in our region; 2) this decreased occurred before the term immediate was recently introduced; 3) There was a sharp fall in cohorts 2 and 4 in 2001, which may reflect the recent findings of an increased number of uterine ruptures in VBAC patients. Speculation: If these trends continue for the year 2002, it is unlikely that the goals set by the Healthy People 2010 task force (45%) will occur.
FACTORS PREDICTIVE OF FAILED OPERATIVE VAGINAL DELIVERY SAMEER GOPALANI1, KENT BENNETT2, CATHY CRITCHLOW2, 1University of Washington, Maternal-Fetal Medicine, Seattle, WA 2University of Washington, Epidemiology, Seattle, WA OBJECTIVE: To determine which maternal, fetal, pregnancy, or providerrelated characteristics are associated with an increased likelihood of failed operative vaginal delivery (FOVD). STUDY DESIGN: We performed a case-control study using the Washington (WA) State Birth Certificate Database. All live-born, singleton births in WA State from 1992-2001 with both cesarean section and an OVD (forceps and/or vacuum) coded as the delivery method were selected as cases (n = 1750). Liveborn, singleton births with only forceps and/or vacuum coded as the delivery method were randomly selected as controls, with frequency matched to cases by year of birth in a 2:1 ratio (n = 3500). We measured the degree of association between FOVD and predictive factors of interest with adjusted odds ratios (ORs), estimated using the Mantel-Haenszel technique. All reported ORs were statistically significant (P < .05). RESULTS: Compared with women of normal weight, overweight (OR 1.6) and obese (OR 1.7) women were more likely to have an FOVD. Women aged 3039 (OR 1.5) and those $40 years (OR 2.7) were more likely to have an FOVD than women younger than 30. Gestational diabetes (OR 1.5), preexisting diabetes (OR 2.8), birthweight $4000 g (OR 2.1), and identification as African American (OR 2.5) independently increased the likelihood of FOVD. CONCLUSION: Maternal weight, age, diabetes, and race, as well as fetal birthweight, were found to be independently associated with FOVD. Identification of factors associated with FOVD will enable providers to better counsel patients as to the likelihood of FOVD and allow improved planning and allocation of surgical resources.
282
LABOR HAS NO EFFECT ON TOTAL COLLAGEN OR COLLAGEN CROSS-LINKS IN THE LOWER UTERINE SEGMENT (LUS) CATALIN BUHIMSCHI1, IRINA BUHIMSCHI1, J. DAN SHARER2, LYNETTE MACKAY3, MICHAEL DIAMOND4, CARL WEINER5, GEORGE SAADE6, ROBERT GARFIELD6, 1Yale University, Ob/Gyn, New Haven, CT 2Emory Univ, Biochem Genetics, Atlanta, GA 3Univ of Texas Medical Branch, Galveston, Ob/Gyn, Galveston, TX 4Wayne State University, Ob/Gyn, Detroit, MI 5 University of Maryland at Baltimore, Ob/Gyn, Baltimore, MD 6University of Texas Medical Branch at Galveston, Obstetrics and Gynecology, Galveston, TX OBJECTIVE: The complex collagen network embedded in the extracellular matrix determines the visco-elastic properties of LUS, the preferred site of cesarean section (LTCS). We hypothesized that labor induces modifications in collagen content or cross-linking in LUS. STUDY DESIGN: Myometrial strips were collected from 25 laboring women undergoing primary LTCS at term (39.4 ± 1.5wks) for active phase arrest and 10 non-laboring women undergoing primary elective LTCS (39.4 ± 1.3wks). Collagen cross-links (pyridinoline [Pyd] and deoxypyridinoline [dPyd]) were measured by reversed-phase HPLC. Collagen content was estimated by hydroxyproline (Hyp) and birefringence after staining biopsies with a polyazo dye Sirius red. A semi-quantitative estimate of collagen content was obtained by averaging luminosity from six fields on each biopsy. This birefringence is highly specific for mature collagen. RESULTS: Labor arrested at a median dilatation of 7 cm [range 4-10] and high pelvic station (median: ÿ2). Labor was unassociated with a change in Hyp (labor: 8.4 ± 2.4; non-labor: 10.1 ± 3.2 lg/mg total protein, P = 0.4) or crosslinks (Pyd: labor: 42.6 ± 12.3; non-labor: 33.2 ± 10.5 pmol/mg, P = 0.5; dPyd: labor: 3.0 ± 0.9; non-labor: 2.3 ± 0.7 pmol/mg, P = 0.3). Myometrial content of Pyd was 10-fold that of dPyd. The Pyd/dPyd ratio was unaffected by labor (labor: 13.6 ± 3.9; 15.7 ± 5.0 pmol/mg, P = 0.24). Examination of Sirius red-stained tissue sections through cross-polars showed large collagen fibers brilliant yelloworange on a black background similar in labor and non-labor (luminosity labor: 56.2% ± 3.7%; non-labor: 61.3% ± 2.6%, P = 0.16). There was a significant correlation between mean luminosity and Hyp (r = 0.46, P = 0.03). CONCLUSION: Sirius staining reflects collagen content and can be used to estimate the relative abundance of mature collagen in tissues. Labor at term per se has no effect on collagen content or collagen cross-links of LUS at cesarean site.
283
AN INNOVATIVE SCORING SYSTEM TO COUNSEL PATIENTS WITH A PRIOR CESAREAN DELIVERY: A STEP TOWARDS A SAFER AND MORE SUCCESSFUL TRIAL OF LABOR EMMANUEL BUJOLD1, ROBERT GAUTHIER2, 1Wayne State University, Obstetrics and Gynecology, Detroit, MI 2Sainte-Justine Hospital, Obstetrics and Gynecology, Montreal, Quebec, Canada OBJECTIVE: To develop and evaluate a single scoring system to predict the rate of successful vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior cesarean delivery. STUDY DESIGN: A scoring system was developed from factors associated with uterine rupture or successful VBAC (MEDLINE 1966-2003). Subsequently, the charts of patients who had a TOL after a previous LTCS between 1988 and 2002 in a tertiary care center were reviewed and a score was calculated for each patient. Patients were divided according to their score. The rates of successful VBAC and symptomatic uterine rupture were calculated. RESULTS: Twelve factors known to be associated with VBAC outcomes have been retained and a score from ÿ2 to 4 (based on published data) was attributed for each of them. Subsequently, out of 2493 patients included, 227 (9.1%) scored < 5; 572 (22.9%) scored from 5 to 7; 933 (37.4%) scored from 8 to 10; and 761 (30.5%) patients scored > 10. The difference between the rate of successful VBAC and the rate of uterine rupture was very significant between the groups (Figures). Patients with a score $8 represented 68% of the total number of patients and they had an overall rate of successful delivery of 81.2% (RR: 1.27, 95%CI: 1.20-.35) and a rate of uterine rupture of 0.4% (RR: 0.15, 95%CI: 0.06-0.35).
Rates of uterine rupture and successful VBAC CONCLUSION: We developed a novel scoring system, which identified more than 2/3 of the patients with a high rate of successful VBAC and a low rate of uterine rupture.