Monochorionic Twin Gestations Research Articles

Twin-twin transfusion and laser therapy.

Twin-to-twin transfusion syndrome (TTTS) is an uncommon, but dangerous, complication of monochorionic diamniotic twin gestations. The purpose of this review is to provide an update on the evolving treatments in TTTS as it pertains primarily to laser photocoagulation, as well as to provide recently published information on outcomes. The Solomon laser technique, in which selective fetoscopic laser photocoagulation is first performed and then followed by laser of the vascular equator from one side of the placenta to the other, reduces TTTS complications of twin anemia-polycythemia syndrome and recurrent TTTS. The addition of fetal echocardiography to the historical staging of TTTS adds important information that may guide future therapies. The postlaser ablation rate of neurodevelopmental delay in TTTS has recently been reported to be 14%. Cotwin demise is a significant complication of untreated TTTS and survival carries a 25% risk of cystic periventricular leukomalacia, middle cerebral artery infarction, and injury to other central nervous system structures as noted by neuroimaging. Laser therapy for TTTS is clearly the only therapy that halts the disease process, allows both fetuses an opportunity to survive and protects a surviving cotwin in the event of the demise of one twin. Laser techniques have evolved greatly over the last 25 years and recent reports with the addition of the Solomon technique appearing to reduce some postlaser complications (twin anemia-polycythemia sequence and recurrent TTTS). Future focus of TTTS therapy should be centered on understanding the pathophysiology of the disease better with improvement in staging of the disease and on comparison of different laser techniques with the overall goal of not only increasing twin survival rates but also reducing long term neurodevelopmental morbidity.

Dicephalus Parapagus Conjoined Twins Diagnosed by First-Trimester Ultrasound.

Conjoined twins are a rare phenomenon, occurring in 1% of monochorionic twin gestation, with an incidence of 1 : 50 000 to 1 : 100 000. Many conjoined twins have abnormalities incompatible with life, so early prenatal diagnosis is very important for optimal management of both pregnancy and delivery. We report a case of dicephalus parapagus conjoined twins, sharing a single heart, diagnosed at 12 weeks' gestation. With early ultrasound diagnosis, we were able to provide appropriate and timely prenatal counseling to the family.

Acardiac Twin: A Rare Case Report

AbstractThe incidence of multifetal pregnancies has dramatically increased due to assisted reproductive technology. As a result, preterm labor, Preterm premature rupture of the membranes, congenital anomalies and fetal losses are commonly encountered by obstetricians. Despite advances in diagnostic modalities and prenatal care, many times the complications associated with multifetal pregnancies may remain undiagnosed. Complications are more with monochorionic twin gestation due to placental sharing. “Twin – reversed arterial perfusion” sequence or “acardiac twin” is one such complication. This case report presents an antenatally undiagnosed monochorionic twin pregnancy, resulting in preterm delivery of a healthy, normal twin along with an acardiac acephalus co-twin.How to cite this articleSrivastava NN, Bhatia T, Narshetty J, Kumar S. Acardiac Twin: A Rare Case Report. Int J Infertil Fetal Med 2016;7(3):103-104.

Abstract 16408: Acute Changes in Tricuspid Annular Plane Systolic Excursion and Myocardial Deformation in Fetuses With Twin-twin Transfusion Syndrome After Selective Fetoscopic Laser Therapy

Introduction: Twin-twin transfusion syndrome (TTTS) is a serious complication affecting 10-15% of monochorionic twin gestations. Right ventricle (RV) function is often abnormal in these fetuses. Tricuspid annular plane systolic excursion (TAPSE) and myocardial strain are used as a marker of RV function in a number of disease processes postnatally. Hypothesis: Monitoring TAPSE and myocardial deformation may aid in assessing response to selective fetoscopic laser therapy (SFLP) in TTTS. Our objective was to determine whether TAPSE and myocardial deformation are altered after SFLP. Methods: Fetal echocardiograms of 22 recipient (RT) and donor (DT) twin pairs with TTTS were prospectively evaluated. TAPSE was obtained via M-mode through the lateral tricuspid annulus in the vertical 4-chamber (4C) view. 2D 4C views were acquired utilizing high frame rates (>30 frames/sec) and were interrogated offline using feature-tracking software for strain analysis. Global RV longitudinal strain, TAPSE, and myocardial performance index (MPI) were compared pre and post-SFLP. Reproducibility of both TAPSE and RV strain was assessed. Results: Initial fetal echo was performed at 20.8 ± 2.3 weeks gestation. Median time between initial study and post-SFLP was 7 days (interquartile range 1 to 11 days). DT showed a slight improvement in strain, but not in TAPSE post-SFLP (Table). There was a significant, acute improvement both in global longitudinal strain and TAPSE among RT after SFLP (Table). Interobserver variability for TAPSE and strain was 4% vs 36%, respectively. Conclusion: After SFLP, there is an acute improvement in the global RV strain and TAPSE in RT, consistent with improved RV long-axis function or loading conditions. TAPSE is feasible in most fetuses, and is considerably more reproducible than myocardial strain. Further work examining the relationship between RV function and outcome post-SFLP is warranted in TTTS population.

Risk assessment for neonatal RDS/TTN using gestational age and the amniotic lamellar body count in twin pregnancies

BackgroundThe amniotic lamellar body count (LBC) is useful for predicting respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN) in twin pregnancies. However, the risk of neonatal respiratory complications varies with gestational age (GA). We herein created a model to predict the risk for RDS and TTN using GA and the LBC in twin pregnancies. MethodsSix hundred thirty-two amniotic fluid samples, comprising 169 dichorionic twin (DCT) and 147 monochorionic twin (MCT) gestations, were obtained at Cesarean section. The samples were analyzed immediately without centrifugation. A logistic regression model including the LBC and GA was used to develop the prediction model for RDS/TTN. ResultsThere were 101 neonates (16.0%) with RDS/TTN. The GA and LBC were significant independent factors affecting RDS/TTN. According to the logistic regression model, we determined the probability of RDS/TTN given the values of GA and the LBC. The overall diagnostic accuracy for predicting neonatal RDS/TTN using GA and the LBC was higher than the use of the LBC alone. ConclusionsGA-specific LBC cutoffs for the risk assessment of neonatal RDS/TTN have been considered to be more accurate in twin pregnancies. Our findings provide valuable, new information for the management of twin pregnancies.

Visualisation of the vascular equator in twin-to-twin transfusion syndrome by virtual fetoscopy.

Twin-to-twin transfusion syndrome (TTTS) is a serious complication of monochorionic twin gestation, which has a high risk of perinatal morbidity and mortality. Fetoscopic laser photocoagulation of the vascular anastomoses is the preferred treatment. Nowadays, Solomon technique which consists the vascular coagulation of all anastomoses in the placental equator is the preferable method. To develop a method of virtual fetoscopy by means of ultrasound and resonance magnetic imaging (MRI) scan data to allow the identification of placental equator. MRI was performed in a twin monochorionic twin pregnancy with 28 weeks previously treated for TTTS with fetoscopic laser photocoagulation. A three-dimensional (3D) file of the placenta was created from overlapping image layers generated by MRI using Mimics software. Virtual fetoscopy allowed adequate visualization of fetuses, umbilical cord insertion and placental equator. Virtual fetoscopy is a non-invasive technique which allowed adequate identification of placental equator, and it may be an important learning method to novice fetal endoscopic surgeons in TTTS cases.

Relationship between the cortisol levels in umbilical cord blood and neonatal RDS/TTN in twin pregnancies

Objective: Twin neonates have a higher risk of respiratory complications, such as respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN), than singleton neonates. The purpose of this study was to evaluate the relationship between the cortisol levels in the umbilical cord and neonatal RDS/TTN in twin pregnancies.Methods: We analyzed data obtained from 106 neonates (53 twin pairs), comprising 33 dichorionic twin (DCT) and 20 monochorionic twin (MCT) gestations. All infants were delivered via scheduled cesarean section without labor. We measured the cortisol levels in umbilical vein blood using enzyme-linked immunosorbent assay.Results: The cortisol levels in the umbilical vein were significantly lower in the RDS/TTN group than in the no RDS/TTN group (p = 0.004). The umbilical cortisol levels in the TTN group were between the values observed in the RDS group and no RDS/TTN group. We subsequently analyzed the cut-off cortisol values for RDS/TTN and observed higher accuracy in the DCTs than in the MCTs.Conclusions: Neonates who develop RDS/TTN have significantly lower cortisol levels in the umbilical cord at birth than no RDS/TTN neonates in twin pregnancies. When applying these data in clinical practice, physicians should pay attention to differences based on chorionicity.

Short-Time Impact of Laser Ablation of Placental Anastomoses on Myocardial Function in Monochorionic Twins with Twin-to-Twin Transfusion Syndrome.

Purpose To evaluate pre- and post-procedure myocardial function in monochorionic twins with TTTS who underwent laser ablation of placental anastomoses using pulsed wave tissue Doppler imaging (pw TDI). Materials and Methods 20 monochorionic twin gestations with TTTS were included and underwent laser ablation at our center between 2011 and 2014. Prior to and after the intervention, cardiac function was assessed by measuring the mitral annular plane systolic excursion (MAPSE), the tricuspid annular plane systolic excursion (TAPSE), Tei index, isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) for the left ventricle in pulsed wave Doppler (pw D) ultrasound as well as ICT, ET, IRT and Tei index in pw TDI for the left and right ventricle. E-, A-, E´- and A´-wave peak velocity and the systolic downward motion (S´) were measured for both ventricles and the E/A, E/E´ and E´/A´ ratios were calculated. In a mean of 1.3 (SD 0.6) days after laser ablation, this measurement protocol was repeated. Results Pre-intervention recipients had longer ICT, ET and IRT in pw D and pw TDI compared to donors not reaching statistical significance for most parameters. Statistically significant were prolonged ICT in pw D (p 0.01) and ET (p 0.01) in pw TDI in recipients. In donor fetuses preoperative myocardial function did not differ significantly from postoperative myocardial function except in increased left ventricular ejection time of the left ventricle in pw TDI (p 0.04) and an increased E´/A´ratio (p 0.01). After laser coagulation, myocardial function was slightly altered in recipients as ICT and IRT shortened and Tei indices decreased but only reaching statistical significance in shortened IRTs in pw TDI for both ventricles. Conclusion Laser ablation of placental anastomoses in TTTS might influence myocardial function in the postoperative period. Shortened IRT intervals may reflect an improvement of diastolic function in recipients.

OC08.03: Feasibility and perinatal outcomes of laser surgery for monochorionic twin gestation with selective intrauterine growth restriction

OC08.03: Feasibility and perinatal outcomes of laser surgery for monochorionic twin gestation with selective intrauterine growth restriction

Amniotic lamellar body count: predicting and distinguishing neonatal respiratory complications in twin pregnancies

BackgroundTwin pregnancies have a higher rate of preterm births, making precise prediction of neonatal respiratory disorders essential. We herein examined the amniotic lamellar body count (LBC) and found it to be an accurate predictor of respiratory disorders in twin pregnancies. MethodsFive hundred fourteen amniotic fluid samples, comprising 132 dichorionic twin (DCT) and 125 monochorionic twin (MCT) gestations, were obtained at cesarean section performed at 29 to 38 gestational weeks. Samples were analyzed immediately without centrifugation. ResultsThere were 26 neonates (5.1%) with respiratory distress syndrome (RDS) and 43 (8.4%) with transient tachypnea of the newborn (TTN). The LBC in neonates with TTN (5.12×104/μl) was between the counts in RDS (1.26×104/μl) and controls (10.6×104/μl), which differed significantly. Twin concordance rates were significantly higher for TTN in MCT gestations than DCT gestations (p=0.003) and delta LBC value was significantly smaller in MCT (3.15±0.4×104/μl) than DCT (5.17±0.5×104/μl) gestations (p=0.003). ConclusionsThe amniotic LBC is useful for predicting respiratory disorders, including RDS and TTN, in twin pregnancies. The data in this study may indicate a genetic predisposition to TTN among MCTs.

Placental weight, birth weight and fetal:placental weight ratio in dichorionic and monochorionic twin gestations in function of gestational age, cord insertion type and placental partition

IntroductionWe established reference values for placental weight, birth weight, and fetal:placental weight ratio (FPR) (a possible index of placental functional efficiency) in monochorionic and dichorionic twin gestations. MethodsPlacental weight, birth weight, and FPR in function of gestational age, cord insertion type and placental sharing were determined in 151 dye-injected diamniotic-monochorionic and 198 double-disc diamniotic-dichorionic twin placentas (25–39 weeks' gestation). ResultsAs expected, FPR values increased with gestational age in both groups. Birth weights and placental weights of monochorionic twins >28 weeks' gestation were significantly lower than those of age-matched dichorionic twins. When stratified per placental weight, the birth weights and FPR values of monochorionic twins were overall lower than those of dichorionic twins within the same placental weight category. However, in the subset of monochorionic twins with small share in unevenly partitioned placentas, birth weights and FPR values per placental weight were similar to those of dichorionic twins, and significantly higher than those of monochorionic twins with larger share or even placental sharing. Cord insertion type did not correlate with birth weight or FPR values per placental weight in either twin type. DiscussionReference values were generated for placental weight, birth weight and FPR in monochorionic and double-disc dichorionic twins. The generally lower FPR per placental weight in monochorionic twins compared with dichorionic twins is suggestive of inherently lower placental functional efficiency in monochorionic gestations. The mechanisms and clinical implications of the apparent differential modulation of FPR/efficiency in monochorionic twins according to placental partitioning remain to be determined.

Maternal and fetal safety of fluid-restrictive general anesthesia for endoscopic fetal surgery in monochorionic twin gestations

Study ObjectiveTo review our experience with general anesthesia in endoscopic fetal surgery for twin-to-twin transfusion syndrome (TTTS), and to compare fetomaternal outcome before and after protocol implementation. DesignRetrospective impact study. SettingUniversity-affiliated medical center. MeasurementsData from 85 consecutive patients who underwent endoscopic laser ablation of placenta vessels for severe TTTS were studied. Outcomes were compared in patients before (2000–2007) and after (2008–2012) a change to strict intraoperative intravenous (IV) fluid and liberal vasopressor management. Perioperative parameters (IV fluid administration, vasopressor use, maternal hemoglobin [Hb] concentration); maternal complication rate (respiratory, hemorrhagic); pregnancy outcome; and fetal and neonatal survival were recorded. Main ResultsPatients in the early group (2000–2007; n = 55) received 1634 ± 949 mL of crystalloid fluid intraoperatively, compared with 485 ± 238 mL (P < 0.001; Student’s t test) given to the late group (2008–2012; n = 30). Maternal pulmonary edema and any respiratory distress were seen in 5.5% and 12.7% of patients in the early group, respectively, and in none of the late group patients (P < 0.05; Chi-square analysis). ConclusionsA significant risk of maternal respiratory complications exists after general anesthesia for endoscopic fetal surgery. Judicious fluid management significantly decreases this risk.

Outcomes of fetal intervention for primary hydrothorax

ObjectivePrimary hydrothorax is a rare congenital anomaly with outcomes ranging from spontaneous resolution to fetal demise. We reviewed our experience with fetuses diagnosed with primary hydrothorax to evaluate prenatal management strategies. MethodsWe reviewed the records of patients evaluated for fetal pleural effusions at our Fetal Treatment Center between 1996 and 2013. To define fetuses with primary hydrothorax, we excluded those with structural or genetic anomalies, diffuse lymphangiectasia, immune hydrops, and monochorionic diamniotic twin gestations. ResultsWe identified 31 fetuses with primary hydrothorax, of whom 24 had hydrops. Hydropic fetuses were more likely to present with bilateral effusions. Of all fetuses with primary hydrothorax, 21 had fetal interventions. Survival without hydrops was 7/7 (100%), whereas survival with hydrops depended on whether or not the patient had fetal intervention: 12/19 (63%) with intervention and 1/5 (20%) without intervention. Premature delivery was common (44%) among those who had fetal intervention. ConclusionsFetal intervention for primary hydrothorax may lead to resolution of hydrops, but preterm birth and neonatal demise still occur. Understanding the pathophysiology of hydrops may provide insights into further prenatal management strategies, including targeted therapies to prevent preterm labor.

Pre-eclampsia and Chorionicity in Women with Twin Gestations

Pre-Eclampsia (PE) affects 6-31% of pregnant women with multiple gestations. There are conflicting reports on the association of PE with Chorionicity and zygosity; however, there is a lack of information on this potential association in a population of pregnant Asian Indian women. To determine as to whether chorionicity and zygosity were associated with PE in a population of Asian Indian women with twin gestations. A retrospective observational study was done at a single tertiary care centre in Southern India. The study included pregnant women with twin gestations, who was delivered at the study institute in 2012. Hypertension in pregnancy was categorized, based on the criteria of the International Society for the Study of Hypertension in Pregnancy. Chorionicity was determined by using ultrasonography and zygosity was determined, based on clinical criteria. Point estimates and the 95% Confidence Intervals (CI) around point estimates of PE and associations of chorionicity and zygosity with PE were determined by using bivariate analysis, logistic regression models and area under Receiver Operator Characteristic (ROC) curves. This study included 208 women with twin gestations. The incidence of PE in dichorionic twin gestations was 13.17% (n=22, 95% CI: 8.66, 18.96), it was 4.87% (n=2, 95% CI: 0.83, 15.19) in monochorionic twin gestations, it was 16.36% (n=9, 95% CI: 8.29, 27.91) in dizygous twin gestations and it was 4.88% (n=2, 95% CI: 0.83, 15.19) in monozygous twin gestations. Neither chorionicity (adjusted OR: 2.59, 95% CI: 0.55, 12.19) nor zygosity (adjusted OR 2.72, 95% CI: 0.49, 15.13) were associated with PE In a multivariate logistic regression model. Although it was not statistically significant, the clinical incidence of PE was higher in dichorionic and dizygous twin gestations.

Perinatal complications of monochorionic diamniotic twin gestations with discordant crown–rump length determined at mid‐first trimester

The aim of this study was to investigate the value of discordance of crown-rump length (DCRL) at mid-first trimester to predict adverse outcomes in monochorionic diamniotic twin gestations (MD). This was a retrospective cohort study of the perinatal outcome in MD pregnancies managed from the first trimester onward. DCRL was evaluated between 8 and 10 weeks of gestation. The association between DCRL and perinatal complications, including fetal death, twin-twin transfusion syndrome, severe discordant birthweight (DB), and twin anemia-polycythemia sequence, was assessed. Among 126 cases, a single fetal demise occurred in two (2%) and demise of both fetuses occurred in eight (6%). Five pregnancies (4%) were complicated with twin-twin transfusion syndrome; one case (1%) was twin anemia-polycythemia sequence and 13 (10%) were DB. Neonatal death occurred in one pair. At 28 days of age, in 115 cases (91%) both twins were alive. In 117 cases (93%), at least one twin survived until 28 days of age. DCRL >12.0% was not related to any perinatal complications but DB (P < 0.01; relative risk: 1.40; 95% confidence interval: 1.06-1.84). DCRL in MD during the mid-first trimester might be useful for predicting DB.

P13.04: Measurement variation of amniotic fluid pocket in monochorionic diamniotic twin gestations suspected of twin‐to‐twin transfusion syndrome

<scp>P13</scp>.04: Measurement variation of amniotic fluid pocket in monochorionic diamniotic twin gestations suspected of twin‐to‐twin transfusion syndrome

Maternal Coagulopathy After Umbilical Cord Occlusion for Twin Reversed Arterial Perfusion Sequence

Twin reversed arterial perfusion sequence is a rare complication of monochorionic twin gestations for which therapy involves the disruption of vascular anastomoses between the pump twin and acardiac twin and death of the acardius. A 37-year-old woman, gravida 11 para 2, with a monochorionic twin pregnancy complicated by twin reversed arterial perfusion sequence who underwent umbilical cord occlusion at 24 weeks of gestation was admitted in preterm labor at 33 weeks of gestation. Maternal disseminated intravascular coagulation (DIC) was diagnosed and her labor was induced. She received multiple blood products to correct her coagulopathy and had an uncomplicated vaginal delivery of the viable pump twin. Maternal DIC may complicate fetal death after umbilical cord occlusion.

What—and Why—the Pathologist Should Know about Twin-to-Twin Transfusion Syndrome

Approximately 20% of all twin pregnancies are monochorionic. Between 9% and 15% of all monochorionic twin gestations are complicated by severe chronic twin-to-twin transfusion syndrome (TTTS), characterized by a gradual shift of blood volume from the donor twin to the recipient twin through placental vascular connections [1 - 3] . The prognosis of severe, untreated chronic TTTS diagnosed in midtrimester fetuses is extremely poor, with mortality rates exceeding 70% [4] . Since publication of the results of the Eurofoetus trial in 2004, laser photocoagulation of the intertwin anastomoses has become accepted as the optimal first-line therapy for severe TTTS diagnosed before 26 weeks of gestation. While laser treatment of vascular communications was initially limited to selected fetal treatment centers, its increasingly widespread use has resulted in the exposure of more pathologists, even in less specialized institutions, to laser-treated placentas. Furthermore, the surge in laser coagulation has revived the general medical, scientific, and public interest in the placental and choriovascular findings in monochorionic twin placentas. The pathologist's understanding of the pathophysiology of TTTS and of TTTS-associated placental pathology, including the findings related to laser ablation of the anastomoses, can be of great benefit to the involved obstetric/neonatal/surgical team and, ultimately, to the patients. In this review, we summarize the current knowledge of the placental contributions to TTTS and other complications of monochorionic twinning and describe the strengths and limitations of placental examination in these settings. It is our expectation that overviews such as this may serve as a template to generate consensus guidelines for standardized and evidence-based pathologic evaluation of monochorionic twin placentas.

Monochorionic twin fetus with VACTERL association after intracytoplasmic sperm injection

We report a rare case of a monochorionic twin gestation after intracytoplasmic sperm injection (ICSI) in which one of the fetuses had VACTERL association. A 27-year-old woman became pregnant by ICSI and was found to have monochorionic twin fetuses. One fetus was noted to have the following anomalies: a multicystic, dysplastic left kidney with a hydroureter, and a dilated colon. A normal-sized stomach and normal amount of amniotic fluid were observed during the prenatal period with no other anomalies. The postnatal examination revealed hypospadias, and anal, esophageal, and duodenal atresia; thus, a diagnosis of VACTERL association was established. Although the prenatal diagnosis of this disorder is a challenge, even in a singleton, some of the characteristic features observed during antepartum ultrasonography may be a clue to the diagnosis, especially in a twin pregnancy after ICSI.

Perinatal outcome and clinical features of monochorionic monoamniotic twin gestation

To clarify perinatal outcomes of monoamniotic (MM) twin pregnancies. MM twins delivered in seven tertiary perinatal centers during the last decade were retrospectively evaluated. All pregnant women were scheduled to begin inpatient management at around 24 weeks of gestation and undergo a planned cesarean section beyond 32 weeks. Pregnancy outcomes, prevalence of fetal death and cord entanglement, perinatal mortality and neuromorbidity rate at discharge were examined. The study group comprised 38 MM twin pregnancies (76 fetuses). Cord entanglement was confirmed in 88% (30/34) of women, and fetal deaths occurred in nine women (eight were both fetal deaths, and one was single fetal death). The cord entanglement accounted for 65% (11/17) of the fetal deaths. The median gestational age at delivery was 31⁺³ weeks, but that for viable infants was 32⁺³ weeks; the median birth weight was 1642 g, the perinatal mortality rate was 2% (1/60), and the neuromorbidity rate was 8% (5/50). The overall survival rate was 75% (57/76). Perinatal outcomes in our study were relatively good irrespective of high frequency of cord entanglement. Close fetal monitoring may allow MM twin pregnancies to extend gestational age, which may contribute to reduce both fetal death and neonatal morbidity by immaturity, although the best delivery weeks remained undetermined.