Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03073382 |
| Other study ID # |
26891 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
January 1, 2017 |
| Est. completion date |
May 26, 2017 |
Study information
| Verified date |
December 2023 |
| Source |
University of Nebraska |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
This is a chart review of all patients who have underwent open prenatal repair of fetal
myelomeningocele. Although prenatal repair is associated with improved neurologic outcomes
and a decreased need for cerebrospinal fluid shunting after birth, one of the major risks is
preterm delivery. This study is intended to identify maternal, fetal or intraoperative risk
factors associated with preterm delivery.
Description:
Myelomeningocele encompasses the most common form of spina bifida. The incidence ranges from
2.73-3.80 per 10,000 births in the United States. The extent of neurologic sequela is
correlated with the level of the lesion but frequently involves a spectrum of motor
dysfunction including paralysis of the lower extremities, contractures in addition to lack of
bladder and bowel control. These result in significant lifestyle limitations for survivors.
Additionally, hydrocephalus, brainstem herniation and Chiari II malformations are commonly
noted. Ventriculoperitoneal shunts are commonly placed in childhood to redirect cerebrospinal
fluid and can require revisions later in life.
The Management of Myelomeningocele Study (MOMS) trial revolutionized management of fetuses
with myelomeningoceles by demonstrating that prenatal compared to standard postnatal repair
resulted in decreased need for cerebrospinal fluid shunts and improved motor function at
thirty months. As a result, various centers around the United States began offering prenatal
repair to patients less than twenty-six weeks gestation with prespecified maternal and fetal
characteristics.
Prenatal repair is not without risk to both the mother and the fetus. The mother must undergo
a laparotomy and accept the risks involved with any intraabdominal surgery including
bleeding, infection, adhesion formation and damage to nearby organs. Unique to this
procedure, a hysterotomy is typically created in the active segment of the uterus to allow
for sufficient exposure of the fetal lesion. Like those women who undergo classical Cesarean
sections, these patients must undergo Cesarean sections around 37 weeks gestation for all
future pregnancies secondary to concern of uterine dehiscence in the setting of labor. This
has major implications for the mother's future childbearing potential, as the number of
previous Cesarean sections increases the risk of intraoperative complications and invasive
placentation in subsequent pregnancies. A fetoscopic approach has reemerged in the United
States as an alternative to the aforementioned open approach and is currently under further
investigation.
Intraoperative fetal distress has been reported and can lead to loss of the pregnancy.
Additionally, fetal surgery carries the risks of spontaneous preterm birth and preterm
premature rupture of membranes, which subject the fetus to the morbidity of prematurity. This
risk of spontaneous preterm delivery is one of the more common and significant drawbacks to
the procedure and represents a major hurdle to overcome. In the MOMS trial, 46% of those in
the study group compared to 8% in the postnatal repair group experienced spontaneous rupture
of membranes. Thirty-eight percent of prenatal repair versus 14% of postnatal repair patients
went into spontaneous labor prior to scheduled delivery. The average gestational age at birth
was 34 weeks for the prenatal surgery group and 37 weeks for the postnatal surgery group. In
another study following the MOMS trial, 100 patient underwent prenatal repair with a reported
32.3% rate of preterm premature rupture of membranes(PPROM) and 37.5% rate of preterm labor.
Also reported a modified surgical approach to the hysterotomy and closure among 43 patients
and found a 22% rate of PPROM. Thirty-nine percent delivered at 37 weeks or later compared
with 21% of the MOMS cohort.
Although the increased risk of preterm delivery is reported, little is known regarding risk
factors associated with preterm delivery following this procedure. Soni et al. found that
chorioamniotic membrane separation was a risk factor for subsequent PPROM. No studies have
been published that assess risk factors for all spontaneous preterm deliveries including both
preterm labor and PPROM. The objective of this study is to determine if any maternal, fetal
or intraoperative factors can be identified that increase the risk of spontaneous preterm
delivery in patients who undergo prenatal open myelomeningocele repair. With the
identification of such factors, counseling of the patient and potentially patient selection
could be refined in the future.
