Laser therapy for twin-twin transfusion syndrome in a dizygotic monochorionic twin pregnancy: A case report.

OBJECTIVE: A monochorionic dizygotic (MCDZ) twin is rare, especially when complicated with twin-twin transfusion syndrome (TTTS) and treated by laser therapy. CASE REPORT: A pregnancy achieved from oocyte donation and intracytoplasmic sperm injection resulted in two embryos transferred. A monochorionic diamniotic twin pregnancy was diagnosed by an early ultrasound; however, at 16 weeks of gestation, instead of the same sex, the ultrasound suspected there was sex discrepancy between the twins. TTTS with severe polyhydramnios occurred at 22 weeks, leading to a laser therapy, which was followed with a smooth post-operation course. Then the Cesarean section was performed at the gestational age of 29 weeks due to severe preeclampsia, giving birth to two live newborns: one female and one male baby both without neurological sequelae at the time of discharge. Blood chromosomes obtained at delivery and 65 days after delivery all revealed an XX and XY chimera from both babies. CONCLUSION: Laser therapy is also effective in MCDZ twin complicated with TTTS. Determination of chorionicity in early pregnancy could timely prompt us to watch out for complications unique to monochorionic twin pregnancy.

In vitro simulation of acute feto-fetal transfusion in case of single intrauterine fetal death in monochorionic twins.

INTRODUCTION: Thanks to shared circulation in monochorionic twins, single intrauterine fetal death (IUD) may lead to acute feto-fetal transfusion (aFFTR). The objective of the study was to describe our model of aFFTR simulation after IUD in monochorionic (MC) twins. METHODS: Prospective study analyzed 99 fresh MC placentas with the physiological course. A specially designed protocol was used for the preparation and analysis of the placentas. A pair of infusion sets fixed together using a mechanical mercury sphygmomanometer cuff was connected to the cannulated umbilical arteries. The tonometer was pressurized up to 30 and 40 mmHg. A positive finding of aFFTR was determined as the amount exceeding 1 ml of dye flowed out of the umbilical cord simulating a dead fetus. The number and types of anastomoses, types, and distances between cords insertions, and the size of the placental areas for each fetus were also statistically analyzed. The placental angioarchitecture with and without proven aFFTR was statistically compared, odds ratio (OR) and multivariable logistic analysis were performed. RESULTS: A total of 49/99 (49.5%) cases of aFFTR was proven, and the average transfusion time of 1 ml was 30 s (19-46 s). aFFTR was present in 49/78 (62.8%) of placentas with arterio-arterial (AA) anastomosis. The median diameter of AA anastomoses with the present, and absent aFFTRF was 2.0 mm and 1.0 mm, respectively. The proven interfetal transfusion was 8%, 31%, and 61% in AA anastomoses with a diameter below 0,5 mm, 0,5-1,5 mm, and above 1,5 mm, respectively (p < 0,001). AA anastomoses diameter >1.5 mm had OR of 44.2 (95% CI 5.54-352.39). In the case of coexistence of AA anastomosis and umbilical cord distance ≤5th percentile, the aFFTRF occurred in 90.9%. DISCUSSION: The potential risk of aFFTR in monochorionic twins is mainly due to the presence and nature of AA anastomoses. The diameter and length of the vessels play a crucial role, which is clinically related to the distance of the umbilical cords insertions.

Fetal and Neonatal Circulatory Disorders in Twin to Twin Transfusion Syndrome (The Secondary Publication).

Twin to twin transfusion syndrome (TTTS) is a major complication of monochorionic diamniotic (MD) twins, and its onset is known to be associated with placental vascular anastomoses and blood flow imbalance. In a typical case of TTTS, the recipient develops polyhydramnios, weight gain, cardiomegaly and hydrops fetalis in the uterus. In contrast, the donor develops oligohydramnios and intrauterine growth restriction. Recently, the significance of the renin-angiotensin-aldosterone system (RAAS) that transfers from the donor to the recipient has attracted interest in the fetal circulation of TTTS. The donor has decreased renal blood flow due to decreased circulating blood volume. For this reason, the secretion of RAAS hormones is augmented in the fetal kidneys of the donor. In TTTS, these RAAS hormones from the donor transfer to the recipient through the anastomosed vessels. In addition to excess preload, the recipient heart is exposed to excess afterload due to systemic vasoconstriction through RAAS hormones. Commonly occurring complications in the recipient include myocardial hypertrophy, atrioventricular valve regurgitation, and pulmonary valve stenosis or pulmonary atresia. Fetoscopic laser photocoagulation (FLP) has been introduced recently because neither mortality nor neurological morbidity have been satisfactorily improved with conventional treatment. FLP is a curative method that may improve the prognosis of TTTS. In Japan, this procedure has been performed frequently, and positive neurological outcomes have been achieved.

Multicystic encephalomalacia and gastrointestinal injury following single fetal death in first trimester and subsequent fetofetal transfusion syndrome in a monochorionic triplet pregnancy: a case report.

BACKGROUND: Monochorionic multifetal pregnancies are at increased risk of adverse perinatal outcome because of placental vascular anastomoses. We present a case of multicystic encephalomalacia and gastrointestinal injury in two surviving fetuses following single fetal death in first trimester and subsequent fetofetal transfusion syndrome in a monochorionic triplet pregnancy. CASE PRESENTATION: A 31-year-old nulliparous woman had a spontaneous monochorionic triamniotic triplet pregnancy. Three live fetuses with single placenta were seen at 8-week ultrasound scan. One fetus demised at 11 weeks and 3 days of gestation. Dilated echogenic bowel and ascites were found in one surviving fetus at 23 weeks of gestation. At 28 weeks of gestation, the pregnancy was complicated by fetofetal transfusion syndrome in which discordant amniotic fluid volumes were found. Two days later, emergency Caesarean section was performed because of worsening of fetal Doppler and biophysical profile. One baby was found to have jejunal atresia requiring surgery at 4 days old. He had periventricular leukomalacia and intracranial haemorrhage, but subsequent normal neurological development. Another baby had gastric perforation requiring surgery at 2 days old. He was confirmed to have multicystic encephalomalacia by cranial ultrasound and magnetic resonance imaging. He suffered from developmental delay, epilepsy and cerebral palsy. CONCLUSION: This case alerts the obstetricians the possible hypoxic-ischemic injury to the survivors of monochorionic triplet pregnancy after the co-triplet death in the first trimester and fetofetal transfusion syndrome. Antenatal assessment and postnatal follow-up are important for these high-risk multiple pregnancies.

Midtrimester isolated oligohydramnios in monochorionic diamniotic multiple gestations.

OBJECTIVE: To describe the natural history and perinatal outcomes of monochorionic diamniotic twins with midtrimester isolated oligohydramnios (iOligo). MATERIALS AND METHODS: We performed a retrospective study of iOligo patients who were initially referred for the management of evolving twin-twin transfusion syndrome (TTTS) or selective intrauterine growth restriction (sIUGR). iOligo was defined as a maximum vertical pocket of amniotic fluid of ≤2 cm in the iOligo twin's sac and normal fluid level (>2 and <8 cm) in the co-twin's sac. "Group A" patients did not subsequently develop TTTS or sIUGR Type II (umbilical artery persistent absent or reversed end-diastolic flow), and "Group B" patients did develop TTTS or sIUGR Type II. Results are reported as median (range). RESULTS: Of the 828 patients with complicated monochorionic twin gestations referred for possible TTTS or sIUGR, 36 (4.3%) were initially diagnosed with iOligo. After initial consultation, two patients terminated and one was lost to follow-up, resulting in a final study population of 33. Group A had 10 patients (30.3%) and Group B had 23 patients (69.7%). In Group A, nine of the 10 were expectantly managed, resulting in a median gestational age (GA) at delivery of 34.7 (18.0-36.4) weeks, a 30-day perinatal survival of at-least-one twin of 88.9% (8/9), and dual 30-day survivors in 8/9 (88.9%). In Group B, 12 (52.2%) developed TTTS and 11 (47.8%) developed sIUGR Type II. Fifteen Group B patients had laser surgery, resulting in a median GA at delivery of 33.7 (26.4-37.1) weeks, a 30-day perinatal survival of at-least-one twin of 100% (15/15), and dual survivorship of 46.7% (7/15). CONCLUSIONS: Our findings show that the majority of patients with midtrimester iOligo have fetal growth restriction of the affected twin and subsequently progress to TTTS or sIUGR Type II.

Chorioamniotic membrane separation after fetoscopy in monochorionic twin pregnancy: incidence and impact on perinatal outcome.

OBJECTIVE: To evaluate the incidence of chorioamniotic membrane separation (CMS) after fetoscopy in monochorionic diamniotic (MCDA) twins and its impact on pregnancy outcome. METHODS: The study group comprised a consecutive series of 338 women with an MCDA pregnancy complicated by twin-twin transfusion syndrome (TTTS) or selective intrauterine growth restriction (sIUGR) treated with selective laser photocoagulation of communicating vessels (SLPCV) or cord occlusion (CO). Data obtained included cervical length, gestational age at procedure, type and duration of surgery and placental location. The incidence of CMS, the rates of miscarriage and preterm prelabor rupture of membranes (PPROM), gestational age at delivery and neonatal survival were recorded. RESULTS: Of the study population of MCDA pregnancies, 270 (79.9%) had TTTS and 68 (20.1%) had sIUGR. SLPCV was performed in 252 (74.6%) cases and CO in 86 (25.4%). Postoperative CMS was observed in 70 (20.7%) cases. Patients with CMS had higher rates of miscarriage (14.3% vs 7.1%; P = 0.049), PPROM before 32 weeks (43.3% vs 13.7%; P < 0.001) and preterm delivery before 32 weeks (53.3% vs 26.1%; P < 0.001) and a lower rate of neonatal survival of at least one twin (81.7% vs 93.6%; P = 0.003). Multivariate analysis showed that gestational age at surgery was the only independent predictor, with the highest proportion of CMS occurring in cases that underwent surgery before 18 weeks' gestation (odds ratio, 2.941 (95% CI, 1.640-5.275); P < 0.001). There was no influence of cervical length, placental location, duration of surgery or type of surgery on the risk of CMS. CONCLUSIONS: CMS complicated one-fifth of all MCDA pregnancies that underwent fetoscopy. It appeared to be more common in those who underwent surgery before 18 weeks' gestation and was associated with poorer outcomes. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Twin anemia-polycythemia sequence after laser surgery for twin-twin transfusion syndrome and maternal morbidity.

Twin anemia-polycythemia sequence (TAPS) is characterized by large inter-twin hemoglobin value differences without inter-twin amniotic fluid discordance. The management of post-laser TAPS remains controversial. Hence, more studies on TAPS, together with the associated maternal complications and outcome of the fetuses and infants are needed. Between 2003 and 2012, we performed 287 cases of fetoscopic laser photocoagulation for twin-twin transfusion syndrome. Among the 114 who were placed under our care until delivery, three cases of TAPS occurred. In one case, we conducted intrauterine intravenous transfusion, while in the other two cases, we adopted expectant management. We performed an emergency caesarean section at 27-30 weeks of gestation in all cases due to a severe condition of anemia in the TAPS donor. Two cases with antenatal TAPS stage 4 had severe maternal complications; one had minute pulmonary embolism, while the other had Mirror syndrome. All three pairs of infants survived. One TAPS donor and one TAPS recipient had neurodevelopmental impairment; bilateral deafness at 9.5 years old and spastic paralysis at 2 years old, respectively. In conclusion, post-laser TAPS in a higher stage can cause severe maternal complications. Close observations for both fetuses and mothers are required for such cases.

Midtrimester isolated polyhydramnios in monochorionic diamniotic multiple gestations.

OBJECTIVE: To identify risk factors for development of twin-twin transfusion syndrome (TTTS) in monochorionic diamniotic multiple gestations complicated by midtrimester isolated polyhydramnios (iPoly). STUDY DESIGN: A retrospective study of patients referred for possible TTTS between 16 and 26 gestational weeks was performed. IPoly was defined as a maximum vertical pocket of ≥8 cm in the iPoly twin's sac and >2 and <8 cm in the co-twin's sac on the consultative ultrasound. RESULTS: Of 628 consecutive patients referred for possible TTTS, 74 were diagnosed with iPoly. The majority of these patients (n = 52, 70.3%) were not subsequently diagnosed with TTTS, and of these, 40 were managed expectantly and 12 had amnioreductions because of symptomatic iPoly; 30-day perinatal survival of at-least-one twin in the non-TTTS group was 93.0% (40/43). TTTS developed in the 22 remaining patients, of which 63.6% were of advanced Quintero Stage. Nineteen underwent laser surgery; 30-day perinatal survival of at-least-one twin was 84.2% (16/19). In a multivariate logistic regression model, 2 characteristics were associated with the development of TTTS: (1) gestational age <20 weeks at the time of diagnosis of iPoly (odds ratio, 13.48; 95% confidence interval, 3.40-53.48; P = .0002); and (2) intrauterine growth restriction of the co-twin (odds ratio, 7.28; 95% confidence interval, 1.72-30.88; P = .0071). CONCLUSION: Among referred patients with midtrimester iPoly, 29.7% subsequently developed TTTS. Early diagnosis (<20 weeks) and/or co-twin intrauterine growth restriction were significant risk factors for development of TTTS in these patients.

[Research of placental vascular distribution and clinical outcome in monochorionic twins].

OBJECTIVE: To study the placental vascular distribution of monochorionic (MC) twins with twin-to-twin transfusion syndrome (TTTS) or birth weight discordance. METHODS: Twenty-eight MC placentas were injected in Peking University Third Hospital between Feb. 2010 and Feb. 2011. The vascular distribution type (parallel, crossed, mixed and monoamniotic), the anastomosis of vessels and the placental sharing were recorded. The outcome of pregnancy and the placental characteristics of birth weight discordance (birth weight discordance≥20%) in non-TTTS MC twins were analyzed. RESULTS: (1) The outcome of pregnancy: the miscarriage or gestational weeks of 28 MC twins were 20 to 38 weeks (median of 35 weeks). Six cases were TTTS, 3 of which received fetoscopic laser occlusion of communicating vessels (FLOC). There were 48 live births, with an average birth weight of (2036±623) g. (2) Type of placental vascular distribution:in the 28 MC placentas, number of parallel, crossed, mixed and monoamniotic type of placental vascular distribution were 4 (14%), 14 (50%), 6 (21%) and 4 (14%) cases, respectively. No parallel type was found in TTTS. There was no significant difference of vascular anastomosis or unequal placental sharing among the different placental vascular distribution types (P>0.05). (3) Characteristics of placental vascular distribution in birth weight discordance twins:there were 20 non-TTTS MC twin pregnancies, all of which got live births of both babies. Birth weight discordance equal to or more than 20% was found in 6 pairs of newborns, while birth weight discordance less than 20% was found in the rest 14 cases. Ratio of unequal placental sharing was significantly different between the two groups (P<0.01). There was no significant difference of umbilical cord insertion, placental vascular distribution and anastomosis in the two groups (P>0.01). CONCLUSIONS: Vascular distribution type of MC twins might be related to TTTS. Unequal placental sharing is a risk factor of birth weight discordance in non-TTTS MC twins.

Twin-to-twin transfusion syndrome: a case study.

Twin-to-twin transfusion syndrome (TTTS) is a disease that affects roughly 15% of monochorionic twins. Although TTTS is not extremely prevalent, the rate of mortality and morbidly approaches 100% without early detection and treatment. The following case study is a triplet pregnancy that included a set of monochorionic twins affected by TTTS. Typically, it is assumed that monochorionicity can identify the zygosity of twins, which was disproven in this case. Research indicates that there has been an increased rate of monochorionic twins with in vitro fertilization. There is great debate about the most appropriate treatment modality for TTTS. Perinatal treatment followed by neonatal management is the standard of care for TTTS. Implications for the neonatal nurse practitioner and care for the patients are discussed.

Twin-twin transfusion syndrome.

OBJECTIVE: We sought to review the natural history, pathophysiology, diagnosis, and treatment options for twin-twin transfusion syndrome (TTTS). METHODS: A systematic review was performed using MEDLINE database, PubMed, EMBASE, and Cochrane Library. The search was restricted to English-language articles published from 1966 through July 2012. Priority was given to articles reporting original research, in particular randomized controlled trials, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Evidence reports and guidelines published by organizations or institutions such as the National Institutes of Health, Agency for Health Research and Quality, American College of Obstetricians and Gynecologists, and Society for Maternal-Fetal Medicine were also reviewed, and additional studies were located by reviewing bibliographies of identified articles. Consistent with US Preventive Task Force guidelines, references were evaluated for quality based on the highest level of evidence, and recommendations were graded accordingly. RESULTS AND RECOMMENDATIONS: TTTS is a serious condition that can complicate 8-10% of twin pregnancies with monochorionic diamniotic (MCDA) placentation. The diagnosis of TTTS requires 2 criteria: (1) the presence of a MCDA pregnancy; and (2) the presence of oligohydramnios (defined as a maximal vertical pocket of <2 cm) in one sac, and of polyhydramnios (a maximal vertical pocket of >8 cm) in the other sac. The Quintero staging system appears to be a useful tool for describing the severity of TTTS in a standardized fashion. Serial sonographic evaluation should be considered for all twins with MCDA placentation, usually beginning at around 16 weeks and continuing about every 2 weeks until delivery. Screening for congenital heart disease is warranted in all monochorionic twins, in particular those complicated by TTTS. Extensive counseling should be provided to patients with pregnancies complicated by TTTS including natural history of the disease, as well as management options and their risks and benefits. The natural history of stage I TTTS is that more than three-fourths of cases remain stable or regress without invasive intervention, with perinatal survival of about 86%. Therefore, many patients with stage I TTTS may often be managed expectantly. The natural history of advanced (eg, stage ≥III) TTTS is bleak, with a reported perinatal loss rate of 70-100%, particularly when it presents <26 weeks. Fetoscopic laser photocoagulation of placental anastomoses is considered by most experts to be the best available approach for stages II, III, and IV TTTS in continuing pregnancies at <26 weeks, but the metaanalysis data show no significant survival benefit, and the long-term neurologic outcomes in the Eurofetus trial were not different than in nonlaser-treated controls. Even laser-treated TTTS is associated with a perinatal mortality rate of 30-50%, and a 5-20% chance of long-term neurologic handicap. Steroids for fetal maturation should be considered at 24 0/7 to 33 6/7 weeks, particularly in pregnancies complicated by stage ≥III TTTS, and those undergoing invasive interventions.

Perinatal outcome of monochorionic diamniotic twin pregnancies managed from early gestation at a single center.

AIM: The aim of this study was to evaluate the perinatal outcome of monochorionic diamniotic (MD) twin gestations managed from early gestation onward at a single center. MATERIAL AND METHODS: This was a retrospective single-cohort study, spanning 6 years, of 219 MD twin pregnancies who received prenatal care before 14 weeks of gestation and delivered at our center. The subjects were all under the same perinatal management protocol. The incidence of fetal or neonatal death, major neurological complications at 28 days of age, twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence, and discordant birth was evaluated. Laser surgery was offered for TTTS at less than 26 weeks; however, selective feticide was not performed. RESULTS: Pregnancy termination was selected in two cases. Miscarriage occurred in two (1%) of the cases and preterm delivery occurred in 91 (42%). In regard to perinatal outcome at 28 days of age, 195 (89%) women possessed two live infants and 205 (94%) possessed at least one live infant. The overall survival rate was 92% (403/438). The prevalence of TTTS was 17 cases (8%), seven of whom underwent laser surgery. Four cases of twin anemia-polycythemia sequence were diagnosed postnatally (2%); discordant birth was diagnosed in 24 (12%). Major neonatal neurological abnormalities were noted in six cases (2%). CONCLUSIONS: The incidence of perinatal complications in 219 sets of MD twins managed from early gestational age to the neonatal period in one perinatal center was demonstrated. The incidence of TTTS was 8%; the survival rate was 89% at 28 days of age.

Accurate and simple evaluation of vascular anastomoses in monochorionic placenta using colored dye.

The presence of placental vascular anastomoses is a conditio sine qua non for the development of twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS)(1,2). Injection studies of twin placentas have shown that such anastomoses are almost invariably present in monochorionic twins and extremely rare in dichorionic twins(1). Three types of anastomoses have been documented: from artery to artery, from vein to vein and from artery to vein. Arterio-venous (AV) anastomoses are unidirectional and are referred to as "deep" anastomoses since they proceed through a shared placental cotyledon, whereas arterio-arterial (AA) and veno-venous (VV) anastomoses are bi-directional and are referred to as "superficial" since they lie on the chorionic plate. Both TTTS and TAPS are caused by net imbalance of blood flow between the twins due to AV anastomoses. Blood from one twin (the donor) is pumped through an artery into the shared placental cotyledon and then drained through a vein into the circulation of the other twin (the recipient). Unless blood is pumped back from the recipient to the donor through oppositely directed deep AV anastomoses or through superficial anastomoses, an imbalance of blood volumes occurs, gradually leading to the development of TTTS or TAPS. The presence of an AA anastomosis has been shown to protect against the development of TTTS and TAPS by compensating for the circulatory imbalance caused by the uni-directional AV anastomoses(1,2). Injection of monochorionic placentas soon after birth is a useful mean to understand the etiology of various (hematological) complications in monochorionic twins and is a required test to reach the diagnosis of TAPS(2). In addition, injection of TTTS placentas treated with fetoscopic laser surgery allows identification of possible residual anastomoses(3-5). This additional information is of paramount importance for all perinatologists involved in the management and care of monochorionic twins with TTTS or TAPS. Several placental injection techniques are currently being used. We provide a simple protocol to accurately evaluate the presence of (residual) vascular anastomoses using colored dye injection.

Twin-to-twin transfusion syndrome (TTTS).

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic (MC) twin pregnancies, characterized by the development of unbalanced chronic blood transfer from one twin, defined as donor twin, to the other, defined as recipient, through placental anastomoses. If left untreated, TTTS is associated with very high perinatal mortality and morbidity rates, due to a combination of fetal and/or obstetric complications. The reported prevalence is 10-15% of all MC twins, or about 1 in 2000 pregnancies. This consensus document reviews available evidence and offers practical guidance to clinicians by providing recommendations on various aspects concerning diagnosis and management of TTTS.

Investigation of the factors affecting the perinatal outcome of monochorionic diamniotic twins.

PURPOSE: To investigate the factors affecting the perinatal outcome in monochorionic diamniotic (MD) twins. METHODS: We conducted a retrospective study of MD twins treated in our hospital between April 1, 2006 and February 28, 2010. The neonatal outcomes of MD twins conceived by assisted reproductive technology or ovulation induction were compared to the outcomes of those conceived naturally. RESULTS: In MD twins with twin-to-twin transfusion syndrome (TTTS), fetoscopic laser photocoagulation (FLP) resulted in the survival of at least one twin. In naturally conceived MD twins with two live births, we found that there was a higher discordance rate and the incidence of intrauterine growth retardation was higher in twins born to nulliparous women than multiparous women. CONCLUSIONS: Further FLP treatment can be performed on twins with TTTS so that prognosis may be improved. Since the risk of discordant growth is significantly greater in twins of nulliparous women, they should be monitored more carefully than multiparous women.

Monozygotic triplet pregnancies after single blastocyst transfer: two cases and literature review.

Following IVF, single blastocyst transfer has been thought to reduce the risks of high-order multiple pregnancies. This is a report of two cases of monozygotic triplet pregnancies after single blastocyst transfer and a review of the current concepts of the pathogenesis of multiple monozygotic pregnancies as well as the options for managing these high-risk pregnancies. Both cases were reduced to a twin pregnancy by selective cord coagulation at 15-16 weeks. Whereas one patient had uneventful pregnancy until labour was induced for growth arrest and cord Doppler abnormalities in one twin, the other developed a severe twin-to-twin transfusion syndrome which required fetoscopic laser surgery at 21 weeks. In both cases, healthy twins were delivered by Caesarean section at 34.5 and 34 weeks, respectively. As the predictors of their occurrence are not fully understood, patients should be informed of the risks of monozygotic pregnancies after single blastocyst transfer.

Monochorionic twin pregnancy: screening, pathogenesis of complications and management in the era of microinvasive fetal surgery.

OBJECTIVE: The management of monochorionic (MC) twin pregnancies varies in different medical centers. This paper compares screening methods to predict the complications of the MC twin pregnancy and different treatment methods. METHODS: We performed a literature search without language restriction in Cochrane library and PubMed (1970-2009). Case series and cohort screening studies, pathogenesis and management of complications of MC pregnancy were included. RESULTS: Elevated risk for intrauterine fetal death (IUFD) and twin-to-twin transfusion syndrome (TTTS) can be detected sonographically. Monitoring of MC pregnancies at increased risk and regular training sessions for the operating team combined with reduced fetoscopic amniotic membrane damage increase fetal survival rate from laser coagulation to nearly 100% for at least one fetus and to 90% for both. CONCLUSION: Monitoring of MC pregnancies at increased risk and laser treatment of TTTS in medical centers with sufficient experience might improve neonatal outcome.

Transfusional fetal complications after single intrauterine death in monochorionic multiple pregnancy are reduced but not prevented by vascular occlusion.

OBJECTIVE: To document co-twin death/pregnancy loss and brain injury after single intrauterine death (sIUD) in monochorionic pregnancies. DESIGN: A total of 135 pregnancies with sIUD were reviewed for co-twin IUD, miscarriage and abnormal antenatal and postnatal neuro-imaging. SETTING: A tertiary referral fetal medicine unit from 2000 to 2007. POPULATION OR SAMPLE: All cases referred with a single fetal death in monochorionic pregnancy, including those where sIUD was spontaneous or occurred after fetoscopic laser treatment, or resulted from selective termination by cord occlusion with bipolar diathermy or intrafetal vascular ablation with interstitial laser. METHODS: Clinical details and ultrasound findings of the study population were retrieved from ultrasound and institutional databases. Delivery and neonatal outcome data were obtained from discharge summaries supplemented by individual chart review. MAIN OUTCOME MEASURES: Co-twin death or pregnancy loss and neurologic injury assessed on antenatal ultrasound and MR-imaging. RESULTS: A total of 81 sIUDs resulted from vascular occlusive feticide (diathermy or interstitial laser), 22 followed placental laser and 32 were spontaneous. In 22 pregnancies (16.8%), the co-twin died in utero and eight pregnancies miscarried (6.1%). Antenatal magnetic resonance (MR) imaging in 76/91 (83.5%) continuing pregnancies detected antenatal brain injury in five (6.6%). Three infants (two not scanned antenatally) had abnormalities detected postnatally. Brain abnormality was detected less often after procedure related (2.6%, 2/77) than spontaneous sIUD (22.2%, 6/27, P = 0.003) and after early compared with late gestation sIUD (3.6%, 4/111 versus 20.0%, 4/20; P = 0.02). CONCLUSIONS: We confirm substantial co-twin loss (22.9%) after monochorionic sIUD, but a low risk of antenatally acquired MRI-identified brain injury, suggesting this risk has been overestimated. Procedures restricting inter-twin transfusion reduce, but do not negate risk of brain injury.