Active management of selective intrauterine growth restriction with abnormal Doppler in monochorionic diamniotic twin pregnancies diagnosed in the second trimester of pregnancy

Infant outcome at 3 years of age of monochorionic twins with Type-II or -III selective fetal growth restriction and isolated oligohydramnios that underwent fetoscopic laser photocoagulation

OBJECTIVE

To examine infant outcomes at 3 years of age in monochorionic twin pregnancies with Type-II or -III selective fetal growth restriction (sFGR) and isolated oligohydramnios who underwent fetoscopic laser photocoagulation (FLP).

METHODS

This multicenter prospective cohort study included monochorionic diamniotic twins that underwent FLP for sFGR between 16 and 25 weeks' gestation. The indication for performing FLP was Type-II or -III sFGR with oligohydramnios of the growth-restricted (FGR) twin in which the maximum vertical pocket of amniotic fluid was ≤ 2 cm. This was done in the absence of a typical diagnosis of twin-twin transfusion syndrome. The primary outcome was intact survival rate of both infants at the corrected gestational age of 40 weeks and at 3 years of age. Intact survival at the corrected age of 40 weeks was defined as survival without Grade-III or -IV intraventricular hemorrhage or cystic periventricular leukomalacia. Intact survival at 3 years of age was defined as survival without neurodevelopmental morbidity, which included cerebral palsy, neurodevelopmental impairment with a total developmental quotient of < 70, bilateral deafness or bilateral blindness.

RESULTS

Among 45 patients with sFGR, 30 (66.7%) were classified as having Type-II and 15 (33.3%) as Type-III sFGR. The prevalence of intact survival at the corrected age of 40 weeks was 51.1% (n = 23) in FGR twins and 95.5% (n = 42) in larger twins. The prevalence of intact survival at 3 years of age was 46.7% (n = 21) in FGR twins and 86.4% (n = 38) in larger twins. There was one case of miscarriage. Among the 24 FGR twins who were not classified as having intact survival at 3 years of age, 22 (91.7%) cases suffered fetal or infant demise (other than miscarriage), and there was one case of neurodevelopmental impairment. All larger twins who were not diagnosed with intact survival at 3 years of age (n = 6 (13.6%)) had neurological morbidity.

CONCLUSIONS

FGR twins and their larger cotwins, when subjected to FLP owing to sFGR coupled with umbilical artery Doppler abnormalities and isolated oligohydramnios, exhibit low rates of neurological morbidity and low mortality, respectively. Therefore, FLP for Type-II or -III sFGR with oligohydramnios may be a feasible management option and one that is preferable to expectant management. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Outcome of laser photocoagulation in monochorionic diamniotic twin pregnancy complicated by Type-II selective fetal growth restriction

OBJECTIVES

To evaluate the outcome of monochorionic diamniotic (MCDA) twins complicated by Type-II selective fetal growth restriction (sFGR) who underwent fetoscopic laser photocoagulation and to validate a previously proposed subclassification system for Type-II sFGR in a large multicenter cohort.

METHODS

This retrospective multicenter cohort study included all MCDA twins complicated by Type-II sFGR who underwent laser photocoagulation of placental anastomoses at four large tertiary fetal-care centers between 2006 and 2020. Cases were subclassified according to a recently proposed system based on Doppler evaluation of the ductus venosus (DV) and middle cerebral artery (MCA) into Type-IIA (normal DV flow and MCA peak systolic velocity (PSV) of the growth-restricted fetus) or Type-IIB (absent or reversed flow in the DV during atrial contraction and/or MCA-PSV ≥ 1.5 multiples of the median of the growth-restricted fetus). Demographic characteristics and pregnancy outcomes were compared between the groups. Data are presented as mean ± SD or n (%) as appropriate. P-values < 0.05 were considered statistically significant.

RESULTS

A total of 98 patients with MCDA twins met our inclusion criteria, with 56 subclassified as Type IIA and 42 as Type IIB. Demographic characteristics were similar between the groups; however, Type-IIB cases had a significantly earlier gestational age at diagnosis and at laser surgery, as well as larger intertwin estimated fetal weight discordance, which may be a reflection of disease severity. Postnatal survival of the growth-restricted fetus to 30 days of age was significantly lower in Type-IIB compared to Type-IIA cases (23.8% vs 46.4%; P = 0.034).

CONCLUSIONS

In MCDA twins complicated by Type-II sFGR and treated with laser photocoagulation of placental anastomoses, preoperative Doppler assessment of the DV and MCA helped identify a subset of patients at increased risk of demise of the growth-restricted fetus following intervention. This study provides valuable information for guiding surgical management and patient counseling. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Management of the smaller twin with impending compromise in twin pregnancies complicated by selective fetal growth restriction: a questionnaire-based study of clinical practice patterns

BACKGROUND

In twin pregnancies complicated by selective fetal growth restriction (sFGR), if the smaller twin is in the state of impending intra-uterine death (IUD), immediate delivery will reduce the risk of IUD of the smaller twin while exposing the larger twin to iatrogenic preterm birth (PTB). Therefore, the management options would either be to maintain pregnancy for the maturation of the larger twin despite the risk of IUD of the smaller twin or immediate delivery to prevent IUD of the smaller twin. However, the optimal gestational age of management transition from maintaining pregnancy to immediate delivery has not been established. The objective of this study was to evaluate the physician's perspective on the optimal timing of immediate delivery in twin pregnancies complicated by sFGR.

METHODS

An online cross-sectional survey was performed with obstetricians and gynecologists (OBGYN) in South Korea. The questionnaire asked the following: (1) whether participants would maintain or immediately deliver a twin pregnancy complicated by sFGR with signs of impending IUD of the smaller twin; (2) the optimal gestational age of management transition from maintaining pregnancy to immediate delivery in a twin pregnancy with impending IUD of the smaller twin; and (3) the limit of viability and intact survival in general preterm neonates.

RESULTS

A total of 156 OBGYN answered the questionnaires. In a clinical scenario of dichorionic (DC) twin pregnancy complicated by sFGR with signs of impending IUD of the smaller twin, 57.1% of the participants answered that they would immediately deliver the twin pregnancy. However, 90.4% answered that they would immediately deliver the pregnancy in the same scenario for monochorionic (MC) twin pregnancy. The participants designated 30 weeks for DC twin and 28 weeks for MC twin pregnancies as the optimal gestational age of management transition from maintaining pregnancy to immediate delivery. The participants regarded 24 weeks as the limit of viability and 30 weeks as the limit of intact survival in general preterm neonates. The optimal gestational age of management transition for DC twin pregnancy was correlated with the limit of intact survival in general preterm neonates (p < 0.001), but not with the limit of viability. However, the optimal gestational age of management transition for MC twin pregnancy was associated with both the limit of intact survival (p = 0.012) and viability with marginal significance (p = 0.062).

CONCLUSIONS

Participants preferred to immediately deliver twin pregnancies complicated by sFGR with impending IUD of the smaller twin at the limit of intact survival (30 weeks) for DC twin pregnancies and at the midway between the limit of intact survival and viability (28 weeks) for MC twin pregnancies. More research is needed to establish guidelines regarding the optimal delivery timing for twin pregnancies complicated by sFGR.

Laser therapy versus expectant management for selective fetal growth restriction in monochorionic twins: A systematic review

Selective fetal growth restriction (sFGR) complicates 10%-26% of monochorionic twins. Treatment options include cord coagulation, expectant management, and fetoscopic laser photocoagulation. This review compared laser to expectant management for situations when cord coagulation is not an option. The MEDLINE, EMBASE, and Cochrane databases were queried for studies that compared laser to expectant management for sFGR. GRADE was used to assess quality prior to meta-analysis. A random-effects model was used to generate relative risks. Six studies were included, encompassing 299 pregnancies. One study was randomized and the remainder were retrospective cohorts. Laser is associated with more fetal deaths of the FGR twin compared to expectant management (risk ratio [RR] 2.5, 95% confidence interval [CI] 1.43-4.37, p = 0.001, I2 = 48%). Neonatal deaths and gestational age at delivery did not differ. Laser was associated with decreased abnormal neuroimaging in the AGA twin (RR 0.25, 95% CI 0.07-0.97, p = 0.05). Neurodevelopmental outcomes did not differ, although these data are limited. Laser causes more fetal deaths of the FGR twin without altering gestational age at delivery or rates of neonatal death. The literature is heterogeneous and the level of bias is high. Randomized trials that address laser for type II sFGR are needed and should include long-term neurological outcomes.

Screening, Management and Delivery in Twin Pregnancy

The following AWMF guideline (DGGG/AGG & DEGUM responsible) deals with the diagnosis, screening and management of twins as well as the timing and mode of birth.Twin pregnancies can be classified as dichorionic diamniotic (DC DA), monochorionic diamniotic (MC DA) and monochorionic monoamniotic (MC MA) which are always monochorionic.Twin pregnancies can be concordant (both twins are affected) or discordant (only one twin is affected) for chromosomal defects, malformations, growth restriction and hemodynamic disorders.Chorionicity is the prognostically most significant parameter. Monochorial twins have significantly higher risks of intrauterine morbidity and mortality compared to dichorial twins.In particular, general aspects of twin pregnancies such as dating, determination of chorionicity and amnionicity, the labeling of twin fetuses and the perinatal switch phenomenon are discussed.Routine monitoring of MC and DC twin pregnancies with ultrasound at 11-13^+ 6 weeks of gestation for chromosomal defects, invasive prenatal diagnosis, first-trimester NT or CRL discrepancies, early diagnosis of fetal anatomical defects, and management of twins with abnormalities, including selective fetocide, is described.Second trimester screening and management for preterm birth, intrauterine selective growth restriction (sFGR), classification of monochorial twins with sFGR, and management of the surviving twin after the death of the co-twin are described.Complications exclusively affecting MC twins include Twin to Twin Transfusion Syndrome (TTTS) with the important topics screening, prognosis, complications of laser therapy, timing of delivery, risks for brain abnormalities and delayed neurological development, Twin Anemia-Polycythemia Sequence (TAPS) and Twin Reversed Arterial Perfusion (TRAP) Sequence. This also includes MC MA twins as well as conjoined twins.Finally, the birth mode and time for DC and MC twin pregnancies are described.The information is summarized in 62 recommendations for action, 4 tables and 8 illustrations with comprehensive background texts.The guideline is an international guideline adaptation (ISUOG, NICE) as well as a systematic literature search and is up-to-date.

Outcome of monochorionic twin pregnancy with selective fetal growth restriction at 16, 20 or 30 weeks according to new Delphi consensus definition

OBJECTIVES

To report the outcome of selective fetal growth restriction (sFGR) diagnosed according to the new Delphi consensus definition, and determine potential predictors of survival, in a cohort of unselected monochorionic diamniotic twin pregnancies.

METHODS

This was a retrospective study of monochorionic diamniotic twin pregnancies followed from the first trimester onward, which were diagnosed with sFGR at 16, 20 or 30 weeks' gestation. sFGR was defined according to the new Delphi consensus criteria as presence of either an estimated fetal weight (EFW) < 3^rd centile in one twin or at least two of the following: EFW of one twin < 10^th centile, abdominal circumference of one twin < 10^th centile, EFW discordance ≥ 25% or umbilical artery pulsatility index of the smaller twin > 95^th centile. The primary outcomes were the overall survival rate (up to day 28 after birth) and risk of loss of one or both twins. We further determined possible predictors of survival using uni- and multivariate generalized estimated equation modeling.

RESULTS

We analyzed 675 pregnancies, of which 177 (26%) were diagnosed with sFGR at 16, 20 or 30 weeks. The overall survival rate was 313/354 (88%) with 146/177 (82%) pregnancies resulting in survival of both twins, 21/177 (12%) in survival of one twin and 10/177 (6%) in loss of both twins. Subsequent twin anemia-polycythemia sequence (TAPS) developed in 6/177 (3%) and twin-twin transfusion syndrome (TTTS) in 17/177 (10%) pregnancies. All TAPS fetuses survived. The survival rate in sFGR pregnancies that subsequently developed TTTS was 65% (22/34), compared with 91% (279/308) in those with isolated sFGR (no subsequent TAPS or TTTS) (P < 0.001). The majority of sFGR cases were Type I (110/177 (62%)) and had a survival rate of 96% (212/220), as compared with a survival of 55% (12/22) in those with Type-II (P < 0.001) and 83% (55/66) in those with Type-III (P = 0.006) sFGR. The majority of sFGR pregnancies (130/177 (73%)) were first diagnosed at 16 or 20 weeks (early onset), with a survival rate of 85% (221/260), as compared with a survival of 98% (92/94) in sFGR first diagnosed at 30 weeks (late onset) (P = 0.04). A major anomaly in at least one twin was present in 28/177 (16%) sFGR cases. In these pregnancies, survival was 39/56 (70%), compared with 274/298 (92%) in those without an anomaly (P < 0.001). Subsequent development of TTTS (odds ratio (OR), 0.18 (95% CI, 0.06-0.52)), Type-II sFGR (OR, 0.06 (95% CI, 0.02-0.24)) and Type-III sFGR (OR, 0.21 (95% CI, 0.07-0.60)) and presence of a major anomaly in at least one twin (OR, 0.12 (95% CI, 0.04-0.34)), but not gestational age at first diagnosis, were independently associated with decreased survival.

CONCLUSIONS

Isolated sFGR is associated with a 90% survival rate in monochorionic diamniotic twin pregnancies. The subsequent development of TTTS, absent or reversed end-diastolic flow in the umbilical artery of the smaller twin and the presence of a major anomaly adversely affect survival in sFGR. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Placental histopathological features of fetoscopic laser photocoagulation for monoaminotic diamniotic twin pregnancies

INTRODUCTION

This study aimed to compare the histopathological placental features of monochorionic diamniotic (MCDA) twins who did and did not undergo fetoscopic laser photocoagulation (FLP).

METHODS

This was a retrospective single-institution cohort study on MCDA twins who underwent FLP between October 2010 and December 2018. The control group included MCDA twins who did not undergo FLP and were delivered during the same period in the institute. The incidence of chorioamnionitis (CAM), funisitis, and other pathological findings was compared between the FLP and control groups after matching by gestational age at delivery.

RESULTS

In total, 292 MCDA pregnant women who underwent FLP and 356 controls gave birth during the study period. After matching the two groups in the ratio 1:1 by gestational age at delivery, each group comprised 194 subjects. The incidence of histological CAM with Blanc association (stage I, 6.2% vs. 3.1%, crude odds ratio (cOR) = 3.1, P = 0.052; stage II, 7.2% vs. 5.7%, cOR = 1.6, P = 0.30; stage III, 2.1% vs. 2.6%, cOR = 0.66, P = 0.52) and funisitis (artery, 5.2% vs. 3.6%, cOR = 1.3, P = 0.63; vein 7.2% vs. 4.1%, cOR = 1.6, P = 0.29) was not statistically significant difference between the FLP and control groups. The FLP group demonstrated a higher incidence of partial placental infarction than the control group (10.3% vs. 3.1%, cOR = 4.3, P = 0.004, adjusted OR = 2.8, P = 0.031).

DISCUSSION

FLP did not appear to increase the incidence of histological CAM or funisitis in subjects matched by gestational age at delivery. The FLP group demonstrated a higher incidence of partial placental infarction than the control group.

Impact of different prenatal management strategies in short- and long-term outcomes in monochorionic twin pregnancies with selective intrauterine growth restriction and abnormal flow velocity waveforms in the umbilical artery Doppler: a retrospective observational study of 108 cases

OBJECTIVES

To review perinatal and neurodevelopmental outcome (NDO) following selective fetoscopic laser coagulation (SFLC), cord coagulation (CC) or expectant management of monochorionic diamniotic twin pregnancies complicated with selective intrauterine growth restriction (sIUGR) and absent or reverse end-diastolic flow (AREDF) in the umbilical arteries (UA).

DESIGN AND SETTING

Single-centre retrospective observational study.

POPULATION

108 cases of sIUGR diagnosed before 26⁺⁶  weeks' gestation with AREDF in the UA.

METHODS

Survival rate and potential risk factors were analysed. NDO was assessed using parental questionnaires.

MAIN OUTCOMES MEASURES

Survival, gestational age at delivery and NDO.

RESULTS

SFLC, CC and EM were performed in 13, 50 and 45 cases, respectively, with an overall survival of 23.1, 40 and 77.8% and intrauterine demise of the co-twin of 30.8, 10 and 6.7% respectively. Intrauterine demise of the sIUGR twin occurred in 76.9 and 17.8% following SFLC and EM, respectively. The discordance in EFW at diagnosis was higher and absent/negative a-wave in the ductus venosus (DV) was more prevalent in the surgical groups. NDO in survivors at follow up was abnormal in 0 and 18% in the smaller twin following SFLC and EM, respectively, and in 25, 24 and 21% in the larger twin following SFLC, CC and EM, respectively.

CONCLUSION

SFLC yielded a poor result. EM seems a valid option when EFW discordance is <30% and a-wave in DV is positive. Otherwise, CC should be considered to protect the AGA co-twin. The long-term outcome of both small and large twins seems unaffected by the choice in primary prenatal management strategy.

TWEETABLE ABSTRACT

In type II sIUGR in MC twins, long-term neurodevelopment is normal in over 80% of the survivors.

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.

Fetal therapies as standard prenatal care in Japan

With recent advances in fetal medicine, various attempts have been made to save fetuses facing perinatal death or devastating consequences despite optimal management after birth. The concept of the fetus as a patient has been established through the application of in utero treatments. This paper reviews fetal therapies in order to highlight the role of perinatal medicine as standard prenatal care. Fetal therapies consist of medical therapy, percutaneous ultrasound-guided surgery, fetoscopic surgery, and open fetal surgery. In the 1980s, with advances in ultrasound imaging, percutaneous ultrasound-guided surgeries such as vesicoamniotic shunting for lower urinary tract obstruction and thoracoamniotic shunting (TAS) for fetal hydrothorax (FHT) were started. In the 1990s, fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) was introduced, and later, a fetoscopic approach for congenital diaphragmatic hernia was also established. The revival of open fetal surgery, introduced in the 1980s by pediatric surgeons, began in the 2010s after a successful clinical study for myelomeningocele. Although many fetal therapies are still considered experimental, some have proven effective, such as FLS for TTTS, TAS for primary FHT, and radiofrequency ablation (RFA) for twin reversed arterial perfusion (TRAP) sequence. These three fetal therapies have been approved for coverage by Japan National Health Insurance as a result of clinical studies performed in Japan. FLS for TTTS, TAS for primary FHT, and RFA for TRAP sequence have become standard prenatal care approaches in Japan. These three minimally invasive fetal therapies will help improve the perinatal outcomes of fetuses with these disorders.

Study protocol: developing, disseminating, and implementing a core outcome set for selective fetal growth restriction in monochorionic twin pregnancies

BACKGROUND

Selective fetal growth restriction in monochorionic twin pregnancies is associated with an increased risk of perinatal mortality and morbidity and represents a clinical dilemma. Interventions include expectant management with early preterm delivery if there are signs of fetal compromise, selective termination of the compromised twin, fetoscopic laser coagulation of the communicating placental vessels or termination of the whole pregnancy. Previous studies evaluating interventions have reported many different outcomes and outcome measures. Such variation makes comparing, contrasting, and combining results challenging, limiting ongoing research on this uncommon condition to inform clinical practice. We aim to produce, disseminate, and implement a core outcome set for selective fetal growth restriction research in monochorionic twin pregnancies.

METHODS

An international steering group, including professionals, researchers, and lay experts, has been established to oversee the development of this core outcome set. The methods have been guided by the Core Outcome Measures in Effectiveness Trials Initiative Handbook. Potential core outcomes will be developed by undertaking a systematic review of studies evaluating interventions for selective fetal growth restriction in monochorionic twin pregnancies. Potential core outcomes will be entered into a three-round Delphi survey and key stakeholders including clinical professionals, researchers, and lay experts will be invited to participate. Repeated reflection and rescoring of individual outcomes should encourage group and individual stakeholder convergence towards consensus outcomes which will be entered into a modified Nominal Group Technique to finalize the core outcome set. Once core outcomes have been agreed, we will establish standardized definitions and recommend high-quality measurement instruments for each outcome.

DISCUSSION

The development, dissemination, and implementation of a core outcome set for selective fetal growth restriction should ensure that future research protocols select, collect, and report outcomes and outcome measures in a standardized manner. Data synthesis will be possible on a broad level and rigorous implementation should advance the quality of research studies and their effective use in order to guide clinical practice, improve patient care, maternal, short-term perinatal outcomes, and long-term neurodevelopmental outcomes.

TRIAL REGISTRATION

Core Outcome Measures in Effectiveness Trials (COMET) registration number: 998. International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42018092697 . 18th April 2018.

Perinatal outcome of monochorionic twin pregnancy complicated by selective fetal growth restriction according to management: systematic review and meta-analysis

OBJECTIVE

To explore the impact of severity and management (expectant, laser treatment or selective reduction) on perinatal outcome of monochorionic twin pregnancies complicated by selective fetal growth restriction (sFGR).

METHODS

MEDLINE, EMBASE, CINAHL, ClinicalTrials.gov and The Cochrane Library databases were searched for studies on outcome following expectant management, laser treatment or selective reduction in monochorionic twin pregnancies complicated by sFGR. Only pregnancies affected by sFGR and categorized according to the Gratacós classification (Type I, II or III) were included. The primary outcome was mortality, including single and double intrauterine (IUD), neonatal (NND) and perinatal deaths. Secondary outcomes were neonatal morbidity, abnormal postnatal brain imaging, intraventricular hemorrhage, periventricular leukomalacia, respiratory distress syndrome, admission to neonatal intensive care unit and survival free from neurological complications (intact survival). Meta-analyses of proportions were used to analyze the extracted data according to management, severity of sFGR and fetal size (smaller vs larger twin).

RESULTS

Sixteen observational studies (786 monochorionic twin pregnancies) were included. In pregnancies complicated by Type-I sFGR managed expectantly, IUD occurred in 3.1% (95% CI, 1.1-5.9%) of fetuses and 97.9% (95% CI, 93.6-99.9%) of twins had intact survival. In pregnancies complicated by Type-I sFGR treated using laser therapy, IUD occurred in 16.7% (95% CI, 0.4-64.1%) of fetuses and, in those treated using selective reduction, IUD occurred in 0% (95% CI, 0-34.9%) of cotwins, with no evidence of neurological complications in the survivors. In pregnancies complicated by Type-II sFGR managed expectantly, IUD occurred in 16.6% (95% CI, 6.9-29.5%) and NND in 6.4% (95% CI, 0.2-28.2%) of fetuses, and 89.3% (95% CI, 71.8-97.7%) of twins survived without neurological compromise. In Type-II sFGR pregnancies treated using laser therapy, IUD occurred in 44.3% (95% CI, 22.2-67.7%) of fetuses, while none of the affected cases experienced morbidity and survivors were free of neurological complications. Of pregnancies undergoing selective reduction, IUD of the cotwin occurred in 5.0% (95% CI, 0.03-20.5%) and NND in 3.7% (95% CI, 0.2-11.1%), and 90.6% (95% CI, 42.3-94.3%) of surviving cotwins were free from neurological complications. In pregnancies complicated by Type-III sFGR managed expectantly, IUD occurred in 13.2% (95% CI, 7.2-20.5%) and NND in 6.8% (95% CI, 0.7-18.6%) of fetuses, and 61.9% (95% CI, 38.4-81.9%) of twins had intact survival. In pregnancies complicated by Type-III sFGR treated with laser therapy, IUD occurred in 32.9% (95% CI, 20.9-46.2%) of fetuses and all surviving twins were without neurological complications. Finally, in pregnancies with Type-III sFGR treated with selective reduction, NND occurred in 5.2% (95% CI, 0.8-12.8%) of cotwins and 98.8% (95% CI, 93.9-99.9%) had intact survival.

CONCLUSION

Type-I sFGR is characterized by good perinatal outcome when managed expectantly, which represents the most reasonable management strategy for the large majority of affected cases. Pregnancies complicated by Type-II or -III sFGR treated with fetoscopic laser ablation have a higher rate of mortality but lower rate of morbidity compared with those managed expectantly, supporting the use of fetal therapy at gestations remote from neonatal viability. Data on outcome following selective reduction are scarce. In view of the lack of evidence from randomized controlled trials, prenatal management of sFGR should be individualized according to gestational age at diagnosis, severity of growth discordance and magnitude of Doppler anomalies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Consensus definition and essential reporting parameters of selective fetal growth restriction in twin pregnancy: a Delphi procedure

OBJECTIVES

Twin pregnancy complicated by selective fetal growth restriction (sFGR) is associated with increased perinatal mortality and morbidity. Inconsistencies in the diagnostic criteria for sFGR employed in existing studies hinder the ability to compare or combine their findings. It is therefore challenging to establish robust evidence-based management or monitoring pathways for these pregnancies. The main aim of this study was to determine, by expert consensus using a Delphi procedure, the key diagnostic features of and the essential reporting parameters in sFGR.

METHODS

A Delphi process was conducted among an international panel of experts in sFGR in twin pregnancy. Panel members were provided with a list of literature-based parameters for diagnosing sFGR and were asked to rate their importance on a five-point Likert scale. Parameters were described as solitary (sufficient to diagnose sFGR, even if all other parameters are normal) or contributory (those that require other abnormal parameter(s) to be present for the diagnosis of sFGR). Consensus was sought to determine the cut-off values for accepted parameters, as well as parameters used in the monitoring, management and assessment of outcome of twin pregnancy complicated by sFGR. The questions were presented in two separate categories according to chorionicity.

RESULTS

A total of 72 experts were approached, of whom 60 agreed to participate and entered the first round; 48 (80%) completed all four rounds. For the definition of sFGR irrespective of chorionicity, one solitary parameter (estimated fetal weight (EFW) of one twin < 3^rd centile) was agreed. For monochorionic twin pregnancy, at least two out of four contributory parameters (EFW of one twin < 10^th centile, abdominal circumference of one twin < 10^th centile, EFW discordance of ≥ 25%, and umbilical artery pulsatility index of the smaller twin > 95^th centile) were agreed. For sFGR in dichorionic twin pregnancy, at least two out of three contributory parameters (EFW of one twin < 10^th centile, EFW discordance of ≥ 25%, and umbilical artery pulsatility index of the smaller twin > 95^th centile) were agreed.

CONCLUSIONS

Consensus-based diagnostic features of sFGR in both monochorionic and dichorionic twin pregnancies, as well as cut-off values for the parameters involved, were agreed upon by a panel of experts. Future studies are needed to validate these diagnostic features before they can be used in clinical trials of interventions. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Outcome reporting across randomized trials and observational studies evaluating treatments for twin-twin transfusion syndrome: systematic review

OBJECTIVE

Twin-twin transfusion syndrome (TTTS) is associated with significant mortality and morbidity. Potential treatments for the condition require robust evaluation. The aim of this study was to evaluate outcome reporting across observational studies and randomized controlled trials assessing treatments for TTTS.

METHODS

Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE were searched from inception to August 2016. Observational studies and randomized controlled trials reporting outcome following treatment for TTTS in monochorionic-diamniotic twin pregnancy and monochorionic-triamniotic or dichorionic-triamniotic triplet pregnancy were included. Outcome reporting was systematically extracted and categorized.

RESULTS

Six randomized trials and 94 observational studies were included, reporting data from 20 071 maternal participants and 3199 children. Six different treatments were evaluated. Included studies reported 62 different outcomes, including six fetal, seven offspring mortality, 25 neonatal, six early childhood and 18 maternal/operative outcomes. Outcomes were reported inconsistently across trials. For example, when considering offspring mortality, 31 (31%) studies reported live birth, 31 (31%) reported intrauterine death, 49 (49%) reported neonatal mortality and 17 (17%) reported perinatal mortality. Four (4%) studies reported respiratory distress syndrome. Only 19 (19%) studies were designed for long-term follow-up and 11 (11%) of these reported cerebral palsy.

CONCLUSIONS

Studies evaluating treatments for TTTS have often neglected to report clinically important outcomes, especially neonatal morbidity outcomes, and most are not designed for long-term follow-up. The development of a core outcome set could help standardize outcome collection and reporting in TTTS studies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

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

AIM

This study aimed to evaluate the incidence of unexpected critical complications (UCC) in monochorionic diamniotic (MCDA) twin pregnancies according to ultrasonographic scan interval.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Fetoscopic laser photocoagulation for twin-twin transfusion syndrome

The aim of this study was to review fetoscopic laser photocoagulation (FLP), which ablates placental vascular anastomoses to treat twin–twin transfusion syndrome (TTTS). A review of studies reporting on the procedures, outcomes, complications and nonconventional applications of FLP for TTTS was conducted. FLP has been established as the primary treatment for monochorionic twin pregnancy associated with TTTS at 16–26 weeks. FLP is the only therapy that directly addresses the underlying pathophysiology. The recent technique modification of FLP, referred to as the ‘Solomon technique’, induces selective coagulation to connect the anastomoses ablation sites and has been introduced to reduce residual anastomoses. The perinatal survival following FLP improved significantly with advances in the technique after its introduction. The recent survival rates of both twins and at least one twin are 70% and more than 90%, respectively. However, there is still an 11–14% risk of long‐term neurodevelopment impairment. The premature rupture of membranes that leads to preterm labor is a common complication after FLP. FLP is a valuable treatment option for feto‐fetal transfusion syndrome in triplets and for TTTS after 26 weeks. FLP for selective intrauterine growth restriction may be potentially beneficial when accompanied by abnormal Doppler findings and oligohydramnios. FLP is the optimal treatment option for TTTS at 16–26 weeks of gestation. FLP appears to be applicable in triplets, TTTS after 26 weeks and cases of selective intrauterine growth restriction with abnormal Doppler findings and oligohydramnios. FLP is the most common and successful fetal intervention. Improvement in the neurodevelopmental outcomes after FLP is a future focus.

Twin-twin transfusion syndrome - What we have learned from clinical trials

Monochorionic twin pregnancies are at increased risk for adverse outcome compared to dichorionic twin pregnancies and singletons. Monochorionic-specific complications include twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence, single intrauterine fetal demise and its consequences on the co-twin, and selective intrauterine growth restriction. Whereas the natural history of monochorionic-specific complications carries a high risk of fetal death or severe neurologic disability, a framework now exists, based on well-designed clinical trials, for optimal treatment of these entities. Fetoscopic selective laser coagulation of anastomotic vessels on the chorionic plate has been clearly demonstrated to improve survival and neurologic outcomes for Quintero stage ≥2 TTTS. However, many challenges remain unsolved, the most important of which is preterm premature rupture of membranes. Further improvement in the outcomes of monochorionic pregnancies will require improvements in the rate of premature delivery, and improved diagnosis and treatment strategies for early and late onset TTTS.

Fetoscopic laser photocoagulation for amniotic fluid discordance bordering on twin-twin transfusion syndrome: Feasibility, perinatal and long-term outcomes

AIM

This study investigated the feasibility and safety of fetoscopic laser photocoagulation (FLP) for amniotic fluid discordance (AFD) bordering on twin-twin transfusion syndrome (TTTS) with an absent or reverse end-diastolic velocity (AREDV) in the umbilical artery (UA), and evaluated the perinatal and long-term outcomes.

METHODS

A prospective intervention study was performed between 20 + 0 and 25 + 6 weeks of gestation (UMIN000004165). AFD bordering on TTTS was defined as maximum vertical pocket (MVP) of amniotic fluid in one twin's sac ≤3 cm and amniotic fluid MVP in the other twin's sac ≥7 cm excluding TTTS. Neurodevelopmental outcome was evaluated at 6 months and at 3 years of age.

RESULTS

Eleven women were treated without complications between September 2010 and July 2011. In all cases amnioinfusion was required, with a median surgical time of 70 min. There were nine cases of selective intrauterine growth restriction in which the growth discordant rate was >25%. The survival rates of the donor and recipient twins were 27.3% (3/11) and 100% (11/11), respectively. None of the surviving donor twins and two of the 11 recipient twins had hemiplegia at 6 months of age. One additional recipient twin had developmental delay at 3 years of age.

CONCLUSIONS

Fetoscopic laser photocoagulation for AFD bordering on TTTS with AREDV in the UA was feasible without complications but frequently resulted in donor twin death and a high survival rate of the recipient twin, albeit with neurodevelopmental abnormalities in some cases. FLP does not seem to be a promising treatment option for AFD bordering on TTTS.

GIFT-Cloud: A data sharing and collaboration platform for medical imaging research

OBJECTIVES

Clinical imaging data are essential for developing research software for computer-aided diagnosis, treatment planning and image-guided surgery, yet existing systems are poorly suited for data sharing between healthcare and academia: research systems rarely provide an integrated approach for data exchange with clinicians; hospital systems are focused towards clinical patient care with limited access for external researchers; and safe haven environments are not well suited to algorithm development. We have established GIFT-Cloud, a data and medical image sharing platform, to meet the needs of GIFT-Surg, an international research collaboration that is developing novel imaging methods for fetal surgery. GIFT-Cloud also has general applicability to other areas of imaging research.

METHODS

GIFT-Cloud builds upon well-established cross-platform technologies. The Server provides secure anonymised data storage, direct web-based data access and a REST API for integrating external software. The Uploader provides automated on-site anonymisation, encryption and data upload. Gateways provide a seamless process for uploading medical data from clinical systems to the research server.

RESULTS

GIFT-Cloud has been implemented in a multi-centre study for fetal medicine research. We present a case study of placental segmentation for pre-operative surgical planning, showing how GIFT-Cloud underpins the research and integrates with the clinical workflow.

CONCLUSIONS

GIFT-Cloud simplifies the transfer of imaging data from clinical to research institutions, facilitating the development and validation of medical research software and the sharing of results back to the clinical partners. GIFT-Cloud supports collaboration between multiple healthcare and research institutions while satisfying the demands of patient confidentiality, data security and data ownership.

Slic-Seg: A minimally interactive segmentation of the placenta from sparse and motion-corrupted fetal MRI in multiple views

Segmentation of the placenta from fetal MRI is challenging due to sparse acquisition, inter-slice motion, and the widely varying position and shape of the placenta between pregnant women. We propose a minimally interactive framework that combines multiple volumes acquired in different views to obtain accurate segmentation of the placenta. In the first phase, a minimally interactive slice-by-slice propagation method called Slic-Seg is used to obtain an initial segmentation from a single motion-corrupted sparse volume image. It combines high-level features, online Random Forests and Conditional Random Fields, and only needs user interactions in a single slice. In the second phase, to take advantage of the complementary resolution in multiple volumes acquired in different views, we further propose a probability-based 4D Graph Cuts method to refine the initial segmentations using inter-slice and inter-image consistency. We used our minimally interactive framework to examine the placentas of 16 mid-gestation patients from MRI acquired in axial and sagittal views respectively. The results show the proposed method has 1) a good performance even in cases where sparse scribbles provided by the user lead to poor results with the competitive propagation approaches; 2) a good interactivity with low intra- and inter-operator variability; 3) higher accuracy than state-of-the-art interactive segmentation methods; and 4) an improved accuracy due to the co-segmentation based refinement, which outperforms single volume or intensity-based Graph Cuts.

Endoscopic Placental Laser Coagulation in Dichorionic and Monochorionic Triplet Pregnancies

OBJECTIVE

To report the outcome of monochorionic (MC) and dichorionic (DC) triamniotic (TA) triplet pregnancies treated with endoscopic laser coagulation of the communicating placental vessels for severe feto-fetal transfusion syndrome (FFTS) and selective fetal growth restriction (sFGR).

METHODS

Laser surgery was performed at 18 (15-24) weeks' gestation in 11 MCTA and 33 DCTA pregnancies complicated by FFTS and 14 DCTA pregnancies complicated by sFGR. Data from our study and previous reports were pooled using meta-analytic techniques.

RESULTS

Survival of at least one baby and survival among all fetuses was 97.0 and 72.7% in DCTA pregnancies with FFTS, 78.6 and 52.4% in DCTA pregnancies with sFGR and 81.8 and 39.4% in MCTA pregnancies with FFTS. In the combined data from our study and previous reports, the pooled survival rates in 132 DCTA pregnancies with FFTS were 94.4 and 76.1%, and in 29 MCTA pregnancies with FFTS, they were 80.6 and 57.5%.

CONCLUSIONS

Survival after laser surgery is higher in DC triplets with FFTS than in those with sFGR and in DC than in MC triplets with FFTS.

Intertwin discrepancy in middle cerebral artery peak systolic velocity and third-trimester fetal growth restriction in monochorionic-diamniotic twin pregnancy

OBJECTIVES

To assess the role of intertwin discrepancy in middle cerebral artery peak systolic velocity (MCA-PSV) for the prediction of late selective intrauterine growth restriction (sIUGR) at birth and birth weight discrepancy of > 25% (BW-25) in otherwise uncomplicated monochorionic-diamniotic (MCDA) twin pregnancies.

METHODS

This was a cohort study including all MCDA pregnancies followed in a tertiary fetal medicine unit between 2008 and 2013. Exclusion criteria were referral after first trimester, abnormal karyotype, structural anomalies, twin-to-twin transfusion syndrome, twin anemia-polycythemia sequence and sIUGR detected before 28 weeks. MCA-PSV values of both twins measured in the second trimester (18-24 weeks) and early third trimester (26-32 weeks) were converted in multiples of the median (MoM). sIUGR was defined as birth weight < 5(th) centile. The relationship between MCA-PSV discrepancy, sIUGR and BW-25 was assessed by logistic regression analysis. Receiver-operating characteristics (ROC) curves were used to ascertain the predictive value of MCA-PSV discrepancy for such complications.

RESULTS

In total, 136 MCDA twin pregnancies were included in the analysis. Thirty (22.1%) were complicated with sIUGR at birth and 12 (8.8%) were complicated with BW-25. Logistic regression analysis identified MCA-PSV discrepancy as an independent predictor for sIUGR. ROC curves identified third-trimester MCA-PSV discrepancy as the best predictor for both sIUGR (area under ROC curve (AUC), 0.73 (95% CI, 0.62-0.85)) and BW-25 (AUC, 0.79 (95% CI, 0.65-0.93)). The optimal cut-off point for MCA-PSV discrepancy was 0.30 MoM (sensitivity, 70% and specificity, 69% for sIUGR; sensitivity, 83% and specificity, 72% for BW-25).

CONCLUSION

In MCDA twin pregnancies, MCA-PSV discrepancy is associated with both sIUGR at birth and BW discordance. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Impact of Monochorionicity and Twin to Twin Transfusion Syndrome on Prenatal Attachment, Post Traumatic Stress Disorder, Anxiety and Depressive Symptoms

Monochronioric (MC) twin pregnancies are considered as high-risk pregnancies with potential complications requiring in-utero interventions. We aimed to assess prenatal attachment, anxiety, post-traumatic stress disorder (PTSD) and depressive symptoms in MC pregnancies complicated with Twin-To-Twin-transfusion syndrome (TTTS) in comparison to uncomplicated monochorionic (UMC) and dichorionic pregnancies (DC). Auto-questionnaires were filled out at diagnosis of TTTS and at successive milestones. Prenatal attachment, PTSD, anxiety and perinatal depression were evaluated respectively by the Prenatal Attachment Inventory (PAI) completed for each twin, the Post-traumatic Checklist Scale (PCLS), the State-Trait Anxiety Inventory (STAI) and the Edinburgh Perinatal Depression Scale (EPDS). There was no significant difference in the PAI scores between the two twins. In the DC and UMC groups, PAI scores increased throughout pregnancy, whilst it didn't for TTTS group. TTTS and DC had a similar prenatal attachment while MC mothers expressed a significantly higher attachment to their fetuses and expressed it earlier. At the announcement of TTTS, 72% of the patients present a score over the threshold at the EPDS Scale, with a higher score for TTTS than for DC (p = 0.005), and UMC (p = 0.007) at the same GA. 30% of mothers in TTTS group have PTSD during pregnancy. 50% of TTTS- patients present an anxiety score over the threshold (STAI-Scale), with a score significantly higher in TTTS than in UMC (p<0.001) or DC (p<0.001). The proportion of subject with a STAI-State over the threshold is also significantly higher in TTTS than in DC at 20 GW (p = 0.01) and at 26 GW (p<0.05). The STAI-state scores in UMC and DC increase progressively during pregnancy while they decrease significantly in TTTS. TTTS announcement constitutes a traumatic event during a pregnancy with an important risk of PTSD, high level of anxiety and an alteration of the prenatal attachment. These results should guide the psychological support provided to these patients.

Feasibility and preliminary outcomes of fetoscopic laser photocoagulation for monochorionic twin gestation with selective intrauterine growth restriction accompanied by severe oligohydramnios

AIM

This study aimed to clarify the feasibility and perinatal outcomes of fetoscopic laser photocoagulation (FLP) for monochorionic twin gestation with selective intrauterine growth restriction (sIUGR) accompanied by both abnormal umbilical artery Doppler waveforms and isolated severe oligohydramnios of the sIUGR twin.

METHODS

In this prospective clinical trial, which included 10 cases with absent or reversed end-diastolic flow in the umbilical artery and severe oligohydramnios of the sIUGR twin, the main outcomes investigated were the feasibility of FLP and the rate of severe FLP-related maternal complications. The survival rate and incidence of neurological abnormalities of the twins at 28 days of age were also evaluated.

RESULTS

FLP was completed for all cases without major intraoperative maternal complications, although one case experienced threatened preterm labor requiring intensive treatment after the procedure. Three sIUGR and 10 larger twins were alive without neurological abnormalities at 28 days of age, while intrauterine fetal death occurred in the remaining seven sIUGR twins.

CONCLUSION

FLP for monochorionic twins with sIUGR, especially when accompanied by abnormal Doppler and severe oligohydramnios of the sIUGR twin, appears to be feasible and potentially beneficial for the larger twin, as well as for some sIUGR twins.

Cord Occlusion in Monochorionic Twins with Early Selective Intrauterine Growth Restriction and Abnormal Umbilical Artery Doppler: A Consecutive Series of 90 Cases

Objective: To describe perinatal outcomes achieved with cord occlusion (CO) in monochorionic twins with severe selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery Doppler in the IUGR twin (types II and III). Methods: We studied a consecutive series of 90 cases of sIUGR with abnormal Doppler treated with CO of the IUGR fetus. Abnormal Doppler was defined as continuous (type II, n = 41) or intermittent (type III, n = 49) absent/reversed end-diastolic flow. All cases presented at least one of the following severity criteria: gestational age (GA) <22 weeks, inter-twin estimated weight discordance >35%, reversed end-diastolic umbilical artery flow or ductus venosus pulsatility index >95th centile. We prospectively recorded pregnancy course and perinatal outcome. Results: Median GA at surgery was 20.6 weeks and mean duration 22.4 min. Miscarriage (<24 weeks) occurred in 3.3% (3/90) and preterm delivery <32 weeks in 7.1% (6/84) of continuing pregnancies. GA at delivery was 36.4 weeks and neonatal survival of the larger twin was achieved in 93.3%. Conclusion: In a consecutive series studied by an experienced team, CO in monochorionic twins with severe sIUGR type II or III was associated with delivery >32 weeks in 92.9% and neonatal survival of the normal twin in 93.3% of pregnancies.

Endoscopic Placental Laser Coagulation in Monochorionic Diamniotic Twins with Type II Selective Fetal Growth Restriction

Objective: To determine predictors of survival in monochorionic diamniotic twins with selective fetal growth restriction type II (sFGR-II), with or without twin-to-twin transfusion syndrome (TTTS), treated by endoscopic placental laser coagulation. Methods: Laser surgery was performed at 20 (15-27) weeks' gestation in 405 cases of sFGR-II with and 142 without coexisting TTTS. Multivariable logistic regression analysis was performed to determine significant predictors of survival to discharge from hospital. Results: There was survival of the small twin in 216 (39.5%) and of the large twin in 379 (69.3%) cases. Significant predictors of survival of both the small and larger twin were ductus venosus Doppler findings in the small twin, gestational age at laser and cervical length, but not the presence of TTTS or Doppler findings in the large twin. Conclusions: In sFGR-II, survival after laser surgery is primarily dependent on the condition of the small twin.

Growth discordance

Poor growth is a common problem in twin pregnancies, and management poses some unique challenges as the wellbeing of both twins have to be taken into account at all times. The decision to deliver the twins to prevent an intrauterine demise of the growth-restricted twin will, therefore, depends on the chances of intact postnatal survival of both twins. In monochorionic twins, management is complicated further by the fact that the wellbeing of one twin critically depends on that of the other twin because of the shared circulation. In the event of demise of the growth-restricted twin, the larger twin may also die or sustain brain damage because of an acute exsanguination into the feto-placental unit of its demised co-twin. In the pre-viable period, invasive fetal therapy may, therefore, be indicated to protect the appropriately growing twin.