Cases Of Twin-twin Transfusion Syndrome Research Articles

252: Impact of selective intrauterine growth restriction on laser therapy outcomes in twin twin transfusion syndrome

To determine if outcomes of fetoscopic laser photocoagulation in twin twin transfusion syndrome (TTTS) differ from TTTS with concomitant selective intrauterine growth restriction (sIUGR). Retrospective cohort study of all cases of TTTS treated in a single center between December 2014 and December 2018. Data was collected from maternal, obstetrical and neonatal chart review. Sixty patients were identified, 24 of them having concomitant sIUGR. One patient was lost to follow-up. Mean gestational age at diagnosis and at treatment was 19.59 and 20.11 for TTTS alone and 20.66 and 21.40 for concomitant sIUGR. Donor fetal death was more frequent in the concomitant sIUGR group. However, there was no difference in overall survival between groups when comparing concomitant type 2-3 sIUGR to concomitant type 1 and TTTS alone. A summary of our results is shown in the table below. After fetoscopic laser photocoagulation, overall twin survival does not differ between the two groups, which could be due to the small sample size. Donor fetal death and preterm labour are more common in the concomitant sIUGR group. Other fetal and obstetrical complications do not differ. To date, there is no published data on the impact of sIUGR on laser therapy outcomes in TTTS. Further study is warranted to help counsel patients facing this procedure.

Early-onset twin-twin transfusion syndrome: Case series and systematic review.

Data on the outcomes of early-onset twin-twin transfusion syndrome (TTTS), diagnosed before 18weeks gestational age (GA), are sparse. We aimed to review the diagnosis, management and outcomes of early-onset TTTS. Pregnancy records at a single referral unit 2010-6 were reviewed. In early-onset TTTS cases, data for pregnancy characteristics, interventions and outcomes were collected. PubMed and Scopus databases were searched for studies including pregnant women with early-onset TTTS. The primary outcome measure was livebirths. Case series: 58 cases of early-onset TTTS 2010-6, with full outcome data in 44. Diagnostic criteria were variable. Median GA at intervention was 17+4 (range 15+0-28+1); 67% of patients had laser therapy (39/58). Overall survival: 60% (53/88). At least one livebirth: 86% (38/44), Two livebirths: 34% (15/44); No survivors: 14% (6/44). GA at delivery was 32+1.5 (range 16+2-37+4). Systematic review: 16 studies included (n=171 pregnancies). Diagnostic criteria varied widely: 79% of studies used Quintero staging. Most offered laser (89%) at median 17+0weeks (range 16+0-21+6). GA at delivery was 23+0-39+5weeks. Overall survival: 69% (129/186). At least one livebirth: 74% (127/171). Two livebirths: 59% (55/93). No survivors: 26% (44/171). In comparison with the commonly accepted overall survival for TTTS treated after 18weeks of 60-90%, outcomes in early-onset TTTS were at the lower bound of this range. Gestational age at intervention is similar to that of later onset TTTS, indicating a lack of therapeutic options when a diagnosis is made before 18weeks.

Twin-Twin Transfusion Syndrome with Anemia-Polycythemia: Prevalence, Characteristics, and Outcome.

The aim of this study was to estimate the prevalence of co-existing anemia-polycythemia (AP) in twin pregnancies with twin-twin transfusion syndrome (TTTS) prior to laser surgery, and to evaluate the characteristics and outcomes in TTTS twins with and without AP. All TTTS cases treated with laser between 2001 and 2019 were retrospectively reviewed for the presence of AP before surgery. AP was defined as delta middle cerebral artery–peak systolic velocity > 0.5 multiples of the median. The primary outcome was a composite of perinatal survival and severe neurodevelopmental impairment (NDI). Secondary outcomes included procedure-related characteristics, severe neonatal morbidity, and disease-free survival. In total, 66% (461/696) of TTTS twin pregnancies were eligible for analysis. AP was detected in 15% (70/461) of the TTTS twins prior to laser surgery. Gestational age at laser was higher in the TTTS+AP group compared to the TTTS-only group—21.0 weeks (interquartile rage (IQR): 18.8–24.0) versus 19.3 weeks (IQR: 17.3–21.9), respectively (p < 0.0001). Fewer placental anastomoses were detected in the TTTS+AP group than in the TTTS-only group—five (IQR: 4–6) versus six (IQR: 5–8), respectively (p < 0.0001). Perinatal survival was 77% (599/782) in the TTTS-only group and 83% (118/142) in the TTTS+AP group (p = 0.130). Severe NDI was 8% (28/370) in TTTS-only and 3% (2/74) in TTTS+AP. TTTS-only twins showed more severe neonatal morbidity than twins with TTTS+AP—23% (132/575) versus 11% (13/115), respectively (p = 0.005). Disease-free survival was lower in the TTTS-only group compared to the TTTS+AP group—62% (341/548) versus 73% (72/98), respectively (p = 0.046). Thus, AP complicates 15% of TTTS twins prior to laser. TTTS+AP twins show a different placental angioarchitecture, a later time of onset of the disease, and a more favorable outcome.

Twin-Twin Transfusion Syndrome with and without Selective Fetal Growth Restriction Prior to Fetoscopic Laser Surgery: Short and Long-Term Outcome.

As twin-twin transfusion syndrome (TTTS) and selective fetal growth restriction (sFGR) are both prevalent complications of monochorionic (MC) twin pregnancies, its coexistence is not uncommon. The aim of this study is to evaluate the short and long-term outcome in TTTS with and without sFGR prior to fetoscopic laser coagulation. All TTTS cases treated with laser surgery at our center between 2001–2019 were retrospectively reviewed for the presence of sFGR, defined as an estimated fetal weight (EFW) <10th centile. We compared two groups: TTTS-only and TTTS + sFGR. Primary outcomes were perinatal survival and long-term severe neurodevelopmental impairment (NDI). Of the 527 pregnancies eligible for analysis, 40.8% (n = 215) were categorized as TTTS-only and 59.2% (n = 312) as TTTS + sFGR. Quintero stage at presentation was higher in the TTTS + sFGR group compared to the TTTS-only group (57% compared to 44% stage III). Separate analysis of donors showed significantly lower perinatal survival for donors in the TTTS + sFGR group (72% (224/311) compared to 81% (173/215), p = 0.027). Severe NDI at follow-up in long-term survivors in the TTTS-only and TTTS + sFGR group was present in 7% (13/198) and 9% (27/299), respectively (p = 0.385). Both sFGR (OR 1.5;95% CI 1.1–2.0, p = 0.013) and lower gestational age at laser (OR 1.1;95% CI 1.0–1.1, p = 0.001) were independently associated with decreased perinatal survival. Thus, sFGR prior to laser surgery is associated with a more severe initial presentation and decreased donor perinatal survival. The long-term outcome was not affected.

Leukocyte Counts and Other Hematological Values in Twin-Twin Transfusion Syndrome and Twin Anemia-Polycythemia Sequence

Objective: The aim of this study was to evaluate the differences in leukocyte counts at birth between donors and recipients with twin-twin transfusion syndrome (TTTS) or twin anemia-polycythemia sequence (TAPS). Methods: We performed a retrospective cohort study in monochorionic twin pairs with TTTS or TAPS. TTTS and TAPS cases treated with fetoscopic laser surgery were excluded. Primary outcome was the difference in leukocyte levels at birth between donor and recipient twins and the presence of leukopenia (defined as leukocyte count <4 × 10⁹/L). Secondary outcomes included early-onset sepsis, necrotizing enterocolitis, use of antibiotics during admission, and neonatal mortality. Results: We included 99 twins pairs, of which 61 twin pairs were affected by TAPS and 38 twin pairs by TTTS. The mean leukocyte count at birth in donors and recipients was 7.5 × 10⁹/L versus 7.4 × 10⁹/L (p = 0.936), respectively. Leukopenia was significantly more common in donor twins compared to recipient twins (7.1% [7/99] vs. 0% [0/99], p = 0.016). Of the 7 donors with leukopenia, 6 were affected by TAPS and 1 by TTTS. Overall, donors were more often affected by early-onset sepsis than recipients, 23.7% (23/97) versus 13% (13.7/95) (p = 0.049), respectively. Conclusions: Leukocyte counts at birth in twins with TTTS or TAPS are similar between donors and recipients, but TAPS donors are at an increased risk of leukopenia. Overall, TTTS and TAPS donors seem to be at an increased risk of early-onset neonatal sepsis compared to recipient twins.

Amnioreduction in cases of polyhydramnios: Indications and outcomes in singleton pregnancies without fetal interventions

ObjectiveTo evaluate indications, pregnancy outcomes, and risk of adverse events following amnioreduction procedures in singleton gestations. Study designStudy of all amnioreduction procedures performed on singleton gestations complicated by polyhydramnios between January 2011 and June 2018 at our tertiary and regional referral fetal center. Clinical indications for amnioreduction procedures were categorized as either maternal shortness of breath, perceived abdominal tightness, or preterm uterine contractions with or without cervical change. Our primary outcome(s) of interest were: preterm premature rupture of membranes (PPROM), placental abruption, chorioamnionitis and/or preterm delivery, each in isolation or as a composite. ResultsAmong 358 patients who underwent amnioreduction in the study period, 251 arose from cases of twin-twin transfusion syndrome (TTTS) and 74 were singletons undergoing additional fetal intervention procedures. Each of the remaining 33 patients underwent a median number of one [range 1–12] amnioreductions over the antepartum interval, yielding a total of 66 amnioreduction procedures. Among the study cohort, there were no instances of PPROM, placental abruption, chorioamnionitis or preterm delivery within the 12 h following the procedure but 10.6% experienced preterm delivery within 48 h of amnioreduction. ConclusionOur data suggests that among singleton gestations, there was a low risk for preterm delivery in close proximity to the procedure and none experienced rupture of membranes, placental abruption, sepsis, fetal demise or neonatal death. This data may be used in counseling of potential candidates for amnioreduction with singleton pregnancies and symptomatic polyhydramnios.

Percent Absent End-Diastolic Velocity and Risk of Donor Twin Demise in Twin-Twin Transfusion Syndrome [19A

INTRODUCTION: We examined the association of percent absent end-diastolic velocity (%AEDV) in the umbilical artery with intrauterine fetal demise (IUFD) of the donor twin after laser surgery in patients with twin-twin transfusion syndrome (TTTS) Quintero stages III/IV. %AEDV was calculated as 100x the proportion of total cardiac cycle spent in AEDV. METHODS: Retrospective study of TTTS stage III/IV patients between 2006 and 2016. Donors were classified as having persistent AEDV (yes/no). In Part 1, we used multiple logistic regression analysis to test whether AEDV was associated with donor IUFD. We stratified these analyses by estimated fetal weight (EFW) discordance of ≥20% or <20%. In Part 2, we used similar models to test only those with AEDV to determine whether %AEDV was associated with IUFD. This was an IRB approved study. RESULTS: Of 344 stage III/IV TTTS cases, 153 (44.5%) donors had preoperative AEDV. In Part 1, we did not confirm an independent association between AEDV and donor IUFD. In Part 2, patients with AEDV who were discordant (N=129), had the following characteristics associated with donor IUFD: %AEDV (OR 1.04, 95% CI 1.01-1.08), %EFW discordance (OR 1.07, 95% CI 1.02-1.13), and presence of arterioarterial anastomoses (OR 5.15, 95% CI 2.06-12.89). In the non-discordant group (N=24), no association was found between %AEDV and donor IUFD. CONCLUSION: The presence of preoperative persistent AEDV was not an independent risk factor for donor IUFD in stage III/IV TTTS patients undergoing laser surgery. However, among donors with preoperative AEDV and EFW discordance ≥20%, %AEDV was positively associated with donor IUFD.

Predisposing factors and neonatal outcomes for twin-twin transfusion syndrome cases developing transient donor hydrops after fetoscopic laser coagulation: a case control study

BackgroundTransient donor hydrops (TDH) is defined as donor hydrops developed within days after laser therapy for twin–twin transfusion syndrome (TTTS) followed by resolution later. The purpose of this study was to evaluate the incidence, neonatal outcomes and predisposing factors of post laser therapy TDH in severe TTTS.MethodsA total of 142 patients with severe TTTS who received laser therapy were included into this study. The pre-operative characteristics and neonatal outcomes were compared between TTTS with and without post laser therapy TDH. All live neonates received cranial ultrasound examination after delivery, mild cerebral injury was defined as exhibiting at least one of the following: intraventricular hemorrhage (IVH) grade I and II, lenticulostriate vasculopathy and subependymal pseudocysts; severe cerebral injury comprised at least one among the following: IVH grade III or grade IV, cystic periventriculoleukomalacia (PVL) grade II or more, porencephalic cysts, and ventricular dilatation. Fetal survival was defined as living more than 30 days after delivery.Results

North American Fetal Therapy Network: timing of and indications for delivery following laser ablation for twin-twin transfusion syndrome

Despite improvements in fetal survival for pregnancies affected by twin-twin transfusion syndrome since the introduction of laser photocoagulation, prematurity remains a major source of neonatal morbidity and mortality. To investigate the indications and factors influencing the timing of delivery following laser treatment, we collected delivery information regarding twin-twin transfusion syndrome cases in a large multicenter cohort. Eleven North American Fetal Therapy Network (NAFTNet) centers conducted a retrospective review of twin-twin transfusion syndrome patients who underwent laser photocoagulation. Clinical, demographic and ultrasound variables including twin-twin transfusion syndrome stage, and gestational age at treatment and delivery were recorded. Primary and secondary maternal and fetal indications for delivery were identified. Univariate analysis was used to select candidate variables with significant correlation with latency and GA at delivery. Multivariable Cox regression with competing risk analysis was utilized to determine the independent associations. A total of 847 pregnancies were analyzed. After laser, the average latency to delivery was 10.11 ± 4.8 weeks and the mean gestational age at delivery was 30.7 ± 4.5 weeks. Primary maternal indications for delivery comprised 79% of cases. The leading indications included spontaneous labor (46.8%), premature rupture of membranes (17.1%), and placental abruption (8.4%). Primary fetal indications accounted for 21% of cases and the most frequent indications included donor non-reassuring status (20.5%), abnormal donor Dopplers (15.1%), and donor growth restriction (14.5%). The most common secondary indications for delivery were premature rupture of membranes, spontaneous labor and donor growth restriction. Multivariate modeling found gestational age at diagnosis, stage, history of prior amnioreduction, cerclage, interwin membrane disruption, procedure complications and chorioamniotic membrane separation as predictors for both gestational age at delivery and latency. Premature delivery after laser therapy for twin-twin transfusion syndrome is primarily due to spontaneous labor, preterm premature rupture of membranes and non-reassuring status of the donor fetus. Placental abruption was found to be a frequent complication resulting in early delivery. Future research should be directed toward the goal of prolonging gestation after laser photocoagulation to further reduce morbidity and mortality associated with twin-twin transfusion syndrome.

190: Optimal surveillance of monochorionic-diamniotic twins for twin-twin transfusion syndrome

Biweekly surveillance ultrasound (US) examination is a strategy recommended to detect early twin-twin transfusion syndrome (TTTS) in monochorionic-diamniotic (MCDA) twins. However, data to support this frequency of surveillance are scarce. Our objective was to determine whether a biweekly scanning paradigm can reliably detect TTTS at an early stage (i.e. < Quintero stage II). This is a retrospective cohort study of women with MCDA twin pregnancies whose first US exam occurred at our center between 2012 and 2018. Women with uncertain chorionicity, less than 2 serial US exams, or those followed outside of our healthcare system were excluded. Routine surveillance consisted of an US exam every 2 weeks starting at 16 weeks gestational age (GA). Univariate analysis of US exam patterns and pregnancy characteristics was performed comparing women that had TTTS to those who did not. For women diagnosed after at least one normal US examination, GA and Quintero stage at diagnosis and length of time since the last normal US exam was determined to assess whether the frequency of US examination was adequate. To assess whether the initial screening US was early enough to detect evolving TTTS, women diagnosed with TTTS on their first US were considered separately. Of 409 women with MCDA twins that met inclusion criteria, 46 (11.3%) developed TTTS. Women with TTTS had less time between scans (7.4 ± 7.6 vs. 12.7 ± 8.0 days, p < 0.01), but baseline characteristics were otherwise similar between the groups (Table 1). Among women with TTTS, 25 (54.4%) were diagnosed at their first US while 21 (46.6%) were diagnosed at a later US. Those diagnosed at the first US had similar GA (20.3 ± 3.8 vs. 22.3 ± 4.9, p = 0.16) and Quintero stage (median II vs. III, p = 0.34) as those diagnosed at a later US exam. The majority of TTTS detected after at a later US (i.e. >1 US) was diagnosed within 2 weeks of the last normal US (16/21, 76%). Most of these twins (9/16, 56%, p = 0.09) had stage II or greater disease on diagnosis (Figure 1). In this cohort of women that had biweekly ultrasounds, most cases of TTTS were detected at an advanced stage (Quintero stage > I). This suggests that biweekly US alone is not adequate to diagnose early TTTS. Further research is required to determine whether more frequent US screening may improve early detection. For women diagnosed on first US, it is unclear from this analysis whether earlier US would detect TTTS earlier.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Intestinal perforation in one of monochorionic twins: a report of two cases and literature review

Objective To report two cases of intestinal perforation in one of monochorionic twins and to analyze relevant clinical manifestations based on literature review. Methods Both cases were admitted to the Obstetrics and Gynecology Hospital of Fudan University in 2017. Relevant articles were retrieved from PubMed, OVID, Elsevier, Full-text Database of China National Knowledge Infrastructure(CNKI) and Wanfang Database from their release dates to February 2018. Clinical manifestations were analyzed through a literature review. Results In case 1, twin boys were born by cesarean section because of selective intrauterine growth restriction (sIUGR) Ⅲ at 31+3 gestational weeks. Signs of abdominal distention were found in one boy the day after birth, whose birth weight was 1 440 g and Apgar scores was all 9 at 1, 5 and 10 min after birth. A large amount of intra-abdominal gas was shown on abdominal X-ray. He was cured after surgery and discharged later. The other boy was fine. In case 2, twin girls were born by cesarean section because of twin-twin transfusion syndrome (TTTS)Ⅲ at 29+1 gestational weeks. The one suffered from intestinal perforation was 810 g at birth and her Apgar scores was all 8 at 1, 5 and 10 minutes. Pneumoperitoneum were observed on abdominal X-ray 16 h after birth. The baby died because of refusal to further treatment after surgery. The other girl was in good condition. Literature search found no relevant report in mainland China, but ten cases had been reported aboard and five of them died. Most cases of TTTS complicated by intestinal perforation occurred in the recipients. Conclusions Complications of monochorionic twins such as TTTS and sIUGR might be potentially associated with intestinal perforation. Early intervention and evaluation is the key to improve the outcomes. Key words: Twin, monochorionic; Diseases in twins; Intestinal perforation; Premature birth

The incidence of unexpected critical complications in monochorionic diamniotic twin pregnancies according to the interval period between ultrasonographic evaluations.

This study aimed to evaluate the incidence of unexpected critical complications (UCC) in monochorionic diamniotic (MCDA) twin pregnancies according to ultrasonographic scan interval. This retrospective single-center cohort study, conducted between January 2005 and April 2015, investigated the incidence of UCC in patients with MCDA twin pregnancies undergoing weekly ultrasound (Group A) and those undergoing biweekly ultrasound (Group B). We also examined the incidence of predictable critical complications according to ultrasound interval. Of all 385 cases, the total incidence of UCC was 20 (5.2%), including 14 cases of twin-twin transfusion syndrome and 6 cases of intrauterine fetal death. The incidence of UCC was 3.9% in Group A and 9.0% in Group B (P = 0.046). In contrast, the incidence of predictable critical complications was 6.7% in Group A and 9.0% in Group B (P = 0.440). The incidence of UCC in patients with MCDA twin pregnancies was significantly lower in patients undergoing weekly ultrasound. Our results suggest that weekly ultrasound evaluation for patients with MCDA pregnancy is more effective for early detection of UCC such as intrauterine fetal death and twin-twin transfusion syndrome ; however, further investigations are needed to determine whether weekly ultrasound evaluation can improve clinical outcomes.

Incidence of and risk factors for severe maternal complications associated with hypertensive disorders after 36 weeks' gestation in uncomplicated twin pregnancies: A prospective cohort study.

To elucidate the incidence of and risk factors for severe hypertensive disorders (HD) and related maternal complications in uncomplicated twin pregnancies that reached 36 weeks' gestation. We conducted a prospective cohort study of twin pregnancies delivered after 36 weeks' gestation. Cases of twin-twin transfusion syndrome, twin anemia-polycythemia sequence, malformed fetuses, monoamniotic twins, selective reduction, fetal therapy and HD or fetal death before 35 weeks' gestation were excluded. The study's primary outcome was the incidence of severe maternal complications, including severe HD, eclampsia, placental abruption, HELLP (hemolysis, elevated liver enzyme and low platelet) syndrome, pulmonary edema and cerebrovascular disease. Perinatal factors associated with the primary outcome were identified using a multivariate logistic regression model. In 330 enrolled women, the number of cases with the primary outcome was 28 (8.5%; 95% confidence interval 5.9-12.0), including 25 cases of severe HD and each one case of placental abruption, HELLP syndrome and eclampsia. The rate of severe maternal complications significantly increased with gestational age, demonstrating 1.2% at 36 weeks, 3.9% at 37 weeks and 6.4% at 38 weeks. Only gestational proteinuria was identified as the independent risk factor for severe maternal complications (adjusted odds ratio 17.1 [95% confidence interval 6.71-45.4]). Severe maternal HD and related complications increased from late preterm to early term; particularly, patients with gestational proteinuria were at high risk.

Preterm premature rupture of membranes is a collateral effect of improvement in perinatal outcomes following fetoscopic coagulation of chorionic vessels for twin-twin transfusion syndrome: a retrospective observational study of 1092 cases.

Preterm premature rupture of membranes (PPROM) is a leading complication following fetoscopic laser coagulation (FLC) for twin-twin transfusion syndrome (TTTS). Our primary objective was to describe the impact of improvements in surgical technique on survival and rate of PPROM over time. The secondary objective was to assess potential risk factors for PPROM. Single-centre retrospective observational study. 1092 consecutive cases of TTTS operated by FLC between 2000 and 2016, with a 6.8% rate of loss to follow up. The incidence of PPROM and potential risk factors were analysed using competing risks models. PPROM, neonatal survival and neurological damage at 28 days. PPROM <32 weeks increased from 15 to 40% between 2000 and 2016 along with an overall improvement of perinatal outcomes: dual survival rose from 42 to 66% whereas dual losses dropped two-fold, from 19 to 9%. Gestational age at surgery at <17 weeks was a significant risk-factor for PPROM, with an additional risk of 10% within the first week of surgery. Although early PPROM at <20 weeks carried a 56% risk of miscarriage, the occurrence of PPROM at >20 weeks did not affect survival, despite an increase in preterm birth at <32 weeks. With significant improvement in perinatal outcomes, possibly related to improvements in surgical technique, postoperative complications have shifted to non-lethal obstetric complications such as PPROM, with rather reassuring postnatal outcomes, despite an increase in preterm birth and, potentially, morbidity. Early surgeries (<17 weeks) are at higher risk of postoperative PPROM. Following laser/TTTS, rates of PPROM increased with perinatal survival; surgeries at <17 weeks are at highest risk.

Cardiac pathophysiology in twin-twin transfusion syndrome: new insights into its evolution.

In twin-twin transfusion syndrome (TTTS), unbalanced transfer of vasoactive mediators and fluid from the donor to the recipient cotwin alters their cardiovascular function. The aims of this study were to describe the impact of TTTS on fetal cardiac function in a large cohort of monochorionic-diamniotic (MCDA) pregnancies, and determine the early hemodynamic response to selective fetoscopic laser photocoagulation (SFLP). Echocardiography was performed in 145 MCDA pregnancies, including 26 uncomplicated MCDA, 61 TTTS Stages I+II and 58 TTTS Stages III+IV pregnancies, prior to SFLP for TTTS. Echocardiographic data after SFLP were available in a subset of 41/119 (34%) TTTS cases at a mean of 1.7 ± 1.9 days. Mitral (MAPSE) and tricuspid (TAPSE) annular systolic excursion, myocardial performance index (MPI), tissue Doppler velocities (E', A', S') and filling pressures (E/E') were measured and transformed into Z-scores. Ventricular pressure was estimated from peak atrioventricular regurgitation velocity. Left ventricular hemodynamics of the recipient twin were affected in early TTTS. In all stages of TTTS, left MPI and E/E' of the recipient twin were elevated in comparison to those of the donor (all P < 0.05), with reduced recipient left S' in TTTS Stages III+IV (P < 0.001). Ventricular pressure was elevated for gestational age (median, 42 mmHg (range, 20-65 mmHg)) in 11 of 14 recipients in which this parameter was measured. Between-group difference in right ventricular E/E' was significant only in TTTS Stages III+IV recipients compared with TTTS Stages I+II (P = 0.007) and uncomplicated MCDA (P = 0.041). Recipient left and right MPI decreased while S', MAPSE and TAPSE increased after SFLP; in donors, left E/E' and cardiac output increased. Cardiac function of the recipient twin in TTTS is abnormal, even in the early stages of the disease. Left ventricular filling pressures are elevated and systolic function is decreased before abnormalities in the right heart become apparent. SFLP produces rapid hemodynamic improvement. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Incidence of and Risk Factors for Residual Anastomoses in Twin-Twin Transfusion Syndrome Treated with Laser Surgery: A 15-Year Single-Center Experience

Objectives: To evaluate the incidence of residual anastomoses (RA) after laser therapy for twin-twin transfusion syndrome (TTS) and investigate risk factors for incomplete laser surgery. Material and Methods: All available TTS placentas treated with laser at our center between 2002 and 2016 were injected with color dye to assess the presence of RA. We evaluated the incidence of RA over the past 15 years by dividing the cohort into three time periods, and studied the association with risk factors and neonatal outcome. Results: Overall, RA were detected in 21.0% (78/371) of placentas. The incidence of RA decreased from 38.8% (26/67) in the initial period to 11.7% (16/137) in the most recent period (p < 0.001). On multivariate analysis, several risk factors were independently associated with the risk of RA, including Solomon laser technique (odds ratio [OR] 0.17, 95% CI 0.09–0.33) and estimation of surgical success (OR 19.28, 95% CI 8.17–45.49). Premature delivery and neonatal morbidity occurred more often in TTS cases with RA. Conclusions: The incidence of RA after laser therapy for TTS decreased significantly in the past 15 years and is now below 15% due to the use of the Solomon technique.

528: North American Fetal Therapy Network: Indications for delivery following laser ablation for twin-twin transfusion syndrome

Despite improvements in fetal survival for pregnancies affected by twin-twin transfusion syndrome (TTTS) since the introduction of laser photocoagulation, prematurity remains a major source of morbidity and mortality. To investigate the role that iatrogenic and procedure-related factors contribute to prematurity, we collected information regarding timing and indication for delivery following laser treatment in a multicenter cohort. Eleven centers from the North American Fetal Therapy Network (NAFTNet) conducted a retrospective review of consecutive cases of TTTS undergoing laser treatment recording clinical and ultrasound variables including TTTS Stage and gestational age (GA) at treatment and delivery. The route as well as the primary and secondary maternal or fetal indications for delivery were noted. Spearman correlations were utilized to determine variables with significant correlation with latency and GA at delivery. Multivariable modeling was utilized to determine the strongest associations. A total of 749 pregnancies were analyzed. Treatment details and outcomes are listed in Table 1. After laser, average latency is 10.2 ± 4.8 weeks and mean GA at delivery 30.7 ± 4.5 weeks. Primary maternal indications for delivery comprised 75% of cases and included spontaneous labor (46.2%), premature rupture of membranes (PROM) (17.6%), and abruption (8.1%). Primary fetal indications included donor non-reassuring fetal surveillance (20.8%), donor growth restriction (16.1%) and abnormal Doppler (16.1%). The most common secondary indications for delivery are PROM, spontaneous labor and donor growth restriction. Table 2 lists the variables with significant correlations to GA at delivery or latency under univariate analysis. After multivariable modeling, cerclage and fetoscopic complications are associated with shorter latency and earlier GA at delivery whereas a history of preterm birth is associated with shorter latency. In our cohort, premature delivery after laser therapy was primarily due to spontaneous labor, PROM or concern regarding the donor. Both modifiable and non-modifiable factors correlated with earlier delivery and shorter latency. Future research should be directed toward the goal of prolonging pregnancy to further reduce morbidity and mortality associated with TTTS.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Aortic Isthmus Flow Recording Predicts the Outcome of the Recipient Twin after Laser Coagulation in Twin-Twin Transfusion Syndrome

Introduction: The objective was to assess the prognostic value of the systolic flow through the aortic isthmus in monochorionic pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated by placental laser ablation. Material and Methods: Fetal echocardiography and outcome data of 105 cases of TTTS treated by laser photocoagulation of placental anastomoses were reviewed. Hemodynamic parameters were collected before and after treatment. The isthmic systolic index (ISI) was calculated as the peak systolic velocity/systolic nadir ratio. Results: A total of 105 laser coagulations were studied. Fetal echocardiography pre- and post-laser were available in 68 cases, including 55 with data on aortic isthmic Doppler. Survival rates were 17, 22, and 61% for 0, 1, or 2 twins, respectively. At least 1 twin was delivered alive in 83% of the pregnancies. The mean gestational age at surgery was 21 weeks (range 16-26). Median ISI values were similar for donor and recipient twins, before and after laser ablation (all p > 0.05). A lower recipient ISI before laser was related to early recipient demise within 24 h (p = 0.04). Discussion: A lower ISI before placental laser ablation for TTTS is associated with postoperative demise of the recipient twin.

OP26.02: A systematic review of diagnosis, management and outcomes for Twin–twin transfusion syndrome (TTTS) diagnosed before 18 weeks' gestation

Current management protocols for TTTS are optimised for twins at 18-24 weeks gestational age (GA), however, up to 25% of cases of TTTS may be diagnosed <18 weeks GA. Methods which could be used prior to fusion of amnion and chorion are needed. We systematically reviewed the published literature on diagnosis, management and outcomes of TTTS diagnosed at <18 weeks GA. PubMed and Scopus databases were searched for articles regarding early onset TTTS, from inception to April 2016. All studies types with primary data on TTTS <18 weeks GA in MCDA pregnancies were included. Exclusion criteria included studies not in English, higher order pregnancies, and diagnosis >18 weeks. Studies were independently assessed for inclusion by two reviewers. Authors of those with incomplete data were contacted. Data was extracted for study characteristics, interventions and outcomes and entered into an Excel spreadsheet and outcomes analysed. 16 studies included for analysis assessed 171 pregnancies. Earliest gestation at diagnosis was 14 weeks. 6 papers used DVP discrepancy for diagnosis, 6 used Quintero staging and the remaining used custom methods, TAPS diagnosis or unspecified criteria. The majority had treatment with laser in 88.9% of pregnancies; median gestational age at laser was 17+0 (range 16+0-21+6). The next commonest intervention (6.4%) was selective reduction. 2.3% underwent amniodrainage and 2.3% of pregnancies were terminated. Median gestational age at delivery was 31+3 (range 23+0-39+5). The rate of double twin survival at birth was 59.8%; at least one twin survived in 80.4% cases and 18.5% pregnancies had no survivors. Heterogeneity in outcomes was high. Outcomes of early gestation TTTS are better than expected. Management of TTTS at <18 weeks GA requires standardisation to standard management protocols. Adjustments of diagnostic criteria and the use and timing of existing invasive and emerging non-invasive treatment options that can be used at earlier gestations should be explored.

OP26.09: Fetal E/e' by dual gate Doppler method in Twin–twin transfusion syndrome and relationship with amniotic fluid brain‐type natriuretic peptide

To investigate the utility of E/e' ratio in the identical cardiac cycle by using Dual gate Doppler method (DD method) in the cases with Twin–twin transfusion syndrome (TTTS) for ventricular diastolic function, and relationship between fetal E/e' and amniotic fluid N-terminal-prohormone BNP (NT-proBNP) as a marker of cardiac dysfunction. This is a prospective study involving cases with TTTS, which were performed fetoscopic laser photocoagulation (FLP) from December 2015 to March 2017. To evaluate E/e' in the same heartbeat, DD method was used in all measurements. The ultrasonography was performed within 24 hours before FLP and 4-7 days after the procedure. Reference values acquired from normal 153 singleton fetuses in our previous study were used to compare with the present data. E/e' >10 was considered elevated from reference values. Amniotic fluid samples for analysis of NT-proBNP were obtained at the time of FLP. Amniotic fluid total protein (TP) concentration was used for correction of the level of NT-proBNP. Twenty-eight TTTS cases were included in this study. Preoperative right E/e' in Quintero stage 3 recipient twins was likely elevated than reference values, and significantly higher than stage 1, 2 recipients (p=0.001). In cases with right E/e' >10, amniotic fluid NT-proBNP/TP was elevated (3,475 vs. 518 ng/g, p=0.008), and ductus venosus pulsatility index (DV-PI) was high (1.34 vs. 0.75, p=0.020). Bilateral E/e' in recipients decreased 4-7 days after FLP (p=0.007). As for donor twins, no significant change was seen in bilateral E/e'. The measurement of fetal E/e' using DD method was convenient and stable. E/e' is seemed a useful parameter of fetal cardiac dysfunction in recipient twins, related with amniotic fluid NT-proBNP and DV-PI. Interestingly, bilateral E/e' of recipients indicated significant decrease within 7 days after FLP. These findings might imply FLP improves pathological condition of diastolic dysfunction in recipient twins.