821: Prediction of uterine rupture or dehiscence during trial of labor after cesarean delivery: a cohort study

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Clinical Ob, Epidemiology, ID, Intrapartum Fetal, Operative Ob, Med-Surg-Diseases, Ob Quality & Safety, Public & Global Health

819 Is operative vaginal delivery safe in the preterm fetus? Tania Esakoff1, Yvonne Cheng2, Jonathan Snowden3, Aaron Caughey3 1

Cedars Sinai Medical Center, Obstetrics and Gynecology, Los Angeles, CA, University of California, San Francisco, Obstetrics and Gynecology, San Francisco, CA, 3Oregon Health and Science University, Obstetrics and Gynecology, Portland, OR 2

OBJECTIVE: Operative vaginal delivery is reported to increase the risk of intracranial hemorrhage in term singletons compared to spontaneous vaginal delivery. There is very limited data on the safety of operative vaginal delivery in preterm fetuses. Our objective was to determine if vacuum assisted vaginal delivery (VAVD) increases the risk of various degrees of neonatal head bleeds compared to forceps assisted vaginal delivery (FAVD) and spontaneous vaginal delivery (SVD) in the preterm cohort. STUDY DESIGN: This was a retrospective cohort study of 111,246 singleton, non-anomalous pregnancies between 32⫹0 and 36⫹6 weeks using the California Birth Registry. The cohort consisted of pregnancies undergoing SVD (105,742), VAVD (5,072) and FAVD (432). Outcomes studied included subgaleal hematoma, intracranial hemorrhage and scalp injury which included cephalohematoma. Chi squared tests and Fisher exact test were used for statistical analysis. RESULTS: In the cohort 32⫹0 to 36⫹6 weeks, VAVD was associated with an increased risk of subgaleal hematoma (0.16% vs 0.01%) and an increased risk of scalp injury (9.78% vs 2.33%) compared to SVD. FAVD did not appear to increase the risk of subgaleal hematoma (0%) and had an intermediate risk of scalp injury (6.25%). There was no difference in intracranial hemorrhage between groups. (Table 1) When the cohort was further subdivided into an earlier preterm group of 32⫹0 to 34⫹6 weeks, similar relationships were seen (Table 2). CONCLUSION: VAVD appears to be associated with an increased risk of subgaleal hematoma and scalp injury compared to SVD and FAVD in the preterm cohort. This should be considered when choosing the mode of delivery in a preterm fetus.

820 Predictive factors of vacuum delivery failure Thomas Popowski1, Thierry Bultez1, Patrick Rozenberg1 1 Poissy Saint-Germain Hospital, Versailles Saint-Quentin-en-Yvelines University, research unit EA 7285, Department of Obstetrics and Gynecology, Poissy, France

OBJECTIVE: To identify clinical and ultrasonographic factors predictive of vacuum delivery failure.

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STUDY DESIGN: We carried out a prospective cohort study in Poissy Saint-Germain Hospital from November 2010 to October 2011. Inclusions criteria were: singletons at 37 WG or more in vertex presentation at station ⫹2 cm or more and an epidural anesthesia. Exclusion criteria were severe fetal distress on cardiotocography. The following data were collected: general and obstetrical maternal characteristics, fetal head position determined by transabdominal ultrasound examination, and station assessed by the angle of progression (AOP) measured by transperineal ultrasound between a line passing through the long axis of the symphysis and a tangent line to the fetal skull at the inferior extremity of the symphysis. Vacuum extraction failure was defined as an extraction duration exceeding 20 minutes or more than 3 cup detachments, leading to a vaginal delivery by forceps or a cesarean sections (CS). RESULTS: A total of 235 women were prospectively recruited. Thirty (29/184 nullipara and 1/51 multipara) (12.8%) vacuum extractions failed, leading to 28 vaginal deliveries by forceps and 2 CS. There was no significant difference between the success and failure groups for the median (Q1-Q3) maternal age [29 (26-32) vs 29 (25-33), p⫽0.85], the median (Q1-Q3) gestational age [40 (39-41) vs 40 (39-41), p⫽0.60], the median (Q1-Q3) BMI [27.5 (25.1-30.9) vs 27.5 (26.331.7), p⫽0.40], the rate of occipito-anterior positions (80.0% vs 83.3%, p⫽0.66), and the rate of vacuum extraction for failures to progress (47% vs 60%, p⫽0.24), respectively. The rate of nullipara was significantly higher in the failure group [97% (29/30) vs 76% (155 /205), p⫽0.009] and the median (Q1-Q3) AOP was significantly lower in the failure group [136.6° (129.8-144.1) vs 145.9° (135.0158.4), p⫽0.003]. The 2 CS were performed in 2 nullipara and the AOP measurements were 124.4° and 137.2°. CONCLUSION: In nullipara women, vacuum extraction should be avoided when the AOP is lower or equal to 144.1°.

821 Prediction of uterine rupture or dehiscence during trial of labor after cesarean delivery: a cohort study Todd Stanhope1, Sherif El-Nashar1, Angelica Garrett1, Adrianne Racek1, Myra Wick1, Jennifer Tessmer-Tuck1, Mary Marnach1, Abimbola Famuyide1 1

Mayo Clinic, Obstetrics and Gynecology, Rochester, MN

OBJECTIVE: Despite the known association between failed TOLAC

success and uterine rupture, there are no predictive models based on that association. We aim to develop a predictive model reflecting the association between the probability of successful TOLAC and uterine rupture or dehiscence. STUDY DESIGN: This historical cohort study includes women who attempted TOLAC at a single midwestern tertiary center over a 10 year period (2001-2010). Data collected included baseline demographics, intrapartum variables including progression of labor, maternal complications, and neonatal outcomes. The primary outcome was uterine rupture or dehiscence (URD). Based on the Grobman model probability of successful TOLAC, the cohort was subdivided into 3 categories (predicted success ⬍50%, ⬍60%, or ⬍70%). The incidence of URD in each subgroup was reported. Univariate and multivariate regression models were used to evaluate predicted probability of successful TOLAC as a predictor for URD and to develop a model based on these statistics (JMP 9.0, SAS Inc Carey, NJ). RESULTS: Of 852 women attempting TOLAC, 18 (2.1%) had URD at the time of Cesarean delivery (CD). The mean probability for success based upon the Grobman model in women who had URD was 62.6% compared to 76.5% in those without URD (P⬍0.001). Women with ⬍50% predicted chance of successful TOLAC had a unadjusted odds ratio (OR) of 9.40(3.30,26.75, P⬍0.001). Other variables that were significantly associated with URD included no prior vaginal delivery 9.40(3.30,26.75), no prior successful TOLAC 4.28(0.98,18.76), and prior CD for abnormal labor 3.17(1.23,8.16) (Table). In multivariate analysis, only Grobman probability ⬍50% was independently predictive of URD with adjusted OR of 5.23(1.53,17.25, P⫽0.007) and ROC-AUC of 0.711 (Fig 1A). A model including Grob-

Supplement to JANUARY 2013 American Journal of Obstetrics & Gynecology

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Clinical Ob, Epidemiology, ID, Intrapartum Fetal, Operative Ob, Med-Surg-Diseases, Ob Quality & Safety, Public & Global Health

man ⬍50% and prior successful TOLAC had an ROC-AUC of 0.705 (Fig 1B). CONCLUSION: Lower predicted probability of successful TOLAC is an independent predictor of uterine rupture and dehiscence.

ROC-AUC for each model

Model A includes 4 variables (Grobman predicted success ⬍50%, no prior vaginal delivery, no prior VBAC, and prior CD for abnormal labor pattern); Model B includes 2 variables (Grobman predicted success ⬍50% and prior successful TOLAC).

Univariate logistic regression analysis

BMI, body mass index; VBAC, vaginal birth after cesarean delivery. *Totals vary between variables based on available data.

822 Genetic susceptibility to preterm birth in the Filipino population in Hawaii Frederico Rocha1, Thomas Slavin2, Dongmei Li3, Sandra Yamamoto1, Gillian Bryant-Greenwood1 1 John A. Burns School of Medicine - University of Hawaii, Department of Obstetrics, Gynecology and Women’s Health, Honolulu, HI, 2John A. Burns School of Medicine - University of Hawaii, Department of Pediatrics, Honolulu, HI, 3John A. Burns School of Medicine - University of Hawaii, Department of Public Health Sciences, Honolulu, HI

OBJECTIVE: Filipinos have the highest preterm birth rate in the State of Hawaii. Relaxin (RLN) is a systemic hormone (sRLN) produced by the corpus luteum but is also produced by the decidua (dRLN) as a local hormone. Elevated maternal sRLN has been associated with increased risk of preterm labor (PTL) and elevated dRLN associated with preterm premature rupture of membranes (PPROM). We have sought associations of two SNPs in the RLN H2 gene promoter in Filipino patients with PTL or PPROM, as well as with their expression of cytoplasmic dRLN protein. STUDY DESIGN: Filipino patients (n⫽60) who delivered at 34-36 weeks gestation were subdivided into PTL (n⫽20) and PPROM (n⫽20) and compared to controls who delivered at term (n⫽20). Maternal DNA was used for identification by specific Taqman RT-PCR of SNPs: rs 472076 and rs 3758239. Formalin fixed sections of parietal decidua from the same patients were immunostained with a Mab to RLN H2 (Abcam) and the ImmPRESS kit (Vector Labs). All slides were blinded for multispectral imaging (Nuance) and quantitated by the Inform

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software. Results were expressed as mean ⫹- SD and significance set at p⬍0.05. Kruskal-Wallis nonparametric ANOVA was used to compare differences in SNP expression and multiple comparisons were determined by the Bonferroni-Dunn’s test. RESULTS: SNP rs4742076 was significantly (p⫽0.0012) associated with PPROM compared to controls. The PPROM patients also had significantly more (p⬍0.001) dRLN expressed compared to controls. SNP rs375839 was significantly associated (p⫽ 0.0025) with both PPROM and PTL compared to the controls. However, dRLN was only significantly increased (p⬍0.001) in the PPROM patients. CONCLUSION: SNP rs4742076 in the RLN gene promoter and increased dRLN protein were associated with PPROM in Filipino patients in Hawaii. SNP rs3758239 was associated with both PPROM and PTL, but dRLN was only increased in the PPROM patients and not in PTL compared to the term controls. Supported by grant NIHNCRR(U54RR026136) NIHMD(U54MD007584).

823 Soluble ␣-klotho, an anti-aging protein, is reduced in patients with intra-amniotic infection Jennifer Lam2, Roberto Romero1, Amol Malshe1, Nandor Gabor Than1, Edgar Hernandez-Andrade2, Zhong Dong1, Sonia Hassan2, Tinnakorn Chaiworapongsa2 1 NICHD/NIH/DHHS, Perinatology Research Branch, Detroit, MI, 2Wayne State University School of Medicine, Department of Obstetrics and Gyneology, Detroit, MI

OBJECTIVE: Klotho has been identified as an aging suppressor gene. This gene is expressed in the human placenta, but its function during pregnancy is unknown. Klotho appears to have anti-inflammatory properties, since it can reduce tumor necrosis factor-␣ induced expression of adhesion molecules and NF-␬B activation. The aim of this study was to determine if the maternal plasma concentration of ␣-klotho changes in the presence of intra-amniotic infection (IAI) in patients with preterm labor with intact membranes (PTL) and in those with preterm prelabor rupture of membranes (pPROM). STUDY DESIGN: A cross-sectional study was performed which included women in the following groups: 1) PTL with IAI (defined as a positive microbial culture of amniotic fluid; n⫽14); 2) PTL without IAI (n⫽79); 3) pPROM with IAI (n⫽30); and 4) pPROM without IAI (n⫽33). Plasma concentrations of soluble ␣-klotho were determined by ELISA. RESULTS: 1) Patients with PTL and IAI had a lower median plasma concentration of ␣-klotho than those without IAI (835pg/mL vs 1124pg/mL; p⫽0.006); 2) similarly, the median plasma concentration of ␣-klotho was significantly lower in patients with pPROM with IAI than in those with pPROM without IAI (766pg/mL vs. 900pg/mL; p⫽0.045); and 3) there was no significant difference in the median plasma concentration of ␣-klotho between pPROM without IAI and PTL without IAI (p⫽0.4). CONCLUSION: Intra-amniotic infection in preterm gestations, regardless of membrane status, was associated with a significant decrease in the maternal plasma concentration of soluble ␣-klotho. These findings suggest that infection of the amniotic cavity may have detrimental effects on ␣-klotho in the maternal circulation. It is also possible that low maternal plasma concentrations of ␣-klotho may predispose patients to intra-amniotic infection.

824 Timing of postpartum IUD placement: a cost-effective analysis Chantel Washington1, Unzila Nayeri2, Roxanne Jamshidi1, Stephen Thung3, Aaron Caughey4, Erika Werner1 1 The Johns Hopkins University School of Medicine, Gynecology and Obstetrics, Baltimore, MD, 2SUNY Upstate Medical University, Obstetrics and Gynecology, Syracuse, NY, 3The Ohio State University Medical School, Obstetrics and Gynecology, Columbus, OH, 4Oregon Health and Science University, Obstetrics and Gynecology, Portland, OR

OBJECTIVE: To determine the cost effectiveness of immediate postpartum (PP) intrauterine device (IUD) placement compared to routine placement at the outpatient PP visit.

American Journal of Obstetrics & Gynecology Supplement to JANUARY 2013