certificate and discharge diagnosis data (All-California, Rapid-Cycle,. Maternal/Infant Database) from the year 2007. Inclusion criteria were singleton ...
Poster Session IV
Operative Obstetrics, Clinical Obstetrics, Intrapartum, Medical-Surgical www.AJOG.org
Medical Center, Sacramento, CA, 4Oregon Health & Science University, Obstetrics and Gynecology, Portland, OR
Failed trial of labor by pre-pregnacy body mass index
OBJECTIVE: To determine the impact of pre-pregnancy body mass
index (BMI) and gestational weight gain on failed trial of labor after cesarean (TOLAC). STUDY DESIGN: This is a retrospective cohort study using linked birth certificate and discharge diagnosis data (All-California, Rapid-Cycle, Maternal/Infant Database) from the year 2007. Inclusion criteria were singleton pregnancies with known pre-pregnancy BMI and gestational weight gain. Institute of Medicine (IOM) guidelines for gestational weight gain by pre-pregnancy BMI were used. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for failed TOLAC were calculated. RESULTS: Of the 60,006 women with one prior cesarean who were eligible for a trial of labor, only 4,035 (6.7%) underwent a trial. Successful VBAC occurred in 72.9% of cases. Women who were obese (BMI30) prior to pregnancy had a 36% increased odds of failed TOLAC (aOR 1.36, 95% CI 1.13-1.64), as compared to normal weight women (BMI 18.5-24.9). Irrespective of pre-pregnancy BMI, women who gained in excess of IOM recommended gestational weight gain had a 26% increased odds of failed TOLAC (aOR1.26, 95% CI 1.07-1.47) when compared to those who gained within the IOM guidelines. When accounting for pre-pregnancy BMI, weight gain in excess of IOM guidelines was associated with an increased odds of failed TOLAC in normal weight (aOR 1.30, 95% CI 1.021.65) and obese women (aOR 1.49, 95% CI 1.03-2.16). CONCLUSION: Both pre-pregnancy BMI and gestational weight gain have an impact on TOLAC, particularly in the obese population. Although pre-pregnancy BMI is not modifiable, the adverse impact of excess maternal weight gain during pregnancy may be important in counseling patients who are contemplating TOLAC.
Adjusted for maternal age, parity, race-ethicity, diabetes, chronic hypertension.
633 Optimal admission cervical dilation to reduce the risk of cesarean delivery in spontaneously laboring women Heather Frey1, Methodius Tuuli1, Aaron Caughey2, Anthony Odibo1, George Macones1, Alison Cahill1 1
Washington University in St. Louis, Obstetrics & Gynecology, St. Louis, MO, Oregon Health & Science University, Obstetrics & Gyneoclogy, Portland, OR
2
OBJECTIVE: Existing data suggest that admission of women in spontaneous labor after 3 cm is associated with a decreased risk of cesarean delivery (CD), as noted in a recent consensus statement. However, given our current understanding of labor progress through the first stage, it is possible that later admission is associated with a further decrease in risk. Our objective was to assess the impact of cervical dilation at admission on risk of CD. STUDY DESIGN: This study was performed within a prospective cohort of consecutive women admitted in labor at term with a non-anomalous singleton gestation. Women with rupture of membranes prior to admission, induction of labor, or prelabor CD were excluded. The association between CD and cervical dilation at time of admission was estimated; CD for arrested dilatation was secondarily explored. Relative risks and 95% confidence intervals were calculated for CD based on cervical dilation at time of admission, using cervical dilation 6 cm as the reference group. Logistic regression was used to adjust for nulliparity. RESULTS: Of 2033 spontaneously laboring women meeting inclusion, 244 (12.0%) had a CD and 1789 (88.0%) delivered vaginally. Each integer of cervical dilation at time of admission
