Laser surgery in the womb could let moms with vasa previa deliver naturally

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Pregnant patient * Singleton pregnancy * Confirmed diagnosis of vasa previa, defined as unprotected fetal vessels running through the membranes at or within 5cm of the internal cervical os. Diagnosis must be confirmed after 26w0d, and before 32w5d * Able to undergo intervention during 30w0d to 32w6d * Type II vasa previa in which one placental lobe is considered to be accessory, defined as constituting less than 20% of the total placental mass seen on MRI and US imaging * Type II vasa previa in which multiple bridging vessels connect the two placental lobes (≥4 vessels), and only 1-2 vessel(s) run through or within 5cm of the internal cervical os * Patient is eligible to undergo anesthesia * Patient and biological father of the fetus (if available) are able to provide signed informed consent Exclusion Criteria: * Gestational age at referral higher than 32w6d * Multiple pregnancy * Vasa previa types I and III * Type II vasa previa in which the accessory lobe constitutes more than 20% of the total placental mass, as determined by the fetal surgeon during diagnostic fetoscopy * Type II vasa previa in which all of the bridging vessels between placental lobes are running over the internal cervical os * Fetal growth restriction, defined as estimated fetal weight or abdominal circumference less than the 10th percentile for gestational age * Abnormal fetal brain MRI, including delayed maturation, hemorrhage, arterial ischemic injury, abnormal ventricular size, or any congenital anomalies * Allergy or previous adverse reaction to ancillary medications with no available alternative * Preterm contractions and PPROM before surgery * Preeclampsia or uterine anomaly during the current pregnancy * Placenta previa, low-lying placenta, placenta accreta spectrum disorder * Suspicion of major recognized congenital syndrome on ultrasound or MRI that is not compatible with postnatal life * Maternal pre-pregnancy BMI \>40 * Active hepatitis B, hepatitis C, or HIV infection * High risk for congenital fetal bleeding disorders * Unreliable pregnancy dating due to an irregular menstrual cycle/uncertain last menstrual period with no confirmed dating from first trimester ultrasound * The surgeon determines that the procedure is not feasible for any other reason after diagnostic fetoscopy