Maternal Fetal Care Center | Fetoscopic laser photocoagulation in Management of vasa previa – FLUMEN Study

During fetoscopic laser photocoagulation, doctors insert a thin scope into the womb and use a laser to coagulate the blood vessels that pass over the cervix, which stops the blood flow within those vessels. The procedure ensures that if labor starts or a pregnant person’s water breaks, there is no longer a concern about bleeding from the vasa previa vessels.

Fetoscopic laser photocoagulation is typically performed between 30 to 33 weeks of gestation. It is a one-day procedure, meaning patients can usually return home the same day or one day after the intervention. Following a successful photocoagulation treatment, patients can continue their pregnancy under the care of their primary doctor, following standard prenatal care protocols and delivery plans. This means that patients can expect a vaginal delivery barring unforeseen circumstances or unless otherwise discussed with their obstetric care team.

Please note the following inclusion criteria for patients, per our FDA and IRB-approved protocol:

1. The patient patient is a pregnant individual between 18 and 55 years of age.
2. Singleton pregnancy (pregnancy with one fetus)
3. Evidence of confirmed diagnosis of vasa previa – defined as unprotected fetal vessels running through the membranes, either over or within 5 cm of the internal cervical os – after 26 0/7 weeks and before 32 5/7 weeks.
4. Gestational age 30 0/7 to 32 6/7 weeks (intervention window).
5. Type II vasa previa, in which one lobe is considered an accessory, is defined as constituting less than 20 percent of the total placental mass as determined by MRI and ultrasound imaging.
6. Type II vasa previa in which in which multiple bridging vessels connect two placental lobes (≥ 4 vessels), and only 1-2 vessel(s) run over or within 5 cm of the internal cervical os.
7. The pregnant person has been approved for the intervention by the Anesthesia team.
8. The patient and, if applicable, the other parent of the fetus, have provided signed informed consent outlining the maternal and fetal risks associated with the procedure.

Fetoscopic laser photocoagulation is generally considered a safe procedure with a high success rate. In this study, pregnant individuals undergoing fetoscopic laser photocoagulation will receive spinal anesthesia, minimizing discomfort during the procedure. While the risks associated with the procedure are minimal, there is a small risk of premature rupture of membranes (water break) due to the insertion of the small scope into the uterus.

Though extremely rare, an unsuccessful procedure or accidental rupture of the vasa previa may occur, leading to emergency cesarean section (C-section) procedure. In such cases, if a complication arises, the patient will already be in the operating room, and the cesarean delivery will be performed promptly to minimize risks.

Referring physicians or eligible patients can contact us at 617-355-6512. We will ask for medical information, including demographic and insurance information, which can be faxed to 617-730-0124 or 617-730-0302 or emailed to MFCCReferrals@childrens.harvard.edu.

After receiving your referral, we will process your records and provide your information to a member of our clinical team, which includes nurses, nurse practitioners, and genetic counselors. A clinical team member will review your information and contact you for a clinical intake. Clinical intake typically involves obtaining additional medical history, assessing your understanding of the fetal diagnosis, and answering questions. Our clinical team will also order all appropriate diagnostic testing and counseling sessions. Our scheduling team will make every attempt to schedule imaging studies and appointments in a timely fashion to best meet your needs. However, please keep in mind that this process requires in-depth clinical expertise and may necessitate multiple calls before your first appointment.