Outcomes of laser surgery for stage I twin-twin transfusion syndrome.

OBJECTIVE: A recent randomized controlled trial (RCT) demonstrated no difference in 6 month survival in expectantly managed stage I twin-twin transfusion syndrome (TTTS) patients and those undergoing immediate laser surgery. We aimed to describe outcomes following immediate laser surgery at a single fetal surgery center. METHODS: A retrospective study of monochorionic diamniotic twins diagnosed with stage I TTTS who underwent laser surgery between 16 and 26 gestational weeks from 2006 to 2019. The primary outcome was 6 month survivorship. Intact survival was also assessed. Secondarily, outcomes were compared to the RCT expectant management group. RESULTS: Of 126 consecutive stage I TTTS patients, 114 (90.5%) met inclusion criteria. Median (range) gestational age at delivery was 34.1 (20.6-39.4) weeks. At 6 months, the proportion of patients with at-least-one survivor in the single-center-laser cohort was 97.4%, with 88.6% dual survivorship. Neurological morbidity outcomes were available in 110 pregnancies (220 fetuses). Severe neurological morbidity occurred in 2.7% (6/220), and 6 month survival without severe neurological morbidity was 90.0%. Outcomes compared favorably with the RCT expectant management group. CONCLUSIONS: Given favorable survival and neurological outcomes, laser surgery is a reasonable treatment option for stage I TTTS at experienced fetal surgery centers. Further study is warranted to optimize treatment strategies.

Selective intrauterine growth restriction (SIUGR) type II: proposed subclassification to guide surgical management.

BACKGROUND: Optimal surgical management of monochorionic diamniotic twins complicated by selective intrauterine growth restriction (SIUGR) type II is unknown. Surgical management may involve selective laser photocoagulation of communicating vessels (SLPCV), which offers the possibility of dual twin survivors versus umbilical cord occlusion (UCO) of the SIUGR twin. OBJECTIVE: To identify patient characteristics associated with SIUGR twin survival for those undergoing SLPCV. STUDY DESIGN: All patients studied were those who underwent fetal treatment for SIUGR type II at our center from 2006-2018. SIUGR type II was defined as an estimated fetal weight <10th percentile with persistent absent and/or reversed end diastolic flow in the umbilical artery of the SIUGR twin, in the absence of twin-twin transfusion syndrome. Patients were offered SLPCV versus UCO, and those undergoing SLPCV, patient characteristics associated with 30-day survival of the SIUGR twin were examined using bivariate analysis and multiple logistic regression models. RESULTS: Fifty-four consecutive SIUGR type II patients were treated, 45 via SLPCV and nine via UCO. Of the 45 SLPCV cases, there were 16 (35.6%) with SIUGR twin (and dual) survival. SIUGR twin survival appeared associated with middle cerebral artery (MCA) peak systolic velocity (psv) <1.5 multiples of the median, and forward atrial systolic flow in the ductus venosus (DV). In a post hoc analysis, we subsequently categorized patients as: SIUGR type IIa (N = 32 (71.1%)): normal MCA psv, and normal DV waveform, versus SIUGR type IIb (N = 13 (28.9%)): MCA psv ≥1.5 multiples of the median, and/or DV with absent or reversed atrial systolic flow. Thirty-day survival of the SIUGR twin was 50% for type IIa and 0% for type IIb. CONCLUSION: Over one-third of SIUGR type II patients experienced dual survival after treatment with laser surgery. Normal MCA psv and normal DV waveforms were associated with SIUGR type II survival of the SIUGR twin. Post hoc exploration and subclassification of SIUGR type II patients by preoperative Doppler indices created two groups, one (type IIa) with 50% survival and one (type IIb) with 0% survival of the SIUGR twin after laser surgery. Upon further confirmation, these findings may provide guidance for counseling patients and conducting fetal therapy.

Selective Fetal Growth Restriction Type III: Application of a Recent Expert Consensus Definition.

OBJECTIVES: Per a recent expert definition, diagnosis of selective fetal growth restriction (sFGR) in monochorionic diamniotic twins is based on an estimated fetal weight (EFW) <3% as sole criterion and/or combinations of 4 contributory criteria (1 twin EFW <10%; 1 twin abdominal circumference <10%; EFW discordance ≥25%; and smaller twin umbilical artery [UA] pulsatility index >95th percentile). We assessed these criteria in sFGR Type III (intermittent absent or reversed end-diastolic flow of the UA [iAREDF]) patients to test whether meeting the more stringent parameters of the consensus definition had worse outcomes, that is, progression to sFGR Type II (persistent AREDF) or twin-twin transfusion syndrome; or secondarily, decreased dual survivorship. METHODS: This was a retrospective study of referred sFGR Type III patients (2006-2017). Patients were retrospectively categorized using consensus criteria for 2 comparisons: 1) EFW <3% versus remaining cohort; 2) EFW <3% or met all 4 contributory criteria versus remaining cohort. RESULTS: Forty-eight patients were studied. Comparison 1: EFW <3% patients (58.3%) were not more likely to demonstrate disease progression (46.4% versus 65.0%, P = .2489) or worse dual survivorship (78.6% versus 85.0%, P = .7161). Comparison 2: EFW <3% or met all 4 contributory criteria (75.0%) patients were not more likely than the others to demonstrate progression (44.4% versus 83.3%, P = .0235) or worse dual survivorship (80.6% versus 83.3%, P = 1.0000). CONCLUSIONS: In a referred cohort of sFGR Type III patients, there was no evidence that meeting more stringent parameters of the consensus definition was associated with disease progression or dual survivorship.

Dual demise following laser surgery for twin-twin transfusion syndrome: Analysis of 52 cases at a single fetal surgery center.

OBJECTIVE: To evaluate all individual cases of dual twin demise following laser surgery for twin-twin transfusion syndrome (TTTS). METHOD: This is an analysis of all monochorionic diamniotic twin gestations with TTTS complicated by dual demise following laser surgery from 2006 to 2019. Cases were reviewed by (1) a fetal surgeon researcher and (2) a panel of independent experienced maternal-fetal medicine specialists to code an etiology of demise for the donor and recipient, and to assess for possible preventability. RESULTS: Of 753 twins that underwent laser surgery for TTTS, 52 (6.9%) had postoperative dual demise. In this subgroup, gestational age at surgery was 19.5 (16.1-24.9) weeks, and 36 (69.2%) patients were Quintero stage III and IV. The most common etiology was the spectrum of disorders leading to preterm delivery, which included cervical insufficiency, preterm premature rupture of membranes, and preterm labor (44.2% and 48.1%, donor and recipient, respectively). Some degree of preventability was estimated for 23.1% of dual demises. CONCLUSIONS: The most common cause of dual demise post laser surgery for TTTS was preterm birth, reinforcing the need for studies regarding the etiology and prevention of post-fetoscopy prematurity. Nearly one-quarter of dual demise cases were deemed potentially preventable.

Fetal blood gases after in utero carbon dioxide insufflation for percutaneous fetoscopic spina bifida repair.

BACKGROUND: Prenatal repair of open spina bifida via the percutaneous fetoscopic approach does not require maternal laparotomy, hysterotomy, or exteriorization of the uterus. This technique requires intrauterine partial CO2 insufflation. Limited data exist on the physiological effects of CO2 insufflation on human fetuses, with no data on open spina bifida repair performed using the entirely percutaneous fetoscopic surgical technique. OBJECTIVE: Our aim was to examine the effects of intrauterine partial CO2 insufflation on fetal blood gases after percutaneous fetoscopic open spina bifida repair. STUDY DESIGN: This was a prospective study of patients who underwent percutaneous fetoscopic open spina bifida repair from February 2019 to July 2020. Fetal cordocentesis of the umbilical vein was performed in cases with favorable access to the umbilical cord. The umbilical vein cord blood samples were obtained under ultrasound guidance immediately at the conclusion of the open spina bifida repair. Simultaneous maternal arterial blood gas samples were also obtained. The results are reported as median (range). RESULTS: Of the 20 patients who underwent percutaneous fetoscopic open spina bifida repair during the study period, 7 patients (35%) underwent fetal blood sampling. The gestational age at the time of surgery was 27.4 (24.0-27.9) weeks and the operative time was 183 (156-251) minutes. The CO2 exposure time was 122 (57-146) minutes with maximum pressure of 13.5 (12.0-15.0) mm Hg. Fetal umbilical vein results were as follows: pH 7.35 (7.30-7.39), partial pressure of O2 56.2 (47.1-99.9) mm Hg, partial pressure of CO2 43.8 (36.2-53.0) mm Hg, HCO3 23.9 (20.1-25.6) mmol/L, and base excess -2.2 (-4.5 to -0.4) mmol/L. Simultaneous maternal arterial blood gas results were as follows: pH 7.37 (7.28-7.42), partial pressure of O2 187.5 (124.4-405.2) mm Hg, partial pressure of CO2 36.6 (30.7-46.0) mm Hg, HCO3 21.3 (18.0-22.8) mmol/L and base excess -3.2 (-5.9 to -1.8) mmol/L. CONCLUSION: Despite prolonged CO2insufflation of the uterus, fetal umbilical vein pH and base excess values did not approach those associated with potentially pathologic fetal acidemia.

Child Temperament Outcomes After Laser Surgery for Twin-Twin Transfusion Syndrome.

OBJECTIVE: Twin-twin transfusion syndrome (TTTS) is a severe pregnancy complication of monochorionic (identical) twins that results in markedly discordant in utero environments for each twin. The aim of this study was to test for differences in temperament between former donor (hypovolemic, smaller) and recipient (hypervolemic, larger) twins with TTTS. METHODS: Parents of dual survivors aged 3 to 7 years who underwent in utero laser surgery for TTTS were surveyed using the Children's Behavior Questionnaire-Very Short Form (CBQ-VSF). The CBQ-VSF assessed 3 traits: Surgency, Negative Affect, and Effortful Control. Differences in traits between donor and recipients were assessed using a paired t test. RESULTS: We studied 85 twin pairs treated in utero for TTTS. There were no statistically significant differences in Surgency, Negative Affect, or Effortful Control between recipients and donors, although score differences for each trait varied widely among sibling pairs. CONCLUSION: Despite varied in utero environments, no temperament differences between donor and recipient monozygotic twins were found for the population as a whole. This finding may be of some reassurance to parents whose pregnancies are complicated by TTTS.

Fetal neurodevelopmental recovery in donors after laser surgery for twin-twin transfusion syndrome.

BACKGROUND: Fetal magnetic resonance imaging (MRI) and spectroscopy (MRS) provide a unique opportunity to non-invasively measure markers of neurodevelopment in survivors of twin-twin transfusion syndrome (TTTS). OBJECTIVE: To characterize fetal brain maturation after laser surgery for TTTS by measuring brain volumes and cerebral metabolite concentrations using fetal MRI + MRS. STUDY DESIGN: Prospective study of dual surviving fetuses treated with laser surgery for TTTS. At 4-5 postoperative weeks, fetal MRI was used together with novel image analysis to automatically extract major brain tissue volumes. Fetal MRS was used to measure major metabolite concentrations in the fetal brain. RESULTS: Twenty-one twin pairs were studied. The average (±SD) gestational age at MRI was 25.89 (±2.37) weeks. Total brain volume (TBV) was lower in the donors, although cerebral volumes were not different between twin pairs. Recipients showed lower proportions of cortical and cerebellar volumes, normalized to TBV and cerebral volumes. MRS data showed that biochemical differences between twin brains were related to discrepancy in their brain volumes. CONCLUSION: Although donors have a smaller TBV compared to recipients, proportionality of brain tissue volumes are preserved in donors. MRS maturational markers of fetal brain development show that recovery in donors persists 4 weeks after surgery.

Risk Factors for Co-Twin Fetal Demise following Radiofrequency Ablation in Multifetal Monochorionic Gestations.

BACKGROUND: Umbilical cord occlusion via radiofrequency ablation (RFA) is utilized to maximize outcomes of the co-twin in complicated multifetal monochorionic (MC) gestations. However, post-procedure co-twin fetal demise is of concern. OBJECTIVE: The aim of this study was to determine risk factors for co-twin fetal demise following RFA. METHODS: This is a retrospective study of MC multiples that underwent RFA. Indications for RFA included twin reversed arterial perfusion (TRAP) sequence, selective fetal growth restriction (sFGR) type II, discordant lethal anomalies, and twin-twin transfusion syndrome (TTTS) with proximate placental cord insertion sites. The primary outcome was co-twin fetal demise. Bivariate analyses and multiple logistic regression modeling of identified risk factors were conducted. RESULTS: Of 36 patients studied, surgical indications were: TRAP (n = 15, 41.7%), sFGR (n = 10, 27.8%), discordant anomalies (n = 9, 25.0%), and TTTS (n = 2, 5.6%). Nine patients (25.0%) experienced a co-twin fetal demise. In multiple logistic regression analysis, fetal growth restriction (FGR) of one co-twin was associated with increased risk of co-twin fetal demise (OR = 10.85, 95% CI 1.03-114.48, p = 0.0474) and a preoperative diagnosis of TRAP was protective against fetal demise (OR = 0.06, 95% CI 0.00-0.84, p = 0.0368). CONCLUSION: Co-twin FGR was associated with an increased risk of post-RFA demise. When compared to other indications, patients with TRAP sequence were less likely to have a co-twin demise.

Survival Outcomes by Fetal Weight Discordance after Laser Surgery for Twin-Twin Transfusion Syndrome Complicated by Donor Fetal Growth Restriction.

INTRODUCTION: Management options for treatment of twin-twin transfusion syndrome (TTTS) with severe donor intrauterine growth restriction (IUGR) include fetoscopic laser surgery and umbilical cord occlusion (UCO). We studied perinatal survival outcomes in this select group after laser surgery, stratifying patients by preoperative estimated fetal weight (EFW) discordance. METHODS: In this retrospective study of monochorionic diamniotic twin gestations with TTTS and selective donor IUGR who underwent laser surgery (2006-2017), preoperative EFW discordance was calculated ([(larger twin - smaller twin)/(larger twin)] × 100) and cases were divided into discordance strata. Severe EFW discordance was defined as >35%. The primary outcome was 30-day donor twin neonatal survival. RESULTS: The 371 cases were distributed by discordance strata: ≤20% (74 [19.9%]), 21-25% (49 [13.2%]), 26-30% (68 [18.3%]), 31-35% (53 [14.3%]), 36-40% (51 [13.7%]), 41-45% (38 [10.2%]), >45% (38 [10.2%]). Donor 30-day survival declined as the discordance strata increased: 86.5, 85.7, 83.8, 75.5, 64.7, 63.2, and 65.8% (p = 0.0046); 30-day survival was inversely associated with severe discordance (>35%) (64.6 vs. 83.2%, p < 0.0001). DISCUSSION: In TTTS cases complicated by donor IUGR with severe growth discordance, laser surgery was associated with donor survivorship greater than 60% suggesting that, in this setting, laser surgery remains a reasonable alternative treatment to UCO.

Fetoscopic Laser Ablation Therapy for Type II Vasa Previa.

BACKGROUND: In type II vasa previa, fetoscopic laser ablation has the potential to avoid prolonged hospitalization, elective prematurity, and cesarean delivery associated with traditional conservative management. OBJECTIVE: To assess the feasibility and to report perinatal outcomes of type II vasa previa patients treated via fetoscopic laser ablation. STUDY DESIGN: This is a retrospective descriptive study of all women with vasa previa treated with laser at our center between 2006 and 2019. After 2010, laser ablation of vasa previa was only offered after 31 gestational weeks. Continuous variables are expressed as means ± SD. RESULTS: 33 patients were evaluated for laser ablation of suspected vasa previa. Fifteen were not candidates (7 had type I vasa previa and 8 had no vasa previa), and the 18 remaining had type II vasa previa. Ten (56%) elected to undergo in utero laser ablation of the vasa previa vessel(s), which was successful in all patients. The mean gestational age (GA) at the time of the procedure was 28.8 ± 5.4 weeks, and the total operative time was 48.1 ± 21.3 min; there were no perioperative complications. The number of vessels lasered were distributed as follows: 1 (2 cases), 2 (5 cases), and 3 (3 cases). All patients except for 1 were subsequently managed as outpatients. The mean GA at delivery was 35.5 ± 3.2 weeks, and vaginal delivery occurred in 5 cases. The 5 patients with singletons who underwent laser ablation for primary diagnosis of type II vasa previa after the protocol change in 2010 had the following outcomes: mean GA of surgery was 32.5 ± 0.8 weeks, mean GA at delivery was 38.1 ± 1.4 weeks, vaginal delivery occurred in all cases, mean birth weight was 2,965 ± 596 g, and none were admitted to the neonatal intensive care unit. CONCLUSION: This cohort represents the largest number of vasa previa cases treated via in utero laser reported to date. Laser occlusion of type II vasa previa was technically achievable in all cases and resulted in favorable outcomes.

Percent Absent End-Diastolic Velocity in the Umbilical Artery and Donor Twin Demise after Laser Surgery for Twin-Twin Transfusion Syndrome.

INTRODUCTION: To examine the association of preoperative absent end-diastolic velocity (AEDV) and percent AEDV (%AEDV) in the umbilical artery (UA) with donor twin intrauterine fetal demise (IUFD) after laser surgery for twin-twin transfusion syndrome (TTTS). METHODS: We performed a retrospective study of stage III/IV TTTS patients who underwent laser surgery from 2006 to 2016. Donors were classified as having preoperative persistent AEDV (yes/no). %AEDV was calculated for those with AEDV as 100× the proportion of the total cardiac cycle in AEDV. Using multiple logistic regression, we tested for an association between the outcome donor IUFD and AEDV risk factors (part 1) and %AEDV (part 2). We stratified these analyses by estimated fetal weight (EFW) discordance ≥20 versus <20%. RESULTS: Of 344 cases, 153 (44.5%) donors had AEDV. Part 1 did not confirm an independent association between AEDV and donor IUFD. In the part 2 analysis of the 153 patients with AEDV, %AEDV was a positive risk factor for donor IUFD only in those with discordance (n = 129) (OR 1.04, 95% CI 1.01-1.08, p = 0.0278) when adjusting for %EFW discordance, presence of arterioarterial anastomoses, and multiparity. DISCUSSION: Among stage III/IV TTTS patients with AEDV, %AEDV was a risk factor for donor IUFD only in the presence of EFW discordance.

Membrane Separation and Perinatal Outcomes after Laser Treatment for Twin-Twin Transfusion Syndrome.

INTRODUCTION: Postoperative membrane separation is a complication of selective laser photocoagulation of communicating vessels (SLPCV) for the treatment of twin-twin transfusion syndrome (TTTS). OBJECTIVE: The aim of this work was to determine whether a quantitative grading system of membrane separation following SLPCV was associated with preterm premature rupture of membranes (PPROM) and preterm delivery (PTD). METHODS: Patients with membrane separation after SLPCV on postoperative day 1 were stratified into greatest width of separation <1 cm (Group A) or ≥1 cm (Group B) and compared to patients without separation by the following outcomes: PPROM ≤21 postoperative days, PTD <28 gestational weeks, and PTD <32 gestational weeks. RESULTS: Of 654 patients, 123 (18.8%) had membrane separation. Of these, 120 patients were eligible for study and divided into Groups A (n = 91) and B (n = 29). Multiple logistic regression analysis yielded associations with PPROM ≤21 days for Groups B (OR 8.60, 95% CI 3.38-21.90, p < 0.0001) and A (OR 2.39, 95% CI 1.05-5.40, p = 0.0369) compared to those without membrane separation. In similar models, Group B was associated with PTD <32 weeks (OR 2.41, 95% CI 1.10-5.28, p = 0.0274). CONCLUSION: Postoperative membrane separation was associated with an increased risk of PPROM ≤21 days. Membrane separation ≥1 cm had a higher risk of PTD <32 weeks.

Quantitative fetal fibronectin to predict spontaneous preterm delivery after laser surgery for twin-twin transfusion syndrome.

Our goal was to assess whether quantitative fetal fibronectin (qfFN) is associated with spontaneous preterm birth (sPTB) after laser surgery for twin-twin transfusion syndrome (TTTS). qfFN was collected within 24 hours before and after laser surgery. Aims were: (1) To determine if qfFN changed with operative fetoscopy; and (2) To estimate the number of patients needed to study the predictive value of qfFN for sPTB <28 and <32 weeks. Results are reported as median (range). Among 49 patients, there was no net difference in qfFN levels after laser surgery [0.0 ng/mL (-37 to +400), p = 0.6041]. However, patients with a qfFN increase >10 ng/mL were 19 times more likely to undergo sPTB at <28 weeks (OR = 19.5). We determined that 383 and 160 patients would be needed to achieve adequate statistical power for qfFN to be predictive of sPTB at a GA <28 weeks and <32 weeks, respectively. In conclusion, laser surgery did not alter the qfFN level within the entire cohort, but qfFN may be useful in identifying a subset of patients at increased risk of preterm delivery.

Neonatal cerebral lesions predict 2-year neurodevelopmental impairment in children treated with laser surgery for twin-twin transfusion syndrome.

OBJECTIVE: The objective of this study is to assess whether postnatally detected cerebral abnormalities are predictive of neurodevelopmental impairment (NDI) in survivors of twin-twin transfusion syndrome (TTTS) that underwent laser surgery. MATERIALS AND METHODS: Ninety-nine children treated for TTTS had neurodevelopmental assessment at age 2-years (±6 weeks). 'High-risk survivors' had cerebral imaging in the neonatal period. 'High-risk survivors' were defined as (1) delivered at <32 weeks; or (2) cerebral imaging clinically indicated. NDI was a composite outcome of: Battelle Developmental Inventory 2nd edition (BDI-2) score <70, cerebral palsy, blindness, and/or deafness. Multilevel logistic regression with robust standard errors was used to evaluate associations between cerebral lesions and NDI. RESULTS: Fifty-six children were 'high-risk survivors' and had neonatal cerebral imaging. Ten twins (18%) had at least one cerebral lesion, including grade 1-2 intraventricular hemorrhage (8), cystic periventricular leukomalacia (2), ventriculomegaly (1), and bilateral subependymal cyst (1). The risk of NDI in the 'high-risk survivors' was 7% (4/56) compared with 0% (0/43) in the remaining group. Among 'high-risk survivors', cerebral lesions were a significant risk factor for NDI (OR = 19.28, p < .001). CONCLUSIONS: Among 'high-risk survivors' of TTTS treated with laser surgery, cerebral lesions identified on neonatal imaging were associated with NDI at 2-years.

Midtrimester isolated oligohydramnios in monochorionic diamniotic multiple gestations.

OBJECTIVE: To describe the natural history and perinatal outcomes of monochorionic diamniotic twins with midtrimester isolated oligohydramnios (iOligo). MATERIALS AND METHODS: We performed a retrospective study of iOligo patients who were initially referred for the management of evolving twin-twin transfusion syndrome (TTTS) or selective intrauterine growth restriction (sIUGR). iOligo was defined as a maximum vertical pocket of amniotic fluid of ≤2 cm in the iOligo twin's sac and normal fluid level (>2 and <8 cm) in the co-twin's sac. "Group A" patients did not subsequently develop TTTS or sIUGR Type II (umbilical artery persistent absent or reversed end-diastolic flow), and "Group B" patients did develop TTTS or sIUGR Type II. Results are reported as median (range). RESULTS: Of the 828 patients with complicated monochorionic twin gestations referred for possible TTTS or sIUGR, 36 (4.3%) were initially diagnosed with iOligo. After initial consultation, two patients terminated and one was lost to follow-up, resulting in a final study population of 33. Group A had 10 patients (30.3%) and Group B had 23 patients (69.7%). In Group A, nine of the 10 were expectantly managed, resulting in a median gestational age (GA) at delivery of 34.7 (18.0-36.4) weeks, a 30-day perinatal survival of at-least-one twin of 88.9% (8/9), and dual 30-day survivors in 8/9 (88.9%). In Group B, 12 (52.2%) developed TTTS and 11 (47.8%) developed sIUGR Type II. Fifteen Group B patients had laser surgery, resulting in a median GA at delivery of 33.7 (26.4-37.1) weeks, a 30-day perinatal survival of at-least-one twin of 100% (15/15), and dual survivorship of 46.7% (7/15). CONCLUSIONS: Our findings show that the majority of patients with midtrimester iOligo have fetal growth restriction of the affected twin and subsequently progress to TTTS or sIUGR Type II.

Long-Term Outcomes After Thoracoamniotic Shunt for Pleural Effusions With Secondary Hydrops.

BACKGROUND: Congenital pleural effusion is a rare condition with an incidence of approximately one per 15,000 pregnancies. The development of secondary hydrops is a poor prognostic indicator and such cases can be managed with a thoracoamniotic shunt (TAS). Our objective is to describe postnatal outcomes in survivors after TAS placement for congenital pleural effusions. MATERIALS AND METHODS: A retrospective study of all cases with fetal pleural effusions treated between 2006 and 2016. Patients with dominant unilateral or bilateral pleural effusions complicated by secondary hydrops fetalis received TAS placement. The results are reported as median (range). RESULTS: A total of 29 patients with pleural effusion with secondary hydrops underwent TAS placement. The gestational age at the initial TAS placement was 27.6 (20.3-36.9) wk. Before delivery, hydrops resolved in 17 (58.6%) patients. The delivery gestational age was 35.7 (25.4-41.0) wk and the overall survival rate was 72.4%. Among the 21 survivors, 19 (90.5%) required admission to the neonatal intensive care unit for 15 (5-64) d. All 21 survivors had postnatal resolution of the pleural effusions. All 21 children were long-term survivors, with a median age of survivorship of 3 y 3 mo (9 mo-7 y 6 mo) at the time of last reported follow-up. CONCLUSIONS: Thoracoamniotic shunting in fetuses with a dominant pleural effusion(s) and secondary hydrops resulted in a 72% survival rate. Nearly all survivors required admission to the neonatal intensive care unit. However, a majority did not have significant long-term morbidity.

Types II and III congenital pulmonary airway malformation with hydrops treated in utero with percutaneous sclerotherapy.

OBJECTIVE: To present outcomes of fetuses with congenital pulmonary airway malformation (CPAM) treated with sclerotherapy. METHODS: Retrospective study of 8 patients with a prenatal diagnosis of CPAM type II or III with secondary hydrops treated with percutaneous sclerotherapy using 5% ethanolamine oleate (EO). All patients underwent ultrasonic measurement of the CPAM volume ratio. Results are expressed as median (range). RESULTS: Gestational age at initial sclerotherapy was 22.0 weeks (19.6-31.4); 3 patients underwent 2 procedures. Intrauterine fetal demise (IUFD) occurred in 4 cases; 2 died on postoperative day #1 (one from inadvertent intravascular EO injection); 2 died >6 weeks after the procedure. Preoperative CPAM volume ratio was 3.6 (1.6-7.8) in survivors and 2.7 (1.7-4.7) in those with IUFD. The volume of EO at the initial sclerotherapy procedure was 3 mL (2-5) in survivors and 7 mL (6-10) in IUFD cases. The gestational age at delivery of the 4 survivors was 38.4 weeks (37.4-39.3); all underwent postnatal resection. CONCLUSION: The efficacy of percutaneous sclerotherapy for CPAM types II and III remains in question. Further studies are needed to determine the optimal dose of sclerotherapy agent and the safety and efficacy of this procedure.

Risks of Preterm Premature Rupture of Membranes and Preterm Birth Post Fetoscopy Based on Location of Trocar Insertion Site.

OBJECTIVE: The objective of this study was to assess whether the location of the trocar insertion site for laser treatment of twin-twin transfusion syndrome was associated with preterm-premature rupture of membranes (PPROM) and preterm birth (PTB). STUDY DESIGN: In this study trocar location was documented in the operating room. Lower uterine segment (LUS) location was defined as any insertion <10 cm vertically from the pubic symphysis. Lateral location was defined as ≥5 cm horizontally from the midline. Patient characteristics were tested against three outcomes: PPROM ≤ 21 days postoperative, PTB < 28 weeks, and PTB < 32 weeks. For each outcome, multiple logistic models were fitted to examine the effect of trocar location, controlling for potential risk factors. RESULTS: A total of 743 patients were studied. Patients with LUS location were twice as likely as those with a more superior location to have PPROM ≤ 21 days (OR = 2.33, 1.12-4.83, p = 0.0236). Patients with both a LUS and Lateral location were over six times more likely to have PPROM ≤ 21 days (OR = 6.66, 2.36-18.78, p = 0.0003). Trocar insertion site was not associated with PTB. CONCLUSION: We found that trocar insertion in the LUS, particularly the lateral LUS, was associated with an increased risk of PPROM.

Management of twin-twin transfusion syndrome with an extremely short cervix.

The objective of this study was to describe the management and perinatal outcomes of patients with twin-twin transfusion syndrome (TTTS) and an extremely short cervical length (CL). This retrospective study examined 17 patients with TTTS and a preoperative CL ≤1.0 cm who had undergone laser surgery and perioperative cervical cerclage placement successfully. In this subset of patients, the median interval between surgery and delivery was 9.6 (range 2.1-13.9) weeks and only one patient had PPROM within 3 weeks of surgery. The median gestational age at delivery was 30.9 (range 23.1-37.6) weeks, 30-day survival of at-least-one twin was 88.2% and dual survivorship was 82.4%. Overall, patients with TTTS and a preoperative CL ≤1.0 cm who were able to undergo successful laser surgery and emergent cerclage placement had favourable outcomes. Impact statement The management of patients with twin-twin transfusion syndrome (TTTS) and extremely short cervical length (CL) varies between foetal surgery centres. This study demonstrates that laser surgery and cerclage placement in such patients are not only technically feasible, but also can result in favourable perinatal outcomes. Patients with an extremely short CL should not be uniformly excluded from laser surgery for TTTS.

The impact of laser surgery on angiogenic and anti-angiogenic factors in twin-twin transfusion syndrome: a prospective study.

OBJECTIVE: To examine the effect of laser surgery on angiogenic and anti-angiogenic factors in patients with twin-twin transfusion syndrome (TTTS). METHODS: Cases of TTTS and uncomplicated monochorionic diamniotic twin pregnancies between 16 and 26 weeks' gestation were prospectively enrolled into the study. Maternal blood samples were obtained to measure angiogenic factors (vascular endothelial growth factor-A [VEGF], placental-derived growth factor [PlGF], and endothelin) and anti-angiogenic factors (soluble fms-like tyrosine kinase (sFlt-1), soluble endoglin (sEng), and sFlt-1/PlGF ratio). For cases, these factors were measured at visit 1 (pre-operatively), visit 2 (postoperative day one), and visit 3 (at least 3 weeks after surgery). In controls, the factors were measured at visit 1 (enrollment) and visit 2 (at least 3 weeks later). Levels of angiogenic and anti-angiogenic factors between cases and controls were compared. RESULTS: At enrollment, the TTTS cases demonstrated an anti-angiogenic state with significantly higher sFlt-1, sEng, sFlt-1/PlGF ratio, and lower PlGF. Laser surgery, comparing visit 1-3, had a partial corrective effect on TTTS cases. sFlt-1 significantly decreased several weeks after surgery. The other factors (PlGF, endothelin, sFlt-1, sEng, and sFlt-1/PlGF ratio) were not statistically significantly different by visit 3. CONCLUSION: Laser surgery partially corrected the angiogenic profile in patients with TTTS.