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

Proof of concept testing of a vascular closure device for use in fetal surgery

OBJECTIVE

Prior clinical findings have demonstrated that maternal laparotomy with trans-amniotic trans-uterine suturing of the fetoscopic port site during in utero myelomeningocele repair reduces the risk of membrane rupture. However, due to laparotomy-associated morbidity, we aimed to explore the feasibility of using a vascular closure device for percutaneous trans-amniotic trans-uterine suturing.

METHODS

This IRB and IACUC-exempt study utilized 2 strategies for proof-of-concept testing of using the Abbott Perclose™ ProStyle™ Device for suture placement; 1. Ultrasound guided application on a high fidelity maternal abdominal uterus model used for fetal procedures and 2. Placement under direct visualization with sheep undergoing cesarean delivery for other research purposes. In the high-fidelity uterus model, the Abbott Perclose™ ProStyle™ device was used to place a transuterine/transamniotic stitch with accompanying video recording of the approach (https://go.screenpal.com/watch/cZfhoDVsYvW password: perclose). Regarding the second approach, at the time of a cesarean section, 12 French Checkflo® cannulas were inserted into the sheep amniotic space via different approaches: (1) Seldinger technique, (2) Seldinger technique insertion of Checkflo® cannula and subsequent use of the Abbott Perclose™ ProStyle™ device to suture the port site after check flow removal, (3) Abbott Perclose™ ProStyle™ device utilized in what is described as a "pre-close" technique, where prior to cannula placement, trans-uterine trans-amniotic stitches are placed followed by the insertion of a 12 French Checkflo® cannula over the same guidewire. Samples of the sutured uterine wall were sent to pathology and H&E staining was performed to assess uterine hole closure and amnion-to-uterus fixation.

RESULTS

The high-fidelity model confirmed that the Perclose™ ProStyle™ Device was easily visualized by ultrasound and suture deployment was without complication. In the animal model, the Perclose™ ProStyle™ device effectively sutured the amnion to the uterus in both the pre- and post-close approach. The pre-close technique achieved better amnion-to-uterus approximation and more appropriate uterine hole closure. H&E staining revealed that without suturing, amnion separation from the chorion layer occurred, and the uterine hole persisted. The post-close technique showed partial connection between the amnion and chorion, but inadequate uterine hole closure with amnion shift into the defect. Optimal closure, with secure amnion-to-chorion fixation and uterine closure, was achieved through the pre-close technique.

CONCLUSION

The Abbott Perclose™ ProStyle™ Device seems to be a feasible device for use of uterine port closure in maternal-fetal surgery, larger animal studies with mid-pregnancy application are needed to further validate or refute these findings.

IL-1β stimulates ADAMTS9 expression and contributes to preterm prelabor rupture of membranes

BACKGROUND

Preterm prelabor rupture of membranes (pPROM) is a leading cause of neonatal morbidity and mortality. While intra-amniotic infection is a well-established driver of pPROM, the role of sterile intra-amniotic inflammation remains unclear. Recent evidence suggests that interleukin-1 beta (IL-1β) promotes extracellular matrix (ECM) remodeling via downstream effectors, a disintegrin-like and metalloproteinase domain with thrombospondin type 1 motif 9 (ADAMTS9), while protein O-fucosyltransferase 2 (POFUT2) facilitates its O-fucosylation and secretion, amplifying ECM degradation. This study investigates how IL-1β-triggered nuclear factor kappa-B (NF-κB) activation promotes ADAMTS9 and POFUT2 expression, ultimately driving fetal membrane ECM remodeling and weakening in pPROM without signs of intra-amniotic infection.

METHODS

A nested case-control study included maternal serum and fetal membrane samples from 60 pregnant women (34 pPROM, 26 full-term births [FTB]). ELISA measured serum levels of IL-1β and ADAMTS9, and their correlations were analyzed. Mechanistic studies utilized primary human amniotic epithelial cells (hAECs) and fetal membrane-decidua explants with IL-1β treatment. The role of NF-κB was explored using chromatin immunoprecipitation (ChIP) and luciferase assays to assess NF-κB binding to the promoters of ADAMTS9 and POFUT2. A murine model of sterile intra-amniotic inflammation under ultrasound-guided IL-1β injection was used to validate in vitro findings and assess pregnancy outcomes.

RESULTS

Serum IL-1β and ADAMTS9 levels at 16 weeks of gestation were significantly higher in pPROM cases compared to FTB controls (P < 0.001). A combined model of these biomarkers demonstrated high predictive accuracy for pPROM (AUC = 0.83). Mechanistically, IL-1β activated NF-κB, leading to its binding to the promoters of ADAMTS9 and POFUT2. NF-κB activation promoted ADAMTS9 expression, while POFUT2 enhanced its secretion. Together, these processes drove versican degradation and ECM weakening. Intra-amniotic administration of IL-1β in mice induced fetal membrane weakening, preterm birth, and adverse neonatal outcomes, which were mitigated by the NF-κB inhibitor BAY 11-7082 treatment.

CONCLUSION

Maternal serum ADAMTS9 levels at mid-gestation are promising non-invasive biomarkers for pPROM risk stratification. Mechanistically, IL-1β-induced NF-κB activation promotes ADAMTS9 expression and POFUT2-dependent secretion, contributing to fetal membrane weakening. These findings provide new insights into the role and potential therapeutic target for sterile intra-amniotic inflammation in pPROM.

Chorioamniotic Membrane Separation after Fetal Spina Bifida Repair: Impact of CMS Size and Patient Management

INTRODUCTION

Chorioamniotic membrane separation (CMS) is a known complication after fetal spina bifida (fSB) repair. This study's goal was to analyze women's outcomes with open fSB repair and CMS (group A) compared to the ones without (group B) and to assess the influence of CMS size and patient management.

METHODS

A total of 194 women with open fSB repair at our center were included in this retrospective study. Outcomes of group A were compared to the ones of group B. Regression analysis was performed to assess risk factors for CMS. Two subgroup analyses assessed the impact of CMS size (small [A-small] vs. large [A-large]) as well as patient management (A1 = hospitalization vs. A2 = no hospitalization) on pregnancy outcomes.

RESULTS

Of 194 women, 23 (11.9%) were in group A and 171 (88.1%) in group B. Preterm premature rupture of membranes (PPROMs) (69.6% vs. 24.1%, p = <0.001), amniotic infection syndrome (AIS) (22.7% vs. 7.1%, p = 0.03), histologically confirmed chorioamnionitis (hCA) (40.0% vs. 14.7%, p = 0.03), length of hospital stay (LOS) after fSB repair (35 [19-65] vs. 17 [14-27] days), and overall LOS (43 [33-71] vs. 35 [27-46] days, p = 0.004) were significantly more often/longer in group A. Gestational age (GA) at delivery was significantly lower in group A compared to group B (35.3 [32.3-36.3] vs. 36.7 [34.9-37.0] weeks, p = 0.006). Regression analysis did not identify risk factors for CMS. Subgroup analysis comparing CMS sized in group A-small versus A-large showed higher AIS rate (42% vs. 0%, p = 0.04), lower LOS (22.0 [15.5-42.5] vs. 59.6 ± 24.1, p = 0.003). Comparison of group A1 versus A2 showed longer LOS (49.3 ± 22.8 vs. 15 [15-17.5] days, p < 0.001), lower planned readmission rate (5.6% vs. 80%, p = 0.003).

CONCLUSION

CMS significantly increased the risk of PPROM, AIS, hCA, caused longer LOS, and caused lower GA at delivery. Women with small CMS had higher AIS rates but shorter LOS compared to women with large CMS, while apart from LOS pregnancy outcomes did not differ regarding patient management (hospitalization after CMS yes vs. no).

Fetal surgery for open neural tube defect with severe ventriculomegaly

OBJECTIVE

Prenatal open neural tube defect (ONTD) repair is performed to decrease the risk of needing treatment for hydrocephalus after birth and to preserve motor function. Some centers may not consider patients to be candidates for surgery if severe ventriculomegaly is present and there is no expected benefit in risk for hydrocephalus treatment. This study sought to compare the postnatal outcome of fetuses with ONTD and severe ventriculomegaly (ventricular width ≥ 15 mm) that underwent prenatal repair with the outcome of fetuses with severe ventriculomegaly that underwent postnatal repair and fetuses without severe ventriculomegaly (< 15 mm) that underwent prenatal repair.

METHODS

This was a retrospective study of fetuses with ONTD that underwent prenatal or postnatal repair between 2012 and 2021 at a single institution. The cohort was divided into two groups based on preoperative fetal ventricular size: those with severe ventriculomegaly (ventricular width ≥ 15 mm) and those without severe ventriculomegaly (< 15 mm). Fetal ventricular size was measured by magnetic resonance imaging before surgery using the standardized approach and the mean size of the left and right ventricles was used for analysis. Motor function of the lower extremities was assessed at the time of referral by ultrasound and if flexion-extension movements of the ankle were seen it was considered as preserved S1 motor function. Postnatal outcomes, including motor function of the lower extremities at birth and the need for a diversion procedure for hydrocephalus treatment during the first year after birth, were collected and compared between groups. Multivariate regression analysis was used to adjust for potential confounders.

RESULTS

In this study, 154 patients were included: 145 underwent fetal surgery (101 fetoscopic and 44 open hysterotomy) and nine with severe ventriculomegaly underwent postnatal repair. Among the 145 patients who underwent fetal surgery, 22 presented with severe ventriculomegaly. Fetuses with severe ventriculomegaly at referral that underwent prenatal repair were significantly more likely to need hydrocephalus treatment by 12 months after birth than those without severe ventriculomegaly (61.9% vs 28.9%, P < 0.01). However, motor function assessment at birth was similar between both prenatal repair groups (odds ratio, 0.92 (95% CI, 0.33-2.59), P = 0.88), adjusted for the anatomical level of the lesion. The prenatal repair group with severe ventriculomegaly had better preserved motor function at birth compared to the postnatal repair group with severe ventriculomegaly (median level, S1 vs L3, P < 0.01; proportion with S1 motor function, 68.2% vs 11.1%, P < 0.01). Fetuses with severe ventriculomegaly that underwent prenatal repair had an 18.9 (95% CI, 1.2-290.1)-times higher chance of having intact motor function at birth, adjusted for ethnicity, presence of club foot at referral and gestational age at delivery, compared with the postnatal repair group. There was no significant difference in the need for hydrocephalus treatment in the first year after birth between prenatal and postnatal repair groups with severe ventriculomegaly (61.9% vs 87.5%, P = 0.18).

CONCLUSIONS

Although fetuses with ONTD and severe ventriculomegaly do not seem to benefit from fetal surgery in terms of postnatal hydrocephalus treatment, there is an increased chance of preserved motor function at birth. Results from this study highlight the benefit of prenatal ONTD repair for cases with severe ventriculomegaly at referral to preserve motor function. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Decreased Maternal Morbidity and Improved Perinatal Results of Magnesium-Free Tocolysis and Classical Hysterotomy in Fetal Open Surgery for Myelomeningocele Repair: A Single-Center Study

Fetal and maternal risks associated with open fetal surgery (OFS) in the management of meningomyelocele (MMC) are considerable and necessitate improvement. A modified technique of hysterotomy (without a uterine stapler) and magnesium-free tocolysis (with Sevoflurane as the only uterine muscle relaxant) was implemented in our new magnesium-free tocolysis and classical hysterotomy (MgFTCH) protocol. The aim of the study was to assess the introduction of the MgFTCH protocol in reducing maternal and fetal complications. The prospective study cohort (SC) included 64 OFS performed with MgFTCH at the Fetal Surgery Centre Bytom (FSCB) (2015-2020). Fetal and maternal outcomes were compared with the retrospective cohort (RC; n = 46), and data from the Zurich Center for Fetal Diagnosis and Therapy (ZCFDT; n = 40) and the Children's Hospital of Philadelphia (CHOP; n = 100), all using traditional tocolysis. The analysis included five major perinatal complications (Clavien-Dindo classification, C-Dc) which developed before the end of 34 weeks of gestation (GA, gestational age). None of the newborns was delivered before 30 GA. Only two women presented with grade 3 complications and none with 4th or 5th grade (C-Dc). The incidence of perinatal death (3.3%) was comparable with the RC (4.3%) and CHOP data (6.1%). MgFTCH lowers the risk of major maternal and fetal complications.

Effect of preoperative low-normal cervical length on perinatal outcome after laparotomy-assisted fetoscopic spina bifida repair

OBJECTIVE

To determine if preoperative cervical length in the low-normal range increases the risk of adverse perinatal outcome in patients undergoing fetoscopic spina bifida repair.

METHODS

This was a retrospective cohort study of patients who underwent fetal spina bifida repair between September 2014 and May 2022 at a single center. Cervical length was measured on transvaginal ultrasound during the week before surgery. Eligibility for laparotomy-assisted fetoscopic spina bifida repair was as per the criteria of the Management of Myelomeningocele Study, although maternal body mass index (BMI) up to 40 kg/m² was allowed. Laparotomy-assisted fetoscopic spina bifida repair was performed, with carbon dioxide insufflation via two 12-French ports in the exteriorized uterus. All patients received the same peri- and postoperative tocolysis regimen, including magnesium sulfate, nifedipine and indomethacin. Postoperative follow-up ultrasound scans were performed either weekly (< 32 weeks' gestation) or twice a week (≥ 32 weeks). Perinatal outcome was compared between patients with a preoperative cervical length of 25-30 mm vs those with a cervical length > 30 mm. Logistic regression analyses and generalized linear mixed regression analyses were used to predict delivery at less than 30, 34 and 37 weeks' gestation.

RESULTS

The study included 99 patients with a preoperative cervical length > 30 mm and 12 patients with a cervix 25-30 mm in length. One further case which underwent spina bifida repair was excluded because cervical length was measured > 1 week before surgery. No differences in maternal demographics, gestational age (GA) at surgery, duration of surgery or duration of carbon dioxide uterine insufflation were observed between groups. Cases with low-normal cervical length had an earlier GA at delivery (median (range), 35.2 (25.1-39.7) weeks vs 38.2 (26.0-40.9) weeks; P = 0.01), higher rates of delivery at < 34 weeks (41.7% vs 10.2%; P = 0.01) and < 30 weeks (25.0% vs 1.0%; P < 0.01) and a higher rate of preterm prelabor rupture of membranes (PPROM) (58.3% vs 26.3%; P = 0.04) at an earlier GA (mean ± SD, 29.3 ± 4.0 weeks vs 33.0 ± 2.4 weeks; P = 0.05) compared to those with a normal cervical length. Neonates of cases with low-normal cervical length had a longer stay in the neonatal intensive care unit (20 (7-162) days vs 9 (3-253) days; P = 0.02) and higher rates of respiratory distress syndrome (50.0% vs 14.4%; P < 0.01), sepsis (16.7% vs 1.0%; P = 0.03), necrotizing enterocolitis (16.7% vs 0%; P = 0.01) and retinopathy (33.3% vs 1.0%; P < 0.01). There was an association between preoperative cervical length and risk of delivery at < 30 weeks which was significant only for patients with a maternal BMI < 25 kg/m² (odds ratio, 0.37 (95% CI, 0.07-0.81); P = 0.02).

CONCLUSIONS

Low-normal cervical length (25-30 mm) as measured before in-utero laparotomy-assisted fetoscopic spina bifida repair may increase the risk of adverse perinatal outcomes, including PPROM and preterm birth, leading to higher rates of neonatal complications. These data warrant further research and are of critical relevance for clinical teams considering the eligibility of patients for in-utero spina bifida repair. Based on this evidence, patients with a low-normal cervical length should be aware of their increased risk for adverse perinatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Are Cervical Length and Fibronectin Predictors of Preterm Birth after Fetal Spina Bifida Repair? A Single Center Cohort Study

Background: A remaining risk of fetal spina bifida (fSB) repair is preterm delivery. This study assessed the value of preoperative cervical length (CL), CL dynamics (∆CL) and fetal fibronectin (fFN) tests to predict obstetric complications and length of stay (LOS) around fSB repair. Methods: 134 patients were included in this study. All patients had CL measurement and fFN testing before fSB repair. ∆CL within the first 14 days after intervention and until discharge after fSB repair were compared in groups (∆CL ≥ 10 mm/<10 mm; ≥20 mm/<20 mm). CL before surgery, ∆CL’s, and positive fFN tests were correlated to obstetric complications and LOS. Results: Mean CL before surgery was 41 ± 7 mm. Mean GA at birth was 35.4 ± 2.2 weeks. In the group of ∆CL ≥ 10 mm within the first 14 days after intervention, LOS was significantly longer (p = 0.02). ∆CL ≥ 10 mm until discharge after fSB was associated with a significantly higher rate of GA at birth <34 weeks (p = 0.03). The 3 positive fFN tests before fSB repair showed no correlation with GA at birth. Conclusion: Perioperative ∆CL influences LOS after fetal surgery. ∆CL ≥ 10 mm until discharge after fSB repair has a 3-times higher rate of preterm delivery before 34 weeks. Preoperative fFN testing showed no predictive value for preterm birth after fSB repair and was stopped.

Anesthesia for fetal operative procedures: A systematic review

Objective

The anesthetic management of fetal operative procedures (FOP) is a highly debated topic. Literature on fetal pain perception and response to external stimuli is rapidly expanding. Nonetheless, there is no consensus on the fetal consciousness nor on the instruments to measure pain levels. As a result, no guidelines or clinical recommendations on anesthesia modality during FOP are available. This systematic literature review aimed to collect the available knowledge on the most common fetal interventions, and summarize the reported outcomes for each anesthetic approach. Additional aim was to provide an overall evaluation of the most commonly used anesthetic agents.

Methods

Two systematic literature searches were performed in Embase, Medline, Web of Science Core Collection and Cochrane Central Register of Controlled Trials up to December 2021. To best cover the available evidence, one literature search was mostly focused on fetal surgical procedures; while anesthesia during FOP was the main target for the second search. The following fetal procedures were included: fetal transfusion, laser ablation of placental anastomosis, twin-reversed arterial perfusion treatment, fetoscopic endoluminal tracheal occlusion, thoraco-amniotic shunt, vesico-amniotic shunt, myelomeningocele repair, resection of sacrococcygeal teratoma, ligation of amniotic bands, balloon valvuloplasty/septoplasty, ex-utero intrapartum treatment, and ovarian cyst resection/aspiration. Yielded articles were screened against the same inclusion criteria. Studies reporting anesthesia details and procedures’ outcomes were considered. Descriptive statistical analysis was performed and findings were reported in a narrative manner.

Results

The literature searches yielded 1,679 articles, with 429 being selected for full-text evaluation. A total of 168 articles were included. Overall, no significant differences were found among procedures performed under maternal anesthesia or maternal-fetal anesthesia. Procedures requiring invasive fetal manipulation resulted to be more effective when performed under maternal anesthesia only. Based on the available data, a wide range of anesthetic agents are currently deployed and no consistency has been found neither between centers nor procedures.

Conclusions

This systematic review shows great variance in the anesthetic management during FOP. Further studies, systematically reporting intraoperative fetal monitoring and fetal hormonal responses to external stimuli, are necessary to identify the best anesthetic approach. Additional investigations on pain pathways and fetal pain perception are advisable.

Percutaneous/mini-laparotomy fetoscopic repair of open spina bifida: a novel surgical technique

Open spina bifida (OSB) is the most common congenital anomaly of the central nervous system compatible with life. Prenatal repair of open spina bifida via open maternal-fetal surgery has been shown to improve postnatal neurological outcomes, including reducing the need for ventriculoperitoneal shunting and improving lower neuromotor function. Fetoscopic repair of OSB minimizes the maternal risks while providing similar neurosurgical outcomes to the fetus. Two fetoscopic techniques are currently in use: (1) the laparotomy-assisted approach, and (2) the percutaneous approach. The laparotomy-assisted fetoscopic technique appears to be associated with less risk of preterm birth compared to the percutaneous approach. However, the percutaneous approach avoids laparotomy and uterine exteriorization, and is associated with less anesthesia risk and improved maternal post-surgical recovery. The purpose of this paper is to describe our experience with a novel surgical approach, which we call percutaneous/mini-laparotomy fetoscopy (PML), in which access to the uterus for one of the ports is done via a mini-laparotomy, while the other ports are inserted percutaneously. This technique draws on the benefits of both the laparotomy-assisted and the percutaneous techniques, while minimizing their drawbacks. This surgical approach may prove invaluable in the prenatal repair of open spina bifida as well as other complex fetal surgical procedures.

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

OBJECTIVE

To compare the perinatal outcomes between pregnancies with and those without iatrogenic chorioamniotic separation (iCAS) following fetoscopic intervention.

METHODS

We performed a search in PubMed, EMBASE, Scopus, Web of Science and Google Scholar from inception up to December 2020 for studies comparing perinatal outcomes between pregnancies that developed and those that did not develop iCAS after fetoscopic intervention for twin-to-twin transfusion syndrome (TTTS), open neural tube defect (ONTD) or congenital diaphragmatic hernia. A random-effects model was used to pool the mean differences (MD) or odds ratios (OR) and the corresponding 95% CI. The primary outcome was neonatal survival. Secondary outcomes included gestational age (GA) at intervention and at delivery, interval from intervention to delivery and incidence of preterm prelabor rupture of membranes (PPROM) and preterm delivery. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa scale.

RESULTS

The search identified 348 records, of which seven studies (six on fetoscopic laser photocoagulation (FLP) for TTTS and one on fetoscopic repair for ONTD) assessed the perinatal outcomes of pregnancies that developed iCAS after fetoscopic intervention. Given that only one study reported on fetoscopic ONTD repair, the meta-analysis was limited to TTTS pregnancies and included six studies (total of 1881 pregnancies). Pregnancies that developed iCAS after FLP for TTTS, compared with those that did not, had significantly lower GA at the time of intervention (weeks) (MD, -1.07 (95% CI, -1.89 to -0.24); P = 0.01) and at delivery (weeks) (MD, -1.74 (95% CI, -3.13 to -0.34); P = 0.01) and significantly lower neonatal survival (OR, 0.41 (95% CI, 0.24-0.70); P = 0.001). In addition, development of iCAS after FLP for TTTS increased significantly the risk for PPROM < 34 weeks' gestation (OR, 3.98 (95% CI, 1.76-9.03); P < 0.001) and preterm delivery < 32 weeks (OR, 1.80 (95% CI, 1.16-2.80); P = 0.008).

CONCLUSIONS

iCAS is a common complication after FLP for TTTS. In patients undergoing FLP for TTTS, iCAS develops more often with earlier GA at intervention and is associated with earlier GA at delivery, higher risk of PPROM < 34 weeks' gestation and preterm delivery < 32 weeks and lower neonatal survival. Given the limitations of this meta-analysis and lack of literature reporting on other types of fetoscopic intervention, the presented findings should be interpreted with caution and should not be generalized to fetoscopic procedures used to treat other fetal conditions. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

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

BACKGROUND

Recent studies have compared maternal and neonatal outcomes associated with fetoscopic surgical approach for repair of myelomeningocele compared with an open approach.

OBJECTIVE

In this study, we compared the cost-effectiveness of these techniques in the setting of a woman seeking future pregnancies.

STUDY DESIGN

A decision-analytical model using TreeAge software was designed to compare the costs and outcomes of fetoscopic vs open repair in patients with prenatally diagnosed myelomeningocele. We assumed a theoretical cohort of 500 women with a pregnancy affected by myelomeningocele planning to have a future pregnancy. Our model accounted for costs and quality-adjusted life years of the woman, the neonate with myelomeningocele, and the neonate in a subsequent pregnancy. Neonatal outcomes from the incident pregnancy included motor function >2 levels better than the anatomic level, motor function <2 levels better than the anatomic level, and same motor function as the anatomic level, preterm birth in the index pregnancy, neonatal death in the index pregnancy, and major neurodevelopmental disability as a result of preterm birth in the index pregnancy. Neonatal outcomes in the subsequent pregnancy included stillbirth, preterm birth, and neonatal and major neurodevelopmental disability as a result of preterm birth. Probabilities were derived from the literature, and we used a willingness-to-pay threshold of $100,000 per quality-adjusted life year.

RESULTS

In the index pregnancy, fetoscopic surgical technique resulted in 140 fewer cases of preterm birth and fewer cases of neurodevelopmental disability and neonatal death. Fetoscopic technique resulted in 130 more cases of functional level >2 levels better than the anatomic level, 35 fewer cases of functional level >2 levels worse than the anatomic level, and 107 fewer cases of function same as the anatomic level. In the subsequent pregnancy, fetoscopic surgery led to 22 fewer cases of delivery complications (uterine dehiscence, uterine rupture, and excessive bleeding), 24 fewer cases of stillbirth, and 22 fewer cases of preterm birth. Although the fetoscopic approach was more costly, it was cost-effective with an incremental cost-effectiveness ratio of $1029 per quality-adjusted life year in our theoretical cohort of 500 patients. Monte Carlo probabilistic sensitivity analysis showed that fetoscopic technique is cost-effective 100% of the time.

CONCLUSION

In our theoretical cohort, the fetoscopic approach was more costly, but resulted in improved outcomes when a subsequent pregnancy was considered.

Role of Imaging in Obstetric Interventions: Criteria, Considerations, and Complications

US has an established role in the prenatal detection of congenital and developmental disorders. Many pregnant women undergo US at 18-20 weeks of gestation for assessment of fetal anatomy and detection of structural anomalies. With advances in fetoscopy and minimally invasive procedures, in utero fetal interventions can be offered to address some of the detected structural and physiologic fetal abnormalities. Most interventions are reserved for conditions that, if left untreated, often cause in utero death or a substantially compromised neonatal outcome. US is crucial for preprocedural evaluation and planning, real-time procedural guidance, and monitoring and assessment of postprocedural complications. Percutaneous needle-based interventions include in utero transfusion, thoracentesis and placement of a thoracoamniotic shunt, vesicocentesis and placement of a vesicoamniotic shunt, and aortic valvuloplasty. Fetoscopic interventions include myelomeningocele repair and tracheal balloon occlusion for congenital diaphragmatic hernia. In rare cases, open hysterotomy may be required for repair of a myelomeningocele or resection of a sacrococcygeal teratoma. Monochorionic twin pregnancies involve specific complications such as twin-twin transfusion syndrome, which is treated with fetoscopic laser ablation of vascular connections, and twin reversed arterial perfusion sequence, which is treated with radiofrequency ablation. Finally, when extended placental support is necessary at delivery for repair of congenital high airway obstruction or resection of lung masses, ex utero intrapartum treatment can be planned. Radiologists should be aware of the congenital anomalies that are amenable to in utero interventions and, when necessary, consider referral to centers where such treatments are offered. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ^©RSNA, 2021.