Workshop for Basic Gynaecological Examinations: Improving Medical Student Learning through Clinical Simulation.

INTRODUCTION: This study was designed to evaluate whether the Workshop on Basic Principles for Clinical Gynaecological Exploration, offered to medical students, improves theoretical-practical knowledge, safety, confidence, global satisfaction and the achievement of the proposed objectives in the area of gynaecological clinical examinations. MATERIALS AND METHODS: This was a quasi-experimental pre-post-learning study carried out at the Gynaecology and Obstetrics department of Gregorio Marañón Hospital in Madrid (Spain). The volunteer participants were 4th-year students earning a degree in Medicine during the 2020-2021 and 2021-2022 academic years. The study period was divided into the following stages: pre-workshop, intra-workshop and 2 weeks post-workshop. In the pre-workshop stage, students completed a brief online course to prepare for the workshop. The effectiveness of the workshop was evaluated through multiple-choice tests and self-administered questionnaires to assess self-assurance, self-confidence, self-satisfaction and the achievement of the objectives. RESULTS: Of the 277 students invited in both academic years, 256 attended the workshop (92.4%), with a total participation in the different stages of the study greater than 70%. A total of 82.5% of the students in the 2020-2021 academic year and 80.6% of students in the 2021-2022 academic year did not have any type of experience performing gynaecological clinical examinations. Between the pre-workshop and 2 weeks post-workshop stages, there was significant improvement in theoretical-practical knowledge (improvement mean = 1.38 and 1.21 in 2020-2021 and 2021-2022 academic years, respectively). The security and confidence of the students prior to the workshop were low (average scores less than 5 points) in both academic years. However, post-workshop scores for satisfaction and the achievement of objectives were high in the two academic years; all the values approached or exceeded 8 points. CONCLUSIONS: Our students, after outstanding participation, evaluated the BPCGE, and improved their theoretical and practical knowledge, as well as their skills in a gynaecological clinical examination. Moreover, in their view, after the workshop, they felt very satisfied, far outreaching the proposed aims. In addition, excellent results were maintained over time, year after year.

Meconium-stained amniotic fluid.

Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.

Atosiban versus ritodrine as tocolytics in external cephalic version.

OBJECTIVE: To assess the efficacy of atosiban versus ritodrine as tocolytics in external cephalic version (ECV). MATERIALS AND METHODS: A prospective comparative trial was carried out in a tertiary hospital. 430 women with singleton breech pregnancies ≥36 weeks were recruited for ECV, 215 with ritodrine and 215 with atosiban as tocolytic agents. The efficacy, complications and perinatal outcomes were compared between both groups. The associations between variables were analyzed using the chi-square test (χ2) (qualitative), Student's t test (quantitative, parametric) or Mann-Whitney test (nonparametric). Statistical significance was established as p < .05. RESULTS: The overall ECV success rate was 47.9% (206/430), 46.0% in the atosiban group (99/215) and 49.8% in the ritodrine group (107/215). This difference showed no statistical significance (p = .440). A higher rate of uterine contractions after the maneuver was observed in the atosiban group (34.4 versus 22.8%; p = .008), but without clinical relevance. Perinatal outcomes were similar in both groups, with no significant differences. CONCLUSION: Atosiban and ritodrine showed similar efficacy as tocolytic agents in ECV, with no differences in complications and perinatal outcomes between these two agents.

Permeability of the amniotic membranes to the natural vanilla molecule.

Purpose: We studied natural vanilla permeability through amniotic membranes.Methods: We studied natural vanilla permeability through amniotic membranes obtained from 45 spontaneous normal deliveries at term. The ferric chloride test (FeCL3) was used to determine the presence or absence of phenols in a given sample. Vanilla is a polyphenol so it gives a reaction to FeCL3 with an intense color change. The diffusion of the vanilla was checked by dropping ferric chloride solution on the gauze once the membranes are lifted with care to avoid contamination. If vanilla has passed through the membranes the distilled water papers would change from an initial ferric yellow in the drops toward a marked gray/greenish color on the papers (positive test).Results: In all cases, the swabs were stained, all the membranes in both directions were permeable to the whole vanilla molecule.Conclusions: This experiment allows us to reevaluate the importance of molecular diffusion through the amniotic membranes with no placental metabolism existing between maternal and fetal environment.

Intrapartum and perinatal results associated with different degrees of staining of meconium stained amniotic fluid.

OBJECTIVE: To determine the intrapartum and perinatal results associated with different degrees of staining of meconium stained amniotic fluid (MSAF). STUDY DESIGN: In a retrospective cohort study of all singleton deliveries over a period of one year (2015) in a tertiary hospital, we compared different degrees of MSAF (yellow, green and thick) to clear amniotic fluids, and analysed in each group maternal, intrapartum and neonatal variables as well as umbilical cord blood gas analysis. RESULTS: Of the 3590 deliveries included, 503 (14%) had MSAF. The incidence of MSAF rises with gestational age at delivery, reaching 20.7% in gestations above 41 weeks compared to 4.3% below 37 weeks. As the amniotic fluid staining progresses we found a higher proportion of intrapartum fevers (p < 0.001), pathological fetal heart rate patterns (p < 0.05), operative vaginal deliveries and cesarean sections (p < 0.001), as well as the need for advanced neonatal resuscitation (p < 0.001). There was also a correlation between MSAF and low Apgar scores at five minutes (p < 0.001) and fetal-neonatal mortality (p < 0.001) but there was not a higher proportion of neonatal intensive care admissions (p > 0.05). We have observed a similar distribution of umbilical artery pH ranges in all groups (p > 0.05). CONCLUSIONS: MSAF was associated with an increase in the rate of pathological fetal heart rate patterns, intrapartum fevers, operative vaginal and cesarean section deliveries, need for neonatal resuscitation, low Apgar scores and higher fetal-neonatal mortality. Moreover, we found that the risks increase as the staining and consistency of the amniotic fluid evolves so it should alert the obstetrician and paediatrician to the potential adverse outcomes.

Intrapartum and perinatal results associated with different degrees of staining of meconium stained amniotic fluid.

OBJECTIVE: To determine the intrapartum and perinatal results associated with different degrees of staining of meconium stained amniotic fluid (MSAF). STUDY DESIGN: In a retrospective cohort study of all singleton deliveries over a period of one year (2015) in a tertiary hospital, we compared different degrees of MSAF (yellow, green and thick) to clear amniotic fluids, and analysed in each group maternal, intrapartum and neonatal variables as well as umbilical cord blood gas analysis. RESULTS: Of the 3590 deliveries included, 503 (14%) had MSAF. The incidence of MSAF rises with gestational age at delivery, reaching 20.7% in gestations above 41 weeks compared to 4.3% below 37 weeks. As the amniotic fluid staining progresses we found a higher proportion of intrapartum fevers (p < 0.001), pathological fetal heart rate patterns (p < 0.05), operative vaginal deliveries and cesarean sections (p < 0.001), as well as the need for advanced neonatal resuscitation (p < 0.001). There was also a correlation between MSAF and low Apgar scores at five minutes (p < 0.001) and fetal-neonatal mortality (p < 0.001) but there was not a higher proportion of neonatal intensive care admissions (p > 0.05). We have observed a similar distribution of umbilical artery pH ranges in all groups (p > 0.05). CONCLUSIONS: MSAF was associated with an increase in the rate of pathological fetal heart rate patterns, intrapartum fevers, operative vaginal and cesarean section deliveries, need for neonatal resuscitation, low Apgar scores and higher fetal-neonatal mortality. Moreover, we found that the risks increase as the staining and consistency of the amniotic fluid evolves so it should alert the obstetrician and paediatrician to the potential adverse outcomes.

Diagnosis of a defect in the uterine wall using 3D ultrasound in the 16th week of gestation.

The 3D volumetric transabdominal study with rendering mode is a very useful tool to perform a detailed study of the uterine wall, and it allows us to create a safe and early strategy during pregnancy in uterine dehiscences, as we show in this case in the 16th week of gestation.

Manejo de la hiponatremia asociada a trastornos hipertensivos del embarazo / Management of hyponatremia associated with hypertensive disorders of pregnancy

La hiponatremia severa es una complicación poco frecuente de los trastornos hipertensivos en la gestación. Actualmente existen pocos casos publicados en la literatura, sin embargo resulta fundamental tener en cuenta este trastorno ante una paciente con preeclampsia. Presentamos dos casos de hiponatremia asociada a trastornos hipertensivos en pacientes gestantes, en los que la clínica y la analítica mejoraron rápidamente tras realizar el diagnóstico e iniciar un tratamiento adecuado, con remisión completa tras el parto (AU)

Severe hyponatremia is a rare complication of hypertensive disorders in pregnancy. Few cases have been reported in the literature. However, it is important to consider this disorder in patients with preeclampsia. We present two cases of hyponatremia associated with hypertensive disorders in pregnant women. Rapid clinical and analytical improvement was observed after diagnosis and appropriate treatment with complete remission following delivery (AU)

Accurate Diagnosis of Severe Hypospadias Using 2D and 3D Ultrasounds.

The hypospadias is the most common urogenital anomaly of male neonates but the prenatal diagnosis of this is often missed before birth. We present the prenatal diagnosis of a severe penoscrotal hypospadias using 2D and 3D ultrasounds. 3D sonography allowed us the best evaluation of the genitals and their anatomical relations. This ample detailed study allowed us to show the findings to the parents and the pediatric surgeon and to configure the best information about the prognosis and surgical treatment.

Resultados perinatales y manejo de las pacientes con seroconversión para toxoplasma durante la gestación / Perinatal outcomes and management of patients with seroconversion to toxoplasma during gestation

Objetivo: conocer los resultados perinatales obtenidos en las pacientes con seroconversión para toxoplasma durante la gestación. Material y Métodos: estudio retrospectivo descriptivo de las gestaciones con seroconversión para toxoplasma durante el embarazo, entre los años 2004 y 2012. Las variables estudiadas hicieron referencia a las características gestacionales, serológicas y perinatales. El tratamiento de los datos se realizó con el programa estadístico SPSS versión 18 paraWindows. Resultados: la población a estudio englobó un total de 139 gestantes, de las cuales un 85% presentó la seroconversión para toxoplasma en el primer trimestre, el 11% en el segundo y el 4% restante en el tercer trimestre.Se realizó un análisis en tres grupos según el resultado de la avidez de la inmunoglobina G: débil (32%), intermedia (17%) y fuerte (50%). Sólo se registró un caso de toxoplasmosis neonatal, correspondiente al grupo de avidez débil, donde el recién nacido presenta actualmente una pérdida auditiva de tipo conductivo de 20 dB en el oído izquierdo y de 10 dB en el oído derecho. Conclusión: los resultados perinatales no son peores en las pacientes con seroconversión para toxoplasma durante la gestación. La tasa de transmisión vertical en nuestro centro fue baja (AU)

Objective: To determine the perinatal results obtained in patients with toxoplasma seroconversion during pregnancy. Material and Methods: Retrospective descriptive of pregnancies with toxoplasma seroconversion during pregnancy, between 2004 and 2012. Studied variables referred to gestational characteristics, serological and perinatal. The data processing was performed using SPSS version 18 for Windows. Results: The study population encompassed a total of 139 pregnant women, of which 85% had seroconversion for toxoplasma in the first quarter, 11% in the second and the remaining 4% in the third quarter. Analysis wasperformed in three groups according to the result of the inmunoglobulin G: weak (32%), intermediate (17%) and strong (50%). Only one case of neonatal toxoplasmosis, corresponding to the avidity weak group, where currently newborn.This Conductive hearing loss of 20 dB in the left ear and 10 dB in the right ear. Conclusion: Perinatal outcomes were not worse in patients with toxoplasma seroconversion during gestation. The vertical transmission rate at our center was low (AU)

In utero gratification behaviour in male fetus.

Fetal masturbation has been described previously once in utero but only as a description of an action. Masturbation is well described in infancy and early childhood when they discover that this practice can give them pleasure. Our letter proves that it could begin in utero as a 'gratification behaviour'. We have shown this pattern clearly by using a volumetric rendering mode study. © 2016 John Wiley & Sons, Ltd.

Resultados perinatales asociados a las gestantes infectadas por el virus de la inmunodeficiencia humana en el Complejo Hospitalario Universitario de Vigo / Perinatal outcomes in HIV-positive pregnant women in the Complejo Hospitalario Universitario de Vigo

Introducción: la infección por el virus de la imnunodeficiencia humana (VIH) tiene gran repercusión sobre la reproducción desde el momento de la concepción, por el riesgo de la transmisión sexual, hasta la posible infección del recién nacido. Por ello, es primordial combatir la transmisión vertical durante el embarazo en toda mujer gestante infectada por este virus. Objetivo: conocer la tasa de transmisión vertical, así como estudiar los resultados perinatales asociados a las gestantes infectadas por el VIH en el Complejo Hospitalario Universitario de Vigo. Material y métodos: se realizó un estudio descriptivo retrospectivo de la población gestante afectada por el VIH desde enero de 2000 hasta enero de 2014. Definimos para el estudio variables maternas, gestacionales, intraparto y neonatales. El tratamiento estadístico de los datos fue realizado con el programa SPSS20 para Windows. Resultados: la población estudiada fue de 100 gestantes seropositivas. El 50% presentó coinfección por el virus de la hepatitis C (VHC) y el 9% por el virus de la hepatitis B (VHB). El 98% de las pacientes recibió tratamiento antirretroviral durante el embarazo, el 97% profilaxis intraparto con zidovudina y el 98% de recién nacidos tratamiento antirretroviral desde el nacimiento. El 45% de los casos cumplió criterios para un parto vaginal. Finalmente, el 28% fueron partos eutócicos y el 4%, instrumentados; en el 13% restante se indicó cesárea urgente intraparto. La transmisión materno-fetal fue del 0%. Conclusión: protocolizar el manejo gestacional y neonatal en las pacientes seropositivas frente al VIH ha permitido obtener un importante descenso en su tasa de transmisión vertical (AU)

Introduction: Human Immunodeficiency Virus (HIV) infection has a major impact on reproduction that includes the risk of sexual transmission at conception and even possible infection of the newborn. Consequently, it is essential to combat vertical transmission during pregnancy in all HIV-infected pregnant women. Objective: The objective of this study was to determine the rate of vertical transmission and perinatal outcomes in HIV-infected pregnant women attended at the University Hospital of Vigo. Material and methods: A retrospective descriptive study was conducted in HIV- pregnant women from January 2000 to January 2014. Maternal, gestational, intrapartum and neonatal variables were defined for the study. The statistical analysis of the data was carried out with SPSS version 20 for Windows. Results: The study population consisted of 100 HIV-seropositive pregnant women. Fifty percent were coinfected with the hepatitis C virus (HCV) and 9% with the hepatitis B virus (HBV). Most (98%) of patients received antiretroviral therapy during pregnancy, 97% received intrapartum prophylaxis with zidovudine and 98% of newborns received antiretroviral treatment from birth. Forty-five percent of the patients met the criteria for vaginal delivery. Delivery was normal in 28% and instrumental in 4%, while intrapartum emergency caesarian section was required in the remaining 13%. Maternal-fetal transmission was 0%. Conclusion: Protocolizing gestational and neonatal management in HIV-seropositive patients significantly decreased the rate of vertical transmission (AU)

¿Por qué no se vacunan nuestras pacientes?: motivos por los que las pacientes fuera de los programas de vacunación sistemática, con infección por el virus del Papiloma Humano, deciden decir no a la vacuna / Reasons for non-vaccination in women outside the routine immunization programs

Objetivo: Conocer los motivos de la no vacunación en mujeres fuera de los programas de vacunación sistemática. Metodología: Se evaluaron mediante cuestionario 226 mujeres con infección por VPH. A todas ellas se les había informado de su patología, del VPH y de la vacuna y se les había recomendado el uso del preservativo previamente. Resultados: El 66,7 por ciento tenían pareja estable; 75 por ciento utilizaban preservativo. La edad de inicio de relaciones sexuales fue 17,8 años y el 47,3 por ciento de las pacientes habían tenido 5 ó más parejas a lo largo de su vida. El 72 por ciento conocía su infección por VPH y el 48,8 por ciento su lesión. El 63,7 por ciento no se vacunó: principalmente rechazaron la vacuna por el precio (49,5 por ciento), información insuficiente (18,7 por ciento) u otras causas como la disparidad de opiniones entre los médicos que la atendieron (15 por ciento). Conclusiones: El coste de la vacuna y el conocimiento sobre el VPH son determinantes para la aceptación de la vacunación.

Objective: The aim of the study was to determine the reasons for non-vaccination in women outside the routine immunization programs. Method: There were evaluated by questionnaire 226 women with HPV infection. All of them had been informed of their disease and type of HPV infected by. We all had recommended the vaccine and the condom use previously. Results: 66.7 percent had a steady partner, 75 percent used condoms. The age of first sexual relationship was 17.8 years old and 47.3 percent of patients had 5 or more partners during their lifetime. 72 percent knew their HPV infection and 48.8 percent knew their injury. 63.7 percent were not vaccinated: they rejected the vaccine mainly for the price (49.5 percent), insufficient information (18.7 percent) or other causes such as primary care opposite point of view (15 percent). Conclusions: The prize of the vaccine and the HPV knowledge are crucial to the acceptance of vaccination.

Trombosis venosa cerebral recurrente en el embarazo / Recurrent cerebral venous thrombosis in pregnancy

La trombosis venosa cerebral es una enfermedad poco frecuente, pero de pronóstico potencialmente grave. Debido a los cambios hemostáticos durante la gestación, es una patología que puede asociarse al embarazo. Presenta un amplio rango de signos y síntomas. El diagnóstico y tratamiento precoz mejoran el pronóstico. Presentamos el caso de una mujer de 30 años, que en la semana 8 de gestación acude a Urgencias por cefalea intensa y cuya resonancia magnética reveló una trombosis venosa cerebral. La paciente presentó un segundo episodio en la semana 33, a pesar del correcto tratamiento anticoagulante recibido.

Cerebral venous thrombosis is a rare disease, but with a potentially serious prognosis. It is a condition that can be associated with pregnancy because of the hemostatic changes during gestation. It has a wide range of signs and symptoms. Early diagnosis and treatment improve prognosis. We report the case of a 30-year-old woman, at week 8 of pregnancy, who came to the emergency department for severe headache and whose magnetic resonance imaging revealed a cerebral venous thrombosis. The patient had a second episode at week 33, despite correct anticoagulation received.

Secuencia TRAP. Diagnóstico diferencial con gemelo muerto / Twin reverse arterial perfusion (TRAP) sequence. Differential diagnosis with intrauterine demise of one twin

La secuencia TRAP (twin reverse arterial perfusion) está presente en el 1% de las gestaciones gemelares monocoriales. Presentamos un caso de secuencia TRAP poco convencional en el que el gemelo acardias está bien formado, identificándose en él estructuras craneales y cardiacas. El diagnóstico diferencial entre fenómeno TRAP y gemelo muerto intraútero se hizo a partir de otros signos ecográficos de sospecha, como la presencia de una arteria umbilical única, un higroma dorsal y el cordón corto. El diagnóstico de certeza se consiguió mediante Doppler, que demostró la presencia de la anastomosis arterio-arterial y el flujo reverso en el gemelo «muerto». Consideramos que la existencia de un fenómeno TRAP debe tenerse en cuenta ante el diagnóstico ecográfico de gestación monocorial con muerte de uno de los gemelos. El pronóstico y manejo de la gestación va a diferir en ambos casos. La presencia de estructuras craneales y corazón no excluye el diagnóstico de TRAP (AU)

TRAP sequence occurs in 1% of monochorionic twin pregnancies. We present an atypical case of TRAP sequence in which the acardiac twin was properly formed and the cranial and cardiac structures could be identified. The differential diagnosis between TRAP phenomenon and intrauterine death of one twin was performed on the basis of other suspicious ultrasound signs, such as the presence of a single umbilical artery, a dorsal hygroma, and a short cord. The definitive diagnosis was established by Doppler, which showed an arterio-arterial anastomosis and reverse flow in the dead twin. We believe that the presence of a TRAP phenomenon should be taken into account in cases of ultrasound diagnosis of a monochorionic pregnancy with intrauterine demise of one twin. The finding of cranial structures and heart does not exclude a diagnosis of TRAP (AU)

Estudio ecográfico 2D y 3D del segmento inferior en gestante con cesárea anterior / Ultrasonographic study of the inferior uterine segment in a pregnant woman with previous cesarean section

La rotura uterina es una complicación potencial y grave en el intento de parto vaginal en mujeres con una cesárea anterior. El adelgazamiento del segmento inferior es la clave. Existe una correlación inversa entre el grosor del segmento y el riesgo de dehiscencia de la cicatriz. Presentamos el caso de una gestante en la que se detectó en la semana 24 una disminución del grosor de la cicatriz de 2mm. Se realizó un seguimiento con ecografía 2D y estudios complementarios 3D/4D. El grosor del segmento se mantuvo estable hasta la semana 34, cuando se apreció un adelgazamiento de hasta 0,7mm en la zona más debilitada. Se realizó una cesárea programada. La exploración mediante proyecciones 3D con volúmenes de alta resolución permite analizar la situación real del segmento. La medición ecográfica del segmento durante la exploración del tercer trimestre puede ayudar a identificar las gestantes con cesárea anterior y riesgo de rotura uterina (AU)

Uterine rupture is a potential and serious complication of any attempt at vaginal delivery in women with a previous cesarean section. The key is narrowing of the inferior uterine segment. There is an inverse correlation between the thickness of the segment and the risk of scar dehiscence. We present the case of a pregnant woman in whom a 2mm decrease in scar thickness was observed at week 24 of pregnancy. The patient was monitored with 2D ultrasound and supplementary 3D/4D studies. The thickness of the segment remained stable until week 34, when narrowing of up to 0.7mm was observed in the weakest area. An elective caesarean section was performed. Examination through 3D views with high resolution volumes allows accurate evaluation of the status of the segment. Ultrasonographic measurement of the inferior segment during the third trimester can help to identify pregnant women with a previous cesarean section and risk of uterine rupture (AU)

Ultrasound-guided transcervical evacuation of interstitial twin pregnancy.

OBJECTIVE: To report the transcervical and transisthmic evacuation of a dichorionic interstitial twin pregnancy guided by ultrasound. DESIGN: Case study. SETTING: Fetal medicine unit of university hospital. PATIENT(S): Dichorionic twin fetuses. INTERVENTION(S): Three-dimensional/four-dimensional (3D/4D) ultrasound-guided transcervical and transisthmic evacuation under direct laparoscopic supervision. MAIN OUTCOME MEASURE(S): Maternal clinical outcome. RESULT(S): A dichorionic interstitial twin pregnancy was successfully evacuated without complications. CONCLUSION(S): The safety and effectiveness of ultrasound-guided transcervical and transisthmic evacuation of dichorionic interstitial twin pregnancy warrants further evaluation.