Third-trimester fetoscopic ablation therapy for types II and III vasa previa.

BACKGROUND: Vasa previa is an obstetrical condition in which fetal vessels located near the cervix traverse the fetal membranes unprotected by underlying placenta. Type I vasa previa arises directly from a velamentous cord root, whereas types II and III arise from an accessory lobe or a distal lobe of the same placenta, respectively. Fetoscopic laser ablation for types II and III vasa previa is a novel therapeutic option with benefits that include surgical resolution of the vasa previa, avoidance of prolonged hospitalization, and opportunity for a term vaginal delivery. The potential risks of fetoscopy can be mitigated by delaying laser surgery until a gestational age of 31 to 33 weeks, immediately before anticipated hospitalized surveillance. OBJECTIVE: This study aimed to assess feasibility and outcomes of types II and III vasa previa patients treated via fetoscopic laser ablation in the third trimester. STUDY DESIGN: This is a retrospective study of singleton pregnancies with types II and III vasa previa treated with fetoscopic laser ablation at a gestational age ≥31 weeks at a single center between 2006 and 2022. Pregnancy and newborn outcomes were assessed. Continuous variables are expressed as mean±standard deviation. RESULTS: Of 84 patients referred for vasa previa, 57 did not undergo laser ablation: 19 either had no or resolved vasa previa, 25 had type I vasa previa (laser-contraindicated), and 13 had type II or III vasa previa but declined laser treatment. Of the remaining 27 patients who underwent laser ablation, 7 were excluded (laser performed at <31 weeks and/or twins), leaving 20 study patients. The mean gestational age at fetoscopic laser ablation was 32.0±0.6 weeks, and total operative time was 62.1±19.6 minutes. There were no perioperative complications. All patients had successful occlusion of the vasa previa vessels (1 required a second procedure). All patients were subsequently managed as outpatients. The mean gestational age at delivery was 37.2±1.8 weeks, the mean birthweight was 2795±465 g, and 70% delivered vaginally. Neonatal intensive care unit admission occurred in 3 cases: 1 for respiratory distress syndrome and 2 for hyperbilirubinemia requiring phototherapy. There were no cases of neonatal transfusion, intraventricular hemorrhage, sepsis, patent ductus arteriosus, or death. CONCLUSION: Laser ablation for types II and III vasa previa at 31 to 33 gestational weeks was technically achievable and resulted in favorable outcomes.

Fetoscopic Laser Ablation Therapy for Type II Vasa Previa.

BACKGROUND: In type II vasa previa, fetoscopic laser ablation has the potential to avoid prolonged hospitalization, elective prematurity, and cesarean delivery associated with traditional conservative management. OBJECTIVE: To assess the feasibility and to report perinatal outcomes of type II vasa previa patients treated via fetoscopic laser ablation. STUDY DESIGN: This is a retrospective descriptive study of all women with vasa previa treated with laser at our center between 2006 and 2019. After 2010, laser ablation of vasa previa was only offered after 31 gestational weeks. Continuous variables are expressed as means ± SD. RESULTS: 33 patients were evaluated for laser ablation of suspected vasa previa. Fifteen were not candidates (7 had type I vasa previa and 8 had no vasa previa), and the 18 remaining had type II vasa previa. Ten (56%) elected to undergo in utero laser ablation of the vasa previa vessel(s), which was successful in all patients. The mean gestational age (GA) at the time of the procedure was 28.8 ± 5.4 weeks, and the total operative time was 48.1 ± 21.3 min; there were no perioperative complications. The number of vessels lasered were distributed as follows: 1 (2 cases), 2 (5 cases), and 3 (3 cases). All patients except for 1 were subsequently managed as outpatients. The mean GA at delivery was 35.5 ± 3.2 weeks, and vaginal delivery occurred in 5 cases. The 5 patients with singletons who underwent laser ablation for primary diagnosis of type II vasa previa after the protocol change in 2010 had the following outcomes: mean GA of surgery was 32.5 ± 0.8 weeks, mean GA at delivery was 38.1 ± 1.4 weeks, vaginal delivery occurred in all cases, mean birth weight was 2,965 ± 596 g, and none were admitted to the neonatal intensive care unit. CONCLUSION: This cohort represents the largest number of vasa previa cases treated via in utero laser reported to date. Laser occlusion of type II vasa previa was technically achievable in all cases and resulted in favorable outcomes.

Abnormal Placentation: Placenta Previa, Vasa Previa, and Placenta Accreta.

Placental disorders such as placenta previa, placenta accreta, and vasa previa are all associated with vaginal bleeding in the second half of pregnancy. They are also important causes of serious fetal and maternal morbidity and even mortality. Moreover, the rates of previa and accreta are increasing, probably as a result of increasing rates of cesarean delivery, maternal age, and assisted reproductive technology. The routine use of obstetric ultrasonography as well as improving ultrasonographic technology allows for the antenatal diagnosis of these conditions. In turn, antenatal diagnosis facilitates optimal obstetric management. This review emphasizes an evidence-based approach to the clinical management of pregnancies with these conditions as well as highlights important knowledge gaps.

Management of vasa previa during pregnancy.

In order to prevent fetal mortality due to vasa previa, it is necessary to obtain an antenatal diagnosis and perform elective cesarean section prior to membrane rupture. Under present circumstances, management strategies for vasa previa depend on each institutional policy. In our institution, patients are not routinely admitted, although precise outpatient management, including confirming the presence of uterine contractions and monitoring the cervical length, fetal growth and fetal heart rate, is provided for pregnant females with vasa previa. In the present report, we reviewed 21 cases of vasa previa managed at our hospital. Some 71% (15/21) of them were required inpatient management due to its complications, resulting in emergency delivery in about half of them. Therefore, our results suggest that only carefully selected asymptomatic patients may be successfully managed as outpatients.

Prenatal diagnosis of vasa previa.

Vasa previa is a rare condition in which unsupported by the placenta, umbilical cord blood vessels runs within the placental membranes between internal os of the cervix and presenting part of the fetus. We report an antenatal diagnostic procedure and management of a patient with low-lying placenta and velamentous cord insertion near to the internal os with two large fetal blood vessels coursing between the internal cervical os and fetal presenting part. An elective cesarean section was performed at 36 weeks gestation.

Term vaginal delivery following fetoscopic laser photocoagulation of type II vasa previa.

Unrecognized vasa previa carries a significant risk of fetal mortality. Advances in ultrasound have improved detection of vasa previa and led to a dramatic reduction in fetal morbidity and mortality. However, current management strategies require prolonged hospitalized surveillance, preterm delivery prior to the onset of labor or rupture of membranes, and a cesarean delivery. Fetoscopic laser ablation of type II vasa previa allows for the possibility of term vaginal delivery. We present a patient who underwent successful laser photocoagulation of a type II vasa previa at 32(5)/7 weeks' gestation. She subsequently delivered vaginally at term without complications. The potential benefits of definitive in utero treatment of non-type I vasa previa, such as vaginal delivery at term, must be weighed against the procedure-related risks of operative fetoscopy.

[A woman with an obstetric curiosity]. / Een vrouw met een obstetrische bijzonderheid.

A primipara underwent a caesarean section for preeclampsia. It so happened that vasa praevia were seen during the operation. A healthy boy was born.

Third trimester fetoscopic laser ablation of type II vasa previa.

OBJECTIVE: Vasa previa is associated with increased perinatal morbidity and mortality because of fetal exsanguination at time of membrane rupture. We report our experience in the treatment of type II vasa previa via in utero laser ablation in the third trimester. METHODS: Two cases of type II vasa previa were identified via endovaginal ultrasound in the second trimester and treated via third trimester fetoscopic laser ablation. RESULTS: In case 1, fetoscopic laser ablation of the vasa previa was performed without complication at 28 3/7 weeks' gestation as a prophylactic measure. The patient delivered at 33 3/7 weeks' gestation after rupture of membranes without sequelae with good perinatal outcome. In case 2, expectant management of twins with a vasa previa was planned. However, significant cervical shortening and funneling was documented at 30 5/7 weeks', and the risk of membrane rupture was deemed relatively high. As a therapeutic alternative to outright preterm delivery, the patient underwent uncomplicated laser ablation of the vasa previa. Delivery occurred at 34 3/7 weeks' after rupture of membranes, and the twins did well. CONCLUSIONS: We suggest that type II vasa previa can be definitively treated in utero by laser photocoagulation in the third trimester. Ablation of the vasa previa may be performed prophylactically or as a therapeutic measure to delay delivery if symptoms of preterm labor and/or cervical shortening develop.