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Abstract Children with congenital heart disease (CHD) are living longer due to effective medical and surgical management. However, the majority have neurodevelopmental delays or disorders. The role of the placenta in fetal brain development is unclear and is the focus of an emerging field known as neuroplacentology. In this review, we summarize neurodevelopmental outcomes in CHD and their brain imaging correlates both in utero and postnatally. We review differences in the structure and function of the placenta in pregnancies complicated by fetal CHD and introduce the concept of a placental inefficiency phenotype that occurs in severe forms of fetal CHD, characterized by a myriad of pathologies. We propose that in CHD placental dysfunction contributes to decreased fetal cerebral oxygen delivery resulting in poor brain growth, brain abnormalities, and impaired neurodevelopment. We conclude the review with key areas for future research in neuroplacentology in the fetal CHD population, including (1) differences in structure and function of the CHD placenta, (2) modifiable and nonmodifiable factors that impact the hemodynamic balance between placental and cerebral circulations, (3) interventions to improve placental function and protect brain development in utero, and (4) the role of genetic and epigenetic influences on the placenta–heart–brain connection. Impact Neuroplacentology seeks to understand placental connections to fetal brain development. In fetuses with CHD, brain growth abnormalities begin in utero. Placental microstructure as well as perfusion and function are abnormal in fetal CHD.

The placenta accreta spectrum (PAS) incidence has risen substantially over the past century, paralleling a rise in cesarean delivery (CD) rates. Prenatal diagnosis of PAS improves maternal outcomes. The Placenta Accreta Index (PAI) is a standardized approach to prenatal diagnosis of PAS incorporating clinical risk and ultrasound (US) findings suggestive of placental invasion. We sought to validate the PAI for prediction of PAS in pregnancies with prior CD.This work was a retrospective cohort study of pregnancies with 1 or more prior CDs that received a US diagnosis of placenta previa or low-lying placenta in the third trimester. Images of third-trimester US with a complete placental evaluation were read by 2 blinded physicians, and the PAI was applied. Surgical outcomes and pathologic findings were reviewed. Placenta accreta spectrum was diagnosed if clinical evidence of invasion was seen at time of delivery or if any placental invasion was identified histologically. International Federation of Gynecology and Obstetrics criteria were used.A total of 194 women met inclusion criteria. Cesarean hysterectomy was performed in 92 (47%), CD in 97 (50%), and vaginal delivery in 5 (3%). Of those who underwent hysterectomy, PAS was histologically confirmed in 79 (85%) pregnancies. Of the remaining 13 who underwent hysterectomy, all met International Federation of Gynecology and Obstetrics grade 1 clinical criteria for PAS. With a threshold of greater than 4, the PAI has a sensitivity of 87%, specificity of 77%, positive predictive value of 72%, and negative predictive value of 90% for PAS diagnosis.Contemporaneous application of the PAI, a standardized approach to US diagnosis, is useful in the prenatal prediction of PAS.

OBJECTIVE. The purpose of this study is to determine whether MRI parameters of placenta accreta spectrum correlate with pathologic and surgical outcomes in high-risk pregnancies. MATERIALS AND METHODS. This retrospective study evaluated second- and third-trimester pregnancies assessed by MRI from 2007 to the present. Women were included in the study if placental invasion was suspected on the basis of a clinical history of cesarean delivery, ultrasound findings, or both. MR images were reviewed by an experienced radiologist who was blinded to the clinical outcomes. Eighteen MRI parameters were assessed and compared with four clinical outcomes: surgical impression of invasion, need for cesarean hysterectomy, pathologic findings, and need for blood transfusion. RESULTS. Of 64 women, 43 required cesarean hysterectomy, 20 underwent cesarean delivery, and one delivered vaginally. There was no statistical difference among the women in terms of maternal age, gestational age, or the number of prior cesarean deliveries. Eight of the 18 MRI parameters assessed showed statistical significance. The five variables with the highest odds ratios were bulge (7.432), placenta previa (7.283), low-attenuation T2 linear bands (5.985), placental heterogeneity near the scar (4.384), and fibrin deposition (4.322), with additional significant variables including interruption of the bladder-serosa interface, the radiologist's interpretation of invasion, and the largest dimension of invasion. Some previously described parameters, such as the degree of maternal pelvic vascularity, were not statistically significant. CONCLUSION. MRI parameters are associated with placental invasion and correlate with the need for cesarean hysterectomy, as well as pathologic and surgical impressions of invasion. From these parameters, an organized template can be created to standardize reporting of placental invasion.

Objectives To prospectively evaluate low implantation of the gestational sac and other first-trimester ultrasound (US) parameters for prediction of placenta accreta spectrum (PAS). Methods Women with a diagnosis of low implantation on clinically indicated first-trimester US underwent a transvaginal US examination at 10 to 13 weeks' gestation to assess the trophoblast location, anechoic areas, bridging vessels, and smallest myometrial thickness (SMT). The placental location was evaluated in the second trimester, and serial US examinations were performed in cases of low placentation. Placenta accreta spectrum was based on clinical findings and confirmed by histologic results. Results Of 68 women, 40 (59%) had prior cesarean delivery (CD). Hysterectomy was performed in 8, all with prior CD. Of these, 7 (88%) had US suspicion of PAS. In 16 with prior CD and basalis overlying the internal os, 9 (56%) had second-trimester placenta previa, and 7 of 9 (78%) underwent hysterectomy with pathologic confirmation of PAS. Of 28 without prior CD, there were no cases of persistent low placentation in the third trimester regardless of the trophoblast location. Ultrasound parameters associated with PAS were a smaller distance from the inferior trophoblastic border to the external os, disruption of the bladder-serosal interface, bridging vessels, anechoic areas, and the SMT. In women with prior CD, use of the SMT in the sagittal plane yielded an area under the receiver operating characteristic curve of 0.96 (95% confidence interval, 0.91-1.00). Conclusions First-trimester low implantation increases the risk of persistent placenta previa and PAS in women with prior CD. All parameters were associated with PAS, the most predictive being the SMT.

OBJECTIVES To characterize population-based use of fetal magnetic resonance imaging (MRI) incorporating recent American College of Radiology (ACR)-Society of Perinatal Radiologists (SPR) guidelines about fetal anomalies for which MRI may provide valuable additional information when sonography is limited. METHODS We conducted a retrospective review of nonreferred singleton pregnancies that received prenatal care and had prenatal sonographic diagnosis of 1 or more major structural anomalies at our hospital between January 2010 and May 2018. Detailed sonography was performed in all anomaly cases. Fetal anomaly information was obtained from a prospectively maintained database, and medical records were reviewed to determine the rationale for why MRI was or was not performed, according to the indication. RESULTS A total of 104,597 singleton pregnancies underwent sonographic assessments of anatomy at our institution during the study period. Major structural anomalies were identified in 1650 (1.6%) of these pregnancies. Potential indications for fetal MRI per ACR-SPR guidelines were identified in 339 cases. However, fetal MRI was performed in only 253 cases, 15% of those with major anomalies and 75% with a potential indication. Magnetic resonance imaging was not performed in 41 (20%) of identified pregnancies because of an improved prognosis on serial sonography (36), because of a poor prognosis (3), or because it would not alter management (2). CONCLUSIONS Fetal MRI was used in 15% of those pregnancies with prenatal diagnosis of a major structural anomaly. This amounted to fewer than 0.3% of singleton deliveries. Judicious application of ACR-SPR guidelines in the context of serial sonography results in a relatively small number of fetal MRI examinations in a nonreferred population.

Purpose: Magnetic resonance imaging has been recently used to examine the abnormalities of the placenta during pregnancy. Segmentation of the placenta and uterine cavity allows quantitative measures and further analyses of the organs. The objective of this study is to develop a segmentation method with minimal user interaction. Approach: We developed a fully convolutional neural network (CNN) for simultaneous segmentation of the uterine cavity and placenta in three dimensions (3D) while a minimal operator interaction was incorporated for training and testing of the network. The user interaction guided the network to localize the placenta more accurately. In the experiments, we trained two CNNs, one using 70 normal training cases and the other using 129 training cases including normal cases as well as cases with suspected placenta accreta spectrum (PAS). We evaluated the performance of the segmentation algorithms on two test sets: one with 20 normal cases and the other with 50 images from both normal women and women with suspected PAS. Results: For the normal test data, the average Dice similarity coefficient (DSC) was 92% and 82% for the uterine cavity and placenta, respectively. For the combination of normal and abnormal cases, the DSC was 88% and 83% for the uterine cavity and placenta, respectively. The 3D segmentation algorithm estimated the volume of the normal and abnormal uterine cavity and placenta with average volume estimation errors of 4% and 9%, respectively. Conclusions: The deep learning-based segmentation method provides a useful tool for volume estimation and analysis of the placenta and uterus cavity in human placental imaging.

Objective: To characterize the natural history of femur length (FL) parameters across gestation in Down syndrome fetuses.Methods: Retrospective review of singletons with fetal Down syndrome deliver...

Objectives Ultrasound (US) prediction of placenta accreta spectrum (PAS) in the first trimester may be aided by postprocessing mechanisms employing color pixel quantification near the bladder-uterine serosal interface. Our objective was to create a postprocessing algorithm of color images to identify findings associated with PAS and compare quantification to sonologist impression in prospectively obtained cine US images. Methods Transverse transvaginal (TV) US color cines obtained in the first trimester as part of a prospective study were reviewed. Investigators blinded to clinical outcomes reviewed anonymized cines that were archived and labeled the bladder-uterine serosal interface. Color pixels within 2 cm of the defined bladder-uterine serosal interface were ascertained using a Python-based plugin in the Horos open-source DICOM viewer. A sonologist classified the findings as suspicious for invasion, indeterminate, or normal. Statistical analysis was performed using Wilcoxon rank-sum test, Cochran-Armitage trend test, and calculation of receiver-operating characteristic (ROC) curves. Results Fifty-four studies met inclusion criteria. Of those, six (11%) required hysterectomy with pathologic confirmation of PAS. Women requiring hysterectomy had a significantly higher color Doppler pixel area than those not requiring hysterectomy (P = .0205). A significant trend was identified in the sonologist impression of invasion (P = .0003). ROC's comparing sonologist impression to Doppler color imaging areas were comparable (P = .054). Conclusions Color Doppler mapping in the first trimester showed an increase in color pixel area near the bladder-uterine serosal interface in women requiring cesarean hysterectomy with histologically confirmed PAS at time of delivery, compared to women without hysterectomy or pathologic evidence of PAS.

Objectives The placenta accreta spectrum (PAS) incidence has risen substantially over the past century, paralleling a rise in cesarean delivery (CD) rates. Prenatal diagnosis of PAS improves maternal outcomes. The Placenta Accreta Index (PAI) is a standardized approach to prenatal diagnosis of PAS incorporating clinical risk and ultrasound (US) findings suggestive of placental invasion. We sought to validate the PAI for prediction of PAS in pregnancies with prior CD. Methods This work was a retrospective cohort study of pregnancies with 1 or more prior CDs that received a US diagnosis of placenta previa or low-lying placenta in the third trimester. Images of third-trimester US with a complete placental evaluation were read by 2 blinded physicians, and the PAI was applied. Surgical outcomes and pathologic findings were reviewed. Placenta accreta spectrum was diagnosed if clinical evidence of invasion was seen at time of delivery or if any placental invasion was identified histologically. International Federation of Gynecology and Obstetrics criteria were used. Results A total of 194 women met inclusion criteria. Cesarean hysterectomy was performed in 92 (47%), CD in 97 (50%), and vaginal delivery in 5 (3%). Of those who underwent hysterectomy, PAS was histologically confirmed in 79 (85%) pregnancies. Of the remaining 13 who underwent hysterectomy, all met International Federation of Gynecology and Obstetrics grade 1 clinical criteria for PAS. With a threshold of greater than 4, the PAI has a sensitivity of 87%, specificity of 77%, positive predictive value of 72%, and negative predictive value of 90% for PAS diagnosis. Conclusions Contemporaneous application of the PAI, a standardized approach to US diagnosis, is useful in the prenatal prediction of PAS.

Objectives To evaluate fetal anomaly detection in pregnancies with pregestational diabetes, according to the gestational age at the time of specialized sonography, use of follow-up sonography, maternal body mass index, and organ system(s) involved. Methods Women with pregestational diabetes who received prenatal care and delivered a live-born or stillborn neonate at our hospital from October 2011 through April 2017 were ascertained. We included all pregnancies with at least 1 confirmed structural anomaly (EUROCAT classification) who had detailed sonography at 18 weeks' gestation or later. We analyzed detection of anomalous fetuses at the initial detailed sonogram and, if no abnormality was identified, during any follow-up sonograms. Statistical analyses were performed with the χ2 test and Mantel-Haenszel χ2 test for trend. Results Seventy-two anomalous neonates (72 of 1060 [6.8%]) were born. Overall detection was 55 of 72 (76%); 49 of 72 (68%) were detected at the initial detailed sonogram, compared to 6 of 15 (40%) of follow-up examinations (P = .04). Recognition at the initial or follow-up examination was not dependent on gestational age or body mass index category (all P > .05). Of individual organ system anomalies, 67 of 89 (75%) were identified. Detection exceeded 85% for central nervous system, genitourinary, and musculoskeletal abnormalities and 43% for craniofacial anomalies. Sixty-five percent of cardiac anomalies were detected, and 14 of 17 (82%) requiring specialized care in the immediate neonatal period were recognized. Conclusions Approximately three-fourths of anomalous fetuses were identified, with greater detection at the initial detailed examination. Fetuses with central nervous system, genitourinary, musculoskeletal abnormalities and those with cardiac anomalies requiring specialized cardiac care were more likely to come to attention.

Objective The objective of this study was to evaluate risk factor prevalence in pregnancies with fetal Down syndrome, in an effort to characterize efficacy of population-based screening. Study Design Retrospective review of singleton pregnancies with delivery of live born or stillborn infant with Down syndrome from 2009 through 2015. Risk factor categories included maternal age ≥35 years, abnormal serum screening, identification of ≥1 ultrasound marker at 16 to 22 weeks (nuchal thickness ≥6 mm, echogenic intracardiac focus, echogenic bowel, renal pelvis dilatation, femur length Results Down syndrome infants represented 1:428 singleton births. All risk categories were assessed in 125 pregnancies and included abnormal serum screen in 110 (88%), ≥1 ultrasound marker in 66 (53%), and ≥1 anomaly in 41 (34%). The calculated risk was at least 1:270 in 93% of Down syndrome pregnancies. More pregnancies had multiple risk factors than had a single risk factor, 90 (72%) versus 30 (24%), p 50% of fetuses in women 75% of those 35 years and older. Conclusion In a population-based cohort, sensitivity of second-trimester Down syndrome screening was 93%, with multiple risk factors present in nearly three-fourths of cases.

Background The aim of the article was to determine if anatomical findings on fetal magnetic resonance imaging (MRI) of venolymphatic malformations of the face and neck (VLMFN) can be used to create a staging system predictive of airway outcomes. Methods We reviewed 13 fetuses evaluated for VLMFN. Stage was assigned based on anatomical findings on fetal MRI. Stage I: no evidence of polyhydramnios with free egress of amniotic fluid and clear visualization of the aryepiglottic folds and larynx. Stage II: lesions of the tongue or epiglottis but with normal aryepiglottic folds without polyhydramnios. Stage III: lesions of the tongue or larynx; nonvisualization of the aryepiglottic folds without free egress of amniotic fluid along with polyhydramnios. Results Six met stage I criteria with no airway involvement, nor any subsequent issues. Two met stage II criteria and were managed by ex-utero intrapartum therapy and intubated. One had minimal involvement of the upper airway, was extubated, and had no subsequent issues. Child two had involvement of the tongue and larynx and received a tracheostomy. Five were assigned stage III, delivered by ex-utero intrapartum therapy and intubated. Postnatal evaluation showed involvement of the upper airway by the lesion and was managed with tracheostomy. All treated by tracheostomy remain cannulated because of persistent symptomatic lesions at follow-up (relative risk 4.0; confidence interval 1.2-13.3). Median follow-up was 4 y (range 2-7 y). Conclusions Although numbers are small, data suggest anatomical details obtained by antenatal fetal MRI appear to correlate with airway outcomes in children affected by a VLMFN. This information may be useful when counseling expectant families of affected fetuses.

BACKGROUND Placenta accreta spectrum (PAS) in women with previous cesarean delivery has become increasingly prevalent. Depending on the severity, patient management may involve cesarean hysterectomy. PURPOSE To investigate textural analyses as the radiomics in MRI of the placenta in predicting the PAS requiring cesarean hysterectomy in a high-risk population. STUDY TYPE Retrospective. POPULATION Sixty-two women with prior cesarean delivery referred for MRI because of sonographic suspicion for PAS. FIELD STRENGTH/SEQUENCE 1.5T with T1 W, T2 W, and diffusion-weighted imaging (DWI). ASSESSMENT Two reviewers independently evaluated MR images based on five established PAS variables. Placental regions of interest (ROIs) were generated on T2 W, DWI, and an apparent diffusion coefficient (ADC) map, based on definitions of areas of placenta in proximity to and remote from previous surgical incision sites. STATISTICAL TESTS Reader agreement was assessed by simple kappa and prevalence adjusted bias adjusted kappa (PABAK). T-tests and chi-square analyses between the primary outcome (hysterectomy vs. no hysterectomy) were performed. Thirteen Haralick texture features calculated from gray-level co-occurrence matrixes were extracted from manually drawn placental ROIs within each of three MR acquisitions. Univariate and multivariable logistic regression were used to assess the association with cesarean hysterectomy. RESULTS Of 62 pregnancies at risk for PAS, 40 required cesarean hysterectomy (65%), with excellent correlation between need for hysterectomy and pathology confirmation of PAS in the hysterectomy specimen [κ = 0.82 (0.62, 1)]. Reader agreement was fair to moderate. Of the 13 Haralick variables within each of three acquisition groups, significant differences (P

To determine if sonographic variables, including fetal femur length to abdominal circumference (FL/AC) ratio, are associated with shoulder dystocia in women with gestational diabetes.This was a retrospective cohort study of women with gestational diabetes who delivered singleton infants at Parkland Hospital from 1997 to 2015. Diagnosis and treatment of gestational diabetes were uniform including sonography at 32-36 weeks. Biometric calculations were evaluated for correlation with shoulder dystocia.During the study period, 6952 women with gestational diabetes underwent a sonogram at a mean gestation of 34.8 ± 1.8 weeks. Of 4183 vaginal deliveries, 66 experienced shoulder dystocia (16/1000). The FL/AC was associated with shoulder dystocia (p 0.001) with an AUC of 0.70 (95% CI: 0.64-0.77). This was similar to age-adjusted AC and head circumference to AC ratio (HC/AC) (both with an AUC of 0.72). All other measurements, including estimated fetal weight, were inferior. When examining the 257 women with multiple sonograms after 32 weeks' gestation, FL/AC was stable with advancing gestational age (p = 0.54) whereas age-adjusted AC and HC/AC were not (p 0.001).The FL/AC is associated with shoulder dystocia in women with gestational diabetes. Additionally, it is a simple ratio that is independent of the reference used and remains stable, unlike age-adjusted AC and HC/AC ratio.

Purpose To provide normal biometry of the cerebellar vermis using fetal MR and determine threshold values associated with abnormal neurologic outcome. Materials and Methods Cerebellar vermis biometry was applied in prospective, cross-sectional evaluation of fetal brains. Vermis length and inferior vermian distance were obtained in mid-sagittal planes using T2-weighted, single-shot sequences with 1.5 Tesla MR. Measurements were compared with reference nomograms from a retrospective review of fetal brains with normal intracranial anatomy. Observed and predicted measurements of the cerebellar vermis were recorded. Neurologic outcome was classified as normal or abnormal. Unpaired t-tests and discriminate analysis were applied to the two measurements and differences between the observed and predicted values. Results The reference group included 64 fetuses of 13 to 38 weeks gestation. Both vermis length and inferior vermian distance increased linearly with time (r = 0.92, P

Purpose To compare saline infusion sonography (SIS) to tissue obtained from SIS-guided endometrial sampling (SISES) to determine sensitivity and specificity for benign and malignant conditions of the endometrium. Methods Added value of SISES after SIS was evaluated over 5 years. SIS and SISES techniques have been previously described. Women with abnormal uterine bleeding and endometrial findings underwent SIS. Criteria for SISES included atypical polypoid mass, focal irregularity or global endometrial thickening, nondiagnostic SIS, discordance between SIS and endometrial biopsy, or request from the primary team. Final surgical pathology was compared with SIS and SISES. Results One-hundred twenty-three SIS patients had SISES. SIS alone had a sensitivity of 100%, specificity of 42%, positive predictive value of 16%, and negative predictive value of 100%. A total of 120 patients had final clinical or surgical outcomes. Specificity was greatly improved with addition of SISES (95.5%, p < 0.001). Combination of SIS with SISES detected all 12 premalignant and malignant endometrial lesions. Three cases had small foci of hyperplasia (n = 2) or atypia (n = 1) in polyps on final surgical pathology, which were not prospectively identified on SISES. Conclusions SISES significantly improves the specificity in the diagnosis of endometrial lesions. False-negative findings of SISES in polyps in postmenopausal women with bleeding suggest the need for surgical removal in this setting. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound, 2016

In 2014, the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Imaging Workshop consensus recommended that sonograms be offered routinely to all pregnant women. In the absence of another indication, this examination is recommended at 18-22 weeks of gestation. Studies of anomaly detection often focus on pregnancies at risk for anomalies and on the yield of detailed sonography, topics less applicable to counseling low-risk pregnancies about the benefits and limitations of standard sonography. The clinical utility of follow-up sonogram in low-risk pregnancies for the purpose of fetal anomaly detection has not been established.The objective of the study was to evaluate the utility of follow-up standard sonography for anomaly detection among low-risk pregnancies in a nonreferred population.We performed a retrospective cohort study of singleton pregnancies that underwent standard sonography at 18-21 6/7 weeks of gestation from October 2011 through March 2018 with subsequent delivery of a live-born infant at our hospital. Pregnancies with indications for detailed sonography in our system were excluded to evaluate fetal anomalies first identified with standard sonography. Anomalies were categorized according to the European Registration of Congenital Anomalies and Twins (EUROCAT) system, with confirmation based on neonatal evaluation. Among those with no anomaly detected initially, we evaluated the rate of subsequent detection according to number of follow-up sonograms, gestational age at sonography, organ system(s) affected, and anomaly severity. Statistical analyses were performed using χStandard sonography was performed in 40,335 pregnancies at 18-21 6/7 weeks, and 11,770 (29%) had at least 1 follow-up sonogram, with a second follow-up sonogram in 3520 (9%). Major abnormalities were confirmed in 387 infants (1%), with 248 (64%) detected initially and 28 (7%) and 5 (1%) detected on the first and second follow-up sonograms. Detection of residual anomalies on follow-up sonograms was significantly lower than detection on the initial standard examination: 64% on initial examination, 45% for first follow-up, and 45% for second follow-up (P.01). A larger number of follow-up examinations were required per anomalous fetus detected: 163 examinations per anomalous fetus detected initially, 420 per fetus detected at the first follow-up examination, and 705 per fetus detected at the second follow-up sonogram (P.01). The number of follow-up examinations to detect each additional anomalous fetus was not affected by gestational age (P = .7). Survival to hospital discharge was significantly lower for fetuses with anomalies detected on initial (88%) than for fetuses with anomalies undetected until delivery (90 of 91, 99%; P.002).In a low-risk, nonreferred cohort with fetal anomaly prevalence of 1%, follow-up sonography resulted in detection of 45% of fetal anomalies that had not been identified during the initial standard sonogram. Significantly more follow-up sonograms were required to detect each additional anomalous fetus.

The purpose of this study is to determine which MRI parameters of fetal head and neck masses predict high-morbidity neonatal outcomes, including ex utero intrapartum treatment (EXIT) procedure.This retrospective study (2004-2016) included parameters of polyhydramnios (based on largest vertical pocket), mass effect on the trachea, mass midline extension, and morphologic grade and size of masses. The morbid cohort included those requiring an EXIT procedure, difficult intubation at delivery, or lethal outcome. Predictive modeling with a multivariable logistic regression and ROC analysis was then performed.Of 36 fetuses, five were delivered by EXIT procedures, there was one neonatal death within 12 hours after delivery, and another neonate required multiple intubation attempts. The remaining 29 fetuses were delivered at outside institutions with no interventions or neonatal morbidity. The largest vertical pocket and mass effect on the trachea were selected as independent predictors by the logistic regression. The cross-validated ROC AUC was 0.951 (95% CI, 0.8795-1).The largest vertical pocket measurement and mass effect on the trachea were the most contributory MRI parameters that predicted significant morbidity in fetuses with masses of the face and neck, along with other significant parameters. These parameters predict significant morbid neonatal outcomes, including the need for EXIT procedures.

Objective To evaluate the relationship between surgical outcomes and ultrasound measurement of placental extension beyond the cervical os in women with placenta previa. Study Design This is a retrospective cohort study of singleton pregnancies with placenta previa undergoing third-trimester ultrasound and delivering at our institution from 2002 through 2011. For study purposes, an investigator measured placental extension, defined as the placental distance from the internal os across the placenta continuing out to the lowest placental edge. If morbidly adherent placentation was suspected, women were excluded. Receiver operating characteristic (ROC) curves were developed for pertinent surgical outcomes, and multivariate analysis was performed to determine the placental extension with the best predictive discriminatory zone. Results In total, 157 women had placenta previa, ultrasound, and delivery data: 86 (55%) had a placental extension of 2,000 mL, blood transfusion, and rate of peripartum hysterectomy. After multivariate analysis, only peripartum hysterectomy and surgical time > 90 minutes remained significant, p ≤ 0.05 and p ≤ 0.01, respectively. Conclusion In women with placenta previa, the placental extension ultrasound measurement of ≥40 mm is a predictor of adverse surgical outcomes.

OBJECTIVES The purpose of this study was to estimate the utility of sonography to detect small-for-gestational-age (SGA) neonates in pregnancies with gastroschisis and to evaluate neonatal outcomes according to birth weight percentile. METHODS We conducted a retrospective cohort study of singleton pregnancies with fetal gastroschisis delivered at our hospital between August 1997 and December 2012. Diagnosis of growth restriction was based on estimated fetal weight below the 10th percentile using the nomogram of Hadlock et al (Am J Obstet Gynecol 1985; 151:333-337), evaluated at 4-week intervals throughout gestation and compared with subsequent birth weight, to evaluate the accuracy of sonography to detect and exclude SGA neonates. Pregnancy and neonatal outcomes were evaluated according to birth weight percentile. RESULTS There were 111 births with gastroschisis (6 per 10,000), and one-third (n = 37) had birth weight below the 10th percentile. The sensitivity and negative predictive value of sonography for an SGA neonate both approached 90% by 32 weeks and were approximately 95% thereafter. Detection increased with advancing gestational age (P = .02). The birth weight percentile was not associated with preterm birth, infection, bowel complications requiring surgery, duration of hospitalization, or perinatal mortality. Delayed closure of the gastroschisis defect was more frequent with birth weights at or below the 3rd percentile (P = .03). CONCLUSIONS Sonography reliably identified SGA neonates with gastroschisis in our series, and its utility improved with advancing gestation. Apart from delayed closure of the defect, a low birth weight percentile was not associated with an increased risk of morbidity or mortality in the immediate neonatal period.

Objective. To determine the accuracy of sonographic-diagnosed polycystic ovaries and clin- ical parameters in predicting polycystic ovarian syndrome. Methods. Medical records and ultrasounds of 151 women with sonographically diagnosed polycystic ovaries were reviewed. Sonographic criteria for poly- cystic ovaries were based on 2003 Rotterdam Euro- pean Society of Human Reproduction and Embryology/American Society for Reproductive Med- icine guidelines: at least one ovary with 12 or more follicles measuring 2-9 mm and/or increased ovarian volume >10 cm 3 . Clinical variables of age, gravidity, ethnicity, body mass index, and sonographic indica- tion were collected. One hundred thirty-five patients had final outcomes (presence/absence of polycystic ovarian syndrome). Polycystic ovarian syndrome was diagnosed if a patient had at least one other of the fol- lowing two criteria: oligo/chronic anovulation and/or clinical/biochemical hyperandrogenism. A logistic regression model was constructed using stepwise selection to identify variables significantly associated with polycystic ovarian syndrome (p < .05). The valid- ity of the model was assessed using receiver operat- ing characteristics and Hosmer-Lemeshow v 2

Objectives To assess the utility of biometric indices and amniotic fluid volume in identifying fetuses with lethal skeletal dysplasia. Methods A review of pregnancies with sonographic diagnosis of skeletal dysplasia between January 1997 and March 2012 from a single institution was conducted. Biometric indices and amniotic fluid volumes were reviewed from the initial targeted sonograms and all subsequent examinations. Outcomes were verified in all cases. Pregnancies that resulted in fetal or neonatal death were considered to have lethal dysplasia, and those with survival to hospital discharge were considered to have nonlethal dysplasia. Results Of 45 fetuses with suspected skeletal dysplasia, 27 (60%) survived to hospital discharge; 9 (20%) died in the immediate neonatal period; 2 (4%) resulted in stillbirth; and in 7 cases (16%), pregnancy termination was elected. Those with lethal dysplasia were more likely to have hydramnios on initial detection than those who survived to hospital discharge (83% versus 27%; P < .01). Pregnancies complicated by lethal skeletal dysplasia had a significantly lower femur length-to-abdominal circumference ratio and were more likely to have a ratio below 0.16 than those with neonatal survival (91% versus 11%; P < 0.01). The lowest femur length-to-abdominal circumference ratio and the proportion with a ratio below 0.16 at any point in gestation were significantly different between those with lethal and nonlethal dysplasia (P< .01). As fetal size increased with advancing gestation, the relationship of sonographic parameters (eg, femur length-to-abdominal circumference ratio) became more pronounced. There was no infant survival when hydramnios was encountered at any point during gestation in the setting of a femur length-to-abdominal circumference ratio below 0.16. Conclusions In our series, a femur length-to-abdominal circumference ratio below 0.16 in conjunction with hydramnios effectively identified fetuses with lethal skeletal dysplasia.

OBJECTIVES The purpose of this study was to review first-trimester transvaginal sonograms of patients with cervicoisthmic implantations and prior cesarean deliveries to determine whether sonographic biometric measurements can distinguish between abnormally adherent trophoblastic implantations and normally implanted pregnancies. METHODS Our database was reviewed from October 2006 through December 2011 for patients with first-trimester sonographic diagnoses of cervicoisthmic implantations and previous cesarean deliveries. Biometric measurements of the smallest distance from the anterior trophoblastic border to the uterine serosa were performed on transvaginal sagittal images of the uterus. Outcomes were classified into 5 categories: cesarean scar pregnancy, placental invasion (accreta/increta/percreta), previa without invasion, spontaneous abortion, and delivered intrauterine pregnancy. Statistical methods included analysis of variance with the Tukey range test and Student t test. RESULTS Of 77 studies, outcome data were available for 56 patients. The mean gestational age was 8.8 weeks (minimum, 2.0 weeks; maximum, 14.9 weeks). The anterior trophoblastic border distances from the uterine serosa were significantly smaller in cesarean scar pregnancies (mean, 1.6 mm; SD, 0.6 mm) and placental invasion pregnancies (mean, 2.2 mm; SD, 1.0 mm) than the normally implanted groups (mean, 7.9 mm, SD, 3.3 mm; P < .0001). CONCLUSIONS Smaller trophoblastic border distances to the anterior uterine serosa are seen in abnormally adherent trophoblastic implantations, and these distances distinguish them from other pregnancy outcomes.

As fetal gestational age increases, other modalities such as ultrasound have demonstrated increased levels of heterogeneity in the normal placenta. In this study, we introduce and apply ROI-based texture analysis to a retrospective fetal MRI database to characterize the second-order statistics of placenta and to evaluate the relationship between heterogeneity and gestational age. Positive correlations were observed for several Haralick texture metrics derived from fetal-brain specific T2-weighted and gravid uterus T1-weighted and T2-weighted images, confirming a quantitative increase in placental heterogeneity with gestational age. Our study shows the importance of identifying baseline MR textural changes at certain gestational ages from which placental diseased states may be compared. Specifically, when evaluating for placental invasion or insufficiency, findings should be evaluated in the context of the normal placental aging process, which occurs throughout gestation.

Fetal magnetic resonance (MR) imaging plays an increasing and valuable role in antenatal diagnosis and perinatal management of fetal gastrointestinal (GI) abnormalities. Advances in MR imaging data acquisition and use of motion-insensitive techniques have established MR imaging as an important adjunct to obstetric ultrasonography (US) for fetal diagnosis. In this regard, MR imaging provides high diagnostic accuracy for antenatal diagnosis of common and uncommon GI pathologic conditions. In the setting of fetal GI disease, T1-weighted images demonstrate the amount and distribution of meconium, which is crucial to the diagnostic capability of fetal MR imaging. Specifically, knowledge of the T1 signal intensity characteristics of fetal meconium, the normal pattern of meconium with advancing gestational age, and the expected caliber of small and large bowel in the fetus is key to diagnosis of abnormalities of the GI tract. Use of ultrafast T2-weighted sequences for evaluation of the expected location and morphology of fluid-containing structures, including the stomach and small bowel, in the fetal abdomen further aids in diagnostic confidence. Uncommonly encountered fetal GI pathologic conditions, especially cloacal dysmorphology, may demonstrate characteristic MR imaging patterns, which may add additional information to that from fetal US, allowing improved fetal and neonatal management. This article discusses common indications for fetal MR imaging of the GI tract, imaging protocols for fetal GI MR imaging, the normal appearance of the fetal GI tract with advancing gestational age, and the imaging appearances of common fetal GI abnormalities, as well as uncommon fetal GI conditions with characteristic appearances. (©)RSNA, 2016.

Although ultrasound is the primary means of screening for fetal central nervous system (CNS) malformations, MRI has demonstrated added value in the evaluation of abnormalities not well assessed with sonography and in select circumstances for screening. In many fetal MRI practices, evaluation of the CNS is the most common indication for fetal MRI. MRI has demonstrated particular utility in evaluating the posterior fossa, midline structures, and cortex in the progressively ossifying fetal skull. The most common CNS indications are identified in Table 6.1 [98].

The objectives of this study were to estimate the rates of sonographically detected anal sphincter defects within 72 h of childbirth and to evaluate intra- and interobserver agreement using three-dimensional (3-D) endoanal sonography data. This is a prospective observational study of primiparous women delivered vaginally. Women without clinically identified anal sphincter lacerations underwent endoanal ultrasonography within 72 h of delivery. Intra- and interobserver agreement for diagnosis of sphincter defects using 3-D endoanal sonography data was calculated using kappa statistics. The rate of sphincter defects in 107 women undergoing 3-D endoanal sonography was 12 %. Characteristics of women with sonographically detected sphincter defects, compared to those without, included a significantly increased rate of clinically diagnosed second-degree lacerations (54 vs 20 %, p 0.008). The intra- and interobserver agreement for diagnosis of sphincter defects using 3-D endoanal sonography data was 0.82 [confidence interval (CI) 0.66–0.99] and 0.72 (CI 0.54–0.92), respectively. Anal sphincter defects detected using endoanal sonography are common, occurring in 12 % of primiparous women, and are significantly associated with other less severe perineal lacerations. Overall and combining sonographically detected defects with clinically diagnosed lacerations, we estimate that 17.8 % of primiparous women delivered vaginally sustain anal sphincter injuries. The intraobserver agreement for diagnosis of sphincter defects is very good and the interobserver agreement is good.

When medical therapy fails for menorrhagia in a premenopausal woman, minimally invasive endometrial ablation can be used as a conservative management alternative to hysterectomy. Endometrial ablation alone is not considered effective contraception, and women of reproductive age can become pregnant after ablative therapy. We now present two cases of pregnancy after endometrial ablation and associated imaging where both cases required cesarean hysterectomy due to post-partum hemorrhage. Pregnancy after endometrial ablation incurs increased morbidity and diagnostic dilemmas.

To estimate the position of the appendix in term pregnancy using magnetic resonance imaging (MRI) technique.Appendiceal distance from the iliac crest and axis rotation were determined in women between 39 and 40 weeks of gestation who were undergoing scheduled repeat cesarean delivery. A single-shot fast spin-echo MRI sequence of the maternal pelvis was performed without gadolinium contrast. A board-certified radiologist interpreted the MRIs and measured the distance from the base of appendix (or cecum) to the iliac crest in centimeters as well as the axis of the appendix using clock position annotation.Seventy-two women had optimal imaging for interpretation. The mean displacement of the appendix above the iliac crest was 45 mm and was significantly higher than previously described in the term pregnant woman (P.001).Despite recent studies supporting the contrary view, the upward displacement of the appendix in term pregnancy is confirmed in this study.II.

Objective. The purpose of this study was to evaluate the effect of maternal habitus on adequate visualization of fetal anatomy during a standard second-trimester ultrasound examination. Methods. This was a retrospective cohort study of singleton pregnancies at 18 to 24 weeks that underwent sonography over a 5-year period. Pregnancies complicated by an indication for targeted sonography were excluded. Standard ultrasound examinations were performed according to American Institute of Ultrasound in Medicine criteria. Ten anatomic components were evaluated for adequacy of visualization: atria of the cerebral ventricles, posterior fossa, midline face, 4-chamber view of the heart, spine, ventral wall, umbilical cord vessels, stomach, kidneys, and bladder. The body mass index (BMI) was based on the patient's weight at the first prenatal visit. Results. Of 10,112 women who underwent a standard ultrasound examination, 2% were underweight; 38% were of normal weight; 34% were overweight; and 26% were obese. Visualization of fetal anatomy decreased significantly with increasing maternal BMI for the complete survey as well as for each individual component with the exception of the fetal bladder (all P < .001 Among those with a normal or underweight BMI, an overweight BMI, and class 1, 2, and 3 obesity, all 10 anatomic components were adequately visualized at the initial examination in 72%, 68%, 57%, 41 %, and 30% of cases, respectively (P < .001 ). Conclusions. Increasing maternal BMI limits visualization of fetal anatomy during a standard ultrasound examination at 18 to 24 weeks. In obese women, the fetal anatomy survey could be completed during the initial examination in only 50% of cases. Counseling may need to be modified to reflect the limitations of sonography in obese women.

OBJECTIVE: To evaluate prospectively whether salineinfusion sonography endometrial sampling will improve diagnosis of benign and malignant endometrial disease compared with blind endometrial biopsy in perimenopausal and postmenopausal women with abnormal uterine bleeding. METHODS: After initial assessments and endometrial biopsies, women aged 40 or older with abnormal uterine bleeding were referred for transvaginal ultrasonography. Patients with abnormal endometrial evaluations were offered sonohysterography and invited to enter the saline-infusion sonography endometrial sampling study. Saline-infusion sonography endometrial sampling was performed at the end of sonohysterography using an endometrial sampling curette at the sight of the endometrial abnormality or at a representative site in the endometrial cavity if the cavity was normal. Histopathologic diagnoses of blind endometrial biopsy and saline-infusion sonography endometrial sampling were compared with final outcomes. Kappa values for the two sampling techniques were calculated for diagnostic accuracy. RESULTS: A total of 88 saline-infusion sonography endometrial samples were obtained; final outcomes were attained in 80 cases. When comparing saline-infusion sonography endometrial sampling with final outcomes, saline-infusion sonography endometrial sampling provided a diagnosis 89% of the time (95% confidence interval [CI] 82–95%) compared with endometrial biopsy at 52% (95% CI 42–62%). Forty-five patients with endometrial biopsies had final outcomes. When comparing endometrial biopsy with final outcomes, endometrial biopsy underestimated the incidence of pathology, especially when focal lesions and malignancy were present. This difference was statistically significant (P

Objective To determine whether endometrial thickness and other parameters are useful predictors of normal intrauterine pregnancy (IUP) in the setting of vaginal bleeding and sonographic diagnosis of pregnancy of unknown location (PUL). Methods We reviewed the clinical and sonographic records of all 591 patients with vaginal bleeding and a sonographic diagnosis of PUL between 1 July 2005 and 30 June 2006. Data on maternal age, gravidity, parity, estimated gestational age by last menstrual period (EGA by LMP), endometrial thickness and serum β-human chorionic gonadotropin (β-hCG) were collected. Complete data were available for 517 patients, 40 (7.7%) of whom ultimately had normal IUPs. A logistic regression model was constructed using a stepwise procedure to identify variables significantly associated with the outcome of normal IUP. The validity of the model was assessed by receiver–operating characteristics (ROC) curve and Hosmer–Lemeshow Chi-square analysis. Results Four variables (maternal age, EGA by LMP, endometrial thickness and serum β-hCG) were significant in the prediction of normal IUP (area under the ROC curve = 0.86). As maternal age, EGA by LMP and β-hCG increased, the likelihood of a normal IUP decreased, while as the endometrial thickness increased, the likelihood of a normal IUP increased. For each millimeter increase in endometrial thickness, the odds increased by 27% that the patient would have a normal IUP. No normal IUP had an endometrial thickness < 8 mm. Conclusion Increased endometrial thickness predicts normal IUP in patients who present with vaginal bleeding and PUL. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.

The objective of this study is to describe magnetic resonance (MR) signal intensity (SI) changes in the cervix during pregnancy. This is an observational cohort study of women with a history of preterm delivery. MR imaging sequences were performed every 3 to 4 weeks. Using 8 regions of interest, the SIs are quantified and analyzed with respect to gestational age. Twenty-seven MR studies were performed on a cohort of 8 women. The SIs of the external os are significantly greater than those of the internal os ( P = .035). Similarly, the SIs of the outer stroma are greater than those of the inner stroma (P = .002). As gestational age advances, the inner to outer stromal SI ratio increases, primarily because of a decreasing SI in the outer stromal layer (P = .03). The MR SIs of the cervical stromal zones display variability during pregnancy and decrease with advancing gestation.

Objective The purpose of this study was to compare middle cerebral artery (MCA) peak systolic velocity (PSV) values in monochorionic (MC) and dichorionic (DC) twin pregnancies. Methods This was a prospective cohort study in which MCA Doppler evaluation was performed in unselected twin pregnancies at time of routine sonography between 28 and 32 weeks. Pregnancies with known fetal anomalies, twin-twin transfusion syndrome, and red cell alloimmunization or other conditions associated with anemia were excluded. The intertwin MCA PSV difference, defined as the larger minus smaller PSV value within a pair, was compared in MC and DC pregnancies and was correlated with estimated fetal weight and birth weight discordance. Statistical analyses included Spearman correlation, analysis of variance, a t test, and a chi(2) test. Results Doppler indices were analyzed from 48 twin pregnancies, of which 32 (67%) were DC and 16 (33%) were MC. There was no difference in proportion of values above or below the singleton median for either the larger or smaller DC or MC twins (all P > or = .3). The median intertwin MCA PSV difference was 4.9 cm/s in MC pregnancies and 4.5 cm/s in DC pregnancies (P = .6). There was no significant correlation between the MCA PSV difference and either estimated fetal weight discordance or birth weight discordance in either MC or DC pregnancies (all P > or = .3). Conclusions Middle cerebral artery PSV values in uncomplicated twin pregnancies are comparable with published singleton norms, with a median intertwin MCA PSV difference of approximately 5 cm/s. We found no significant correlation between the intertwin MCA PSV difference and discordance in MC or DC twin gestations.

To evaluate pregnancy outcomes with low-lying placenta according to the distance from placenta to cervical os.Retrospective cohort study of singleton pregnancies with low-lying placenta (placenta edge within 20 mm of internal os on transvaginal sonography) delivered at our hospital from 2002 to 2012, excluding suspected placenta accreta and vasa previa. Vaginal delivery was offered in the absence of another indication for cesarean. Outcomes were stratified according to placenta-os distance ≤10 mm and 11-20 mm.Of 98 pregnancies with low-lying placenta, 41% had placenta-os distance ≤10 mm and 59% placenta-os distance 11-20 mm. Fifty-four percent had a trial of labor. Six (15%) with placenta-os ≤10 mm and 21 (36%) with placenta-os 11-20 mm delivered vaginally, p = 0.02. Bleeding necessitating cesarean occurred in 25%, and postpartum hemorrhage in 43%; neither complication associated with placenta-os distance. Third-trimester bleeding prior to delivery hospitalization was reported in 44% and associated with later bleeding requiring cesarean in 51% versus 4% of those without third-trimester bleeding, p 0.001.Whereas low-lying placenta does not contraindicate labor, we found significant risk for bleeding complications, regardless of the planned mode of delivery. Placenta-os distance did not significantly affect outcomes in our series.

Objectives The purpose of this study was to evaluate the association between first-trimester sonographic findings and morbidly adherent placenta at delivery. Methods We conducted a retrospective review of all first-trimester sonographic examinations from pregnancies that underwent third-trimester sonography for placenta previa or low-lying placenta between September 1997 and October 2011. Only women with a prior cesarean delivery were included. Transabdominal and transvaginal images from these first-trimester studies were reviewed for the following sonographic parameters: distance from the inferior border of the gestational sac to the external cervical os, location of the decidua basalis, presence of anechoic areas, uterine-bladder interface irregularity, and smallest anterior myometrial thickness. Morbidly adherent placentation was confirmed on histologic examination of hysterectomy specimens. Statistical methods included univariate and multivariate analyses. Results Thirty-nine patients met inclusion criteria, of whom 14 (36%) had confirmed placental invasion. The number of prior cesarean deliveries was significantly associated with placental invasion (P < .0001). The only first-trimester sonographic finding associated with invasion was the smallest anterior myometrial thickness measured in the sagittal plane (P< .02). Multivariate analysis based on these two variables yielded an area under the receiver operating characteristic curve of 0.94 (95% confidence interval, 0.87–1.00) and significantly improved the prediction of placental invasion compared to using the number of prior cesarean deliveries alone. Conclusions In women with persistent placenta previa or low-lying placenta and prior cesarean delivery, the smallest anterior myometrial thickness on first-trimester sonography significantly improved detection of morbidly adherent placenta.

Objective To evaluate the incidence of vaginal bleeding in women with placenta accreta according to gestational age at delivery. Methods This is a retrospective cohort study of women with prior cesarean delivery and persistent placenta previa delivered at our institution between December 1997 and December 2011. Diagnosis of invasion was based on hysterectomy performed for an abnormally adherent placenta with histologic confirmation. Suspicion for invasion was based on the impression of the attending physician at the time of ultrasonography. Records were reviewed to identify indication for delivery and estimated blood loss. Statistical analyses were performed using Student's t test, χ2 test, and Mantel-Haenszel and Jonckheere-Terpstra tests for trend. Results Of 216 women with prior cesarean delivery and persistent previa, 65 (30%) required cesarean hysterectomy and had histologic confirmation of invasion. Urgent delivery for bleeding was performed in 20% of these pregnancies (13/65). Delivery for bleeding decreased significantly with advancing gestation (P=.001). In our series, 71% with accreta were delivered at 36 weeks of gestation or greater with delivery for bleeding in five (11%), and estimated blood loss was not increased in these pregnancies. Of 79 women with ultrasonographic suspicion for accreta, the incidence of vaginal bleeding prompting urgent delivery also decreased with advancing gestation (P Conclusion Likelihood of vaginal bleeding necessitating delivery declined with advancing gestation in pregnancies with placenta accreta as did blood loss. Most were delivered at 36 weeks of gestation or greater, nearly 90% in the absence of bleeding complications. Thus, although preterm delivery is an important consideration when placenta accreta is suspected, our findings support individualizing delivery planning.

The purpose of this study was to evaluate neural tube defect (NTD) detection according to whether serum alpha-fetoprotein (AFP) screening or standard ultrasound are performed.Prenatal and neonatal datasets were reviewed to identify pregnancies with NTDs from 1 institution between January 2000 and December 2003. AFP screening was offered21 weeks and considered elevated ifor = 2.50 multiples of the median. Standard ultrasound was performed for specific indications in low-risk pregnancies.There were 66 NTDs, 1 per 950 deliveries. AFP sensitivity was 65%. If the gestational age used for AFP calculation was confirmed with ultrasound, sensitivity improved to 86%. The sensitivity of standard ultrasound was 100%, P.001 compared with AFP screening. NTDs detected with standard ultrasound were identified later in gestation, as examinations were performed for other indications.Standard ultrasound improved NTD detection over AFP screening alone, by improving AFP test sensitivity and identifying NTDs in low-risk pregnancies.

Objective To study whether magnetic resonance imaging (MRI) pelvimetry has the ability to identify those women who require cesarean delivery for labor dystocia. Methods From July 2003 to April 2004, nulliparous women scheduled for a labor induction for prolonged pregnancy (42 weeks) were asked to participate in a pelvimetry study. Those who consented underwent fast-acquisition MRI that included two 90-second acquisitions to evaluate fetal biometry and volumetry and maternal pelvimetry, including novel measurements of pelvic bony and soft tissue volumes as determined by MRI. Information about each patient's pregnancy, labor course, and neonatal outcome was prospectively collected. Pelvimetry results for those women undergoing operative delivery for labor dystocia were compared with those who did not. Single fetal and maternal pelvic measurements, as well as ratios of both, were analyzed. In addition, previously described radiographic pelvimetry techniques and formulas to predict dystocia were used. Results One hundred one women underwent MRI, and 22 of these underwent cesarean delivery for dystocia. No single fetal measurement was statistically associated with dystocia. Several maternal pelvic measures, fetal-to-maternal ratios, and previously reported pelvimetric techniques were significantly associated with dystocia. The ratio of magnetic resonance (MR) fetal head volume to pelvic soft tissue volume had statistical significance (P = .04). Receiver operator characteristic curves were developed for the different measurements, ratios, and formulas studied to assess whether any of the techniques could accurately predict labor dystocia requiring operative delivery. The area under the curve values ranged from 0.6 to 0.8, with the ratio of MR head volume to pelvic soft tissue being 0.7. These values suggest that MRI can identify those women at greatest risk for dystocia, but it cannot with accuracy predict which ones will require a cesarean. Conclusion We found significant associations with MRI pelvimetry and labor dystocia, but MRI was not a significant improvement over previously described pelvimetric techniques. Level of evidence II-3.

Objective: The purpose of this study was to compare the relationship between the actual amnionic fluid volume that was measured at delivery and magnetic resonance amnionic fluid volume determination, largest vertical pocket, and amnionic fluid index. Study design: Three hours before cesarean delivery, 80 women had sonographic measurement of the amnionic fluid index and the largest vertical pocket. Magnetic resonance imaging was then completed, and the magnetic resonance amnionic fluid volume was determined. At surgery, the amnionic fluid was collected. Pearson correlations were determined. Receiver operating characteristic curves were developed for each method as a measure of predictability for oligohydramnios. Results: The correlations for the magnetic resonance amnionic fluid volume, amnionic fluid index, and largest vertical pocket to amnionic fluid volume was 0.84, 0.77, and 0.71, respectively. Magnetic resonance amnionic fluid volume has a statistically higher correlation than the largest vertical pocket (P = .046). The 3 methods, however, are statistically comparable for identifying oligohydramnios. Conclusion: Magnetic resonance imaging is comparable with ultrasound evaluation for the prediction of oligohydramnios. Correlations to actual amnionic fluid volume are also comparable.

Objective: The purpose of this study was to compare third trimester and nonpregnant cerebral blood flow of women with preeclampsia to normotensive control subjects with the use of magnetic resonance imaging techniques.Study design: Nine normotensive pregnant women and 12 untreated women with preeclampsia underwent velocity-encoded phase contrast magnetic resonance imaging of the bilateral middle and posterior cerebral arteries in the third trimester and at 6 to 8 weeks after delivery. The Student t test was used for comparison, with a probability value ofResults: Third-trimester large cerebral artery blood flow was significantly higher in preeclampsia. Mean vessel diameter was unchanged, except for the left posterior cerebral artery. There was no difference in mean vessel diameter or cerebral blood flow between the 2 groups while the women were not pregnant.Conclusion: Cerebral blood flow is increased significantly in preeclampsia. We hypothesize that increased cerebral blood flow ultimately could lead to eclampsia through hyperperfusion and the development of vasogenic edema. (C) 2004 Elsevier Inc. All rights reserved.