Vasa previa: A condition with diverse management approaches.

Vasa previa is a rarely reported condition in which the fetal blood vessels, unsupported by either the umbilical cord or placental tissue, traverse the fetal membranes of the lower segment of the uterus below the presenting part. The condition has a high fetal mortality due to fetal exsanguination resulting from fetal vessels tearing when the membranes rupture. Despite improvements in medical technology, vasa previa often remains unsuspected until this fatal fetal vessel rupture occurs. Significant reduction in the fetal mortality from this condition depends on a high index of suspicion leading to antenatal diagnosis, and elective delivery by cesarean. We believe transvaginal ultrasound in combination with color Doppler is the most effective tool in the antenatal diagnosis of vasa previa and should be utilized in patients at risk, specifically those with bilobed, succenturiate-lobed, and low-lying placentas, pregnancies resulting from in vitro fertilization, and multiple pregnancy. Where there has been antepartum or intrapartum hemorrhage, especially when associated with fetal heart irregularities, we also recommend a test to exclude fetal blood in the vaginal blood. Similarly, amnioscopy before amniotomy may help to diagnose this condition. Cesarean delivery is the method of delivery of choice, and aggressive resuscitation of the affected neonate may be life saving. With a high index of suspicion, antenatal diagnosis using transvaginal sonography in combination with color Doppler, elective delivery by cesarean, and aggressive resuscitation of the neonate where fetal vessel rupture has occurred, the mortality from this complication may be considerably reduced. Obstetricians & Gynecologists, Family Physicians. After completion of this article, the reader will be able to identify the risk factors and associated conditions for vasa previa, to identify the various clinical presentations and management of vasa previa, and to be aware of the diagnostic tools available to make the antepartum diagnosis of vasa previa.

Vasa previa is a condition where unprotected fetal vessels cross the cervix within the membranes, posing a considerable risk of fetal death or severe morbidity if the membranes rupture before or during delivery. There has not been a definitive in utero treatment for this condition. Patients are typically closely monitored and hospitalized in the early third trimester and scheduled for cesarean delivery before term. This approach poses considerable physical, social, psychological, and financial challenges for pregnant patients and their families. Furthermore, fetal vessel rupture may lead to severe hypoxic-ischemic injury and consequent neurodevelopmental impairment. Finally, babies delivered early due to vasa previa may face both the short- and long-term consequences of prematurity. Recently, fetoscopic laser photocoagulation using a single-port fetoscope has emerged as a potential therapeutic option for patients with types II and III vasa previa. This innovative approach aims to reduce hospital stays, increases the chance of successful vaginal delivery, and potentially allows pregnancies to reach full term, providing lifelong benefits for the infant. Preliminary clinical studies on human subjects have demonstrated promising results concerning the feasibility, safety, and efficacy of this intervention for a subset of patients with types II and III vasa previa. After reviewing the current state of the art, we argued that offering fetoscopic laser photocoagulation in specialized centers under IRB supervision meets the ethical obligations of beneficence and non-maleficence for both pregnant and fetal patients, as well as the autonomy-based obligations for pregnant patients.

(Am J Obstet Gynecol 2015;213(5):615–619) Vasa previa is a condition that occurs in approximately 1 per 2500 deliveries when fetal blood vessels that are unprotected by the umbilical cord or placenta run through the amniotic membranes and pass across the cervix. Rupture of membranes causes these vessels to rupture, resulting in fetal hemorrhage, exsanguination, fetal asphyxia, or even death. Type I vasa previa occurs when a velamentous cord insertion between the umbilical cord and placenta is present, and fetal vessels that run freely within the amniotic membranes overlie the cervix. Type II vasa previa occurs when the placenta has a succenturiate lobe or is multilobed, and fetal vessels that connect the 2 placental lobes pass over or are near the cervix.

The aim of this study was to review fetoscopic laser photocoagulation (FLP), which ablates placental vascular anastomoses to treat twin–twin transfusion syndrome (TTTS). A review of studies reporting on the procedures, outcomes, complications and nonconventional applications of FLP for TTTS was conducted. FLP has been established as the primary treatment for monochorionic twin pregnancy associated with TTTS at 16–26 weeks. FLP is the only therapy that directly addresses the underlying pathophysiology. The recent technique modification of FLP, referred to as the ‘Solomon technique’, induces selective coagulation to connect the anastomoses ablation sites and has been introduced to reduce residual anastomoses. The perinatal survival following FLP improved significantly with advances in the technique after its introduction. The recent survival rates of both twins and at least one twin are 70% and more than 90%, respectively. However, there is still an 11–14% risk of long‐term neurodevelopment impairment. The premature rupture of membranes that leads to preterm labor is a common complication after FLP. FLP is a valuable treatment option for feto‐fetal transfusion syndrome in triplets and for TTTS after 26 weeks. FLP for selective intrauterine growth restriction may be potentially beneficial when accompanied by abnormal Doppler findings and oligohydramnios. FLP is the optimal treatment option for TTTS at 16–26 weeks of gestation. FLP appears to be applicable in triplets, TTTS after 26 weeks and cases of selective intrauterine growth restriction with abnormal Doppler findings and oligohydramnios. FLP is the most common and successful fetal intervention. Improvement in the neurodevelopmental outcomes after FLP is a future focus.

Purpose: The aim of this study was to evaluate the effect of gestational age (GA) at the time of fetoscopic laser photocoagulation (FLP) for severe twin–twin transfusion syndrome (TTTS) on perinatal outcomes in a single center in Taiwan. Materials and methods: Severe TTTS was defined as a diagnosis of TTTS before a GA of 26 weeks. Consecutive cases of severe TTTS treated at our hospital with FLP between October 2005 and September 2022 were included. The evaluated perinatal outcomes were preterm premature rupture of membranes (PPROM) within 21 days of FLP, survival 28 days after delivery, GA at delivery, and neonatal brain sonographic imaging findings within 1 month of delivery. Results: We included 197 severe TTTS cases; the mean GA at the time of FLP was 20.6 weeks. After the cases were divided into cases of FLP at early (below 20 weeks) and late GAs (more than 20 weeks), the early-GA group was discovered to be associated with a deeper maximum vertical pocket in the recipient twin, a higher rate of PPROM development within 21 days of FLP, and lower rates of survival of one or both twins. In the cases of stage I TTTS, the rate of PPROM within 21 days of FLP was higher in the group that underwent FLP at an early GA than in the group that underwent FLP at a late GA (50% (3/6) vs. 0% (0/24), respectively, p = 0.005). Logistic regression analysis revealed that the GA at the time of FLP and the cervical length before FLP is implemented are significantly associated with the survival of one twin and the incidence of PPROM development within 21 days of FLP. The GA at the time of FLP, the cervical length before FLP, and TTTS being stage III TTTS were associated with the survival of both twins after FLP. Neonatal brain image anomalies were associated with GA at delivery. Conclusions: FLP being performed at an earlier GA is a risk factor for lower fetal survival and PPROM development within 21 days of FLP in cases of severe TTTS. Delaying FLP for cases involving stage I TTTS diagnosed at an early GA without risk factors, such as maternal symptoms, cardiac overload in the recipient twin, or a short cervical length, may be considered, but whether delaying FLP would improve surgical outcomes and, if so, how long the delay should be may need further trials to answer.

Iatrogenic premature rupture of membrane (PROM) is one of the major complications related to fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS). However, amniotic fluid leakage (AFL) sometimes spontaneously disappears. This study evaluated the incidence and clinical characteristics of transient AFL after FLP. We retrospectively reviewed pregnancies that underwent FLP for TTTS at a single center. Patients with apparent AFL within 2 weeks after FLP were divided into two groups: transient AFL, defined by the disappearance of fluid leakage within a week; and PROM, if AFL persisted continuously for more than a week or premature birth occurred, including miscarriage, within a week of the first symptom of AFL. Among 201 monochorionic twin pregnancies that underwent FLP during the study period, nine patients (4.5%) were diagnosed with AFL within a week after FLP. Four patients (2.0%) were classified as transient AFL and five as PROM. Median gestational age at FLP was not significantly different between the groups; operative time in the PROM group was significantly longer (P = 0.01). The surgery to delivery interval and median gestational age at delivery were greater in the transient AFL group (87.8 vs 17.6 days, P = 0.01; 32.5 vs 23.6 weeks, P = 0.01, respectively). The incidence of transient AFL after FLP was 2%. Perinatal outcomes of transient AFL might be better than that of PROM.

Pregnancy outcomes following early fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome at 16 weeks’ gestation

#37: Diagnosis and management of vasa previa

BackgroundRight ventricular outflow tract obstruction (RVOTO) is the most frequently encountered congenital heart disease in patients with twin –twin transfusion syndrome (TTTS) and is especially prevalent in the recipient twin. In this retrospective study, we evaluated the incidence, prognosis, postnatal management, and perinatal outcomes of and risk factors for RVOTO in the recipient twin in severe TTTS cases which diagnosed before 26 weeks after fetoscopic laser photocoagulation (FLP) at a single center in Taiwan.MethodsRVOTO was diagnosed using fetal or postnatal echocardiography. The fetal outcomes evaluated were perinatal survival rate, neonatal brain image anomalies rate, gestational age at delivery, and birth weight.ResultsTotal 187 severe TTTS cases were included; 14 (7.49%) had a recipient twin with RVOTO (12 cases of pulmonary stenosis and 2 of pulmonary atresia). Of these 14 cases, 3 (21.4%) demonstrated improvements in outflow obstruction after FLP, and 11 (78.6%) resulted in perinatal survival. Of the 11 survivors, 5 (45.5%) received transcatheter balloon valvuloplasty to alleviate the RVOTO. The perinatal survival rate, gestational age at delivery, neonatal brain image anomaly rate, and birth weights did not significantly differ between the groups in which the recipient twin had versus did not have RVOTO. Generally, the recipient twin had RVOTO received FLP at a younger gestational age (in weeks; 19.3 ± 2.4 vs. 20.7 ± 2.6, p = 0.048) and had a higher percentage of cases at Quintero stage IV (50.0% vs. 12.1%, p < 0.001) than those in which the recipient twin did not have with RVOTO. Using logistic regression, we discovered that FLP at a younger gestational age (p = 0.046, odds ratio = 0.779) and TTTS at Quintero stage IV (p = 0.001, odds ratio = 7.206) were risk factors for the recipient twin developing RVOTO after FLP in severe TTTS cases.ConclusionsThe post-FLP perinatal outcomes of cases of severe TTTS in which the recipient twin had versus did not have RVOTO were comparable in this study, which may have been due to the similar gestational ages at delivery and strong influence of high Quintero stages (stages III and IV).

332: Variation in outcome reporting in studies on Vasa Previa: A Systematic Review

Fetoscopic laser photocoagulation (FLP), a treatment option for twin-to-twin transfusion syndrome (TTTS) in monochorionic twin pregnancies, is currently the treatment of choice at our centre. We previously reported on our experience of FLP from June 2011 to March 2014. This paper audits our fetal surgery performance since then. 15 consecutive patients who underwent FLP for Stage II-III TTTS before 26 weeks of gestation from June 2011 to January 2017 were retrospectively reviewed, consisting of five cases from our initial experience and ten subsequent cases. Perioperative, perinatal and neonatal outcomes were analysed. Of 15 pregnancies, 10 (66.7%) and 5 (33.3%) were for Stage II and III TTTS respectively, with FLP performed at an earlier Quintero stage in the later cohort. Overall mean gestational ages at presentation, laser and delivery were comparable between the cohorts at 19.7 (15.4-24.3) weeks, 20.3 (16.3-25.0) weeks and 31.2 (27.6-37.0) weeks, respectively. 2 (13.3%) cases had intra-amniotic bleeding and 1 (6.7%) had iatrogenic septostomy. 1 (6.7%) case had persistent TTTS requiring repeat FLP, and another (6.7%) had preterm premature rupture of membranes at seven weeks post procedure. The overall perinatal survival rate was 21 (75.0%) out of 28 infants. One mother underwent termination of pregnancy for social reasons at 1.4 weeks post procedure. Double survival occurred in 8 (57.1%) out of 14 pregnancies, while 13 (92.9%) had at least one survivor. FLP requires a highly specialised team and tertiary neonatal facility. Continual training improves maternal and perinatal outcomes, ensuring comparable standards with international centres.

To evaluate the impact of amnioinfusion and other peri-operative factors on pregnancy outcomes in the setting of Twin-twin transfusion syndrome (TTTS) treated via fetoscopic laser photocoagulation (FLP). Retrospective study of TTTS treated via FLP from 2010 to 2019. Pregnancies were grouped by amnioinfusion volume during FLP (<1L vs.≥1L). The primary outcome was latency from surgery to delivery. An amnioinfusion statistic (AIstat) was created for each surgery based on the volume of fluid infused and removed and the preoperative deepest vertical pocket. Regression analysis was planned to assess the association of AIstat with latency. Patients with amnioinfusion of ≥1L at the time of FLP had decreased latency from surgery to delivery (61±29.4 vs. 73±28.8days with amnioinfusion <1L, p<0.001) and increased preterm prelabor rupture of membranes (PPROM) <34weeks (44.7% vs. 33.5%, p=0.042). Amnioinfusion ≥1L was associated with an increased risk of delivery <32 weeks (aRR 2.6, 95% CI 1.5-4.5), 30 weeks (aRR 2.4, 95% CI 1.5-3.8), and 28weeks (aRR 1.9, 95% CI 1.1-2.3). Cox-proportional regression revealed that AIstat was inversely associated with latency (HR 1.1, 95% CI 1.1-1.2). Amnioinfusion ≥1L during FLP was associated with decreased latency after surgery and increased PPROM <34weeks.

Literature suggests that both the government and professional bodies are supportive of role development and changing of professional boundaries, but is this representative of current clinical practice? All 97 mainland UK National Health Service Breast Screening Programme (NHSBSP) centres were surveyed. Postal questionnaires were sent to both radiographer film readers and departmental superintendent radiographers centring on practical, clinical and managerial issues concerning the current practice and implementation of extended roles. An overall response rate of 79% was achieved. Of radiographers working in breast screening, 10% are trained in image interpretation and reporting in mammography. Only 43% of these read annually a minimum of 5,000 mammograms – the quality guidelines for radiologists. Many barriers inhibiting the utilisation of radiographer film readers were identified: 1. Resource constraints, both human and financial 2. Time constraints 3. Quality assurance issues 4. National structure. This study demonstrated under-utilisation of radiographer film readers in the UK NHSBSP, raising the issue of 'Is training radiographers to film read an efficient and effective use of scarce health care resources?' Further research into this contentious issue is necessary to fully evaluate and ensure effective use of clinical skills; better service to the patient; and efficient use of health care resources is undertaken.

Variations in reported outcomes in studies on vasa previa: a systematic review

Vasa previa represents an uncommon and life-threatening condition for the fetus. The prenatal identification of the condition may improve the outcome. The aim of this study was to synthesize and compare published evidence of 4 national guidelines on diagnosis and management of vasa previa. A descriptive review of 4 recently published national guidelines on vasa previa was conducted: Royal College of Obstetricians and Gynaecologists on "Vasa Praevia: Diagnosis and Management," Society for Maternal-Fetal Medicine on "Diagnosis and Management of Vasa Previa," Society of Obstetricians and Gynaecologists of Canada on "Guidelines for the Management of Vasa Previa," and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists on "Vasa Praevia." These guidelines were compared regarding recommendations on diagnosis and management, while the quality of evidence was also reviewed based on each method of reporting. There were many similar recommendations in the compared guidelines regarding the diagnosis and management of vasa previa. Early prenatal diagnosis using ultrasound and color Doppler imaging, hospitalization or management as outpatients, and cesarean delivery in a tertiary center with experienced clinicians are the main recommendations. Evidence-based guidelines may increase the awareness of the diagnosis and management of vasa previa among health care professionals and lead to more favorable perinatal outcomes.