Methods: The distance between the leading edge of the placenta and the internal cervical os were ... of prior Cesarean delivery. Ten blinded reviewers analyzed ...
22nd World Congress on Ultrasound in Obstetrics and Gynecology
Short oral presentation abstracts
of these high risk pregnancies. Effective use of sonographic resources may be best achieved by a planned ultrasound schedule.
without accreta. Data were collected on placental location and the presence of markers for placenta accreta. Provider suspicion for accreta and possible effect on documenting, managing and counseling were scored on a scale of 1 to 10. Results: Markers for placenta accreta and their corresponding sensitivities, specificities, positive and negative predictive values and likelihood ratios are shown in Table 1. Suspicion for accreta was significantly increased based on sonographic findings and in combination with surgical history (5.6 vs. 3.9 and 6.7 vs. 5.0, respectively; P < 0.001). The likelihood of commenting on placental appearance (7.2 vs. 5.3), desire for additional studies (6.4 vs. 4.9) and counseling about accreta (6.4 vs. 4.5) were all significantly increased is cases of accreta (P < 0.001). Conclusions: Sonographic markers of placenta accreta are present as early as the first trimester. In high-risk populations identifying such markers may allow for earlier investigation, diagnosis, counseling and treatment planning.
OP25.04 Transabdominal versus transvaginal assessment of placental site in relation to the internal cervical os S. C. Westerway1 , J. Hyett2 , L. Henning Pedersen2,3 1
Northern Womens Imaging, Hornsby, NSW, Australia; Fetal Medicine, RPA Womens & Babies, Sydney, NSW, Australia; 3 O&G Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark 2
Objectives: Localization of the placenta is traditionally performed transabdominally (TA) at the time of the routine 18–20 week scan. In circumstances where the placenta is described as being low, a second scan is arranged at 34 weeks gestation. Whilst the value of transvaginal (TV) assessment for cases with a posterior placenta at 34 weeks is well recognized, there is little data comparing TA and TV approaches earlier in pregnancy. This study compares TA and TV approaches to placental localization. Methods: The distance between the leading edge of the placenta and the internal cervical os were measured in a series of pregnancies presenting for routine obstetric ultrasound scans at 12–36 weeks gestation. Bland Altman plots and paired t-tests were used to look at the differences in TA and TV measurement and the screening efficacy of an initial TA assessment in defining a group for TV evaluation is also reported. Results: 282 consented to participate in the study. A Bland Altman plot shows that TA measurements overestimated the distance compared with the TV measurements; the average difference in measurement was 11.6 mm (95% CI: 4.4–18 mm). Assuming the TV scan measurements are the ‘gold standard’, TA assessment accurately predicted that the leading edge of the placenta was within 25 mm of the internal cervical os in 22/82 (27%) of cases assessed at 16–23 weeks and 1/2 (50%) of cases > 24 weeks. The specificity of the TA approach was 96% and 97% for these two categories respectively. Conclusions: TA sonography has a low sensitivity for detecting a low-lying placenta. Placental localization is best performed by transvaginal scan.
OP25.05 Sonographic markers for placenta accreta in the first trimester: are they reliable? J. Ballas, D. H. Pretorius, A. D. Hull, R. Resnik, G. A. Ramos Reproductive Medicine, University of California, San Diego, CA, USA Objectives: To assess the diagnostic utility of sonographic markers for placenta accreta in the first trimester. Methods: Retrospective case control study of women with a history of prior Cesarean delivery. Ten blinded reviewers analyzed first trimester images from 30 cases: 10 with placenta accreta and 20
OP25.06 Sonographic evaluation of the lower uterine segment in pregnant women with prior Caesarean section, a systematic review N. Kok, I. Wiersma, B. Opmeer, I. de Graaf, B. J. Mol, E. Pajkrt Department of Obstetrics, AMC, Amsterdam, Netherlands Objectives: To evaluate the accuracy of antenatal sonographical measurement of the the lower uterine segment (LUS) thickness in the prediction of the risk of uterine rupture during a trial of labor in women with a previous Caesarean section (CS). Methods: We performed an electronic search of Pubmed and EMBASE for relevant articles published between 1980 and 2011. We used the keywords pregnancy, lower uterine segment, Caesarean section, ultrasound and uterine defect to search PubMed and EMBASE. We included studies that reported on pregnant women with at least one previous CS that reported on the sonographic LUS appearance during pregnancy in relation to uterine defects observed during or immediately after delivery. Only studies that allowed construction of two-by-two tables comparing sonographic LUS appearance and the occurrence of uterine scar defect were included. A bivariate meta-regression model was used to calculate pooled estimates of sensitivity and specificity for risk score cut-off values. Results: The incidence rates for uterine defects ranged from 0% to 3.7% and for uterine dehiscence from 1.5% to 25%. The vaginal birth after Caesarean rate ((number of VBAC / number of all women with a previous CS) × 100)) varied from 19% to 68% (median incidence 43%) and the vaginal birth after Caesarean success rate ((number of VBACs / number of women ondergoing a TOL) × 100)) from 20% to 78% (median incidence 64%). LUS thickness measurement using cutoffs between 1.4–2.5 mm reached a specificity of 89% (95% CI 75% to 96%) at a sensitivity of 85% (95% CI 60% to 95%). LUS thickness measurement using cutoffs between 2.5–3.5 mm reached a specificity of 91% (95% CI 75% to 0.97%) at a sensitivity of 71% (95% CI 32% to 92%). Conclusions: In this review, we found a good association between the thickness of LUS measured by ultrasound and the LUS thickness
OP25.05: Table Marker
Placental lakes (any) Placental lakes (2 or more) Low implantation Abnormal myometrial interface Abnormal bladder interface Placenta previa Anterior placenta Subchorionic hemorrhage
Sensitivity
Specificity
PPV (CI)
NPV (CI)
LR (CI)
P-value
43 97 16 57 24 86 86 13
73 12 92 60 98 41 41 92
44 (34–55) 35 (30–42) 11 (7.8–15) 41 (33–50) 82 (63–93) 44 (35–54) 36 (29–43) 45 (27–64)
72 (65–79) 89 (70–97) 68 (62–74) 73 (66–80) 72 (66–77) 84 (71–93) 75 (65–82) 68 (62–73)
1.6 (1.2–2.2) 1.1 (1.04–1.2) 1.8 (1.0–3.6) 1.4 (1.1–1.8) 9.6 (3.8–24.4) 1.4 (1.2–1.8) 1.2 (0.99–1.4) 1.6 (0.81–3.2)
0.004* 0.006* 0.041* 0.005* < 0.001* < 0.001* 0.05 0.121
PPV = Positive predictive value (%), NPV = Negative predictive value (%); LR = Likelihood ratio (%); CI = 95% Confidence interval; * denotes statistical significance.
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during delivery. Antenatal sonography is potentially effective in the prediction of the risk of uterine defect during labor.
OP25.07 Ultrasound evaluation of the cesarean scar: comparison between one and two layer uterotomy closure J. Glavind, L. D. Madsen, N. Uldbjerg, M. Dueholm Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark Objectives: To compare the residual myometrial thickness and the size of the cesarean scar defect after one- and two layer uterotomy closure. Methods: From July 2010 a continuous two-layer uterotomy closure technique replaced a continuous one-layer technique after cesarean delivery at the Department of Obstetrics and Gynecology at Aarhus University Hospital. A total of 149 consecutively invited women (68 women with one-layer and 81 women with two-layer closure) had their cesarean scar examined with 2D transvaginal sonography (TVS) 6–16 months post partum. Inclusion criteria were non-pregnant women with one previous elective cesarean, no post-partum uterine infection or uterine re-operation, and no type 1 diabetes. Scar defect width, depth, and residual myometrial thickness were measured on the sagittal plane, and scar defect length was measured on the transverse plane. Results: The median residual myometrial thickness was 4.6 mm (interquartile range (iqr) ± 3.1) after one-layer closure and 5.8 mm (iqr ± 3.7) after two-layer closure (P = 0.04). A scar defect was visible in 66/68 women (97%) with one-layer closure, and 78/81 women (96%) with two-layer closure, respectively. Median defect width was 6.8 mm (iqr ± 4.1) after one-layer compared to 5.6 mm (iqr ± 2.9) after two-layer closure (P = 0.01). No significant differences were found in defect height and length between women with one- and two-layer closure. Conclusions: Two-layer closure of the uterotomy significantly increases residual myometrial thickness and decreases defect width. Results do not prove but imply increased scar strength after two-layer closure.
OP25.08 Ultrasonic evaluation of a scar on uterus in primiparous women 6 weeks and 6 months after Caesarean section J. Hanacek, L. Krofta Institute for the Care of Mother and Child, Prague, Czech Republic Objectives: Quality of a scar after Caesarean section is important particularly with regard to possible complications during the following pregnancy. Methods: In this prospective cohort study 6 weeks and 6 months after Caesarean section patients undergo 3D ultrasound examination of the uterus. We evaluate the type of the scar and its relation to the external orifice and internal orifice of the uterus and the fundus of the uterus. We analyse obstetric data related to the Caesarean section. Results: We have evaluated 158 women; the average age was 31.4; SD ± 4.15; BMI 23.3; SD ± 4.5; pregnancy week 40.17; SD ± 1.26. Hysterotomy suture was closed in a single layer in 41.4% of the cases and in two layers in 58.6% of the cases. A wall defect was found in 78.5% of the cases. This mostly involved inclusive cysts and fissures out of contact with the uterine cavity (73.8%). On the average, the scar was situated 30.2 mm from the external orifice; SD ± 6.6 mm; 10.13 mm from the internal orifice; SD ± 2.5 mm; 38.5 mm from the apex of the uterine cavity; SD ± 7.5 mm; and 50.3 mm from the fundus of the uterus; SD ± 8.3 mm. The myometrium above the scar is 12.16 mm high; SD ± 2.8 mm. The myometrium is 12.16 mm high above the scar; SD ± 2.8 mm and 11.2 mm high under the scar; SD ± 2.6 mm. During the period from the 6th week to the 6th month, the position of the uterus changed from retroversion to anteversion in 8.4% of the cases. When we compared Caesarean
Ultrasound in Obstetrics & Gynecology 2012; 40 (Suppl. 1): 55–170
Short oral presentation abstracts
sections performed on a fully dilated orifice and other findings, we did not find any significant correlation, except for the parameters of the location of the scar from the external orifice of the uterus and the fundus of the uterus and the height of myometrium above the defect (independent sample t-Test). Conclusions: 6 weeks after the Caesarean section marked wall defects are apparent. We have not found any significant difference between a uterine wall defect and hysterotomy suture in a single layer or two layers.
OP25.09 The impact of obstetric ultrasound in reducing maternal mortality in rural communities of Africa: an OBGYN resident’s experience B. O. Oluborode Obstetrics & Gynaecology, Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria Objectives: Ultrasound imaging is unequally distributed in developing countries where maternal mortality is very high. With the peculiarities of the environment, the development of portable ultrasound machines provides a broader use of ultrasound. This motivated the need to assess the impact of its use in improving maternal health in the rural communities devoid of basic infrastructure. Methods: Obstetric ultrasounds done and the outcome of resultant clinical decisions over a 10 year period of several medical outreaches using ultrasound machines in several rural communities in Nigeria was reviewed. Existing literature on ultrasound, maternal mortality and issues relating to the use of medical technology in a low-resource setting was reviewed. The authors’ decade of field-experience in medical outreach programs in several rural communities in Nigeria was evaluated as a platform for wider use. Results: There were 15 medical mission outreaches during a 10 year period, 3254 patients were enrolled for ultrasound scan. The most frequent indications were pregnancy-related (97.9%), followed by gynecological conditions (2.1%). 90% of the obstetric scans were in patients receiving care from traditional birth attendants. In 361 patients (11.1%), increased risks of hemorrhage and prolonged labor were first detected on scanning and none had had an earlier scan. Three patients with transverse lie in labor were referred for surgery. A threefold turnout of pregnant women observed on days ultrasound scanning was done gave an enhanced opportunity for health education. Conclusions: Without proper tools in widespread use, maternal mortality will not reduce. Medical technology, such as ultrasound, is worthless unless the people who need it have adequate access. It provides an effective means of reducing maternal mortality and also serves as a vehicle for simultaneous dissemination of efforts required to address several causes of maternal mortality, thus, heightening the potential for improving clinical outcomes in a cost effective manner.
OP25.10 Assessment of maternal cardiac dysfunction following doxorubicin exposure: is any level of exposure during pregnancy cardiotoxic? A. Patil, A. James, M. Small Obstetrics and Gynecology, Duke University Medical Center, Durham, NC, USA Objectives: Strategies to prevent doxorubicin-dependent cardiomyopathy include an empiric dose limit of 500 mg/m2 of body surface area. Doxorubicin is known to cause a dose-dependent cardiomyopathy due to oxidative stress and cellular injury. The cardiovascular adaptations of pregnancy include transient left ventricular remodeling in response to hemodynamic changes. We evaluated the impact of doxorubicin-containing chemotherapeutic regimens on maternal cardiac function.
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