The investigators propose a standardized prenatal management, based on the scientific
evidence published in the literature, to manage prenatally fetuses with lower urinary tract
obstruction (LUTO). The present study is a prospective registry that will evaluate and
validate this standardized prenatal management for LUTO.
Patients with LUTO will come for clinical evaluation as part of the standard clinical care
at the our Fetal Center. The standardized prenatal management of plan for fetuses with LUTO
is described in details bellow.
All pregnant women carrying fetuses with LUTO are assigned to the nurse coordinator and the
prenatal records are obtained. The multidisciplinary team (maternal-fetal intervention team,
pediatric urologists, pediatric nephrologist, neonatologist, genetic counselors and fetal
cardiologists) will be notified. A one-day visit is planned with the following: 1. a fetal
comprehensive ultrasound is scheduled for the confirmation of the diagnosis, investigation
of associated anomalies and evaluation of prognostic factors; 2. a genetic counseling is
performed and fetal invasive tests (FISH/fetal karyotype/fetal CMA) are offered to the
patients; 3. Fetal echocardiogram is also performed to evaluate the presence of associated
cardiac anomalies and the fetal cardiac function; 4. A consultation with the Fetal
Intervention team (maternal-fetal specialty) is scheduled as well.
If the gestational age is less than 18 weeks and isolated LUTO is confirmed on
ultrasonography, patient is giving the option for prenatal expectant management, or fetal
intervention or termination of pregnancy. If patient elects to proceed with fetal
intervention, vesico-amniotic shunting is performed and patient is followed by ultrasound
once a week. In case the shunt migrates or seems to be obstructed, we will offer repeating
the procedure to the patient. If patient elects to proceed with expectant management,
follow-up will be every 4 weeks. Delivery date and type of delivery depend on the
For fetuses at gestational age greater than 18 and less than 30 weeks, if oligohydramnios is
present, investigation of fetal renal biochemistry is offered. In case of favorable fetal
renal biochemistry, vesico-amniotic shunt is offered as a fetal therapeutic intervention. In
case the fetal urinary biochemistry is considered not favorable, then we will repeat the
urinary examination in 24 hours. If the fetal urinary biochemistry is still not favorable,
we will repeat the examination for the last time (maximum of 3 times). If it is still not
favorable, then fetal vesico-amniotic shunt is not offered. However, if a fetal urinary
examination reveals improvement favorable urinary biochemistry), fetal vesico-amniotic
shunting is considered. Prenatal follow-up and delivery follow the same algorithm described
If gestational age is greater than 30 weeks and less than 34 weeks and isolated LUTO is
diagnosed, fetal intervention is offered if oligohydramnios is present. If no
oligohydramnios is identified, no fetal intervention is offered and patient is followed
until delivery. Delivery date and type of delivery depend on the obstetrical indications.
For those fetuses with gestational age greater than 34 weeks, if oligohydramnios is present,
pre-term delivery is indicated. If a normal amount of amniotic fluid is seen, patient is
followed weekly by ultrasound examination and delivery is at term.
Fetuses with other associated anomalies independent from the gestational age will undergo
further investigation with fetal magnetic resonance imaging and evaluation by the
All infants with LUTO will have the same routine standard clinical care. All infants with
LUTO are evaluated postnatally by the pediatric urology and nephrology services and may need
surgical intervention. At birth, the clinical evaluation will include a renal ultrasound,
voiding cysto-urethrogram (VCUG) as well as clinical laboratory examinations such as serum
creatinine, sodium, calcium, potassium and chloride, and a urine analysis will be performed
as part of the standard clinical care. The infant will be followed every 6 months up until
24 months of life, and then annually afterwards. Information from these routine examinations
will be collected and documented.
- Pregnant women whose fetuses have diagnosis of LUTO independently from the gestational
age at diagnosis.
- Presence of abnormal chromosomal/genetic disease
- Presence of other associated structural anomaly that is not part of LUTO.