Vasa previa in singleton pregnancies: diagnosis and clinical management based on an international expert consensus.

BACKGROUND: There are limited data to guide the diagnosis and management of vasa previa. Currently, what is known is largely based on case reports or series and cohort studies. OBJECTIVE: This study aimed to systematically collect and classify expert opinions and achieve consensus on the diagnosis and clinical management of vasa previa using focus group discussions and a Delphi technique. STUDY DESIGN: A 4-round focus group discussion and a 3-round Delphi survey of an international panel of experts on vasa previa were conducted. Experts were selected on the basis of their publication record on vasa previa. First, we convened a focus group discussion panel of 20 experts and agreed on which issues were unresolved in the diagnosis and management of vasa previa. A 3-round anonymous electronic survey was then sent to the full expert panel. Survey questions were presented on the diagnosis and management of vasa previa, which the experts were asked to rate on a 5-point Likert scale (from "strongly disagree"=1 to "strongly agree"=5). Consensus was defined as a median score of 5. Following responses to each round, any statements that had median scores of ≤3 were deemed to have had no consensus and were excluded. Statements with a median score of 4 were revised and re-presented to the experts in the next round. Consensus and nonconsensus statements were then aggregated. RESULTS: A total of 68 international experts were invited to participate in the study, of which 57 participated. Experts were from 13 countries on 5 continents and have contributed to >80% of published cohort studies on vasa previa, as well as national and international society guidelines. Completion rates were 84%, 93%, and 91% for the first, second, and third rounds, respectively, and 71% completed all 3 rounds. The panel reached a consensus on 26 statements regarding the diagnosis and key points of management of vasa previa, including the following: (1) although there is no agreement on the distance between the fetal vessels and the cervical internal os to define vasa previa, the definition should not be limited to a 2-cm distance; (2) all pregnancies should be screened for vasa previa with routine examination for placental cord insertion and a color Doppler sweep of the region over the cervix at the second-trimester anatomy scan; (3) when a low-lying placenta or placenta previa is found in the second trimester, a transvaginal ultrasound with Doppler should be performed at approximately 32 weeks to rule out vasa previa; (4) outpatient management of asymptomatic patients without risk factors for preterm birth is reasonable; (5) asymptomatic patients with vasa previa should be delivered by scheduled cesarean delivery between 35 and 37 weeks of gestation; and (6) there was no agreement on routine hospitalization, avoidance of intercourse, or use of 3-dimensional ultrasound for diagnosis of vasa previa. CONCLUSION: Through focus group discussion and a Delphi process, an international expert panel reached consensus on the definition, screening, clinical management, and timing of delivery in vasa previa, which could inform the development of new clinical guidelines.

The significance of hindbrain herniation reversal following prenatal repair of neural tube defects.

OBJECTIVE: The aim of this study was to determine whether reversal of hindbrain herniation (HBH) on MRI following prenatal repair of neural tube defects (NTDs) is associated with reduced rates of ventriculoperitoneal (VP) shunt placement or endoscopic third ventriculostomy (ETV) within the 1st year of life. METHODS: This is a secondary analysis of prospectively collected data from all patients who had prenatal open repair of a fetal NTD at a single tertiary care center between 2012 and 2020. Patients were offered surgery according to inclusion criteria from the Management of Myelomeningocele Study (MOMS). Patients were excluded if they were lost to follow-up, did not undergo postnatal MRI, or underwent postnatal MRI without a report assessing hindbrain status. Patients with HBH reversal were compared with those without HBH reversal. The primary outcome assessed was surgical CSF diversion (i.e., VP shunt or ETV) within the first 12 months of life. Secondary outcomes included CSF leakage, repair dehiscence, CSF diversion prior to discharge from the neonatal intensive care unit (NICU), and composite neonatal morbidity. Demographic, prenatal sonographic, and operative characteristics as well as outcomes were assessed using standard univariate statistical methods. Multivariate logistic regression models were fit to assess for independent contributions to the primary and secondary outcomes. RESULTS: Following exclusions, 78 patients were available for analysis. Of these patients, 38 (48.7%) had HBH reversal and 40 (51.3%) had persistent HBH on postnatal MRI. Baseline demographic and preoperative ultrasound characteristics were similar between groups. The primary outcome of CSF diversion within the 1st year of life was similar between the two groups (42.1% vs 57.5%, p = 0.17). All secondary outcomes were also similar between groups. Patients who had occurrence of the primary outcome had greater presurgical lateral ventricle width than those who did not (16.1 vs 12.1 mm, p = 0.02) when HBH was reversed, but not when HBH was persistent (12.5 vs 10.7 mm, p = 0.49). In multivariate analysis, presurgical lateral ventricle width was associated with increased rates of CSF diversion before 12 months of life (adjusted OR 1.18, 95% CI 1.03-1.35) and CSF diversion prior to NICU discharge (adjusted OR 1.18, 95% CI 1.02-1.37). CONCLUSIONS: HBH reversal was not associated with decreased rates of CSF diversion in this cohort. Predictive accuracy of the anticipated benefits of prenatal NTD repair may not be augmented by the observation of HBH reversal on MRI.

Risk Factors and Outcomes Following Septostomy during Fetoscopic Surgery for Twin-to-Twin Transfusion Syndrome.

Fetoscopic laser photocoagulation (FLP) of placental anastomoses is the preferred treatment for twin-to-twin transfusion syndrome (TTTS). Iatrogenic septostomy (IOS) during FLP is associated with increased risk of neonatal morbidity and mortality. We sought to identify risk factors for IOS and quantify the resultant outcomes. This is a secondary analysis of prospectively collected cases of TTTS in monochorionic diamniotic twins following FLP at a single center. Pre-operative ultrasound characteristics and operative technique (i.e., cannula size, total energy used) were compared between cases with vs. without IOS. Pregnancy and neonatal outcomes were also compared. Of 475 patients that had FLP, 33 (7%) were complicated by IOS. There was no association between operative technique and IOS. IOS was more common with later diagnosis, but less likely when selective fetal growth restriction (sFGR) was present. Survival was similar between groups (76% vs. 76% dual survivors, p = 0.95); however, IOS was associated with earlier delivery (29.7 vs. 32.0 wks, p < 0.01) and greater composite neonatal morbidity (25% vs. 8% in both twins, p = 0.02). Risks of IOS at greater gestational ages without sFGR may be related to a larger collapsed intervening membrane area and the resulting increased risk of puncture on entry.

Fortnightly surveillance of monochorionic diamniotic twins for twin to twin transfusion syndrome: Compliance and effectiveness.

OBJECTIVES: To determine the compliance and effectiveness of fortnightly ultrasound surveillance for detection of twin-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twin gestations. METHODS: This is a retrospective study of ultrasound surveillance of MCDA twins for TTTS. Our surveillance protocol requires fortnightly ultrasounds starting at 16 weeks of gestational age (GA) continuing until delivery. Compliance was assessed by determining the GA of surveillance initiation and time between ultrasounds. GA and Quintero Stage at diagnosis were evaluated to determine whether TTTS was detected prior to advanced disease (Quintero Stage III +) or fetal demise. RESULTS: Of 442 women, 264 (59.7%) initiated surveillance after 16 weeks; follow-up ultrasounds were late in 17.4% of cases. TTTS was diagnosed in 43 (9.7%) women at a median GA of 19.7 [17.4, 23.9] weeks. Of 25/43 (58.1%) cases diagnosed during protocol compliance, 12 had advanced disease and two had fetal demise. A similar proportion of diagnoses (n = 18), made while non-compliant, exhibited advanced disease (11/18, 61.1%, P = .40). Thirteen diagnoses occurred during periods of increased ultrasound frequency due to abnormalities (ie, fluid/estimated fetal weight discrepancies or Doppler abnormalities). CONCLUSIONS: In this population, fortnightly ultrasound compliance was suboptimal. Advanced disease and fetal demise occurred during protocol compliance.

Utilidad de los marcadores ultrasonográficos de cromosomopatía / Usefulness of ultrasonographic markers of chromosomopathy

Durante un periodo de tres años y medio, en 132 mujeres embarazadas se diagnosticó la presencia de una amplia variedad de anomalías morfológicas fetales, sugestivas de cromosomopatía, utilizando un equipo de ultrasonido de alta definición y la participación multidisciplinaria. En 95 casos se realizó amniocentesis para estudio del cariotipo fetal. En esta población se determinó la incidencia de cromosomopatía, su contribución al total de las alteraciones cromosómicas diagnosticadas en el periodo de estudio y la expresión fenotípica de las diferentes aneuploidías. Se encontraron 29 cariotipos fetales anormales; 11 con tisomía 18, siete con monosomía del X, cuatro trisomía 21, tres con trisomía 13, uno tetraploidía (29xxyy), uno con mosaico para Turner (45XO 68 por ciento, 46XY 32 por ciento) y dos con inversión en el cromosoma nueve. Del total de las cromosomopatías diagnosticadas en el mismo periodo (N=50), el grupo con anomalías morfológicas representó 49.2 por ciento, mientras que las otras poblaciones de riesgo, de cinco a 15 por ciento. Se diagnosticaron 224 anormalías morfológicas, 43 (19 por ciento) aisladas y 181 (81 por ciento) asociadas. Un número de 80 (36 por ciento) se presentaron en las cromosomopatías. Los marcadores que tuvieron mayor asociación fueron la atresia duodenal, la cardiopatía, la microcefalia, la fosa posterior amplia y el higroma quístico. Se encontró un patrón de marcadores específicos para cada alteración cromosómica. Se concluyó que el ultrasonido puede ser el método más útil para seleccionar el grupo de embarazadas con mayor riesgo de cariotipo anormal