Outcome of twin-to-twin transfusion syndrome in monochorionic monoamniotic twin pregnancy: systematic review and meta-analysis

Magnetic resonance imaging of intracranial anomalies in pregnancies complicated by twin anemia-polycythemia sequence

PURPOSE

To describe fetal brain Magnetic Resonance Imaging (MRI) findings in a large series of monochorionic (MC) pregnancies complicated by Twin Anemia-Polycythemia Sequence (TAPS) prenatally diagnosed, so to characterize the potential intracranial complications associated with this condition, their frequency and potential treatment options.

METHODS

This is a retrospective study of MC twin pregnancies complicated by TAPS and undergone fetal MRI in a single institution from 2006 to 2023. MRI control was performed and post-natal ultrasound (US) or MRI were available.

RESULTS

1250 MC pregnancies were evaluated in our institution. 50 pregnancies (4%) were diagnosed with TAPS, 29 underwent a fetal brain MRI. 13/29 pregnancies (44.8%) demonstrated brain findings at MRI in at least a twin. Neuroradiological findings were detected in 14/57 twins (24.6%). We detected four main categories of findings: hemorrhagic lesions, T2-weighted white-matter hyperintensities (WMH), brain edema-swelling and venous congestion. Nineteen findings were present in the anemic and three in the polycythemic twins, with a statistically significant ratio between the two groups (p-value = 0.01). Intrauterine MRI follow-up demonstrated the sequalae of hemorrhagic lesions. A complete regression of brain swelling, veins prominence and T2-WMHs was demonstrated after treatment. Postnatal imaging confirmed prenatal features.

CONCLUSIONS

Our work demonstrates that TAPS-related MRI anomalies consisted in edematous/hemorrhagic lesions that occur mostly in anemic rather than in polycythemic twins. Fetoscopic laser surgery could have a potential decongestant role. Therefore, prenatal MRI may help in counselling and management in TAPS pregnancies, especially for the planning of therapy and the monitoring of its efficacy.

Ultrasonographic Diagnosis of Twin-to-Twin Transfusion Syndrome

INTRODUCTION

Twin-twin transfusion syndrome (TTTS) is a typical complication of monochorionic twin pregnancies (MCTP). Placental vessels that communicate in the chorionic plate between donor and recipient, are responsible for the imbalance of blood flow. Circulatory imbalance causes hypovolemia in donor and hypervolemia in recipient fetus. In a typical case, recipient fetus develops polyhydramnios, weight gain, cardiomegaly and hydrops fetalis. In contrast, donor fetus develops oligohydramnios and fetal growth restriction.

AIM

The objective of this review is to evaluate in detail the main diagnostic aspects and add other important data for diagnosis of TTTS.

SCIENTIFIC BASES

The main diagnostic event for this condition is based on the ultrasonographic discovery of oligohydramnios-polyhydramnios sequence. Other useful elements for diagnosis, staging and prognosis are fetal urinary bladder visualization, urinary bladder volumen measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves and cardiac evaluation.

CONCLUSION

Considerations regarding diagnosis of TTTS make it possible to emphasize that role of physicians treating patients with MCTP is to identify ultrasound sequence of oligohydramnios-polyhydramnios. Other ultrasonographic fetal data as fetal urinary bladder visualization, urinary bladder volumen measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves and cardiac evaluation; may help diagnosis, staging and prognosis of TTTS. It is their responsibility to accurately assess severity, therapeutic possibilities and prognosis.

KEY POINTS

· The role of physicians treating patients with MCTP, regarding diagnosis of TTTS, must be to identify ultrasound sequence of oligohydramnios-polyhydramnios.. · Other ultrasonographic fetal data may help diagnosis, staging, and prognosis of TTTS as follows: fetal urinary bladder visualization, urinary bladder volume measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves, and cardiac evaluation.. · It is physicians' responsibility to accurately assess severity, therapeutic possibilities, and prognosis of patients with MCTP and diagnosis of TTTS..

Risk factors for adverse outcomes in twin pregnancies: a narrative review

PURPOSE

Globally, the incidence of twin pregnancies is rising owing to the use of assisted reproductive technologies (ART), emigration and deferment of pregnancy until advanced maternal age (AMA). While twin pregnancies have higher absolute risks of adverse outcomes, including miscarriage, stillbirth, neonatal death and preterm delivery, the impact of specific exposures and risk factors related to these outcomes may differ between twin pregnancies and singleton pregnancies. Regarding modifiable factors, data are sometimes based on evidence extrapolated from singleton or whole obstetric populations. Therefore, targeted evidence is required to provide care tailored to twin pregnancies to prevent adverse outcomes. We aimed to comprehensively review the association between different risk factors and adverse outcomes in twin pregnancies, including data on chorionicity, and to compare these to singletons.

MATERIALS AND METHODS

This review examines the risks associated with chorionicity, AMA, body mass index (BMI), socioeconomic and ethnic inequalities, maternal smoking, use of ART, maternal perception of fetal movement, and maternal comorbidities, including hypertensive disorders of pregnancy (HDP) and gestational diabetes mellitus (GDM). Adverse outcomes reported were preterm birth, admission to the neonatal intensive care unit (NICU), stillbirth and neonatal mortality. As such, fetal mortality and morbidity will be under-represented, as pregnancy loss before 22-24 weeks is omitted.

RESULTS

Monochorionicity increases the risk of stillbirth, NICU admission, and preterm delivery in twin pregnancy. AMA predisposes twin pregnancies to higher risks of mortality, admission to the NICU, and preterm birth than singleton pregnancies do. Conversely, the impact of BMI, socioeconomic inequalities, smoking, ART, and HDP on adverse outcomes appears to be lower in twin pregnancies than in singleton pregnancies. This attenuation might be explained by the higher baseline risk of adverse outcomes such as preterm birth in twin pregnancies. Some exposures, such as ART use and GDM, appear to be "protective" against perinatal mortality in twin pregnancies, despite being established risk factors for adverse outcomes in singleton pregnancies, potentially related to access to specialist care. There is a paucity of evidence available to counsel mothers of twin pregnancies regarding reduced fetal movement.

CONCLUSIONS

Overall, the risk factors for adverse pregnancy outcomes differ between twin and singleton pregnancies. This highlights the need for further studies to examine the association between risk factors and adverse outcomes in twin pregnancies. The resulting data would facilitate tailored guidance for twin pregnancies, contribute to improved antenatal care, and inform wider public health strategies.

Managing Monoamniotic Twin Pregnancies

Monoamniotic twins comprise a rare subset of twins at risk of unique and serious complications. In addition to the risks faced by all twins (premature birth, growth restriction), all monochorionic twins (twin-to-twin transfusion syndrome), and all monozygotic twins (congenital anomalies), monoamniotic twins face the unique risk of cord entanglement, in addition to a markedly increased risk of congenital anomalies. Early diagnosis, screening for fetal anomalies and surveillance for twin-twin transfusion syndrome are critical. After fetal viability, frequent fetal monitoring reduces the risk of intrauterine fetal demise.

Outcome following laser surgery of twin-twin transfusion syndrome complicated by selective fetal growth restriction: systematic review and meta-analysis

OBJECTIVE

The published literature reports mostly on the outcome of twin pregnancies complicated by twin-twin transfusion syndrome (TTTS) without considering whether the pregnancy is also complicated by another pathology, such as selective fetal growth restriction (sFGR). The aim of this systematic review was to report on the outcome of monochorionic diamniotic (MCDA) twin pregnancies undergoing laser surgery for TTTS that were complicated by sFGR and those not complicated by sFGR.

METHODS

MEDLINE, EMBASE and Cochrane databases were searched. The inclusion criteria were studies reporting on MCDA twin pregnancies with TTTS undergoing laser therapy that were complicated by sFGR and those not complicated by sFGR. The primary outcome was the overall fetal loss following laser surgery, defined as miscarriage and intrauterine death. The secondary outcomes included fetal loss within 24 h after laser surgery, survival at birth, preterm birth (PTB) prior to 32 weeks of gestation, PTB prior to 28 weeks, composite neonatal morbidity, neurological and respiratory morbidity, and survival free from neurological impairment. All outcomes were explored in the overall population of twin pregnancies complicated by sFGR vs those not complicated by sFGR in the setting of TTTS and in the donor and recipient twins separately. Random-effects meta-analysis was used to combine data and the results are reported as pooled odds ratios (OR) with 95% CI.

RESULTS

Five studies (1710 MCDA twin pregnancies) were included in the qualitative synthesis and four in the meta-analysis. The overall risk of fetal loss after laser surgery was significantly higher in MCDA twin pregnancies with TTTS complicated by sFGR (20.90% vs 14.42%), with a pooled OR of 1.6 (95% CI, 1.3-1.9) (P < 0.001). The risk of fetal loss was significantly higher in MCDA twin pregnancies with TTTS and sFGR for the donor but not for the recipient twin. The rate of live twins was 79.1% (95% CI, 72.6-84.9%) in TTTS pregnancies with sFGR and 85.6% (95% CI, 81.0-89.6%) in those without sFGR (pooled OR, 0.6 (95% CI, 0.5-0.8)) (P < 0.001). There was no significant difference in the risk of PTB prior to 32 weeks of gestation (P = 0.308) or prior to 28 weeks (P = 0.310). Assessment of short- and long-term morbidity was affected by the small number of cases. There was no significant difference in the risk of composite (P = 0.506) or respiratory (P = 0.531) morbidity between twins complicated by TTTS with vs those without sFGR, while the risk of neurological morbidity was significantly higher in those with TTTS and sFGR (pooled OR, 1.8 (95% CI, 1.1-2.9)) (P = 0.034). The risk of neurological morbidity was significantly higher for the donor twin (pooled OR, 2.4 (95% CI, 1.1-5.2)) (P = 0.029) but not for the recipient twin (P = 0.361). Survival free from neurological impairment was observed in 70.8% (95% CI, 45.0-91.0%) of twin pregnancies with TTTS complicated by sFGR and in 75.8% (95% CI, 51.9-93.3%) of those not complicated by sFGR, with no difference between the two groups.

CONCLUSIONS

sFGR in MCDA pregnancies with TTTS represents an additional risk factor for fetal loss following laser surgery. The findings of this meta-analysis may be useful for individualized risk assessment of twin pregnancy complicated by TTTS and tailored counseling of the parents prior to laser surgery. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Perinatal outcome in monoamniotic twin pregnancies during a 10-year period: a single center, descriptive study

PURPOSE

To retrospectively investigate perinatal outcome of monoamniotic twin pregnancies in a tertiary center during a 10 year period.

METHODS

A retrospective analysis of all monoamniotic pregnancies managed at Karolinska University Hospital, Stockholm, Sweden 2010-2019 was performed. The primary outcomes were live birth rate, neonatal death and perinatal survival. The secondary outcomes were late miscarriage, gestational age at delivery and frequency of fetal complications.

RESULTS

Twenty-two monoamniotic pregnancies, with 44 fetuses, were identified. Thirty-five of 44 fetuses (80%) were liveborn. Of 36 fetuses reaching 24 weeks gestation, 35 (97%) were liveborn. There were no neonatal deaths, thus the perinatal survival was 97%. The mean gestational age at birth was 32.5 weeks (SD ± 1.5).

CONCLUSIONS

The live birth rate and perinatal survival of monoamniotic pregnancies managed at Karolinska University Hospital was high and comparable to previously published data.

Solomon technique vs selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: systematic review and meta-analysis of maternal and perinatal outcomes

OBJECTIVE

To ascertain maternal and perinatal outcomes of monochorionic twin pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated with the Solomon technique compared with selective fetoscopic laser photocoagulation (SFLP) of placental anastomoses.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched to identify relevant studies. The outcomes observed were perinatal loss and survival, preterm prelabor rupture of membranes (PPROM), preterm birth (PTB), gestational age (GA) at delivery, interval between laser treatment and delivery, maternal bleeding, septostomy or chorioamniotic separation, placental abruption, twin anemia-polycythemia sequence (TAPS), recurrence of TTTS, neonatal morbidity and neurological morbidity. Random-effects head-to-head meta-analyses were used to analyze the data. Pooled odds ratios (OR) and mean differences (MD) and their 95% CIs were calculated.

RESULTS

Nine studies were included in the systematic review. There was generally no difference in the main maternal and pregnancy characteristics between pregnancies treated using the Solomon technique and those treated using SFLP of placental anastomoses. The risks of fetal loss (pooled OR, 0.69 (95% CI, 0.50-0.95); P = 0.023), neonatal death (pooled OR, 0.37 (95% CI, 0.16-0.84); P = 0.018) and perinatal loss (pooled OR, 0.56 (95% CI, 0.38-0.83); P = 0.004) were significantly lower in pregnancies treated using the Solomon technique than in those treated with SFLP. Likewise, pregnancies treated using the Solomon technique had a significantly higher chance of survival of at least one twin (pooled OR, 2.31 (95% CI, 1.03-5.19); P = 0.004) and double survival (pooled OR, 2.18 (95% CI, 1.29-3.70); P = 0.001). There was no difference in the risk of PPROM (P = 0.603), PPROM within 10 days from laser surgery (P = 0.982), PTB (P = 0.207), maternal bleeding (P = 0.219), septostomy or chorioamniotic separation (P = 0.224) or chorioamnionitis (P = 0.135) between the two groups, while the risk of placental abruption was higher in pregnancies treated using the Solomon technique (pooled OR, 2.90 (95% CI, 1.55-5.44); P = 0.001). In the Solomon technique group, pregnancies delivered at a significantly earlier GA than did those treated with SFLP (pooled MD, -0.625 weeks (95% CI, -0.90 to -0.35 weeks); P < 0.001), while there was no difference in the interval between laser treatment and delivery (P = 0.589). The rate of recurrence of TTTS was significantly lower in pregnancies undergoing the Solomon technique (pooled OR, 0.43 (95% CI, 0.22-0.81); P < 0.001), while there was no difference in the risk of TAPS between the two groups (P = 0.792). Finally, there was no difference in the overall risk of neonatal morbidity (P = 0.382) or neurological morbidity (P = 0.247) between the two groups.

CONCLUSIONS

Monochorionic twin pregnancies complicated by TTTS undergoing laser treatment using the Solomon technique had a significantly higher survival rate and lower recurrence rate of TTTS but were associated with an increased risk of placental abruption and earlier GA at delivery compared to those treated with SFLP. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Excellent perinatal outcome of monoamniotic twin pregnancy with timely diagnosis and optimal management - a retrospective cohort study

OBJECTIVES

Monoamniotic twins represent a high-risk pregnancy requiring intense follow-up, elective birth and careful consideration of the mode and timing of delivery. We conducted this study to evaluate the perinatal and neonatal outcomes of monoamniotic twin pregnancies in the largest tertiary hospital in Finland.

METHODS

This was a retrospective cohort study including all monoamniotic twin pregnancies during a 17-year period (2002-2018) managed in Helsinki University Hospital. Data on mothers and children were collected from patient files. Chorionicity and amnionicity were defined in first-trimester ultrasound screening.

RESULTS

There were altogether 31 monoamniotic twin pregnancies during the study period, including four cases of conjoined twins which all underwent termination of pregnancy, and three miscarriages. In the remaining 24 pregnancies that continued past 24 weeks of gestation there was 97.9% survival (one intrauterine death). Three pregnancies were complicated with twin-to-twin transfusion syndrome. All children were delivered by cesarean section with a mean gestational age of 32 + 5 weeks (27 + 1-34 + 2 weeks). Respiratory distress syndrome (RDS) was observed in 57% (27/47) of neonates and grade I-II intraventricular haemorrhage (IVH) in 6.3% (3/47) of neonates. There were no neonatal deaths and no maternal complications.

CONCLUSIONS

Monoamniotic twinning is a rare form of pregnancy and carries risks for perinatal and neonatal complications. With timely diagnosis, close monitoring in specialized feto-maternal unit and elective delivery at 32-34 weeks the outcome is usually excellent.

Neonatal management and outcome in complicated monochorionic twins: What have we learned in the past decade and what should you know?

Monochorionic (MC) twin pregnancies are at increased risk of neonatal morbidity and mortality due to the shared placenta with vascular connections that can give rise to various complications, including twin-twin transfusion syndrome, twin anemia polycythemia sequence (TAPS), selective fetal growth restriction, and other hematological imbalances at birth. Each complication presents its own challenges and considerations in the neonatal period. Measurement of hemoglobin levels and reticulocyte count is required to establish a correct diagnosis. Placenta dye injection is needed to properly distinguish between the various conditions. Risk factors for adverse outcome in MC twins include prematurity, severe cerebral injury, and the type of MC pregnancy complication. We, therefore, recommend cerebral ultrasound examinations in all complicated MC twins at birth to rule out a severe brain injury. Lastly, we strongly encourage screening for hearing loss using automated auditory brainstem response in all spontaneous TAPS donors to prevent permanent speech development delay.

Neonatal Morbidity of Monoamniotic Twin Pregnancies: A Systematic Review and Meta-analysis

OBJECTIVE

This study was aimed to report the incidence of neonatal morbidity in monochorionic monoamniotic (MCMA) twin pregnancies according to gestational age at birth and type of management adopted (inpatient or outpatient).

STUDY DESIGN

Medline and Embase databases were searched. Inclusion criteria were nonanomalous MCMA twins. The primary outcome was a composite score of neonatal morbidity, defined as the occurrence of at least one of the following outcomes: respiratory morbidity, overall neurological morbidity, severe neurological morbidity, and infectious morbidity, necrotizing enterocolitis at different gestational age windows (24-30, 31-32, 33-34, and 35-36 weeks). Secondary outcomes were the individual components of the primary outcome and admission to neonatal intensive care unit (NICU). Subanalysis according to the type of surveillance strategy (inpatient compared with outpatient) was also performed. Random effect meta-analyses were used to analyze the data.

RESULTS

A total of 14 studies including 685 MCMA twin pregnancies without fetal anomalies were included. At 24 to 30, 31 to 32, 33 to 34, and 35 to 36 weeks of gestation, the rate of composite morbidity was 75.4, 65.5, 37.6, and 18.5%, respectively, the rate of respiratory morbidity was 74.2, 59.1, 35.5, and 12.2%, respectively, while overall neurological morbidity occurred in 15.3, 10.2, 4.3, and 0% of the cases, respectively. Infectious morbidity complicated 13, 4.2, 3.1, and 0% of newborns while 92.1, 81.6, 58.7, and 0% of cases required admission to NICU. Morbidity in pregnancies delivered between 35 and 36 weeks of gestation was affected by the very small sample size of cases included. When comparing the occurrence of overall morbidity according to the type of management (inpatient or outpatient), there was no difference between the two surveillance strategies (p = 0.114).

CONCLUSION

MCMA pregnancies are at high risk of composite neonatal morbidity, mainly respiratory morbidity that gradually decreases with increasing gestational age at delivery with a significant reduction for pregnancies delivered between 33 and 34 weeks. We found no difference in the occurrence of neonatal morbidity between pregnancies managed as inpatient or outpatient.

KEY POINTS

· MCMA pregnancies are at high risk of composite neonatal morbidity, mainly respiratory morbidity.. · Neonatal morbidity gradually decreases with increasing GA at delivery, mostly between 33 and 34 weeks.. · There is no difference in the occurrence of neonatal morbidity between in- or outpatient management..

Twin-to-twin transfusion syndrome and coronavirus disease 2019: Impact on diagnosis, referral, eligibility for fetoscopic laser therapy and outcomes

BACKGROUND

Because of the progressive nature of twin-to-twin transfusion syndrome, difficulties in healthcare access during the COVID-19 pandemic may lead to delayed diagnosis and referral to fetal surgery centers, which may have repercussions on outcomes.

OBJECTIVE

This study aimed to assess the clinical impact of the COVID-19 pandemic on pregnancies complicated with twin-to-twin transfusion syndrome.

STUDY DESIGN

A retrospective cohort study of consecutive monochorionic diamniotic twin pregnancies complicated with twin-to-twin transfusion syndrome evaluated in our national referral fetal surgery center at Queretaro, Mexico, for possible surgical fetoscopy was conducted. Maternal-fetal characteristics and perinatal outcomes of cases evaluated during the first year of the World Health Organization's COVID-19 pandemic declaration (March 11, 2020 to March 10, 2021) were retrospectively compared with outcomes of cases evaluated during the same period in the previous year (March 11, 2019 to March 10, 2020).

RESULTS

Overall, 109 consecutive twin-to-twin transfusion syndrome cases were evaluated during the 2-year study period, 54 during the COVID-19 pandemic and 55 in the previous year. In the former group, a higher proportion of cases with fetal surveillance interval longer than 2 weeks (70.4% vs 47.3%; P=.01); twin-to-twin transfusion syndrome complications precluding laser therapy, such as intrauterine fetal demise, preterm rupture of membranes, or cervical dilatation with prolapsed amniotic membranes (18.5% vs 1.8%; P<.01); advanced twin-to-twin transfusion syndrome (53.7% vs 36.4%; P=.07); preoperative short cervix (25.9% vs 10.9%; P<.05); and lower overall perinatal survival (56.9% vs 80.0% [P=.01; at least 1 twin] and 39.2% vs 56.4% [P=.08; both twins], respectively) were observed. A significantly lower number of cases were selected for fetoscopic laser therapy during the pandemic (75.9% vs 92.7%; P=.01), with similar postoperative outcomes seen in both study periods.

CONCLUSION

In pregnancies with twin-to-twin transfusion syndrome, the COVID-19 pandemic has shown an adverse impact involving suboptimal fetal surveillance, advanced stages at diagnosis, poorer survival rates, and higher number of complications that preclude fetoscopic laser therapy.

Monochorionic monoamniotic twin pregnancies

Monoamniotic twin pregnancies are rare, but early diagnosis of such pregnancies is critical, as the incidence of complications in these pregnancies is much higher than in diamniotic or dichorionic twin pregnancies. Overall, only 70% of all monoamniotic twins will survive. Furthermore, approximately half of fetal deaths in these pregnancies are because of the high incidence of fetal anomalies (15%-25%), such as twin reversed arterial perfusion sequence and conjoined twinning. Therefore, early anatomy screening in the first trimester of pregnancy is recommended. Other causes of fetal death in these pregnancies include twin-twin transfusion syndrome, tight cord entanglement, or acute hemodynamic imbalances through the large placental vascular anastomoses. After viability, fetal surveillance can be intensified, as this decreases the risk of in utero death. Both inpatient and outpatient surveillance are reasonable. If otherwise uncomplicated, monoamniotic twins should be delivered at 33 to 34 weeks' gestation. Most centers will deliver by cesarean delivery, but some continue to advocate for vaginal delivery. Lastly, neonatal morbidity is high in monoamniotic twin pregnancies and is mainly related to prematurity.

Management of monoamniotic twin pregnancies: Where, when, how?

Management difficulties for monochorionic monoamniotic (MCMA) twin pregnancy reflect the absence of high-quality research into optimal types of monitoring, essential as MCMA twins have a high risk of intrauterine and neonatal death with perinatal mortality. D'Antonio et al's meta-analysis and the MonoMono study published in 2019, investigated the impact of monitoring location, out- or in-patient, of MCMA pregnancies and concluded that no specific management location is associated with improvement in prognosis. To evaluate the optimal timing for delivery of MCMA pregnancies, Van Mieghem and Chitrit carried out retrospective studies comparing gestational age of intrauterine death and risk of neonatal complication. The crossover point between the propective risk of intrauterine fetal death and neonatal complication was found at 32,33 weeks of gestation (WG), in accordance with American College of Obstetricians and Gynecologists and Royal College of Obstetricians and Gynaecologists recommendations but inclusion of complicated pregnancies and analysis of fetuses individually may be regarded as a bias. The majority of studies of MCMA pregnancies focused on elective scheduled cesareans, with only rare retrospective studies reporting on vaginal delivery. Of these, two recent studies carried out by French teams suggest that vaginal deliveries may be as safe as cesarean births for MCMA twin pregnancies when specific criteria are met. In summary, concerning MCMA pregnancies, prognosis is not found to improve with inpatient management, optimal timing for delivery is at approximately 33 GW and vaginal delivery should not be excluded.

Pregnancy and parenting experiences of women with twin-to-twin transfusion syndrome: a qualitative study

Background

Qualitative research can reflect the actual thoughts and experience of research subjects and can be used to explore the experiences of women presenting with twin-to-twin transfusion syndrome (TTTS) to facilitate the provision of targeted psychological support.

Methods

A semi-structured interview method was used to assess the pregnancy and parenting experiences of women with TTTS. Colaizzi method was used for data analysis.

Results

Eighteen women participated in the study. We found that women with TTTS during pregnancy experienced persistent worry about their children’s health from the disease diagnosis to the subsequent parenting processes, even in case of minor changes in their children’s health. The lack of an efficient referral process and health information increased their uncertainty about their children’s health.

Conclusion

In addition to the children’s health, other difficulties encountered during pregnancy and parenting may aggravate the pressure. Clinicians in the first-visit hospital and foetal medicine centre should improve the referral process and establish a follow-up system to provide women with health information and psychological support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04057-0.

Fetoscopic laser ablation in twin-to-twin transfusion syndrome: tips for counselling

Twin-to-twin transfusion syndrome (TTTS) is a serious complication that affects approximately 10-15% of monochorionic twin pregnancies. The most important role for the development of this condition is the presence of an unbalanced flow through the inter-twin vascular anastomoses. Depending on the number, type and direction of the connecting vessels, blood can be transfused disproportionately from one twin (the donor) to the other twin (the recipient). The diagnosis is defined prenatally by ultrasound and involves of two main criteria: the presence of a monochorionic diamniotic (MCDA) pregnancy; and the presence of oligohydramnios in the donor's sac- deep vertical pocket (DVP) 2 cm - and polyhydramnios in the recipient's sac- DVP>8 cm. Once diagnosed, TTTS is usually graded by using the Quintero staging system, that is composed by five stages, from oligohydramnios in the donor and polyhydramnios in the recipient twin to fetal demise in one or both twins. Photocoagulation of the anastomotic vessels, usually followed by equatorial dichorionization, it has currently become the most common fetoscopic operation today and is considered as the gold standard for stage II-IV TTTS. pPROM, chorioamniotic separation and iatrogenic preterm birth are among the most common complications of fetoscopic laser ablation, and the mean gestational age at delivery after laser procedure is about 31 weeks.

Outcome of twin-twin transfusion syndrome according to Quintero stage of disease: systematic review and meta-analysis

OBJECTIVES

To report the outcome of pregnancies complicated by twin-twin transfusion syndrome (TTTS) according to Quintero stage.

METHODS

MEDLINE, EMBASE and CINAHL databases were searched for studies reporting the outcome of pregnancies complicated by TTTS stratified according to Quintero stage (I-V). The primary outcome was fetal survival rate according to Quintero stage. Secondary outcomes were gestational age at birth, preterm birth (PTB) before 34, 32 and 28 weeks' gestation and neonatal morbidity. Outcomes are reported according to the different management options (expectant management, laser therapy or amnioreduction) for pregnancies with Stage-I TTTS. Only cases treated with laser therapy were considered for those with Stages-II-IV TTTS and only cases managed expectantly were considered for those with Stage-V TTTS. Random-effects head-to-head meta-analysis was used to analyze the extracted data.

RESULTS

Twenty-six studies (2699 twin pregnancies) were included. Overall, 610 (22.6%) pregnancies were diagnosed with Quintero stage-I TTTS, 692 (25.6%) were Stage II, 1146 (42.5%) were Stage III, 247 (9.2%) were Stage IV and four (0.1%) were Stage V. Survival of at least one twin occurred in 86.9% (95% CI, 84.0-89.7%) (456/552) of pregnancies with Stage-I, in 85% (95% CI, 79.1-90.1%) (514/590) of those with Stage-II, in 81.5% (95% CI, 76.6-86.0%) (875/1040) of those with Stage-III, in 82.8% (95% CI, 73.6-90.4%) (172/205) of those with Stage-IV and in 54.6% (95% CI, 24.8-82.6%) (5/9) of those with Stage-V TTTS. The rate of a pregnancy with no survivor was 11.8% (95% CI, 8.4-15.8%) (69/564) in those with Stage-I, 15.0% (95% CI, 9.9-20.9%) (76/590) in those with Stage-II, 18.6% (95% CI, 14.2-23.4%) (165/1040) in those with Stage-III, 17.2% (95% CI, 9.6-26.4%) (33/205) in those with Stage-IV and in 45.4% (95% CI, 17.4-75.2%) (4/9) in those with Stage-V TTTS. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS. Overall, the incidence of PTB and neonatal morbidity increased as the severity of TTTS increased, but data on these two outcomes were limited by the small sample size of the included studies. When stratifying the analysis of pregnancies with Stage-I TTTS according to the type of intervention, the rate of fetal survival of at least one twin was 84.9% (95% CI, 70.4-95.1%) (94/112) in cases managed expectantly, 86.7% (95% CI, 82.6-90.4%) (249/285) in those undergoing laser therapy and 92.2% (95% CI, 84.2-97.6%) (56/60) in those after amnioreduction, while the rate of double survival was 67.9% (95% CI, 57.0-77.9%) (73/108), 69.7% (95% CI, 61.6-77.1%) (203/285) and 80.8% (95% CI, 62.0-94.2%) (49/60), respectively.

CONCLUSIONS

Overall survival in monochorionic diamniotic pregnancies affected by TTTS is higher for earlier Quintero stages (I and II), but fetal survival rates are moderately high even in those with Stage-III or -IV TTTS when treated with laser therapy. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS treated with laser and expectant management, respectively. In pregnancies affected by Stage-I TTTS, amnioreduction was associated with slightly higher survival compared with laser therapy and expectant management, although these findings may be confirmed only by future head-to-head randomized trials. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of Twin-to-Twin Transfusion Syndrome Using Characteristic Waveforms of Ductus Venosus in Recipient Twins

We aimed to investigate whether the alterations of time intervals and velocity-time integrals (VTIs) of ductus venosus (DV) Doppler flow could predict evolving twin-to-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MD) twin pregnancies in the second trimester. DV Doppler waveforms of MD twin pregnancies were retrospectively analyzed. Time intervals and VTIs of the accelerating phase of S-wave (S1 and VTI-1), decelerating phase of S-wave (S2 and VTI-2) and phase of D-wave (D and VTI-diast) were measured in the recipient twins of TTTS and the larger twins of uncomplicated MD twins. Each parameter was normalized to total time intervals and VTIs. DV parameters of prerecipient twins in pre-TTTS conditions were analyzed. The pre-TTTS condition was defined as the condition within 2 weeks before when TTTS cases fulfilled the criteria. Both recipient twins in TTTS cases and prerecipient twins in pre-TTTS condition showed significantly shorter S1, longer S2, shorter D, smaller VTI-1, larger VTI-2 and smaller VTI-diast than did the larger twins in uncomplicated MD twins (p < .05). Receiver-operating characteristic curve analysis showed that VTI-2 had better performance, and VTI-2 >45.5% had 87.0% sensitivity, 90.9% specificity, 81.0% positive predictive value and 93.0% negative predictive value for detecting prerecipient twins. Recipient twins complicated with TTTS have characteristic alterations in time intervals and VTIs of DV Doppler flow, which is present even before fulfilling the TTTS criteria. Furthermore, VTI-2 >45.5% is a possible predictive parameter for TTTS in the second trimester.