Twin-twin Transfusion Syndrome Research Articles

Placental Vascular Anastamoses and Associated Pathologies in Dichorionic Twin Gestations.

Placental vascular anastomoses are traditionally thought to exist exclusively in monochorionic pregnancies. However, they have been reported in dichorionic twin pregnancies as well. In turn, twin to twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS) have also been noted to impact some of these gestations. Through discussion of one such case at our institution along with a review of the available literature, we review the proposed pathophysiology of placental vascular anastamoses in dichorionic twin gestations, and aim to raise awareness of the possibility of associated pathologies in dichorionic gestations. This is an emerging area of literature that will require future study to guide prenatal surveillance and mitigate morbidity.

Differential postnatal cardiovascular course of donor-recipient twins and associated pathophysiology-a cohort study.

Fetal echocardiography in twin to twin transfusion pregnancies treated with photocoagulation noted impaired cardiac function. Systematic information about cardiac structure or function and arterial distensibility after birth is not available. This study evaluated cardiovascular function and arterial dynamic properties in survivors of twin to twin transfusion syndrome. Eleven pairs of donor-recipient twins were compared with each other, and with 20 singletons of comparable gestational age. The twin cohort was born at 31.5±2 weeks gestational age; birthweights of donors-recipients were comparable (donors: 1358±421g vs recipients: 1617±460g, P=0.2). Significant inter-twin differences were noted for cardiac function parameters. Recipients had greater septal thickness (donors: 2.3±0.15 vs recipients: 2.7±0.36mm, P=0.01) and globularity (lower sphericity index [donors: 1.76±0.1 vs recipients: 1.62±0.12, P=0.009]). They also had lower cardiac function (tricuspid annular plane systolic excursion [donors: 4.6±0.5 vs recipients: 4.1±0.4mm, P=0.02) and right ventricular fractional area change [donors: 30±1 vs recipients: 27.7±1.3%, P=0.0001]). Comparing with singletons, differences were statistically more significant for recipients. Arterial distensibility however, was more affected in donors (higher arterial wall stiffness index [donors: 2.5±0.2 vs recipients: 2.2±0.2, P=0.008] and lower pulsatile diameter [donors: 51±5 vs recipients: 63±10 µm, P<0.0001). Comparing with singletons, the differences were statistically more significant for donors. Evaluation in the neonatal period noted that cardiac function and arterial distensibility is affected in TTTS twins. These cohorts will benefit from close postnatal follow up for resolution of cardiac and arterial impairments.

Features of placental angioarchitectonics with favorable and unfavorable outcome after laser coagulation of placental anastomoses

Background. One of the most common and severe complications of monochorionic pregnancy is feto-fetal transfusion syndrome (FFTS). The incidence of transfusion syndrome in monochorial diamniotic twins ranges from 10 to 15%.Objective. To analyze the angioarchitecture of the placenta in FFTS, to determine its features with a favorable and unfavorable outcome after laser coagulation of placental anastomoses (LPCA).Materials and methods. Continuous prospective, cohort, comparative study 90 pregnant women with monochorionic diamniotic twins were examined: in 60 people (the main group) the pregnancy was complicated by FFTS, in 30 patients (the comparison group) the pregnancy was characterized by a normal course; their newborns and afterbirths. The main group was divided into 2 subgroups depending on the outcome of LCPA in order to correct FFTS: subgroup 1 — favorable outcome (n=50), subgroup 2 — unfavorable outcome (n=10). Result. The angioarchitecture of the placenta in FFTS with a favorable outcome of LCPA is characterized by the presence of large arteriovenous placental anastomoses in combination with “central-central” and “central-marginal” variants of umbilical cord attachment. A larger number of anastomoses is recorded in monochorionic twins with FFTS and vascular patterns with two or more arteriovenous anastomoses (“Type B” and “Type D”), in our study they were more common with an unfavorable outcome of laser coagulation of placental anastomoses (OR = 5.23 (95%CI 2.13;12.8);p&lt;0.001).Conclusion. Angioarchitectonics of the placenta in feto-fetal transfusion syndrome with a favorable outcome of laser coagulation of placental anastomoses is characterized by the presence of large arteriovenous placental anastomoses in combination with “central-central” and “central-marginal” variants of umbilical cord confluence.

Predictive Indicators and Outcomes of Pregnancies Affected by Stage I Twin-Twin Transfusion Syndrome Treated With Fetoscopic Laser Photocoagulation.

The significance of fetoscopic laser photocoagulation (FLP) in stage I twin-twin transfusion syndrome (TTTS) remains controversial. This study aimed to clarify the outcomes and prognostic factors of stage I TTTS after FLP. We conducted a retrospective cohort study on patients with stage I TTTS who underwent FLP in Japan. The primary outcome was neonatal survival at 28days. The adjusted odds ratios (aOR) of pre- and intraoperative factors for mortality in recipient and donor twins were calculated. This study included 272 twin pairs. The survival rate of at least one twin and both twins was 98% (267 pairs) and 85% (232 pairs), respectively. Survival of the recipient twin was observed in 253 cases (93%). No factor was associated with the mortality of the recipients. Among the donor twins, 246 (90%) survived. Preoperative twin anemia-polycythemia sequence (aOR, 17.45; 95% CI, 3.16-96.31) and arterio-arterial vascular anastomosis (AAA) identified at FLP (aOR, 2.78; 95% CI, 1.10-7.06) were independently associated with mortality of the donors. The neonatal survival rate for both recipient and donor twins was >90% among patients with stage I TTTS who underwent FLP. AAA is a risk factor for mortality in donors following FLP, though the pathophysiology of AAA remains to be clarified.

Selective Extrauterine Placental Perfusion in Monochorionic Twins Is Feasible-A Case Series.

Monochorionic (MC) twins are at risk for severe twin-to-twin transfusion syndrome (TTTS) or twin anemia-polycythemia sequence (TAPS). In the case of preterm delivery, cesarean section (CS) with immediate umbilical cord clamping (ICC) of both twins is usually performed. While the recipient is at risk for polycythemia and may benefit from ICC, this procedure may result in aggravation of anemia with increased morbidity in the anemic donor. The purpose of this study was to demonstrate that the novel approach of selective extrauterine placental perfusion (EPP) with delayed umbilical cord clamping (DCC) in the donor infant is feasible in neonatal resuscitation of MC twins and may prevent severe anemia in donor and polycythemia in the recipient. Preterm MC twins with antenatal suspected severe anemia of the donor as measured by Doppler ultrasound, born with birthweights < 1500 g by CS, were transferred to the neonatal resuscitation unit with placenta and intact umbilical cords. In the donor, the umbilical cord was left intact to provide DCC with parallel respiratory support (EPP approach), while the cord of the recipient was clamped immediately after identification. Selective EPP was performed in three cases of MC twins with TAPS and acute peripartum TTTS. All donor twins had initial hemoglobin levels ≥ 13.0 g/dL, and none of them required red blood cell transfusion on the first day after birth. Selective EPP may be a feasible strategy for neonatal resuscitation of MC preterm twins with high stage TAPS and TTTS to prevent anemia-related morbidities and may improve infant outcome.

Twin-to-Twin Transfusion Syndrome in a Dichorionic Diamniotic Pregnancy with Unusual Ultrasound Findings

Abstract Introduction/Objective Twin-to-twin transfusion syndrome (TTTS) is a complication of twin gestations which affects approximately 1-3 per 10,000 births and is most commonly observed in monochorionic diamniotic twins. The authors present a rare case of TTTS occurring in dichorionic diamniotic twins and literature review. Methods/Case Report The patient was initially found to have a twin pregnancy at 12 weeks of gestation with ultrasound findings suggestive of monochorionic diamniotic twins, but subsequent ultrasounds demonstrated a twin- peak sign, indicating a dichorionic diamniotic gestation. Her pregnancy was subsequently complicated by the discovery of TTTS at 26 weeks of gestation leading to her hospitalization for inpatient fetal surveillance and amnioreduction. She was discharged in stable condition. However, despite close follow-up, there was ultimately intrauterine demise of Twin B (donor twin) at 30 weeks and 6 days gestational age. There were no other complications during the course of pregnancy. Examination of the placenta at autopsy was consistent with a dichorionic diamniotic pregnancy with anastomoses within the fused placenta and evidence of prolonged oligohydramnios by presence of amnion nodosum, supporting the clinical and sonographic findings of TTTS. Results (if a Case Study enter NA) NA Conclusion In summary, this is a rare case of TTTS occurring in a dichorionic diamniotic twin gestation with clinical, sonographic, and pathologic findings. Only five cases have been reported thus far in the literature.

Fetal MRI findings, etiology, and outcome in prenatally diagnosed schizencephaly.

Schizencephaly is a rare brain anomaly which is increasingly detected in utero. There are limited data on the etiology and outcomes in fetal schizencephaly to guide workup and counselling. We aim to determine the associated imaging findings, etiology, and outcomes in schizencephaly detected in utero. This retrospective cohort study included 22 fetuses with a total of 34 schizencephaly defects identified by keyword search of fetal MRI reports from 1996-2022 followed by image review. Follow-up fetal and postnatal imaging, when available, were reviewed. Data on demographics, etiology, and outcomes were extracted from the electronic medical record. The schizencephaly defect was open in 28/34, most common in the MCA territory (23/34), and commonly involved the frontal (16/34) lobe. Additional intracranial abnormalities were seen in all fetuses including other cortical malformations (CM, 13/22), abnormal posterior fossa (12/22), abnormal corpus callosum (10/20), and intraparenchymal hemorrhage (9/22).The cause of schizencephaly was classified as secondary (as evidenced by intraparenchymal hemorrhage at schizencephaly, monochorionic twin gestation, infection, or maternal/placental risk factor) in 64% (14/22), potentially genetic in 9% (2/22), and unknown in 27% (6/22). Among those liveborn (n=8), the following outcomes were observed: postnatal death (1/8), tube feeding (1/7), shunted hydrocephalus (1/7), epilepsy (4/7). Among those >1 year of age, cerebral palsy (4/5) and speech delay or intellectual disability (3/5) were common. CM remote from schizencephaly was associated with epilepsy (p=0.03). On postnatal imaging, open defects often involuted (8/11) and there were high rates of new/additional findings (4/6). In this cohort, fetal schizencephaly was always associated with additional intracranial abnormalities. In most cases, there was evidence that schizencephaly was likely secondary to prior injury. Imaging characteristics may provide clues regarding neurodevelopmental outcome. Postnatal imaging is crucial in assessing evolution as well as for detection of additional abnormalities. ICH = intracranial hemorrhage; CM = cortical malformation; VM = ventriculomegaly; DGN = deep grey nuclei; SP = septum pellucidum; IPH = intraparenchymal hemorrhage; CC = corpus callosum; PMG = polymicrogyria; PVNH = periventricular nodular heterotopia; TTTS = twin-twin transfusion syndrome; GA = gestational age; CP = cerebral palsy.

Early experience of fetal laser photocoagulation for twin-to-twin transfusion syndrome in the Philippines

Objectives: This study aims to review the outcomes of monochorionic pregnancies with Twin-to-Twin Transfusion Syndrome (TTTS) treated with fetal laser photocoagulation (FLP) in the Philippines and to compare these with outcomes from the early experiences of other nearby centers in Southeast and East Asia. Methods: This is a single center retrospective cohort study of 7 patients who underwent FLP for TTTS before 26 weeks of gestation from June 2021 to March 2024. Preoperative, perioperative, perinatal, and neonatal outcomes were analyzed and a comparison with other Asian centers was performed. Results: Patients treated were in advanced stages III-IV of TTTS (86%). Gestational age at FLP was 22.1 ± 2.8 weeks. The perinatal overall survival rate was 64% with a double survivor rate of 57%, a single survivor rate of 14%, and at least one survivor in 71%. The interval between FLP and delivery was 36.6 ± 25.2 days with age at delivery of 27.1 ± 4.3 weeks. Compared to 5 other Asian centers, procedures performed per year ranged from 2.5 to 14.2 cases. Overall fetal survival rates were between 64 to 82%. Conclusion: Our center’s early experience of treating TTTS with FLP reflects the current conditions of prenatal screening and access to specialized care in the country. Early recognition of TTTS is key to providing patients and their families timely management and support. Devising local standardized assessments for education and performance of FLP, establishing the surgical learning curve, facilitating audits, and initiating research will improve fetal surgery benchmarks in the country.

Innovative study of the fetal heart in monochorionic multiple births

Introduction. Fetal echocardiography is currently one of the main methods of prenatal diagnosis. However, in recent years, attention has shifted towards the use of ultrasound to assess fetal myocardial function.The aim of this study is compare global longitudinal deformation of the myocardium of the left (LV) and right ventricles (RV) of the heart in fetuses with uncomplicated singleton pregnancy, in fetuses from monochorionic twins with transfusion syndrome, selective growth retardation and in uncomplicated monochorionic multiple pregnancy.Material and methods. A prospective cohort study was conducted which included 60 pregnant patients: Group I — patients with an uncomplicated singleton pregnancy (n=25); Group II — 35 patients with monochorionic diamniotic twins, whose pregnancy in 10 cases was complicated by feto-fetal transfusion syndrome (stages I-III according to Quintero R.A.), in 10 cases — selective growth retardation of the second fetus and in 15 cases monochorionic twins without complications. The following parameters were determined: global longitudinal deformation (GLD) of the myocardium of the ventricles of fetal hearts using the speckle tracking method of ejection fraction (EF), end-diastolic and end-systolic volumes of the ventricles of the heart.Results. Significant differences were established in GLD of RV and LV between singleton and monochorionic multiple pregnancies (LV: -21.2 ± 2.03 versus -23.41 ± 0 .25, p = 0.003); RV: — 20.3 ± 2.5 versus -23.3 ± 2.5, p = 0.013). Significant differences were revealed in GLD of the LV and RV in recipient fetuses before and after laser coagulation of placental anastomoses (LPCA) [LV in recipients before LCPA (- 20.4 ± 2.98) versus LV recipient after LCPA (-24.2 ± 3.3), p = 0.018], [RV in recipients before LKPA (- 20.4 ± 2.8) vs. RV in recipients after laser coagulation of placental anastomoses (-23.7 ± 3.4, p = 0.012].Conclusion. Assessment of the cardiac function of fetuses from monochorionic twins using the echocardiographic speckle tracking technique makes it possible to identify early changes in fetal myocardial function in twins from monochorionic diamniotic twins, as well as to carry out reliable testing monitoring changes in cardiac function over time.

Dichorionic triamniotic triplets after two blastocysts transfer underwent multifetal pregnancy reduction: two case reports and literature review

BackgroundThe increase in the rate of multiple pregnancies in clinical practice is associated with assisted reproductive technology (ART). Given the high risk of dichorionic triamniotic (DCTA) triplet pregnancies, reducing DCTA triplet pregnancies to twin or singleton pregnancies is often beneficial.Case presentationThis article reports on two cases of DCTA triplet pregnancies resulting from two blastocyst transfers. Given the high risk of complications such as twin-to-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twin pregnancies, patients have a strong desire to preserve the dichorionic diamniotic (DCDA) twins. Multifetal pregnancy reduction (MFPR) was performed in both cases to continue the pregnancy with DCDA twins by reducing one of the MCDA twins. Both of the pregnant women in this report eventually gave birth to healthy twins at 37 weeks.ConclusionsFor infertile couples with multiple pregnancies but with a strong desire to remain the DCDA twins, our report suggests that reducing DCTA triplets to DCDA twin pregnancies may be an option based on clinical operability and assessment of surgical difficulty.

Stage-based recipient and donor outcome in twin-to-twin transfusion syndrome treated by fetoscopic laser surgery using Solomon technique.

To evaluate twin survival stratified by Quintero stage in patients with twin-to-twin transfusion syndrome (TTTS) after Solomon laser treatment. This was a single-center study at Johns Hopkins Center for Fetal Therapy, investigating a cohort of consecutive twin pregnancies treated with the Solomon laser technique for TTTS. Preoperative Quintero stage, perioperative characteristics and obstetric factors were investigated in relation to neonatal survival of the recipient and donor twins at discharge. Determinants of twin survival were evaluated using univariate logistic regression and cumulative survival probability analyses. Of 402 pregnancies with TTTS that underwent Solomon laser treatment, 80 (19.9%) were diagnosed with Quintero Stage-I TTTS, 126 (31.3%) with Stage II, 169 (42.0%) with Stage III and 27 (6.7%) with Stage IV. Post-laser twin anemia polycythemia sequence or recurrent TTTS occurred in 19 (4.7%) patients and 11 (2.7%) required repeat laser surgery. Preterm prelabor rupture of membranes occurred in 150 (37.3%) patients and median gestational age at delivery was 32 + 1 weeks. In 303 (75.4%) patients, both twins were alive at discharge; 67/80 (83.8%) were Stage I, 101/126 (80.2%) were Stage II, 113/169 (66.9%) were Stage III and 22/27 (81.5%) were Stage IV (P = 0.062). Donor twin survival was lower than that of recipients in cases with Stage-III TTTS (118/169 (69.8%) vs 145/169 (85.8%) (χ2 = 26.076, P < 0.0001)). Higher intertwin size discordance and absent or reversed umbilical artery (UA) end-diastolic velocity (EDV) were associated with donor demise (Nagelkerke R2, 0.38; P < 0.001). Overall, spontaneous post-laser donor demise occurred in 53 (39.6%) patients, accounting for the majority of all losses. Cumulative donor survival decreased from 92% to 65% when intertwin size discordance was >30% and to 48% when UA-EDV was absent or reversed (P < 0.001). The Solomon laser technique achieves TTTS resolution and double twin survival in a high proportion of cases. Recipient and donor survival is comparable unless there is significant intertwin size discordance and placental dysfunction. This degree of unequal placental sharing, typically found in Stage-III TTTS, is the primary factor preventing double survival due to a higher rate of donor demise. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Monochorionic diamniotic twin pregnancy complicated with twin-twin transfusion syndrome presenting with a lambda sign in the first trimester

Monochorionic diamniotic twin pregnancy complicated with twin-twin transfusion syndrome presenting with a lambda sign in the first trimester

Fetal Intraparenchymal Hemorrhage Imaging Patterns, Etiology, and Outcomes: A Single Center Cohort Study.

This study examines associations among fetal brain magnetic resonance imaging (MRI) injury patterns, etiologies, and outcomes in fetal intraparenchymal hemorrhage (IPH). This is a retrospective, single-center cohort study of IPH diagnosed on fetal MRI (1996-2022). IPH and associated abnormalities were categorized by 2 pediatric neuroradiologists; electronic medical records were reviewed by 2 pediatric neurologists to classify etiology and outcomes including cerebral palsy, epilepsy, developmental delay, and death. Forty-four fetuses with IPH were identified (34 singleton and 10 twin gestations) with MRI at median 24 weeks gestation (interquartile range [IQR] = 22-28 weeks). IPH was commonly supratentorial (84%) and focal (50%) or focal with diffuse injury (43%) and was often associated with germinal matrix hemorrhage (GMH; 75%) and/or intraventricular hemorrhage (IVH; 52%). An etiology was identified in 75%, including twin-twin transfusion syndrome (TTTS, n = 10), COL4A1/2 variants (n = 8), or other fetal/maternal conditions (n = 15). COL4A1/2 variants were associated with focal IPH and the presence of hemorrhagic porencephaly, and intrauterine transfusion was associated with infratentorial hemorrhage. Twenty-two fetuses were liveborn, and 18 pregnancies were terminated. Among those with follow-up ≥ 12 months (median = 7 years), 12 of 13 had cerebral palsy, 6 of 13 had developmental delay, and 5 of 13 had epilepsy. An etiology for fetal IPH with or without GMH-IVH is identified in most cases in our cohort and is commonly TTTS, COL4A1/2 variants, or other maternal/fetal comorbidities. Pattern of fetal IPH on MRI is associated with etiology. Cerebral palsy and neurodevelopmental impairment were common in liveborn infants. Genetic studies should be considered in cases of fetal IPH without an otherwise apparent cause. ANN NEUROL 2024.

Real-time placental vessel segmentation in fetoscopic laser surgery for Twin-to-Twin Transfusion Syndrome

Twin-to-Twin Transfusion Syndrome (TTTS) is a rare condition that affects about 15% of monochorionic pregnancies, in which identical twins share a single placenta. Fetoscopic laser photocoagulation (FLP) is the standard treatment for TTTS, which significantly improves the survival of fetuses. The aim of FLP is to identify abnormal connections between blood vessels and to laser ablate them in order to equalize blood supply to both fetuses. However, performing fetoscopic surgery is challenging due to limited visibility, a narrow field of view, and significant variability among patients and domains. In order to enhance the visualization of placental vessels during surgery, we propose TTTSNet, a network architecture designed for real-time and accurate placental vessel segmentation. Our network architecture incorporates a novel channel attention module and multi-scale feature fusion module to precisely segment tiny placental vessels. To address the challenges posed by FLP-specific fiberscope and amniotic sac-based artifacts, we employed novel data augmentation techniques. These techniques simulate various artifacts, including laser pointer, amniotic sac particles, and structural and optical fiber artifacts. By incorporating these simulated artifacts during training, our network architecture demonstrated robust generalizability. We trained TTTSNet on a publicly available dataset of 2060 video frames from 18 independent fetoscopic procedures and evaluated it on a multi-center external dataset of 24 in-vivo procedures with a total of 2348 video frames. Our method achieved significant performance improvements compared to state-of-the-art methods, with a mean Intersection over Union of 78.26% for all placental vessels and 73.35% for a subset of tiny placental vessels. Moreover, our method achieved 172 and 152 frames per second on an A100 GPU, and Clara AGX, respectively. This potentially opens the door to real-time application during surgical procedures. The code is publicly available at https://github.com/SanoScience/TTTSNet.

Sensitive detection of hemodynamic changes after fetoscopic laser photocoagulation by assessing intraventricular pressure difference in fetuses with twin-to-twin transfusion syndrome.

To assess the hemodynamics of twin-to-twin transfusion syndrome (TTTS), we measured the intraventricular pressure difference (IVPD), a sensitive marker of myocardial diastolic function, using fetal echocardiography. We included 28 monochorionic diamniotic (MD) twins diagnosed with TTTS who underwent fetoscopic laser photocoagulation (FLP) between 2018 and 2022. Color M-mode Doppler images of both cardiac ventricles were obtained before and after FLP. According to this evaluation, the IVPDs were divided into three groups; those with total, basal, and mid-apical IVPD. Of the 28 twins, 21 were available for analysis (including eight, eight, three, and two cases in stages Quintero Ⅰ, Ⅱ, Ⅲd, and Ⅲr, respectively). Comparing the pre and postFLP results, significant increases in total and mid-apical IVPD in the left ventricle (LV) of recipient twins were noted (total and mid-apical IVPD: p=0.026 and 0.013, respectively). In the LV of the donor twins, all IVPDs were significantly increased after FLP (total, basal, and mid-apical IVPD: p=0.003, 0.001, and 0.022, respectively). In addition, comparisons between the donor and recipient groups did not show significant differences in either ventricle before FLP. IVPD detected subtle hemodynamics changes, such as volume overload and diastolic dysfunction in TTTS before and after FLP. Therefore, IVPD may be a useful marker for monitoring myocardial diastolic function in TTTS.

Elevated middle cerebral artery peak systolic velocity and risk of death in donor twin affected by twin-twin transfusion syndrome but not twin anemia-polycythemia sequence.

To determine the association between elevated (> 1.5 multiples of the median (MoM)) middle cerebral artery (MCA) peak systolic velocity (PSV) and fetal demise of the donor twin in pregnancies complicated by twin-twin transfusion syndrome (TTTS) in the absence of twin anemia-polycythemia sequence (TAPS). Secondary objectives were to evaluate if donor or recipient MCA-PSV is associated with a risk for their corresponding fetal death, and to compare the proportion of donor fetuses with low MCA pulsatility index (PI) among donor twins with high MCA-PSV and those with normal MCA-PSV to evaluate the contribution of blood-flow redistribution to the fetal brain in donor twins with high MCA-PSV. This prospective cohort study included TTTS cases that underwent laser surgery between 2011 and 2022 at a single center. TAPS cases were excluded from the study. Multivariable and Poisson regression analysis were performed to explore the association between isolated elevated donor MCA-PSV and fetal demise, adjusted for TTTS stage, selective fetal growth restriction (sFGR) and other confounders. Of 660 TTTS cases, donor MCA-PSV was not recorded in 48 (7.3%) cases. Of the remaining 612 patients, nine (1.5%) were lost to follow-up and 96 TAPS cases were excluded; thus, 507 cases were included in the study. High donor MCA-PSV was seen in 6.5% (33/507) of cases and was an independent risk factor for donor fetal demise (adjusted relative risk (aRR), 4.52 (95% CI, 2.72-7.50)), after adjusting for confounders. Regression analysis restricted to each Quintero TTTS stage demonstrated that high donor MCA-PSV was an independent risk factor for fetal demise of the donor in Quintero Stage II (aRR, 14.21 (95% CI, 1.09-186.2)) and Quintero Stage III (aRR, 3.41 (95% CI, 1.82-6.41)). Donor MCA-PSV in MoM was associated with fetal demise of the donor (area under the receiver-operating-characteristics curve (AUC), 0.69; P < 0.001), but recipient MCA-PSV in MoM was not associated with fetal demise of the recipient (AUC, 0.54; P = 0.44). A higher proportion of donor twins in the group with high MCA-PSV had a low MCA-PI compared to the group with normal MCA-PSV (33.3% vs 15.5%; P = 0.016). Elevated donor MCA-PSV without TAPS prior to laser surgery for TTTS is associated with a 4-fold increased risk for donor fetal demise, adjusted for sFGR, TTTS stage and other confounders. Doppler evaluation of donor MCA-PSV prior to laser surgery may help stratify TTTS staging to evaluate the risk of donor fetal demise. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Pre- and Periviable PPROM after Fetoscopic Laser Surgery: Are Survival Outcomes Better than We Think?

Limited data exist regarding outcomes when pre- and periviable PPROM (PPROM ≤26 weeks of gestation) occurs as a complication of fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS). This is a retrospective cohort study of FLS cases performed at a single institution between January 2015 and May 2021. Study inclusion was limited to patients with monochorionic-diamniotic twin pregnancies complicated by TTTS who underwent FLS. Patients were grouped by pPPROM status, and further stratified to those continuing with expectant management, and outcomes were compared between groups. The primary outcome was survival to live birth of at least one twin. During the study period, 171 patients underwent FLS and a total of 96 (56.1%) subjects satisfied inclusion criteria. Among included subjects, 18 (18.8%) experienced pPPROM after FLS and 78 (81.2%) did not. Baseline characteristics were similar between groups. Among patients with pPPROM, 11 (61.1%) pursued expectant management and 7 (38.9%) opted for pregnancy termination. Among expectantly managed subjects, median pPPROM-to-delivery interval was 47.0 days (6.0-66.0 IQR) with a median gestational age at delivery of 29+1 weeks (24 + 4-33 + 6 IQR). Rates of survival to live birth of at least one twin (90.9% vs. 96.2% p = 0.42) were similar between those with pPPROM undergoing expectant management and those without pPPROM. Dual survivorship (45.5% vs. 78.2%, p = 0.03), perinatal survival to live birth (68.2% vs. 87.2%, p = 0.05), and perinatal survival to newborn hospital discharge (59.1% vs. 85.9%, p = &lt;0.01) were all significantly lower among those with pPPROM. Gestational age at delivery was lower among those continuing with pregnancies complicated by pPPROM (29 + 1 vs. 32+5 weeks, p = &lt;0.01). Survival of at least one twin to live birth remained high among those pursing expectant management after experiencing post-FLS pPPROM, suggesting that the outlook after this complication is not necessarily poor. However, this complication was associated with lower chances of dual survival and greater prematurity.

Should We Stitch-Close the Fetoscopic Percutaneous Access? A Case-Series of Laparotomy to Trans-Amniotic Membrane Suturing for Intrauterine Port Placement in Fetoscopic Surgery for Twins

Introduction: Maternal laparotomy-assisted fetoscopic surgery for in-utero myelomeningocele repair has shown that a trans-amniotic membrane suture during fetoscopic port placement can reduce postsurgical complications. Fetoscopic laser photocoagulation (FLP) for complex twins is typically performed percutaneously without a transmembrane stitch. However, in scenarios without a placental-free window, maternal laparotomy may be used for recipient sac access. Here, we present the outcomes of our series of laparotomy-assisted FLP cases, including a trans-amniotic membrane suturing of the fetoscopic port. Methods: Retrospective series of twin-twin transfusion syndrome or twin anemia-polycythemia sequence (TAPS) cases treated at 2 fetal centers that underwent maternal laparotomy to FLP from September 2017 to January 2023. We recorded preoperative and operative characteristics, as well as pregnancy and neonatal outcomes. Results: During the study period, 9 maternal laparotomy to FLP cases were performed. Two were excluded for prior percutaneous FLP in the pregnancy. The remaining seven utilized a maternal laparotomy to trans-amniotic membrane stitch with confirmation of proper suture placement under ultrasound guidance, and all surgeries were performed with a single 10 F Check-Flo® cannula. Mean gestational age (GA) at surgery was 19.1 weeks (range 16 weeks 4 days–23 weeks 3 days), with delivery occurring at a mean GA of 35.0 weeks (range 32 weeks 0 days–37 weeks 1 day), resulting in a mean latency of 15.8 weeks, significantly longer than what is reported in the literature and our own data (mean latency for percutaneous FLP 10.2, 95% CI 9.9–10.5). Furthermore, all cases underwent iatrogenic delivery before labor onset, with the lone delivery prior to 34 weeks due to concern for post-laser TAPS. Conclusion: This case series of laparotomy to FLP with trans-amniotic stitch, demonstrated no cases of spontaneous preterm birth and a longer-than-expected latency from surgery to delivery. Larger studies are warranted to investigate this approach.

Randomized controlled trial of twin-twin transfusion syndrome laser surgery: the sequential trial

Intraoperative blood transfer between twins during laser surgery for twin-twin transfusion syndrome can vary by surgical technique and has been proposed to explain differences in donor twin survival. This trial compared donor twin survival with 2 laser techniques: the sequential technique, in which the arteriovenous communications from the volume-depleted donor to the volume-overloaded recipient are laser-occluded before those from recipient to donor, and the selective technique, in which the occlusion of the vascular communications is performed in no particular order. A single-center, open-label, randomized controlled trial was conducted in which twin-twin transfusion syndrome patients were randomized to sequential vs selective laser surgery. Nested within the trial, a second trial randomized patients with superficial anastomoses (arterioarterial and venovenous) to ablation of these connections first (before ablating the arteriovenous anastomoses) vs last. The primary outcome measure was donor twin survival at birth. A total of 642 patients were randomized. Overall donor twin survival was similar between the 2 groups (274 of 320 [85.6%] vs 271 of 322 [84.2%]; odds ratio, 1.12 [95% confidence interval, 0.73-1.73]; P=.605). Superficial anastomoses occurred in 177 of 642 cases (27.6%). Donor survival was lower in the superficial anastomosis group vs those with only arteriovenous communications (125 of 177 [70.6%] vs 420 of 465 [90.3%]; adjusted odds ratio, 0.33 [95% confidence interval, 0.20-0.54]; P<.001). In cases with superficial anastomoses, donor survival was independent of the timing of ablation or surgical technique. The postoperative mean middle cerebral artery peak systolic velocity was lower in the sequential vs selective group (1.00±0.30 vs 1.06±0.30 multiples of the median; P=.003). Post hoc analyses showed 2 factors that were associated with poor overall donor twin survival: the presence or absence of donor twin preoperative critical abnormal Doppler parameters and the presence or absence of arterioarterial anastomoses. Depending on these factors, 4 categories of patients resulted: (1) Category 1 (347 of 642 [54%]), no donor twin critical abnormal Doppler+ no arterioarterial anastomoses: donor twin survival was 91.2% in the sequential and 93.8% in the selective groups; (2) Category 2 (143 of 642 [22%]), critical abnormal Doppler present+ no arterioarterial anastomoses: donor survival was 89.9% vs 75.7%; (3) Category 3 (73 of 642 [11%]), no critical abnormal Doppler+ arterioarterial anastomoses present: donor survival was 94.7% vs 74.3%; and (4) Category 4 (79 of 642 [12%]), critical abnormal Doppler present+ arterioarterial anastomoses present: donor survival was 47.6% vs 64.9%. Donor twin survival did not differ between the sequential vs selective laser techniques and did not differ if superficial anastomoses were ablated first vs last. The donor twin's postoperative middle cerebral artery peak systolic velocity was improved with the sequential vs the selective approach. Post hoc analyses suggest that donor twin survival may be associated with the choice of laser technique according to high-risk factors. Further study is needed to determine whether using these categories to guide the choice of surgical technique will improve outcomes.

Fetal and neonatal neuroimaging in twin-twin transfusion syndrome.

To describe the types of brain injury and subsequent neurodevelopmental outcome in fetuses and neonates from pregnancies with twin-twin transfusion syndrome (TTTS). Additionally, to determine risk factors for brain injury and to review the use of neuroimaging modalities in these cases. This was a retrospective cohort study of consecutive TTTS pregnancies treated with laser surgery in a single fetal therapy center between January 2010 and January 2020. The primary outcome was the incidence of brain injury, classified into predefined groups. Secondary outcomes included adverse outcome (perinatal mortality or neurodevelopmental impairment), risk factors for brain injury and the number of magnetic resonance imaging (MRI) scans. Cranial ultrasound was performed in all 466 TTTS pregnancies and in 685/749 (91%) liveborn neonates. MRI was performed in 3% of pregnancies and 4% of neonates. Brain injury was diagnosed in 16/935 (2%) fetuses and 37/685 (5%) neonates and all predefined injury groups were represented. Four fetal and four neonatal cases of cerebellar hemorrhage were detected. Among those with brain injury, perinatal mortality occurred in 11/16 (69%) fetuses and 8/37 (22%) neonates. Follow-up was available for 29/34 (85%) long-term survivors with brain injury and the mean age at follow-up was 46 months. Neurodevelopmental impairment was present in 9/29 (31%) survivors with brain injury. Adverse outcome occurred in 28/53 (53%) TTTS individuals with brain injury. The risk of brain injury was increased after recurrent TTTS/post-laser twin anemia-polycythemia sequence (TAPS) (odds ratio (OR), 3.095 (95% CI, 1.581-6.059); P = 0.001) and lower gestational age at birth (OR per 1-week decrease in gestational age, 1.381 (95% CI, 1.238-1.541); P < 0.001). Based on dedicated neurosonography and limited use of MRI, brain injury was diagnosed in 2% of fetuses and 5% of neonates with TTTS. Adverse outcome was seen in over half of cases with brain injury. Brain injury was related to recurrent TTTS/post-laser TAPS and a lower gestational age at birth. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.