The purpose of the study is to study the outcomes of maternal and fetal patients who are undergoing fetal intervention for severe isolated lower urinary tract obstruction (LUTO).

Inclusion Criteria:

1. Pregnant women
2. Singleton pregnancy
3. Maternal age ≥ 18 years
4. Male fetus with LUTO, dilated bladder, "keyhole sign" and bilateral hydronephrosis
5. Oligohydramnios or Anhydramnios
6. Favorable urine analysis defined as urinary sodium is < 100 milliequivalents per liter (mEq/L), chloride < 90 mEq/L, and osmolality < 200 milliosmoles per kilogram (mOsm/kg) after 20 weeks and in the absence of previous in utero intervention for the disease (vesicoamniotic shunt placement or fetal cystoscopy).
7. Absence of chromosomal abnormalities and associated anomalies
8. Gestational age at the time of the procedure will be between 16 0/7 weeks and 25 6/7 weeks
9. Normal karyotype by invasive testing (amniocentesis or Chorionic Villus Sampling (CVS)). Patients declining invasive testing will be excluded.
10. Family have considered and declined the option of termination of the pregnancy at less than 24 weeks.
11. Family meets psychosocial criteria, including sufficient social support and ability to understand requirements of the study.
12. Parents or guardian are willing to provide signed informed consent.

Exclusion Criteria:

1. Fetal anomaly unrelated to LUTO
2. Congenital cardiac anomaly
3. Female fetus
4. Increased risk for preterm labor including short cervical length (<1.5 cm), history of incompetent cervix with or without cerclage, and previous preterm birth
5. Placental abnormalities (previa, abruption, accreta) known at time of enrollment
6. Contraindications to surgery including previous hysterotomy in active uterine segment
7. Technical limitations precluding fetoscopic surgery, such as uterine fibroids, fetal membrane separation, uterine anomalies incompatible with fetoscopy
8. Maternal-fetal Rh isoimmunization, Kell sensitization or neonatal alloimmune thrombocytopenia affecting the current pregnancy
9. Maternal HIV, Hepatitis-B, Hepatitis-C status positive because of the increased risk of transmission to the fetus during maternal-fetal surgery. If the patient's HIV or Hepatitis status is unknown, the patient must be tested and found to have negative results before enrollment
10. Maternal medical condition that is a contraindication to surgery or anesthesia
11. Patient does not have health insurance to cover routine clinical care including prenatal care, prenatal ultrasound, amniocentesis, tocolysis, admission, delivery, and fetal vesico-amniotic shunting. The exception will be fetal cystoscopy which is considered an experimental procedure.
12. Inability to comply with travel and follow-up requirements of the trial
13. Participation in another intervention study that influences maternal and fetal morbidity and mortality or participation in this trial in a previous pregnancy
14. Patients declining invasive testing
15. Family does not meet psychosocial criteria including insufficient