Chorioamniotic membrane separation following fetal myelomeningocele repair: incidence, risk factors and impact on perinatal outcome

Abstract

Objectives Prenatal myelomeningocele (MMC) repair has been shown to provide significant benefits to the infant, decreasing the postnatal need for ventriculoperitoneal shunt and improving motor outcome. Chorioamniotic membrane separation (CAS) is a potential complication following prenatal MMC repair and may increase the risk of preterm prelabor rupture of membranes (PPROM) and preterm birth. The objectives of this study were: (1) to evaluate the incidence of CAS after prenatal MMC repair; (2) to determine risk factors associated with its occurrence; and (3) to assess its association with adverse perinatal outcomes. Methods This was a retrospective cohort study of patients who underwent fetal MMC repair between November 2011 and December 2018. Surgery was performed using either a fetoscopic (laparotomy or exteriorized uterus) approach or an open‐hysterotomy approach. Eligibility criteria were those reported in the Management of Myelomeningocele Study. If CAS was detected on ultrasound (US), its severity was graded as ‘mild’ if amnion detachment involved < 25% of the uterine cavity, ‘moderate’ if it involved 25–50% and ‘severe’ if it involved > 50%. Evolution of CAS was classified as stable, increasing or decreasing based on the difference in severity grading between the time at first diagnosis and the last US scan before delivery. Logistic regression analysis was performed to identify pre‐ or perisurgical factors associated with the development of CAS and to determine the risk of adverse perinatal outcome associated with CAS. Results In total, 91 cases were included. Fetoscopic or open‐hysterotomy repair of MMC was performed in 52/91 (57.1%) and 39/91 (42.9%) cases, at a median gestational age (GA) of 25.0 weeks (range, 22.9–26.0 weeks) and 25.0 weeks (range, 21.3–25.9 weeks), respectively. CAS was diagnosed in 31/91 (34.1%) patients, at a median GA of 28.1 weeks (range, 24.4–37.6 weeks). Anterior placenta was identified as a risk factor for the postoperative development of CAS (odds ratio (OR), 3.72 (95% CI, 1.46–9.5); P < 0.01). This risk was dependent on the repair technique. An anterior placenta significantly increased the risk of CAS after fetoscopic repair (OR, 3.94 (95% CI, 1.14–13.6); P = 0.03) but not after open repair (OR, 2.8 (95% CI, 0.6–12.5); P = 0.16). There was no significant difference in the rate of CAS after fetoscopic repair (21/52 (40.4%)) vs open‐hysterotomy repair (10/39 (25.6%)) (P = 0.14), nor were there any differences in GA at diagnosis of CAS, interval between surgery and diagnosis, distribution of CAS severity or progression of CAS between the two groups. CAS increased the risk of PPROM (50% in those with vs 12% in those without CAS) (OR, 7.6 (95% CI, 2.5–21.9); P < 0.01) and preterm delivery (70% vs 38%) (OR, 3.2 (95% CI, 1.3–8.1); P < 0.01). Fetoscopically repaired cases with CAS had a higher rate of PPROM (12/20 (60.0%) vs 2/31 (6.5%); P < 0.01) and preterm delivery (13/20 (65.0%) vs 5/31 (16.1%); P < 0.01) than those that did not develop CAS, while the differences were not...

Perinatal outcomes of iatrogenic chorioamniotic separation following fetoscopic surgery: systematic review and meta‐analysis

“…Although in this review we were not able to comment on additional possible complications associated with iCAS, such as the risk of pseudoamniotic band formation and cord accidents, due to lack of reporting in the included studies, these concerns have been described in cases of spontaneous CAS and individual case reports following intervention 5,14,16 .…”

Fetoscopic compared with open repair of myelomeningocele: a 2-delivery cost-effectiveness analysis

“…4,18,29 There has been question regarding the risk of chorio-amnion membrane separation (CAS) resulting from the two techniques, however recent studies have showed no significant difference in the two groups, so we did not include CAS as an outcome in our tree. 30 While there is still much progress to be done in ensuring safety with this approach with large trials, the significant improvement in maternal morbidity is promising.…”

Update on prenatal diagnosis and fetal surgery for myelomeningocele

“…• Gestational age at the time of surgery: the risk appears to decrease with a longer gestational age at the time of the procedure. Soni et al 71 73 In fetoscopic surgeries, it is believed that certain aspects, such as membrane dehydration due to the effect of carbon dioxide (CO 2 ), could play a role; for this reason, a common practice now is to use humidified CO 2 and hydrate the membranes every 15 minutes (Figure 10) or to separate the membranes during port insertion, so it was proposed to have 4 fixation points of the membranes to the myometrium for each port, instead of 2 (Figure 10). 73 c. What are the prognostic factors for VPS requirement in fetuses subjected to prenatal surgery?…”