Colombian Consensus on the Treatment of Placenta Accreta Spectrum (PAS) / Consenso Colombiano de Tratamiento del Espectro de Acretismo Placentario (EAP)

Introduction: Placenta accreta spectrum (PAS) is a condition associated with massive postpartum bleeding and maternal mortality. Management guidelines published in high income countries recommend the participation of interdisciplinary teams in hospitals with sufficient resources for performing complex procedures. However, some of the recommendations contained in those guidelines are difficult to implement in low and medium income countries. Objectives: The aim of this consensus is to draft general recommendations for the treatment of PAS in Colombia. Materials and methods: Twenty-three panelists took part in the consensus with their answers to 31 questions related to the treatment of PAS. The panelists were selected based on participation in two surveys designed to determine the resolution capabilities of national and regional hospitals. The modified Delphi methodology was used, introducing two successive discussion rounds. The opinions of the participants, with a consensus of more than 80%, as well as implementation barriers and facilitators, were taken into consideration in order to issue the recommendations. Results: The consensus draftedfive recommendations, integrating the answers of the panelists. Recommendation 1. Primary care institutions must undertake active search of PAS in patients with risk factors: placenta praevia and history of myomectomy or previous cesarean section. In case of ultrasound signs suggesting PAS, patients must be immediately referred, without a minimum gestational age, to hospitals recognized as referral centers. Online communication and care modalities may facilitate the interaction between primary care institutions and referral centers for PAS. The risks and benefits of telemedicine modalities must be weighed. Recommendation 2. Referral hospitals for PAS need to be defined in each region of Colombia, ensuring coverage throughout the national territory. It is advisable to concentrate the flow of patients affected by this condition in a few hospitals with surgical teams specifically trained in PAS, availability of specialized resources, and institutional efforts at improving quality of care with the aim of achieving better health outcomes in pregnant women with this condition. To achieve this goal, participants recommend that healthcare regulatory agencies at a national and regional level should oversee the process of referral for these patients, expediting administrative pathways in those cases in which there is no prior agreement between the insurer and the selected hospital or clinic. Recommendation 3. Referral centers for patients with PAS are urged to build teams consisting of a fixed group of specialists (obstetricians, urologists, general surgeons, interventional radiologists) entrusted with the care of all PAS cases. It is advisable for these interdisciplinary teams to use the "intervention bundle" model as a guidance for building PAS referral centers. This model comprises the following activities: service preparedness, disease prevention and identification, response to the occurrence of the disease, and debriefing after every event. Telemedicine facilitates PAS treatment and should be taken into consideration by interdisciplinary teams caring for this disease. Recommendation 4. Obstetrics residents must be instructed in the performance of maneuvers that are useful for the prevention and treatment of massive intraoperative bleeding due to placenta praevia and PAS, including manual aortic compression, uterine tourniquet, pelvic packing, retrovesical bypass, and Ward maneuver. Specialization Obstetrics and Gynecology programs in Colombia must include the basic concepts of the diagnosis and treatment of PAS. Referral centers for PAS must offer online and in-person training programs for professionals interested in improving their competencies in PAS. Moreover, they must offer permanent remote support (telemedicine) to other hospitals in their region for patients with this condition. Recommendation 5. Patients suspected of having PAS and placenta praevia based on imaging, with no evidence of active vaginal bleeding, must be delivered between weeks 34 and 36 6/7. Surgical treatment must include sequential interventions that may vary depending on the characteristics of the lesion, the clinical condition of the patient and the availability of resources. The surgical options (total and subtotal hysterectomy, one-stage conservative surgical management and watchful waiting) must be included in a protocol known by the entire interdisciplinary team. In situations in which an antepartum diagnosis is lacking, that is to say, in the face of intraoperative finding of PAS (evidence of purple bulging or neovascularization of the anterior aspect of the uterus), and the participation of untrained personnel, three options are considered: Option 1: In the absence of indication of immediate delivery or of vaginal delivery, the recommendation is to postpone the cesarean section (close the laparotomy before incising the uterus) until the recommended resources for safe surgery are secured. Option 2: If there is an indication for immediate delivery (e.g., non-reassuring fetal status) but there is absence of vaginal bleeding or indication for immediate PAS management, a two-stage management is suggested: cesarean section avoiding placental incision, followed by uterine repair and abdominal closure, until the availability of the recommended resources for safe surgery is ascertained. Option 3: In the event of vaginal bleeding that prevents definitive PAS management, the fetus must be delivered through the uterine fundus, followed by uterine repair and reassessment of the situation. Sometimes, fetal delivery diminishes placental flow and vaginal bleeding is reduced or disappears, enabling the possibility to postpone definitive management of PAS. In case of persistent significant bleeding, hysterectomy should be performed, using all available resources: manual aortic compression, immediate call to the surgeons with the best available training, telemedicine support from expert teams in other hospitals. If a patient with risk factors for PAS (e.g., myomectomy or previous cesarean section) has a retained placenta after vaginal delivery, it is advisable to confirm the possibility of such diagnosis (by means of ultrasound, for example) before proceeding to manual extraction of the placenta. Conclusions: It is our hope that this first Colombian consensus on PAS will serve as a basis for additional discussions and collaborations that can result in improved clinical outcomes for women affected by this condition. Additional research will be required in order to evaluate the applicability and effectiveness of these recommendations.

Introducción: el espectro de acretismo placentario (EAP) es una condición asociada a sangrado masivo posparto y mortalidad materna. Las guías de manejo publicadas en países de altos ingresos recomiendan la participación de grupos interdisciplinarios en hospitales con recursos suficientes para realizar procedimientos complejos. Sin embargo, algunas de las recomendaciones de estas guías resultan difíciles de aplicar en países de bajos y medianos ingresos. Objetivos: este consenso busca formular recomendaciones generales para el tratamiento del EAP en Colombia. Materiales y métodos: en el consenso participaron 23 panelistas, quienes respondieron 31 preguntas sobre el tratamiento de EAP. Los panelistas fueron seleccionados con base en la participación en dos encuestas realizadas para determinar la capacidad resolutiva de hospitales en el país y la región. Se utilizó la metodología Delphi modificada, incorporando dos rondas sucesivas de discusión. Para emitir las recomendaciones el grupo tomó en cuenta la opinión de los participantes, que lograron un consenso mayor al 80 %, así como las barreras y los facilitadores para su implementación. Resultados: el consenso formuló cinco recomendaciones integrando las respuestas de los panelistas. Recomendación 1. Las instituciones de atención primaria deben realizar búsqueda activa de EAP en pacientes con factores de riesgo: placenta previa e historia de miomectomía o cesárea en embarazo previo. En caso de haber signos sugestivos de EAP por ecografía, las pacientes deben ser remitidas de manera inmediata, sin tener una edad gestacional mínima, a hospitales reconocidos como centros de referencia. Las modalidades virtuales de comunicación y atención en salud pueden facilitar la interacción entre las instituciones de atención primaria y los centros de referencia para EAP. Se debe evaluar el beneficio y riesgo de las modalidades de telemedicina. Recomendación 2. Es necesario que se definan hospitales de referencia para EAP en cada región de Colombia, asegurando el cubrimiento de la totalidad del territorio nacional. Es aconsejable concentrar el flujo de pacientes afectadas por esta condición en unos pocos hospitales, donde haya equipos de cirujanos con entrenamiento específico en EAP, disponibilidad de recursos especializados y un esfuerzo institucional por mejorar la calidad de atención, en busca de tener mejores resultados en la salud de las gestantes con esta condición. Para lograr ese objetivo los participantes recomiendan que los entes reguladores de la prestación de servicios de salud a nivel nacional, regional o local vigilen el proceso de remisión de estas pacientes, facilitando rutas administrativas en caso de que no exista contrato previo entre el asegurador y el hospital o la clínica seleccionada (IPS). Recomendación 3. En los centros de referencia para pacientes con EAP se invita a la creación de equipos que incorporen un grupo fijo de especialistas (obstetras, urólogos, cirujanos generales, radiólogos intervencionistas) encargados de atender todos los casos de EAP. Es recomendable que esos grupos interdisciplinarios utilicen el modelo de "paquete de intervención" como guía para la preparación de los centros de referencia para EAP. Este modelo consta de las siguientes actividades: preparación de los servicios, prevención e identificación de la enfermedad, respuesta ante la presentación de la enfermedad, aprendizaje luego de cada evento. La telemedicina facilita el tratamiento de EAP y debe ser tenida en cuenta por los grupos interdisciplinarios que atienden esta enfermedad. Recomendación 4. Los residentes de Obstetricia deben recibir instrucción en maniobras útiles para la prevención y el tratamiento del sangrado intraoperatorio masivo por placenta previa y EAP, tales como: la compresión manual de la aorta, el torniquete uterino, el empaquetamiento pélvico, el bypass retrovesical y la maniobra de Ward. Los conceptos básicos de diagnóstico y tratamiento de EAP deben incluirse en los programas de especialización en Ginecología y Obstetricia en Colombia. En los centros de referencia del EAP se deben ofrecer programas de entrenamiento a los profesionales interesados en mejorar sus competencias en EAP de manera presencial y virtual. Además, deben ofrecer soporte asistencial remoto (telemedicina) permanente a los demás hospitales en su región, en relación con pacientes con esa enfermedad. Recomendación 5. La finalización de la gestación en pacientes con sospecha de EAP y placenta previa, por imágenes diagnósticas, sin evidencia de sangrado vaginal activo, debe llevarse a cabo entre las semanas 34 y 36 6/7. El tratamiento quirúrgico debe incluir intervenciones secuenciales que pueden variar según las características de la lesión, la situación clínica de la paciente y los recursos disponibles. Las opciones quirúrgicas (histerectomía total y subtotal, manejo quirúrgico conservador en un paso y manejo expectante) deben incluirse en un protocolo conocido por todo el equipo interdisciplinario. En escenarios sin diagnóstico anteparto, es decir, ante un hallazgo intraoperatorio de EAP (evidencia de abultamiento violáceo o neovascularización de la cara anterior del útero), y con participación de personal no entrenado, se plantean tres situaciones: Primera opción: en ausencia de indicación de nacimiento inmediato o sangrado vaginal, se recomienda diferir la cesárea (cerrar la laparotomía antes de incidir el útero) hasta asegurar la disponibilidad de los recursos recomendados para llevar a cabo una cirugía segura. Segunda opción: ante indicación de nacimiento inmediato (por ejemplo, estado fetal no tranquilizador), pero sin sangrado vaginal o indicación de manejo inmediato de EAP, se sugiere realizar manejo en dos tiempos: se realiza la cesárea evitando incidir la placenta, seguida de histerorrafia y cierre de abdomen, hasta asegurar la disponibilidad de los recursos recomendados para llevar a cabo una cirugía segura. Tercera opción: en presencia de sangrado vaginal que hace imposible diferir el manejo definitivo de EAP, es necesario extraer el feto por el fondo del útero, realizar la histerorrafia y reevaluar. En ocasiones, el nacimiento del feto disminuye el flujo placentario y el sangrado vaginal se reduce o desaparece, lo que hace posible diferir el manejo definitivo de EAP. Si el sangrado significativo persiste, es necesario continuar con la histerectomía haciendo uso de los recursos disponibles: compresión manual de la aorta, llamado inmediato a los cirujanos con mejor entrenamiento disponible, soporte de grupos expertos de otros hospitales a través de telemedicina. Si una paciente con factores de riesgo para EAP (por ejemplo, miomectomía o cesárea previa) presenta retención de placenta posterior al parto vaginal, es recomendable confirmar la posibilidad de dicho diagnóstico (por ejemplo, realizando una ecografía) antes de intentar la extracción manual de la placenta. Conclusiones: esperamos que este primer consenso colombiano de EAP sirva como base para discusiones adicionales y trabajos colaborativos que mejoren los resultados clínicos de las mujeres afectadas por esta enfermedad. Evaluar la aplicabilidad y efectividad de las recomendaciones emitidas requerirá investigaciones adicionales.

Consenso Colombiano de Tratamiento del Espectro de Acretismo Placentario (EAP) / Colombian Consensus on the Treatment of Placenta Accreta Spectrum (PAS)

RESUMEN Introducción: el espectro de acretismo placentario (EAP) es una condición asociada a sangrado masivo posparto y mortalidad materna. Las guías de manejo publicadas en países de altos ingresos recomiendan la participación de grupos interdisciplinarios en hospitales con recursos suficientes para realizar procedimientos complejos. Sin embargo, algunas de las recomendaciones de estas guías resultan difíciles de aplicar en países de bajos y medianos ingresos. Objetivos: este consenso busca formular recomendaciones generales para el tratamiento del EAP en Colombia. Materiales y métodos: en el consenso participaron 23 panelistas, quienes respondieron 31 preguntas sobre el tratamiento de EAP. Los panelistas fueron seleccionados con base en la participación en dos encuestas realizadas para determinar la capacidad resolutiva de hospitales en el país y la región. Se utilizó la metodología Delphi modificada, incorporando dos rondas sucesivas de discusión. Para emitir las recomendaciones el grupo tomó en cuenta la opinión de los participantes, que lograron un consenso mayor al 80 %, así como las barreras y los facilitadores para su implementación. Resultados: el consenso formuló cinco recomendaciones integrando las respuestas de los panelistas. Recomendación 1. Las instituciones de atención primaria deben realizar búsqueda activa de EAP en pacientes con factores de riesgo: placenta previa e historia de miomectomía o cesárea en embarazo previo. En caso de haber signos sugestivos de EAP por ecografía, las pacientes deben ser remitidas de manera inmediata, sin tener una edad gestacional mínima, a hospitales reconocidos como centros de referencia. Las modalidades virtuales de comunicación y atención en salud pueden facilitar la interacción entre las instituciones de atención primaria y los centros de referencia para EAP. Se debe evaluar el beneficio y riesgo de las modalidades de telemedicina. Recomendación 2. Es necesario que se definan hospitales de referencia para EAP en cada región de Colombia, asegurando el cubrimiento de la totalidad del territorio nacional. Es aconsejable concentrar el flujo de pacientes afectadas por esta condición en unos pocos hospitales, donde haya equipos de cirujanos con entrenamiento específico en EAP, disponibilidad de recursos especializados y un esfuerzo institucional por mejorar la calidad de atención, en busca de tener mejores resultados en la salud de las gestantes con esta condición. Para lograr ese objetivo los participantes recomiendan que los entes reguladores de la prestación de servicios de salud a nivel nacional, regional o local vigilen el proceso de remisión de estas pacientes, facilitando rutas administrativas en caso de que no exista contrato previo entre el asegurador y el hospital o la clínica seleccionada (IPS). Recomendación 3. En los centros de referencia para pacientes con EAP se invita a la creación de equipos que incorporen un grupo fijo de especialistas (obstetras, urólogos, cirujanos generales, radiólogos intervencionistas) encargados de atender todos los casos de EAP. Es recomendable que esos grupos interdisciplinarios utilicen el modelo de "paquete de intervención" como guía para la preparación de los centros de referencia para EAP. Este modelo consta de las siguientes actividades: preparación de los servicios, prevención e identificación de la enfermedad, respuesta ante la presentación de la enfermedad, aprendizaje luego de cada evento. La telemedicina facilita el tratamiento de EAP y debe ser tenida en cuenta por los grupos interdisciplinarios que atienden esta enfermedad. Recomendación 4. Los residentes de Obstetricia deben recibir instrucción en maniobras útiles para la prevención y el tratamiento del sangrado intraoperatorio masivo por placenta previa y EAP, tales como: la compresión manual de la aorta, el torniquete uterino, el empaquetamiento pélvico, el bypass retrovesical y la maniobra de Ward. Los conceptos básicos de diagnóstico y tratamiento de EAP deben incluirse en los programas de especialización en Ginecología y Obstetricia en Colombia. En los centros de referencia del EAP se deben ofrecer programas de entrenamiento a los profesionales interesados en mejorar sus competencias en EAP de manera presencial y virtual. Además, deben ofrecer soporte asistencial remoto (telemedicina) permanente a los demás hospitales en su región, en relación con pacientes con esa enfermedad. Recomendación 5. La finalización de la gestación en pacientes con sospecha de EAP y placenta previa, por imágenes diagnósticas, sin evidencia de sangrado vaginal activo, debe llevarse a cabo entre las semanas 34 y 36 6/7. El tratamiento quirúrgico debe incluir intervenciones secuenciales que pueden variar según las características de la lesión, la situación clínica de la paciente y los recursos disponibles. Las opciones quirúrgicas (histerectomía total y subtotal, manejo quirúrgico conservador en un paso y manejo expectante) deben incluirse en un protocolo conocido por todo el equipo interdisciplinario. En escenarios sin diagnóstico anteparto, es decir, ante un hallazgo intraoperatorio de EAP (evidencia de abultamiento violáceo o neovascularización de la cara anterior del útero), y con participación de personal no entrenado, se plantean tres situaciones: Primera opción: en ausencia de indicación de nacimiento inmediato o sangrado vaginal, se recomienda diferir la cesárea (cerrar la laparotomía antes de incidir el útero) hasta asegurar la disponibilidad de los recursos recomendados para llevar a cabo una cirugía segura. Segunda opción: ante indicación de nacimiento inmediato (por ejemplo, estado fetal no tranquilizador), pero sin sangrado vaginal o indicación de manejo inmediato de EAP, se sugiere realizar manejo en dos tiempos: se realiza la cesárea evitando incidir la placenta, seguida de histerorrafia y cierre de abdomen, hasta asegurar la disponibilidad de los recursos recomendados para llevar a cabo una cirugía segura. Tercera opción: en presencia de sangrado vaginal que hace imposible diferir el manejo definitivo de EAP, es necesario extraer el feto por el fondo del útero, realizar la histerorrafia y reevaluar. En ocasiones, el nacimiento del feto disminuye el flujo placentario y el sangrado vaginal se reduce o desaparece, lo que hace posible diferir el manejo definitivo de EAP. Si el sangrado significativo persiste, es necesario continuar con la histerectomía haciendo uso de los recursos disponibles: compresión manual de la aorta, llamado inmediato a los cirujanos con mejor entrenamiento disponible, soporte de grupos expertos de otros hospitales a través de telemedicina. Si una paciente con factores de riesgo para EAP (por ejemplo, miomectomía o cesárea previa) presenta retención de placenta posterior al parto vaginal, es recomendable confirmar la posibilidad de dicho diagnóstico (por ejemplo, realizando una ecografía) antes de intentar la extracción manual de la placenta. Conclusiones: esperamos que este primer consenso colombiano de EAP sirva como base para discusiones adicionales y trabajos colaborativos que mejoren los resultados clínicos de las mujeres afectadas por esta enfermedad. Evaluar la aplicabilidad y efectividad de las recomendaciones emitidas requerirá investigaciones adicionales.

ABSTRACT Introduction: Placenta accreta spectrum (PAS) is a condition associated with massive postpartum bleeding and maternal mortality. Management guidelines published in high income countries recommend the participation of interdisciplinary teams in hospitals with sufficient resources for performing complex procedures. However, some of the recommendations contained in those guidelines are difficult to implement in low and medium income countries. Objectives: The aim of this consensus is to draft general recommendations for the treatment of PAS in Colombia Materials and Methods: Twenty-three panelists took part in the consensus with their answers to 31 questions related to the treatment of PAS. The panelists were selected based on participation in two surveys designed to determine the resolution capabilities of national and regional hospitals. The modified Delphi methodology was used, introducing two successive discussion rounds. The opinions of the participants, with a consensus of more than 80 %, as well as implementation barriers and facilitators, were taken into consideration in order to issue the recommendations. Results: The consensus drafted five recommendations, integrating the answers of the panelists. Recommendation 1. Primary care institutions must undertake active search of PAS in patients with risk factors: placenta praevia and history of myomectomy or previous cesarean section. In case of ultrasound signs suggesting PAS, patients must be immediately referred, without a minimum gestational age, to hospitals recognized as referral centers. Online communication and care modalities may facilitate the interaction between primary care institutions and referral centers for PAS. The risks and benefits of telemedicine modalities must be weighed. Recommendation 2. Referral hospitals for PAS need to be defined in each region of Colombia, ensuring coverage throughout the national territory. It is advisable to concentrate the flow of patients affected by this condition in a few hospitals with surgical teams specifically trained in PAS, availability of specialized resources, and institutional efforts at improving quality of care with the aim of achieving better health outcomes in pregnant women with this condition. To achieve this goal, participants recommend that healthcare regulatory agencies at a national and regional level should oversee the process of referral for these patients, expediting administrative pathways in those cases in which there is no prior agreement between the insurer and the selected hospital or clinic. Recommendation 3. Referral centers for patients with PAS are urged to build teams consisting of a fixed group of specialists (obstetricians, urologists, general surgeons, interventional radiologists) entrusted with the care of all PAS cases. It is advisable for these interdisciplinary teams to use the "intervention bundle" model as a guidance for building PAS referral centers. This model comprises the following activities: service preparedness, disease prevention and identification, response to the occurrence of the disease, and debriefing after every event. Telemedicine facilitates PAS treatment and should be taken into consideration by interdisciplinary teams caring for this disease. Recommendation 4. Obstetrics residents must be instructed in the performance of maneuvers that are useful for the prevention and treatment of massive intraoperative bleeding due to placenta praevia and PAS, including manual aortic compression, uterine tourniquet, pelvic packing, retrovesical bypass, and Ward maneuver. Specialization Obstetrics and Gynecology programs in Colombia must include the basic concepts of the diagnosis and treatment of PAS. Referral centers for PAS must offer online and in-person training programs for professionals interested in improving their competencies in PAS. Moreover, they must offer permanent remote support (telemedicine) to other hospitals in their region for patients with this condition. Recommendation 5. Patients suspected of having PAS and placenta praevia based on imaging, with no evidence of active vaginal bleeding, must be delivered between weeks 34 and 36 6/7. Surgical treatment must include sequential interventions that may vary depending on the characteristics of the lesion, the clinical condition of the patient and the availability of resources. The surgical options (total and subtotal hysterectomy, one-stage conservative surgical management and watchful waiting) must be included in a protocol known by the entire interdisciplinary team. In situations in which an antepartum diagnosis is lacking, that is to say, in the face of intraoperative finding of PAS (evidence of purple bulging or neovascularization of the anterior aspect of the uterus), and the participation of untrained personnel, three options are considered: Option 1: In the absence of indication of immediate delivery or of vaginal delivery, the recommendation is to postpone the cesarean section (close the laparotomy before incising the uterus) until the recommended resources for safe surgery are secured. Option 2: If there is an indication for immediate delivery (e.g., non-reassuring fetal status) but there is absence of vaginal bleeding or indication for immediate PAS management, a two-stage management is suggested: cesarean section avoiding placental incision, followed by uterine repair and abdominal closure, until the availability of the recommended resources for safe surgery is ascertained. Option 3: In the event of vaginal bleeding that prevents definitive PAS management, the fetus must be delivered through the uterine fundus, followed by uterine repair and reassessment of the situation. Sometimes, fetal delivery diminishes placental flow and vaginal bleeding is reduced or disappears, enabling the possibility to postpone definitive management of PAS. In case of persistent significant bleeding, hysterectomy should be performed, using all available resources: manual aortic compression, immediate call to the surgeons with the best available training, telemedicine support from expert teams in other hospitals. If a patient with risk factors for PAS (e.g., myomectomy or previous cesarean section) has a retained placenta after vaginal delivery, it is advisable to confirm the possibility of such diagnosis (by means of ultrasound, for example) before proceeding to manual extraction of the placenta. Conclusions: It is our hope that this first Colombian consensus on PAS will serve as a basis for additional discussions and collaborations that can result in improved clinical outcomes for women affected by this condition. Additional research will be required in order to evaluate the applicability and effectiveness of these recommendations.

Doppler evaluation of the posterior cerebral artery in normally grown and growth restricted fetuses.

OBJECTIVE: To evaluate Doppler parameters of the two segments of the posterior cerebral artery (PCA) in normally grown and growth restricted (IUGR) fetuses. METHODS: Normal reference values of the pulsatility index (PI), peak systolic velocity, end-diastolic velocity, and time-averaged maximum velocity from the two segments of the PCA (segment one, PCA-S1; segment two, PCA-S2) were constructed in 350 pregnant women from 20 to 40 weeks of gestation. The association of the two PCA segments with the middle cerebral artery (MCA), and with the umbilical artery was evaluated in 50 IUGR fetuses. RESULTS: In normal fetuses, Doppler parameters from PCA-S1 and PCA-S2 showed similar behavior throughout gestation. In IUGR fetuses, the PI of the two PCA segments was significantly reduced with no differences between them. PCA-S2 PI showed a higher correlation with the MCA-PI (r = 0.73) than PCA-S1 PI (r = 0.63; p = 0.001). IUGR fetuses showed vasodilatation in the PCA earlier than in the MCA disregarding the umbilical artery-PI value. CONCLUSION: In IUGR fetuses, the two segments of the PCA show signs of vasodilatation earlier than the MCA. As IUGR fetuses deteriorate, the two segments of the PCA and the MCA behave similarly.

Amniotic band sequence: prenatal diagnosis, phenotype descriptions, and a proposal of a new classification based on morphologic findings.

OBJECTIVE: The aim of this study is to describe the phenotype of fetuses affected by amniotic band sequence (ABS) that were diagnosed at the Instituto Nacional de Perinatología Isidro Espinosa de los Reyes and to propose a new classification based on morphologic findings. MATERIAL AND METHODS: Cases with a final diagnosis of amniotic band sequence, diagnosed between January 1993 and July 2010 in the Department of Maternal Fetal Medicine, were reviewed. Demographic, clinical, and periconceptional data were collected, and the defects were described and classified. The association frequencies of the defects were also determined. RESULTS: We included 50 cases with prenatal diagnosis of amniotic band sequence. The mean maternal age was 25.7 ± 6.9 years. Of these patients, 54% (27/50) were primiparous compared to 22% (11/50) who had three or more previous pregnancies. Craniofacial defects were seen in 78% (39/50) of the cases, followed by defects of the extremities 70% (35/50), abdominal wall, spine, and/or thorax 52% (26/50). The most frequent defects were the following: a) Encephalocele and facial clefts in the craniofacial group. b) Shortening at any level in the limb defects group, and c) Alterations of the spinal column curvature in the group of "other" defects. CONCLUSIONS: The amniotic band sequence shows a tendency to affect women who are in their earlier years of reproduction. We observed an inverse relationship between the number of pregnancies and the frequency of presentation of this pathology. The majority of affected fetuses showed a phenotype that fit into one of many groups. Therefore, we propose classifying the amniotic band sequence phenotypes into the following groups: I. Craniofacial defect + limb defect. II. Craniofacial defect + limb defect + abdominal wall, spinal column, and/or thoracic defects. III. Limb defect + abdominal wall, spinal column, and/or thoracic defects; and IV. Isolated defect (craniofacial, limb, or thoraco-abdominal wall). This classification system will be helpful in diagnosing amniotic band sequence. Based on future research studies, we hope that we can use this classification system as a prognosis fetal factor to establish a more accurate fetal prognosis and recurrence probability. Finally, we created a flowchart describing all of the steps that were followed by our Department from the moment an amniotic band was found by ultrasound until the definitive diagnosis was made and the follow up according to the fetal findings.

Automatic segmentation of the fetal cerebellum on ultrasound volumes, using a 3D statistical shape model.

Previous work has shown that the segmentation of anatomical structures on 3D ultrasound data sets provides an important tool for the assessment of the fetal health. In this work, we present an algorithm based on a 3D statistical shape model to segment the fetal cerebellum on 3D ultrasound volumes. This model is adjusted using an ad hoc objective function which is in turn optimized using the Nelder-Mead simplex algorithm. Our algorithm was tested on ultrasound volumes of the fetal brain taken from 20 pregnant women, between 18 and 24 gestational weeks. An intraclass correlation coefficient of 0.8528 and a mean Dice coefficient of 0.8 between cerebellar volumes measured using manual techniques and the volumes calculated using our algorithm were obtained. As far as we know, this is the first effort to automatically segment fetal intracranial structures on 3D ultrasound data.

Evaluation of conventional Doppler fetal cardiac function parameters: E/A ratios, outflow tracts, and myocardial performance index.

Structural evaluation of the fetal heart is well established. Functional evaluation using pulsed-wave Doppler may also be performed. E/A ratios express the relationship between the maximal velocities of the E and A waveforms of ventricular filling. In normal fetuses, E/A ratios are usually <1 but show a constant increment during gestation, mainly related to the increment of the E wave. In intrauterine growth restriction (IUGR) fetuses, E/A ratios are lower compared to values in normally grown fetuses at the same gestational age. Cardiac outflows provide information on the time-velocity integral that, combined with the vessel area, allows calculation of the left and right cardiac outputs. In normal fetuses there is a predominance of the right ventricle (55-60%) in contributing to the combined cardiac output. In IUGR fetuses this predominance shifts to the left ventricle in order to increase the flow to the upper part of the fetal body and brain. The myocardial performance index (MPI) also provides information on systolic and diastolic cardiac function. The MPI is an early and consistent marker of cardiac dysfunction which becomes altered in early stages of chronic hypoxia or in cases with cardiac overload such as in twin-to-twin transfusion syndrome.

Major craniofacial defects: case series and prenatal diagnosis at the Instituto Nacional de Perinatología, Mexico.

OBJECTIVE: To describe the prenatal diagnosis, characteristics, development, perinatal outcome, and final diagnosis of pregnancies complicated by fetuses with major craniofacial defects, at the Instituto Nacional de Perinatologia, México, 1997-2008. MATERIAL AND METHODS: A retrospective, descriptive study from January of 1997 to January 2008, analyzed 152 pregnancies complicated by fetuses with major craniofacial defects, diagnosed at the Department of Fetal Medicine of the National Institute of Perinatology. Data were obtained from patients clinical records. RESULTS: . The mean age was 28 +/- 8 years, with the largest number of cases between 20 and 24. The mean gestational age at diagnosis was 27.5 +/- 6.4 gestational weeks. The average termination of pregnancy was at 35 +/- 5 gestational weeks. In 43.4% of cases there were no major structural defects associated with the facial defect. The most commonly associated structural alterations were cerebral, cardiac, and limb abnormalities. Karyotyping was performed in only 57 cases, and was abnormal in 25. CONCLUSIONS: Structural ultrasound should be performed on all pregnant women between weeks 18 and 24 for detection of major craniofacial defects. Where defects are found, a thorough review of other structures should be carried out to determine whether the defects are syndromic. A systematic and multidisciplinary approach is essential to providing the best care and appropriate advice to parents.

Automatic segmentation of the cerebellum of fetuses on 3D ultrasound images, using a 3D Point Distribution Model.

Analysis of fetal biometric parameters on ultrasound images is widely performed and it is essential to estimate the gestational age, as well as the fetal growth pattern. The use of three dimensional ultrasound (3D US) is preferred over other tomographic modalities such as CT or MRI, due to its inherent safety and availability. However, the image quality of 3D US is not as good as MRI and therefore there is little work on the automatic segmentation of anatomic structures in 3D US of fetal brains. In this work we present preliminary results of the development of a 3D Point Distribution Model (PDM), for automatic segmentation, of the cerebellum in 3D US of the fetal brain. The model is adjusted to a fetal 3D ultrasound, using a genetic algorithm which optimizes a model fitting function. Preliminary results show that the approach reported is able to automatically segment the cerebellum in 3D ultrasounds of fetal brains.

[Prevalence and complications of monochorionic diamniotic twin pregnancy]. / Prevalencia y complicaciones del embarazo gemelar monocorial biamniótico.

BACKGROUND: Monochorionic biamniotic (MC/BA) twin pregnancies are at higher risk for twin-to-twin transfusion syndrome (TTTS), selective intrauterine growth restriction (sIUGR) and structural defects. MATERIAL AND METHOD: During an 18 months period all MC/BA twins referred to our unit for clinical surveillance were evaluated. Chorionicity was assessed based on the characteristics of the intertwin amniotic membrane. MC complicated cases were labeled either as, TTTS or sIUGR and classified according to severity. All cases were closely evaluated for structural defects. RESULTS: There were 34 MC/BA pregnancies, from them 20 presented TTTS, 6 in a moderate stage of severity, and 14 severely affected. Four cases had sIUGR, all severely affected. Four pregnancies showed a structural defect, 2 cardiac, 1 urological, and 1 open neural tube defect. Six twin MC/BA pregnancies underwent gestation without complications. CONCLUSION: The presence of a MC/BA twin pregnancy warrants close monitoring, including a detailed anatomical review and hemodynamic assessment of the umbilical arteries and ductus venosus of both twins.

Cardiac dysfunction and cell damage across clinical stages of severity in growth-restricted fetuses.

OBJECTIVE: The purpose of this study was to assess cardiac function and cell damage in intrauterine growth-restricted (IUGR) fetuses across clinical Doppler stages of deterioration. STUDY DESIGN: One hundred twenty appropriate-for-gestational-age and 81 IUGR fetuses were classified in stages 1/2/3 according umbilical artery present/absent/reversed end-diastolic blood flow, respectively. Cardiac function was assessed by modified-myocardial performance index, early-to-late diastolic filling ratios, cardiac output, and cord blood B-type natriuretic peptide; myocardial cell damage was assessed by heart fatty acid-binding protein, troponin-I, and high-sensitivity C-reactive protein. RESULTS: Modified-myocardial performance index, blood B-type natriuretic peptide, and early-to-late diastolic filling ratios were increased in a stage-dependent manner in IUGR fetuses, compared with appropriate-for-gestational-age fetuses. Heart fatty acid-binding protein levels were higher in IUGR fetuses at stage 3, compared with control fetuses. Cardiac output, troponin-I, and high-sensitivity C-reactive protein did not increase in IUGR fetuses at any stage. CONCLUSION: IUGR fetuses showed signs of cardiac dysfunction from early stages. Cardiac dysfunction deteriorates further with the progression of fetal compromise, together with the appearance of biochemical signs of cell damage.

[Doppler ultrasound to detect Rh: a systematic review]. / Ultrasonido doppler para detección rh: una revisión sistemática.

BACKGROUND: Red cell alloimmunization is an important cause of perinatal morbidlity and mortality. Invasive procedures used to diagnose fetal anemia are associated with serious fetal and maternal complications. The development of noninvasive techniques as Doppler ultrasound can help us in the fetal anemia diagnosis. OBJECTIVES: To evaluate the effect of the Doppler ultrasound in prediction of fetal anemia caused by red cell alloimmunization. Strategy search: Relevant studies were identified by reviewing the registry of COCHRANE, and OVID, PROQUEST, MEDLINE and EMBASE data bases from 1966 to 2004. SELECTION CRITERIA: All prospective studies with clinically relevant results with comparison of Doppler ultrasound in fetal umbilical artery, fetal descendent aorta, middle cerebral fetal artery or esplecnic fetal artery with hemoglobin or fetal hematocrit. DATA COLLECTION AND ANALYSIS: Data were extracted from each report. The quality revision of the studies and the data compilation were made by the reviewers. MAIN RESULTS: Eighteen articles were included. Two studies reached the level of evidence 1 for diagnostic tests. The diagnostic tests had variations depending on the different cut-off of each study. Studies with level 1 of evidence reported detection of 100% for moderate to severe fetal anemia. CONCLUSIONS: Implementation of Doppler ultrasound for prediction of fetal anemia in complicated pregnancies with alloimmunization could reduce the number of invasive procedures and therefore its complications. The level of present evidence reveals to us that the studies do not fulfill the criteria of methodological quality.