Fetal lower urinary tract obstruction: international Delphi consensus on management and core outcomes set.

OBJECTIVE: To reach a Delphi-generated international expert consensus on the diagnosis, prognostic, management, and core outcome set (COS) of fetal Lower Urinary Tract Obstruction (LUTO). METHODS: A three-round Delphi procedure was conducted among an international panel of LUTO experts. The panel was provided with a list of literature review-generated parameters for the diagnosis, prognostic, management, and outcomes. A parallel procedure was conducted along with patient groups during the development of COS. RESULTS: A total of 160 experts were approached, of whom 99 completed the first round and 80 (80/99, 80.8%) completed all three rounds. In the first trimester, an objective measurement of longitudinal bladder diameter (with ≥7 mm being abnormal) should be used to suspect LUTO. In the second trimester, imaging parameters of LUTO could include: a) an enlarged bladder, b) a keyhole sign, c) bladder wall thickening, d) bilateral hydro (uretero) nephrosis, and e) male sex. There was a lack of consensus on the current prognostic scoring literature. However, experts agreed on the value of amniotic fluid volume (< 24 weeks) to predict survival and that the value of fetal intervention is to improve neonatal survival. While experts endorsed the role of sonographic parameters of renal dysplasia, at least one vesicocentesis, and urine biochemistry for prognosis and counseling, these items did not reach a consensus for determining fetal intervention candidacy. On the other hand, imaging parameters suggestive of LUTO, absence of life-limiting structural or genetic anomalies, gestational age of ≥16 weeks, and oligohydramnios defined as deepest vertical pocket (DVP) <2 cm should be used as candidacy criteria for fetal intervention based on experts' consensus. If a bladder refill was evaluated, it should be assessed subjectively. Vesicoamniotic shunt should be the first line of fetal intervention. In the presence of suspected fetal renal failure, serial amnioinfusion should only be offered as an experimental procedure under research protocols. The core outcome set for future studies was agreed upon. CONCLUSION: International consensus on the diagnosis, prognosis, and management of fetal LUTO, as well as the Core Outcome Set, should inform clinical care and research to optimize perinatal outcomes. This article is protected by copyright. All rights reserved.

Percutaneous fetoscopic spina bifida repair: effect on ambulation and need for postnatal cerebrospinal fluid diversion and bladder catheterization.

OBJECTIVE: A trial comparing prenatal with postnatal open spina bifida (OSB) repair established that prenatal surgery was associated with better postnatal outcome. However, in the trial, fetal surgery was carried out through hysterotomy. Minimally invasive approaches are being developed to mitigate the risks of open maternal-fetal surgery. The objective of this study was to investigate the impact of a novel neurosurgical technique for percutaneous fetoscopic repair of fetal OSB, the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique, on long-term postnatal outcome. METHODS: This study examined descriptive data for all patients undergoing fetoscopic OSB repair who had available 12- and 30-month follow-up data for assessment of need for cerebrospinal fluid (CSF) diversion and need for bladder catheterization and ambulation, respectively, from eight centers that perform prenatal OSB repair via percutaneous fetoscopy using a biocellulose patch between the neural placode and skin/myofascial flap, without suture of the dura mater (SAFER technique). Univariate and multivariate logistic regression analyses were used to examine the effect of different factors on need for CSF diversion at 12 months and ambulation and need for bladder catheterization at 30 months. Potential cofactors included gestational age at fetal surgery and delivery, preoperative ultrasound findings of anatomical level of the lesion, cerebral lateral ventricular diameter, lesion type and presence of bilateral talipes, as well as postnatal findings of CSF leakage at birth, motor level, presence of bilateral talipes and reversal of hindbrain herniation. RESULTS: A total of 170 consecutive patients with fetal OSB were treated prenatally using the SAFER technique. Among these, 103 babies had follow-up at 12 months of age and 59 had follow-up at 30 months of age. At 12 months of age, 53.4% (55/103) of babies did not require ventriculoperitoneal shunt or third ventriculostomy. At 30 months of age, 54.2% (32/59) of children were ambulating independently and 61.0% (36/59) did not require chronic intermittent catheterization of the bladder. Multivariate logistic regression analysis demonstrated that significant prediction of need for CSF diversion was provided by lateral ventricular size and type of lesion (myeloschisis). Significant predictors of ambulatory status were prenatal bilateral talipes and anatomical and functional motor levels of the lesion. There were no significant predictors of need for bladder catheterization. CONCLUSION: Children who underwent prenatal OSB repair via the percutaneous fetoscopic SAFER technique achieved long-term neurological outcomes similar to those reported in the literature after hysterotomy-assisted OSB repair. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Percutaneous fetoscopic closure of large open spina bifida using a bilaminar skin substitute.

OBJECTIVE: We have described previously our percutaneous fetoscopic technique for the treatment of open spina bifida (OSB). However, approximately 20-30% of OSB defects are too large to allow primary skin closure. Here we describe a modification of our standard technique using a bilaminar skin substitute to allow closure of large spinal defects. The aim of this study was to report our clinical experience with the use of a bilaminar skin substitute and a percutaneous fetoscopic technique for the prenatal closure of large OSB defects. METHODS: Surgery was performed between 24.0 and 28.9 gestational weeks with the woman under general anesthesia, using an entirely percutaneous fetoscopic approach with partial carbon dioxide insufflation of the uterine cavity, as described previously. If there was enough skin to be sutured in the midline, only a biocellulose patch was placed over the placode (single-patch group). In cases in which skin approximation was not possible, a bilaminar skin substitute (two layers: one silicone and one dermal matrix) was placed over the biocellulose patch and sutured to the skin edges (two-patch group). The surgical site was assessed at birth, and long-term follow-up was carried out. RESULTS: Percutaneous fetoscopic OSB repair was attempted in 47 consecutive fetuses, but surgery could not be completed in two. Preterm prelabor rupture of membranes (PPROM) occurred in 36 of the 45 (80%) cases which formed the study group, and the mean gestational age at delivery was 32.8 ± 2.5 weeks. A bilaminar skin substitute was required in 13/45 (29%) cases; in the remaining 32 cases, direct skin-to-skin suture was feasible. There were 12 cases of myeloschisis, of which 10 were in the two-patch group. In all cases, the skin substitute was located at the surgical site at birth. In five of the 13 (38.5%) cases in the two-patch group, additional postnatal repair was needed. In the remaining cases, the silicone layer detached spontaneously from the dermal matrix (on average, 25 days after birth), and the lesion healed by secondary intention. The mean operating time was 193 (range, 83-450) min; it was significantly longer in cases requiring the bilaminar skin substitute (additional 42 min on average), although the two-patch group had similar PPROM rate and gestational age at delivery compared with the single-patch group. Complete reversal of hindbrain herniation occurred in 68% of the 28 single-patch cases and 33% of the 12 two-patch cases with this information available (P < 0.05). In four cases there was no reversal; half of these occurred in myeloschisis cases. CONCLUSIONS: Large OSB defects may be treated successfully in utero using a bilaminar skin substitute over a biocellulose patch through an entirely percutaneous approach. Although the operating time is longer, surgical outcome is similar to that in cases closed primarily. Cases with myeloschisis seem to have a worse prognosis than do those with myelomeningocele. PPROM and preterm birth continue to be a challenge. Further experience is needed to assess the risks and benefits of this technique for the management of large OSB defects. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Early prediction of twin-to-twin transfusion syndrome: systematic review and meta-analysis.

OBJECTIVE: To assess the role of first- and early second-trimester markers in the prediction of twin-to-twin transfusion syndrome (TTTS) in monochorionic twin pregnancies. METHODS: Electronic databases MEDLINE, EMBASE and ClinicalTrials.gov were searched from inception to April 2014, using the MeSH term 'fetofetal transfusion' in combination with phrases 'predictive value', 'sensitivity', 'specificity', 'false positive', 'false negative', 'screening', 'accuracy' and 'ROC'. Study quality was assessed using the PRISMA guidelines and QUADAS-2 tool. A meta-analysis was planned for the following predictive factors: intertwin nuchal translucency (NT) discrepancy; NT > 95th percentile in at least one twin; intertwin crown-rump length (CRL) discrepancy as a percentage of the larger CRL; abnormal ductus venosus (DV) flow in at least one twin. The outcome assessed was TTTS, defined according to the presence of a twin oligohydramnios-polyhydramnios sequence. The diagnostic performance of the predictive factors was evaluated for each included study. RESULTS: The electronic search identified 152 records, of which 23 were assessed in full for eligibility. We identified 13 eligible studies that reported the predictive accuracy of ultrasound parameters, measured before 16 weeks, for the development of TTTS, including a total of 1991 pregnancies, of which 323 developed TTTS. An increased risk of TTTS was associated with: intertwin NT discrepancy (positive likelihood ratio (LR+), 1.92 (95% CI, 1.25-2.96); negative likelihood ratio (LR-), 0.65 (95% CI, 0.50-0.84)); NT > 95th percentile (LR+, 2.63 (95% CI, 1.51-4.58); LR-, 0.85 (95% CI, 0.75-0.96)); CRL discrepancy > 10% (LR+, 1.80 (95% CI, 1.05-3.07); LR-, 0.92 (95% CI, 0.81-1.05)); abnormal DV flow (LR+, 4.77 (95% CI, 1.33-17.04; LR-, 0.49 (95% CI, 0.17-1.41)). The highest sensitivities were observed for intertwin NT discrepancy (52.8% (95% CI, 43.8-61.7%)) and abnormal DV flow (50.0% (95% CI, 33.4-66.6%)). CONCLUSION: Monochorionic twin pregnancies with intertwin NT discrepancy, NT > 95th percentile, intertwin CRL discrepancy > 10% or abnormal DV flow on first-trimester ultrasound examination are at significantly increased risk of developing TTTS. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Selective laser photocoagulation of communicating vessels in severe twin-twin transfusion syndrome in women with an anterior placenta.

BACKGROUND: We describe two techniques for the laser treatment of twin-twin transfusion syndrome in women with anterior placentas. TECHNIQUE: In the first technique, anastomoses were photocoagulated using a flexible endoscope through a single port. The second technique used a side-firing laser fiber with a rigid angled-view endoscope (two ports). EXPERIENCE: Seventy-two women had surgery between July 1997 and December 1999, 35 (48.6%) of whom had anterior placentas. Survival was similar for fetuses with anterior (80%) and posterior (75.6%) placentas, but operating time was significantly longer for those with anterior placentas (81.1 compared with 64.4 minutes for the anterior and posterior placentas, respectively; P = .02, Student t test). At least one fetus survived in 76% (16 of 21) of women treated with flexible endoscopes and 86% (12 of 14) of those treated with the side-firing lasers. Six of 72 women (8.3%) had patent vascular anastomoses on placental examination, and five of them had anterior placentas (P = .08, Fisher exact test). CONCLUSION: Although anterior placentas are surgically more challenging than posterior placentas, both techniques allow an effective percutaneous approach to the laser treatment of twin-twin transfusion syndrome.

Fetal muscle biopsy: collaborative experience with varied indications.

OBJECTIVE: To develop a fetal muscle biopsy technique for immunohistochemical diagnosis of Duchenne and Becker muscular dystrophies. METHODS: Data from two clinical centers and one reference laboratory were combined to show 12 completed cases, ten at risk for Duchenne muscular dystrophy, one for Becker muscular dystrophy, and one for mitochondrial myopathy. Samples of fetal gluteal muscle were obtained percutaneously under ultrasound guidance (some with endoscopic assistance) with a biopsy gun. The samples were frozen and assayed for dystrophin by immunohistochemical techniques. RESULTS: Samples were obtained in 11 of 12 (92%) cases, and spontaneous abortion after the procedure occurred in two of 12 (17%) cases. Laboratory diagnoses were possible on small samples, and four of 12 fetuses (33%) were affected. Endoscopy with direct visualization might aid in the procedure. CONCLUSIONS: The development of fetal muscle biopsy allows for an expansion of the diagnostic possibilities for myopathies. The experiences of our two clinical centers show that the procedure can be done with accuracy and acceptable safety. The evolving laboratory experience has reduced the amount of tissue necessary for the diagnosis, increased the sophistication of the immunohistochemical analysis, allowed the diagnosis of abnormalities in different parts of the dystrophin gene, and expanded the indications for the use of fetal muscle biopsy. Fetal muscle biopsy can be used successfully for the diagnosis in otherwise uninformative cases, and there is a wide variety of indications beyond traditional Duchenne muscular dystrophy possible, including female fetuses at risk because of X-autosomal translocations.

Embryoscopy and fetoscopy.

The introduction of transabdominal fiberoptic thin-gauge visualization of the embryo or fetus in the first trimester allows an earlier diagnosis of congenital anomalies currently beyond the resolution of ultrasound. In addition, it has the true potential of providing access to the fetal circulation at an early age, an accomplishment that would have enormous diagnostic and therapeutic implications. In the second and third trimester, operative fetoscopic techniques promise to open a new frontier in the diagnosis and management of fetal surgical and medical conditions.

Staging of twin-twin transfusion syndrome.

OBJECTIVE: The purpose of this study was to evaluate the prognostic value of sonographic and clinical parameters to develop a staging classification of twin-twin transfusion syndrome (TTTS). STUDY DESIGN: Severe TTTS was defined as the presence of polyhydramnios (maximum vertical pocket of > or = 8 cm) and oligohydramnios (maximum vertical pocket of < or = 2 cm). Nonvisualization of the bladder in the donor twin (-BDT) and absence of presence of hydrops was also noted. The middle cerebral artery, umbilical artery, ductus venosus, and umbilical vein in both fetuses were assessed with pulsed Doppler. Critically abnormal Doppler studies (CADs) were defined as absent/reverse end-diastolic velocity in the umbilical artery, reverse flow in the ductus venosus, or pulsatile flow in the umbilical vein. TTTS was staged as follows: stage I, BDT still visible; stage II, BDT no longer visible, no CADs; stage III, CADs; stage IV, hydrops; stage V, demise of one or both twins. Laser photocoagulation of communicating vessels (LPCV) or umbilical cord ligation was performed depending on the severity of the condition. The study was approved by the Institutional Review Board of St. Joseph's Hospital in Tampa and by the Fetal Therapy Board at Hutzel Hospital, Detroit, and all patients gave informed consent. RESULTS: A total of 80 of 108 referred patients met criteria for surgery, but only 65 were treated surgically: 48 with LPCV and 17 with umbilical cord ligation. Complete Doppler data were obtainable in 41 of 48 LPCV patients. Survival rates by stage for one or two fetuses were statistically different (chi-squared analysis = 12.9, df = 6, p = 0.044). Neither percent size discordance nor gestational age at diagnosis were predictive of outcome. CONCLUSION: Staging of TTTS using the proposed criteria has prognostic significance. This staging system may allow comparison of outcome data of TTTS with different treatment modalities.

New horizons in the treatment of preterm premature rupture of membranes.

In the last 5 years, significant experience has been gained in the clinical understanding and treatment of PPROM. From this work, one can conclude that iatrogenic PPROM is not only a different entity etiologically, but also in its clinical behavior and response to therapeutic measures. The current success rate with the amniopatch allows the author [figure: see text] to suggest that iatrogenic PPROm should no longer be viewed as a devastating complication of pregnancy. Instead, it should be viewed as a readily treatable condition with the aminopatch. Regarding spontaneous PPROM, work suggests that perhaps, in a select group of patients in which infection has not set in and in which a smaller and better defined membrane defect may exist, there is the potential for developing a surgical technique that may successfully graft the defect and allow the integrity of the amniotic membrane to be restored. The actual surgical technique, the materials to be used, and the approach (transabdominal versus transcervical) are all areas of research for the future. Meanwhile, continued efforts are warranted to decipher whether this obstetric complication can one day be conquered.

Ethical issues surrounding multifetal pregnancy reduction and selective termination.

MFPR and selective terminations satisfy the criteria of enabling pregnancies to continue with the least harm and most benefits to all involved. The surviving infants can be saved from certain death (abortion) or higher risks of severe harm and death and of an extended stay in neonatal intensive care (premature delivery). In the hands of trained operators, MFPR and selective termination is, in our opinion, the best means to protect the mother's health and well-being, given it is available and approved by the parents. MFPR and selective termination avoid the trauma of abortion of a wanted pregnancy, enable the parents to achieve the goal of having their own child, and avoid the dangers of delivery of multiple premature infants. There is no doubt that any procedure that involves the death of a fetus will be hotly argued despite the potential for greater good. We acknowledge that it will be impossible to convince those who cannot morally accept the taking of any life regardless of the circumstances. We hope, however, that we have shown there is a place for MFPR and selective termination in a very limited number of circumstances and the ethical probity of MFPR and selective termination as an option in such cases.

In vivo endoscopic assessment of arterioarterial anastomoses: insight into their hemodynamic function.

OBJECTIVE: To assess endoscopically the hemodynamic function of arterioarterial (AA) anastomoses in twin-twin transfusion syndrome (TTTS) and monochorionic selective intrauterine growth restriction (IUGR). MATERIALS AND METHODS: The videotapes of TTTS and IUGR patients undergoing laser surgery between July 1997 and December 2001 were reviewed for the presence of AA anastomoses. The hemodynamic equator was defined as the site within the AA anastomosis with color flashing. AA anastomoses were classified as having unidirectional flow, having bi-directional flow, or being non-functional, depending on whether the hemodynamic equator reached a returning vein to one, both, or neither twin, respectively. TTTS was classified in stages as previously described. RESULTS: AA anastomoses were present in 35/183 (19.1%) of TTTS and in 12/24 (50%) IUGR patients. Of these, the hemodynamic equator was visible in 8/35 (22.8%) TTTS patients (all in stage III, and mostly in atypical stage III) and in 6/12 (50%) IUGR patients (overall 14/47, 29.8%). Of the 14 patients with a visible hemodynamic equator, 13 (92.8%) AA anastomoses showed unidirectional (9/13, 69.2% from the smaller to the larger twin) flow, and only 1/14 (7.1%) showed bi-directional flow. CONCLUSION: The hemodynamic equator is visible in approximately 30% of patients with AA anastomoses. Within this group, most AA anastomoses behave as functional arteriovenous anastomoses, and the direction of flow can be from the smaller to the larger twin or vice versa. The data suggest a correlation between sonographic findings and placental vascular design, also implying possible interfetal oxygenation differences. Further assessment of the functional behavior of AA anastomoses is warranted to understand the pathophysiology of TTTS and selective IUGR.

Twin-twin transfusion syndrome with only superficial placental anastomoses: endoscopic and pathological evidence.

Deep arteriovenous placental anastomoses in monochorionic placentas have been considered an essential etiological factor in twin-twin transfusion syndrome (TTTS). Moreover, some investigators have suggested that superficial anastomoses have a protective role. We report on confirmed cases of TTTS with only superficial anastomoses.

Umbilical cord transection in twin-reverse arterial perfusion syndrome with the use of a coaxial bipolar electrode (Versapoint).

Umbilical-cord occlusion has been proposed for the treatment of twin-reverse arterial perfusion syndrome (TRAP). Transection of the umbilical cord is necessary in patients with monoamniotic or 'pseudomonoamniotic' TRAP to avoid subsequent cord entanglement and demise of the pump twin. We present a case of TRAP in which the umbilical cord was successfully ligated with suture and transected with the Versapoint electrode.

Twin-twin transfusion syndrome in a dizygotic monochorionic-diamniotic twin pregnancy.

We present a case of twin-twin transfusion syndrome with discordant gender. Monochorionicity was confirmed by surgical pathology. Cytogenetic analysis showed normal 46,XX and 46,XY karyotypes. Microsatellite analysis using reliable pericentromeric markers was consistent with dispermic fertilization of two separate ova. This suggests that monochorionicity, rather than zygosity, may be responsible for the development of placental vascular anastomoses.

Minimally invasive treatment of twin-to-twin transfusion syndrome.

Selective laser photocoagulation of communicating vessels (SLPCV) is an application of minimally invasive endoscopic fetal surgery (i.e., surgical fetoscopy) performed for severe cases of twin-to-twin transfusion syndrome (TTTS), a complication of monochorionic twin pregnancies. Advances in ultrasound and endoscopy have aided the identification and treatment of this potentially lethal or fatal condition. Surgical fetoscopy, an innovation in the field of surgery and maternal-fetal medicine, benefits patients by reducing the morbidity and mortality associated with TTTS, with minimal risks to the mother.

Percent absent end-diastolic velocity in the umbilical artery waveform as a predictor of intrauterine fetal demise of the donor twin after selective laser photocoagulation of communicating vessels in twin-twin transfusion syndrome.

OBJECTIVE: Absent end-diastolic velocity (AEDV) in the umbilical artery of the donor twin is a known risk factor for intrauterine fetal demise (IUFD) of this fetus after selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS). The aim of this study was to assess the proportion of time, expressed as a percentage, of the cardiac cycle spent in AEDV (%AEDV) as a predictor of IUFD of the donor. METHODS: All patients referred for possible SLPCV underwent complete preoperative staging evaluation including Doppler assessment of the umbilical artery. %AEDV was calculated retrospectively as 100 x (time of the cycle spent in AEDV divided by duration of total cardiac cycle). Patients without AEDV were considered to have a %AEDV of 0. Follow-up Doppler studies were performed 16-24 h after SLPCV. IUFD of the donor was recorded if the donor twin died any time prior to delivery. RESULTS: Of 401 patients undergoing SLPCV, 127 had AEDV. Preoperative AEDV of the donor twin was associated with an increased risk of IUFD of the donor (40.9% vs. 14.2%, P < 0.0001). %AEDV was measured in 72/127 (56.7%) donors with AEDV for whom digital images were available. Within these 72 patients, the mean %AEDV was significantly higher in patients with IUFD of the donor (36.5% vs. 29.6%, P = 0.01). IUFD of the donor was similar in patients with AEDV, regardless of whether %AEDV was measured (36% vs. 47%, P = 0.2). A %AEDV > 30 was associated with a 4.3-fold increase in the risk of IUFD of the donor (95% CI, 1.4-12.7), a sensitivity of 77% and a negative predictive value of 81.3%. Logistic regression showed that %AEDV, but not number of anastomoses, placental location, presence of artery-to-artery anastomoses or the presence or absence of EDV was associated significantly with IUFD of the donor. CONCLUSION: %AEDV is a novel Doppler parameter in the assessment of patients with TTTS. %AEDV, rather than AEDV alone, is a significant risk factor for IUFD of the donor twin and %AEDV > 30 is associated with an increased risk of IUFD of the donor in TTTS patients treated with SLPCV. Assessment of %AEDV should be considered part of the preoperative evaluation of TTTS patients.

Percutaneous ultrasound-guided sclerotherapy for complicated fetal intralobar bronchopulmonary sequestration.

Bronchopulmonary sequestration (BPS), which can be intralobar or extralobar, is a rare developmental anomaly of the lung characterized by nonfunctional pulmonary tissue without communication with the tracheobronchial tree and with an aberrant systemic arterial blood supply. The intralobar type is typically within the pleural cavity with an arterial feeding vessel generally arising from the thoracic aorta and with venous drainage into the left atrium. The prognosis is poor in cases diagnosed before 26 weeks' gestation and when there is mediastinal shift, polyhydramnios and fetal hydrops. The ideal prenatal management option remains undefined. We present a series of three complicated cases of intralobar BPS treated prenatally with percutaneous ultrasound-guided fetal sclerotherapy (FST). The feeding vessel was successfully accessed percutaneously under ultrasound guidance in all cases. FST with polidocanol resulted in complete obliteration of the blood flow to the mass. Abnormal Doppler findings, ascites, hydrops and polyhydramnios resolved and all patients were delivered at term. Antenatal treatment of patients with complicated BPS can be successfully achieved with FST, which is a simple and inexpensive technique. Comparison of risks and benefits of this approach with other techniques is warranted.

Management of twin-twin transfusion syndrome in pregnancies with iatrogenic detachment of membranes following therapeutic amniocentesis and the role of interim amniopatch.

OBJECTIVE: Detachment of membranes may occur after therapeutic amniocentesis for twin-twin transfusion syndrome (TTTS). Subsequent amniocenteses or endoscopic fetal therapy may be hindered or made altogether impossible by this complication. The purpose of this study was to describe our experience in the assessment and management of TTTS patients with iatrogenic detached membranes (IDM). METHODS: Patients with IDM referred for fetal surgery for TTTS were considered ineligible for standard surgery and were offered different alternatives, including expectant management, serial amniocentesis, or an attempt at surgery with or without prior amniopatch. Pregnancy outcomes were compared between surgical and non-surgical patients. RESULTS: Nine hundred and forty-four patients with a diagnosis of TTTS were referred between July 1997 and December 2004, of whom 322 (34.1%) had a prior therapeutic amniocentesis. Twenty-six of the 322 patients (8%) had IDM. Ten patients opted to be managed with subsequent amniocenteses, two of which had an amniopatch. One patient had voluntary interruption of pregnancy. Fifteen patients underwent surgery, 10 of whom underwent an amniopatch. Overall, resealing of membranes occurred in 8/12 (66%) patients treated with an amniopatch. Survival of at least one fetus was greater in patients treated surgically with or without an amniopatch (12/15, 80% vs. 4/11, 36%, P = 0.04). CONCLUSION: Membrane detachment is an important complication of therapeutic amniocentesis in the treatment of TTTS. Although successful treatment of IDM can be achieved with an interim amniopatch, this alternative is not without risks. Therapeutic amniocenteses should be discouraged in patients considering endoscopic fetal surgery for TTTS.