Fetal blood sampling immediately before and within 24 hours of death in monochorionic twin pregnancies complicated by single intrauterine death

Extensive Aplasia Cutis Congenita Encircling the Trunk Associated with Fetus Papyraceus

Aplasia cutis congenita associated with fetus papyraceus, though rare, is well known. On the other hand, aplasia cutis congenita associated with fetus papyraceus presenting with symmetrical circumferential scarring encircling the trunk has not been previously reported. Herein, we report a 2-month-old girl with symmetrical circumferential scarring encircling the trunk associated with fetus papyraceus.

Risk Factors for Co-Twin Fetal Demise following Radiofrequency Ablation in Multifetal Monochorionic Gestations

BACKGROUND

Umbilical cord occlusion via radiofrequency ablation (RFA) is utilized to maximize outcomes of the co-twin in complicated multifetal monochorionic (MC) gestations. However, post-procedure co-twin fetal demise is of concern.

OBJECTIVE

The aim of this study was to determine risk factors for co-twin fetal demise following RFA.

METHODS

This is a retrospective study of MC multiples that underwent RFA. Indications for RFA included twin reversed arterial perfusion (TRAP) sequence, selective fetal growth restriction (sFGR) type II, discordant lethal anomalies, and twin-twin transfusion syndrome (TTTS) with proximate placental cord insertion sites. The primary outcome was co-twin fetal demise. Bivariate analyses and multiple logistic regression modeling of identified risk factors were conducted.

RESULTS

Of 36 patients studied, surgical indications were: TRAP (n = 15, 41.7%), sFGR (n = 10, 27.8%), discordant anomalies (n = 9, 25.0%), and TTTS (n = 2, 5.6%). Nine patients (25.0%) experienced a co-twin fetal demise. In multiple logistic regression analysis, fetal growth restriction (FGR) of one co-twin was associated with increased risk of co-twin fetal demise (OR = 10.85, 95% CI 1.03-114.48, p = 0.0474) and a preoperative diagnosis of TRAP was protective against fetal demise (OR = 0.06, 95% CI 0.00-0.84, p = 0.0368).

CONCLUSION

Co-twin FGR was associated with an increased risk of post-RFA demise. When compared to other indications, patients with TRAP sequence were less likely to have a co-twin demise.

Perinatal outcomes of intrauterine transfusion for the surviving twin in monochorionic twin gestation involving a single fetal demise

AIM

This study aimed to evaluate the feasibility and outcome of intrauterine transfusion (IUT) for the surviving co-twin in monochorionic diamniotic (MCDA) twin gestations involving single intrauterine fetal death (sIUFD).

METHODS

Cases of MCDA twin gestations involving emergent IUT for co-twins experiencing acute feto-fetal hemorrhage (AFFH) subsequent to sIUFD during the second trimester were reviewed. Fetal anemia was confirmed via fetal blood sampling, and perinatal data were retrieved from medical charts to determine the outcomes of surviving co-twins. A poor outcome at 28 days of age was defined as fetal death, neonatal death or neurological impairment such as severe intraventricular hemorrhage or cystic periventricular leukomalacia (PVL).

RESULTS

This study included 16 cases of sIUFD diagnosed at a median of 22.5 weeks of gestation (range: 18-25 weeks). The median interval in hours between diagnosis of fetal demise and IUT was approximately 4.2 (0-22) hours. All cases achieved IUT without significant intraoperative complications. Four cases experienced a fetal loss of the co-twin, whereas 12 co-twins were born alive (including 9 preterm births), with only 1 poor outcome in a preterm infant with PVL.

CONCLUSION

IUT may be a feasible prenatal intervention for surviving co-twins with AFFH. However, more extensive or pooled studies are needed to determine the efficacy of this intervention.

Intraparenchymal hemorrhage and cerebral venous thrombosis in an adult with congenital porencephalic cyst presenting for generalized tonic-clonic seizures

Prothrombotic conditions are known risk factors for porencephalic cyst formation and cerebral vein thrombosis. Intracerebral hemorrhage is a potential complication of a cerebral vein thrombosis. Porencephaly is a risk factor for intracerebral hemorrhage and cerebral vein thrombosis formation. We present the case of an adult patient with a past medical history of epilepsy and congenital porencephalic cyst with de novo mutation of the COL4A1 gene who presented for episodes of generalized tonic-clonic seizure after a substantial symptom-free period. A brain CT scan showed an intracerebral hemorrhage with porencephalic cyst and superior sagittal sinus thrombosis despite negative thrombophilia work-up. A CT perfusion study, CT angiography, and brain MRI confirmed the diagnosis. The cause-and-effect relationship between porencephalic cysts, cerebral venous thrombosis, and intracerebral hemorrhage is still not clear in the literature.

Case of resuscitation from cardiac failure by intrauterine transfusion after single fetal death in monochorionic twin pregnancy

In case of a single fetal death in monochorionic twin pregnancy, the surviving fetus is thought to become hypovolemic. However, there is no report of any evidence of fetal circulatory insufficiency in such cases. We present a case of a single fetal death in a monochorionic twin pregnancy with type III selective intrauterine growth restriction that involved low fractional shortening, high myocardial performance index, elevated pulsatility index in the middle cerebral artery and fetal ascites. After immediate intrauterine transfusion, each parameter improved promptly. The surviving baby grew up without cardiac and neurological complications. To the best of our knowledge, this is the first report on transient circulatory insufficiency and decreased cardiac function in the surviving fetus.

Fetal stroke and cerebrovascular disease: Advances in understanding from lenticulostriate and venous imaging, alloimmune thrombocytopaenia and monochorionic twins

Fetal stroke is an important cause of cerebral palsy but is difficult to diagnose unless imaging is undertaken in pregnancies at risk because of known maternal or fetal disorders. Fetal ultrasound or magnetic resonance imaging may show haemorrhage or ischaemic lesions including multicystic encephalomalacia and focal porencephaly. Serial imaging has shown the development of malformations including schizencephaly and polymicrogyra after ischaemic and haemorrhagic stroke. Recognised causes of haemorrhagic fetal stroke include alloimmune and autoimmune thrombocytopaenia, maternal and fetal clotting disorders and trauma but these are relatively rare. It is likely that a significant proportion of periventricular and intraventricular haemorrhages are of venous origin. Recent evidence highlights the importance of arterial endothelial dysfunction, rather than thrombocytopaenia, in the intraparenchymal haemorrhage of alloimmune thrombocytopaenia. In the context of placental anastomoses, monochorionic diamniotic twins are at risk of twin twin transfusion syndrome (TTTS), or partial forms including Twin Oligohydramnios Polyhydramnios Sequence (TOPS), differences in estimated weight (selective Intrauterine growth Retardation; sIUGR), or in fetal haemoglobin (Twin Anaemia Polycythaemia Sequence; TAPS). There is a very wide range of ischaemic and haemorrhagic injury in a focal as well as a global distribution. Acute twin twin transfusion may account for intraventricular haemorrhage in recipients and periventricular leukomalacia in donors but there are additional risk factors for focal embolism and cerebrovascular disease. The recipient has circulatory overload, with effects on systemic and pulmonary circulations which probably lead to systemic and pulmonary hypertension and even right ventricular outflow tract obstruction as well as the polycythaemia which is a risk factor for thrombosis and vasculopathy. The donor is hypovolaemic and has a reticulocytosis in response to the anaemia while maternal hypertension and diabetes may influence stroke risk. Understanding of the mechanisms, including the role of vasculopathy, in well studied conditions such as alloimmune thrombocytopaenia and monochorionic diamniotic twinning may lead to reduction of the burden of antenatally sustained cerebral palsy.

Brain-injured Survivors of Monochorionic Twin Pregnancies Complicated by Single Intrauterine Death: MR Findings in a Multicenter Study

Purpose To describe and classify the range of brain injuries present at prenatal, in-utero magnetic resonance (MR) imaging in co-twin survivors of monochorionic (MC) twin pregnancies complicated by single intrauterine death (SIUD). Materials and Methods This retrospective, observational study from six tertiary fetal medicine centers that perform tertiary-level prenatal in-utero MR studies reviewed cases in which prenatal in-utero MR imaging had shown a brain injury in a surviving co-twin of a twin pregnancy with a MC component complicated by SIUD. Results Forty-two surviving MC twins were described. The primary distinction of brain abnormalities was into nonfocal and focal lesions. The nonfocal lesions included periventricular leukomalacia (group 1; two fetuses), generalized encephalomalacia (group 2; nine fetuses), posterior encephalomalacia (group 3; seven fetuses), and bilateral parasagittal and perisylvian injury (group 4; three fetuses). The focal lesions included nonhemorrhagic lesions (group 5; 14 fetuses) and hemorrhagic lesions (group 6; seven fetuses). Focal brain lesions were more likely to be found in the surviving MC pregnancies complicated by twin-twin transfusion syndrome (TTTS) (odds ratio, 2.4; 95% confidence interval: 1.3, 18.5; P = .01) and in fetuses that underwent an obstetric intervention (odds ratio, 2.8; 95% confidence interval: 1.8, 23.6; P = .006). Conclusion Brain injury of the surviving co-twin after SIUD in MC pregnancies is usually of ischemic origin and spares the brainstem and cerebellum. Focal brain lesions are more frequent in pregnancies complicated by TTTS or in those where an intervention has been performed.

Early 2nd trimester fetal demise in a monochorionic twin pregnancy: A cautionary tale

It is well established that the death of one fetus in a monochorionic twin pregnancy places the surviving twin at significant risk for neuro-developmental delay or death. Although the early 1st trimester "vanishing twin" has not traditionally been considered a major risk, the precise gestational threshold beyond which a surviving twin is at risk remains uncertain. Most experts recommend serial ultrasounds and fetal MRI in the survivor, to look for evidence of ischaemic brain injury. We present a case of early monochorionic twin demise at 14-16 weeks, with evolving ventriculomegaly and ischaemic changes on fetal MRI in the co-twin, leading to termination of pregnancy at 28 weeks.

Significance of Velamentous Cord Insertion for Twin-Twin Transfusion Syndrome

INTRODUCTION

The objective of this study was to evaluate the actual association between velamentous cord insertion (VCI) and twin-twin transfusion syndrome (TTTS) in the native cohort concerning the natural history of monochorionic twin pregnancies.

MATERIAL AND METHODS

All monochorionic diamniotic twin pregnancies who received prenatal care from <16 weeks of gestation until delivery at our center between 2004 and 2013 were included in this retrospective cohort study. Macroscopically defined cord insertion site was recorded as velamentous, marginal, or central. The effects of VCI on TTTS and a composite of adverse outcomes, including abortion, death, and neurological morbidities ≤28 days of age, were evaluated with a multiple logistic regression model.

RESULTS

A total of 357 monochorionic diamniotic twin pregnancies were analyzed. VCI in both twins was noted in 2.5% of cases and VCI in at least one twin was noted in 22.1% of cases. The incidence of TTTS was 8.4%; the incidence of a composite of adverse outcomes in at least one twin was 9.8%. There was no correlation between VCI and TTTS as well as a composite of adverse outcomes.

DISCUSSION

VCI in monochorionic twin pregnancies was not a risk factor for TTTS and severe perinatal morbidities.

Ultrasound predictors of mortality in monochorionic twins with selective intrauterine growth restriction

OBJECTIVES

The aim of this study was to evaluate the use of ultrasound assessment to predict risk of mortality in expectantly managed monochorionic twin fetuses with selective intrauterine growth restriction (sIUGR).

METHODS

This was a retrospective study of 101 monochorionic twin pregnancies diagnosed with sIUGR before 26 weeks of gestation. All patients were under expectant management during the observation period. At the initial evaluation, the presence or absence of each of the following abnormalities was documented: oligohydramnios; stuck twin phenomenon; severe IUGR < 3(rd) centile of estimated fetal weight; abnormal Doppler in the umbilical artery; and polyhydramnios in the larger twin. The relationships between these ultrasound findings and mortality of sIUGR fetuses were evaluated using multiple logistic regression analysis.

RESULTS

Of 101 sIUGR twins, 22 (21.8%) fetuses suffered intrauterine demise and nine (8.9%) suffered neonatal death; 70 (69.3%) survived the neonatal period. Multiple logistic regression analysis revealed that the stuck twin phenomenon (odds ratio (OR): 14.5; 95% CI: 2.2-93.2; P = 0.006) and constantly absent diastolic flow in the umbilical artery (OR: 29.4; 95% CI: 3.3-264.0; P = 0.003) were significant risk factors for mortality.

CONCLUSIONS

Not only abnormal Doppler flow in the umbilical artery but also severe oligohydramnios should be recognized as important indicators for mortality in monochorionic twins with sIUGR.

[Twin pregnancy with single fetal death: etiology, management and outcome]

INTRODUCTION

Intra-uterine fetal death (IUFD) of one twin is a relatively frequent complication of twin pregnancy. Prognosis of the surviving twin seems to be the main problem. Management is not consensual and suffers from the lack of guidelines.

OBJECTIVES

To report the main involved etiologies, assess the surviving co-twin outcome and discuss strategies of management.

PATIENTS AND METHODS

Retrospective study of 33 twin pregnancies complicated by single intrauterine fetal death after 26 weeks of gestation, admitted in the department "A" of obstetrics and gynecology of the Tunisian center of maternity and neonatalogy from January 2000 to October 2008.

RESULTS

Prevalence was 2.98%. Chorionicity was precised for 28 GG; 67.9% (n=19) were bichorionic (BC) and 32.1% (n=9) monochorionic (MC). The mean gestational age at the time of fetal death diagnosis was 31 weeks+2 days. Main involved pathologies in case of BC pregnancy were: intrauterine growth restriction (36.8%), pre-eclampsia (21%) and gestational diabetes (15.8%) and in case of MC pregnancy: twin-to-twin transfusion syndrome (44.4%). Prematurity rate was 85.2%. IUFD of the second twin occurred in one case and neonatal death in six cases. Tranfontanellar ultrasound on the seventh day of life found cerebral abnormalities in six liveborns.

CONCLUSION

Surviving co-twin prognosis was mainly compromised by prematurity and its consequences.

Incidence, mechanisms, and patterns of fetal cerebral lesions in twin-to-twin transfusion syndrome

OBJECTIVE

To determine the incidence of fetal cerebral lesions and their characteristics in twin-to-twin transfusion syndrome (TTTS).

DESIGN AND SETTING

This was a retrospective analysis at a single center for the period 1999 to 2004 in which 299 cases of severe TTTS at 15-28 weeks of gestation were reviewed.

METHODS

Only cerebral injuries diagnosed during pregnancy or ischemic lesions diagnosed within the first week of life were considered in order to exclude those related to prematurity. We only included cases resulting in at least one survivor at one week after delivery, as well as fetuses that were terminated because of severe cerebral abnormalities. We excluded all fetuses delivered at <24 weeks of gestation that died prior to undergoing postnatal cranial ultrasonography. The main outcome measures were fetal cerebral lesions, intrauterine death, survival, and neonatal death.

RESULTS

Two hundred and ninety-nine pregnancies were evaluated. Three hundred and fifteen fetuses were reviewed. Cerebral abnormalities developed antenatally in 26/315 fetuses (8.25%). All lesions but one were diagnosed prenatally. Prenatal diagnosis of these lesions was achieved primarily by ultrasound (US) and magnetic resonance imaging (MRI), in 20/25 (80%) and in 5/25 (20%) fetuses, respectively. Cerebral abnormalities developed following primary laser coagulation in 12/222 (5.40%), following serial amnioreduction in 9/66 (13.63%), and following expectant management in 3/14 (21.4%) fetuses. Abnormalities developed after single intrauterine fetal death (IUFD) in 14 cases.

CONCLUSIONS

Cerebral morbidity in TTTS mainly occurs following vascular disruptive lesions. Both donors and recipients are at risk of developing either ischemic or hemorrhagic lesions. The risk of developing cerebral lesions in single survivors is significantly lower following laser treatment. Combined use of a targeted US and fetal MRI could detect most cerebral abnormalities antenatally. Timing of the triggering event is critical for planning serial US and MRI follow-up examinations.

Symmetric truncal aplasia cutis congenita following multifetal reduction of a sextuplet pregnancy

Aplasia cutis congenita (ACC) in a symmetric, stellate pattern on the trunk or extremities is classically associated with a fetus papyraceus. We report symmetric truncal ACC in a neonate born of a sextuplet pregnancy that had been reduced to twins. This case highlights truncal ACC as a consequence of modern reproductive medicine.

Diffusion-weighted magnetic resonance imaging of acute hypoxic-ischemic cerebral lesions in the survivor of a monochorionic twin pregnancy: case report

Monochorionic twin pregnancies complicated by the death of one twin are associated with substantial morbidity in the survivor, with a high risk of developing hypoxic-ischemic brain damage. In this report, we demonstrate how prenatal diffusion-weighted magnetic resonance imaging detected focal ischemic lesions in the survivor of a monochorionic twin pregnancy within 1-2 days of cotwin death. A very early diagnosis of cerebral ischemic lesions might influence the management of the pregnancy. Published by John Wiley & Sons, Ltd.

[Obstetrical care of multiple pregnancies up to the 24th week of pregnancy--a survey]

The number of multiple pregnancies increases, as does the knowledge of their (patho)physiology, and of diagnostic and therapeutic difficulties. The role of sonography in prenatal medicine has developed dramatically over the years, especially in assessing and treating fetuses in multiple pregnancies. Therefore this article reflects this development. It gives an overview of the current knowledge and literature.

A Case of Monochorionic Twin Pregnancy Complicated with Intrauterine Single Fetal Death with Successful Treatment of Intrauterine Blood Transfusion in the Surviving Fetus

We report a case of monochorionic twin pregnancy complicated with single fetal demise that received successful treatment of intrauterine transfusion for severe anemia of the surviving fetus. A single fetal demise occurred at 20 weeks of gestation and middle cerebral artery peak systolic velocity (MCA-PSV), a marker for fetal anemia, showed marked elevation in the surviving fetus. Fetal blood sampling was immediately done and severe fetal anemia (hemoglobin = 5.5 g/dl, hematocrit = 16.8%) was confirmed, and then intrauterine transfusion was performed. After transfusion, MCA-PSV rapidly decreased to the normal value and remained within normal range until delivery. A healthy 2,640 g male infant was delivered at 35 weeks of gestation without anemic status and no neurological problem was found at 1-year old. The present report supports that intrauterine rescue transfusion is a useful treatment to prevent the adverse outcome of surviving fetus in monochorionic twin pregnancy complicated with single fetal demise, and monitoring of MCA-PSV is also useful to assess anemic status of the surviving fetus.

Accurate neurosonographic prediction of brain injury in the surviving fetus after the death of a monochorionic cotwin

OBJECTIVE

To assess the feasibility of the prenatal diagnosis using fetal neurosonography of brain injuries in the surviving fetus after the demise of a monochorionic cotwin.

METHODS

This was a retrospective observational study in the period 1990-2004 of monochorionic twin pregnancies with a single fetal demise. A detailed sonographic evaluation of the intracranial anatomy of the surviving twin had been performed whenever possible using a multiplanar approach and from 1999, fetal magnetic resonance imaging was offered as well. Postnatal follow-up was obtained in all cases.

RESULTS

In six of nine cases, abnormal neurosonographic findings were identified including intracranial hemorrhage, brain atrophy, porencephaly and periventricular echogenicities evolving into polymicrogyria. Prenatal diagnosis of brain lesions was confirmed postnatally and all affected infants who survived had severe neurological sequelae. Two fetuses had normal cerebral structures both on the prenatal neurosonogram and on postnatal imaging and were following normal developmental milestones, one at 1 and the other at 5 years of age. In one case the neurosonographic examination was suboptimal and the infant was found at birth to have a porencephalic cyst. Fetal magnetic resonance imaging was performed in two cases and confirmed the ultrasound diagnosis.

CONCLUSIONS

Prenatal neurosonography is a valuable tool for the prediction of neurological outcome in fetuses surviving after the intrauterine death of a monochorionic cotwin. Although our experience is limited, we suggest that magnetic resonance imaging should also be offered.

[Neurological outcome of children from twin pregnancies]

The neurological outcome is an important issue regarding twin pregnancies. In fact, twin pregnancy is clearly associated with an important neurological morbidity, roughly 4 times higher than singleton pregnancy. It is possible to distinguish some high-risk situations, making it possible to calculate more accurately the individual risk. The different aetiologies are analysed: hypotrophy, prematurity, malformations, prenatal occurrence of anoxic and ischemic lesions, and particularly the link with monochorionicity. The neurological outcome is mainly depending on hypotrophy and prematurity. However, the rate of long-term neurological complications is not different between twins and singletons after adjustment for term and birth weight. An increased risk of malformation is associated with twin pregnancies, essentially a high rate of abnormal neural tube closing (RR=2). Monochorionic pregnancies have a specific morbidity, not related to these aetiologies, with characteristic anoxic and ischemic lesions. Cerebral palsy is observed in 10-20% of the monochorionic pregnancies, vs 3.7% of the bichorionic ones. These complications are linked to the constant vascular anastomoses, between the circulations of the two monochorionic twins. When the twin-to-twin transfusion syndrome is severe, a poor neurological outcome is observed in 4 to 18% of the surviving children. However, this rate depends on studies, treatments, and methods of neurological evaluation. The laser destruction of anastomoses could decrease this morbidity. The stillbirth rate, either associated or not with twin to twin transfusion syndrome, is increased by monochorionicity. The death of one of the twins is associated with a 20% higher risk of neurological sequelae for the surviving co-twin.

Selective termination procedures in monochorionic pregnancies

Monochorionic twins have placental anastomoses that to varying degrees create a common circulation. This presents unique challenges for the performance of selective fetal termination in cases of twin-twin transfusion syndrome, twin reversed arterial perfusion sequence, or discordant twin abnormalities. Multiple methods of interrupting the affected twin's circulation have been attempted with variable success. One of the most frequent complications of any approach is iatrogenic preterm premature rupture of membranes. Laser coagulation in the midtrimester appears to be safe and effective; however, it is only available at limited centers. Currently, bipolar coagulation is the method of choice in the second half of pregnancy. The recently reported technique of radiofrequency ablation appears to be successful with minimal complications. Exploration of further percutaneous and noninvasive techniques, as well as interventions to decrease the morbidity arising from preterm membrane rupture, may lead to increased survival of the remaining twin and reduced risk of maternal complications.

Diagnosis and management of obstetrical complications unique to multiple gestations

Obstetrical complications unique to multiple gestations pose a number of unique challenges. The presence of more than one fetus complicates the diagnosis and management of a pregnancy when one fetus has a structural or chromosomal abnormality, intrauterine demise, preterm premature rupture of the membranes, or delivers prematurely. Similarly, the diagnosis and management of monoamniotic twins and conjoined twins is challenging. These obstetrical complications that are unique to multiple gestations require thorough counseling of the expectant parents, as well as care by physicians with expertise in the management of multiple gestations.

Do multiple gestations raise the risk of cerebral palsy?

There is an increased risk of CP in multiple as compared with singleton pregnancies, and the higher the number of fetuses the greater is the prevalence of CP. Although LBW and preterm birth are the most significant risk factors for CP, the disadvantage of twins is apparent near term. Moreover, the excessive risk is not only the result of over-representation of multiples among premature babies, but seems to be associated with circumstances that are unique to the twinning process. The risk of CP should be acknowledged not only when a multiple pregnancy is diagnosed, but also when counseling infertility patients in whom iatrogenic multiple pregnancies are an actual risk.

Management of other complications specific to monochorionic twin pregnancies

Monochorionic (MC) twins have a 3-10-fold higher perinatal mortality and morbidity than dichorionic twins. This is largely attributable to their common vascular architecture and the high rate of discordant fetal growth, growth restriction and congenital abnormalities. In the event of a single intrauterine death (IUD), intertwin agonal transfusion results in up to a 38% risk of death and a 46% risk of neurological injury to the co-twin. This chapter addresses the management of complications unique to MC twins. The primary aim of management is to prevent single IUD or, if inevitable, prevent agonal transfusion occurring by vascular occlusive selective feticide. Older fetoscopic techniques have been replaced by the simpler ultrasound-guided techniques of interstitial laser and bipolar cord occlusion. Their application in twin reversed-arterial perfusion sequence has been associated with a 50% reduction of perinatal mortality in the pump twin. Moreover, prophylactic interstitial laser therapy in early pregnancy might obviate the technical and clinical difficulties in the presence of fetal decompensation in later pregnancy. Recent strategies to reduce the high perinatal mortality due to cord entanglement in antenatally diagnosed monoamniotic twins including medical amnioreduction and elective caesarean delivery at 32 weeks, are also discussed.

How can we diagnose and manage twin–twin transfusion syndrome?

Severe mid-trimester twin-twin transfusion syndrome (TTS) complicates about 15% of monochorionic twin pregnancies. If left untreated, the mortality is 80-100%. The pathophysiological prerequisite for the onset of TTS is unequal blood flow via arteriovenous placental anastomoses from the so-called donor to the recipient twin. This can result in hypovolemia, hypotension and oligo- or anuria in the donor, and hypervolemia, hypertension, polyuria and finally heart failure in the recipient. Leading sonographic signs of TTS include severe oligo- or anhydramnios and a small or absent bladder filling in the donor in contrast to polyhydramnios with increased bladder filling in the recipient. Patients might present with clinical symptoms due to massive polyhydramnios. In severe mid-trimester TTS, fetoscopic laser occlusion of the anastomosing vessels on the placental surface under local anaesthesia plus subsequent amniodrainage is the most promising therapeutic option at present. In acute TTS after 26 weeks of gestation, amniodrainage is the therapy of choice. All patients suspected of this high-risk condition should be referred to a specialized fetal medicine centre.

Management of single fetal demise in a multiple gestation

Intrauterine fetal demise of 1 twin in a multiple gestation is a complex clinical situation. Chorionicity, gestational age at diagnosis, problems specific to the pregnancy, and the emotional needs of the patient can impact management. Strategies to optimize outcomes may include a multidisciplinary team approach and fetal surveillance. The following article reviews (1) adverse fetal and neonatal outcomes associated with intrauterine fetal demise of 1 twin, (2) the potential maternal impact, and (3) the strategies to possibly prevent poor outcomes. It is important to remember that even the most vigilant care may not avoid adverse sequelae in a portion of at-risk pregnancies.

Cause and risk of stillbirth in twin pregnancies: a retrospective audit

BACKGROUND

The epidemiology of twin pregnancies complicated by stillbirth of one or both fetuses is a scarcely examined area. The risk of perinatal death in twin pregnancies is increased 2-5 times compared to singletons, and the identification of preventable risk factors becomes increasingly important as the number of multiple pregnancies is rising. We report the causes of death in twin pregnancies and their respective risk factors.

METHODS

Twin pregnancies (n = 54) complicated by antepartum or intrapartum stillbirth of one or both twins (n = 68) and twin pregnancies with normal outcome (n = 103) in the counties of Oslo and Akershus, Norway, from 1986 to 1995 were included. The cases were classified and compared to the controls in multiple logistic regression analyses with regard to risk factors.

RESULTS

The risk of stillbirth increased with monochorionicity, non-Western origin and assisted reproduction techniques (ART). The cases could be divided into eight different groups according to the primary diagnosis. The groups did not fit any of the existing cause-of-death classifications used on singleton stillbirths.

CONCLUSIONS

The identification of monochorionic gestation should be made early in pregnancy to designate the level of risk. Assisted reproduction techniques leading to a high incidence of twins should be avoided. Health care professionals in the immigrant population should address the detrimental effects of consanguinity on reproductive outcome. We emphasize the need of a new cause-of-death classification for twin stillbirths.

Selective feticide in monochorionic twin pregnancies by ultrasound-guided umbilical cord occlusion

OBJECTIVES

To evaluate the feasibility and the follow-up of three different ultrasound-guided procedures of selective feticide in monochorionic twin pregnancies.

METHODS

This was a retrospective observational study of patients who underwent percutaneous umbilical cord occlusion between July 1993 and January 2002 after diagnosis of previable, abnormal, monochorionic twin pregnancy, with imminent cardiac failure of one of the fetuses. Selective feticide was performed under general anesthesia using three different ultrasound-guided techniques: cord ligation using a suture (four cases), cord coagulation using bipolar forceps (five cases) and cord compression by squeezing the cord against the uterine wall (two cases).

RESULTS

During the study period, 11 patients underwent selective feticide before 28 weeks' gestation in our department (eight recipient twins with twin-twin transfusion syndrome (TTTS), one of which also had a congenital diaphragmatic hernia, and three acardiac twins). One procedure failed due to maternal hemorrhage following insertion of the trocar (both fetuses died after emergency Cesarean section). One cotwin died a few minutes after the procedure and one survivor died within the neonatal period. The mean gestational age at the time of the procedure was 24 weeks of gestation and the mean gestational age at delivery was 31.1 weeks. Premature rupture of membranes occurred in four cases. Eight babies were alive and well at the time of writing.

CONCLUSIONS

Ultrasound guidance can enable selective feticide to be performed via a single port. Although bipolar coagulation seemed to be the easiest technique, the choice of procedure depends on local conditions.

The value of middle cerebral artery peak systolic velocity in the diagnosis of fetal anemia after intrauterine death of one monochorionic twin

OBJECTIVE

The purpose of this study was to assess the value of the fetal middle cerebral artery peak systolic velocity in the prediction of anemia within 24 hours of the death of one monochorionic twin in twin-to-twin-transfusion syndrome and to establish the correlation between middle cerebral artery peak systolic velocity and hemoglobin concentration in fetuses who are at risk for acute anemia.

STUDY DESIGN

Doppler examination of the middle cerebral artery peak systolic velocity was performed in 20 monochorionic survivors of pregnancies that were complicated by twin-to-twin-transfusion syndrome that occurred between 20 and 34 weeks of gestation. Doppler examination was performed before cordocentesis and after intrauterine transfusion when appropriate. Both hemoglobin concentration and middle cerebral artery peak systolic velocity were expressed in multiples of the median. Severe anemia was defined as hemoglobin concentration of <0.55 multiples of the median, and we used the cutoff point of 1.50 times the median values at any gestational age to calculate the sensitivity and specificity of middle cerebral artery peak systolic velocity in detecting moderate or severe anemia.

RESULTS

Fetal anemia was confirmed in 10 of 20 fetuses. We performed seven intrauterine transfusions. The sensitivity and specificity of middle cerebral artery peak systolic velocity in the prediction of severe fetal anemia were of 90%, with a false-negative rate of 10%. The correlation between peak systolic velocity and hemoglobin concentration both before and after transfusion was evaluated by regression analysis and was strongly significant.

CONCLUSION

In fetuses who are at risk of acute anemia, the measurement of middle cerebral artery peak systolic velocity was found to be a reliable noninvasive diagnostic tool and may be helpful in counseling and planning invasive assessment.

Management of single fetal death in twin-to-twin transfusion syndrome: a role for fetal blood sampling

OBJECTIVE

Intrauterine death of one twin in monochorionic pregnancies is associated with an increased mortality and morbidity of the cotwin. This is likely to occur as a consequence of acute hemodynamic changes due to feto-fetal hemorrhage at the time of death of the cotwin. We assessed the role of fetal blood sampling and intrauterine transfusion to rescue the survivor.

MATERIALS AND METHODS

We managed 12 cases of single intrauterine death at between 17 and 26 weeks' gestation in monochorionic twins complicated by twin-to-twin transfusion syndrome (TTTS). All these cases had been treated either by laser therapy or by serial amniodrainage. When the demise of one twin occurred, ultrasound-guided fetal blood sampling was performed in the surviving twin using a 20-gauge needle within 24 h of death. Intrauterine transfusion was performed at the same time in cases where the survivor was anemic. All survivors were assessed in the neonatal period and at 1 year of age.

RESULTS

Six of the 12 surviving fetuses were found to be anemic and underwent intrauterine transfusion. All fetuses survived the procedure. Four of these fetuses had normal neurological development at 1 year of age. Periventricular leukomalacia developed in one case and the patient underwent termination of pregnancy at 34 weeks. In one case delivery occurred at 34 weeks' gestation and the baby developed periventricular leukomalacia at 1 month of age. In all six non-anemic fetuses pediatric examination was normal at birth and at 1 year of age.

CONCLUSION

Intrauterine death of one monochorionic twin in TTTS puts the survivor at high risk of intrauterine death or of developing ischemic/hypoxic lesions. Our results suggest that fetal blood sampling is a useful diagnostic tool to identify those fetuses that are not anemic and hence unlikely to be at risk of developing a cerebral lesion.

The twin-twin transfusion syndrome

The aetiology of twin-twin transfusion syndrome (TTTS), which affects 10-15% of monochorionic (MC) twin pregnancies, remains poorly understood. Although all MC twins have placental vascular anastomoses, unbalanced intertwin transfusion has been shown by ex vivo injection and in vivo Doppler studies of chorionic plate vasculature to be mediated by > or =1 arterio-venous anastomoses (AVA) in association with absent bi-directional arterio-arterial anastomoses (AAA). TTTS presents in the mid trimester with the oligo-polyhydramnios sequence, the donor may have a small or non-visible bladder and abnormal umbilical artery Doppler, while the recipient has a large bladder and may develop cardiac hypertrophy, triscupid regurgitation, and eventually hydrops. Recently, discordant renal renin angiotensin expression, endothelin and atrial natriuretic peptide have been implicated in the pathogenesis. Survival has increased from <20% to <60-70% with modern treatments, although survivors remain at increased risk of antenatally acquired cerebral white matter injury, and neurodevelopmental sequelae are documented in c.10% (range 5-23%). The recent introduction of a staging system for TTTS facilitates selection of therapy with less invasive amnioreduction and septostomy preferred for early stage disease, and more aggressive modalities such as laser ablation and cord occlusion with their attendant risk of procedure related fetal loss, reserved for advanced stage disease.

Intrauterine death of one twin, with rescue of the other, in twin-twin transfusion syndrome

Single intrauterine death may occur in twin-twin transfusion syndrome. We investigated why the outcome of the surviving twin is fairly good when the donor twin dies first compared with when the recipient twin dies first. A detailed hemodynamic study was performed using Doppler ultrasound in a twin pregnancy affected by twin-twin transfusion syndrome before and after a single intrauterine death that occurred in the donor twin at 26 weeks' gestation. The recipient twin was expected to die due to severe right cardiac failure with functional stenosis of the pulmonary artery 2 days before the cotwin's death. The donor twin's death caused a prompt resolution of cardiac failure and improvement in other indices, including flow velocity waveform patterns of the umbilical vein, the middle cerebral artery and the ductus venosus. A healthy, premature female neonate weighing 1630 g with a hemoglobin concentration of 17.8 g/dL was delivered by Cesarean section following rupture of the fetal membranes 28 days after the episode. Hemorrhaging from the surviving twin to the dead twin that occurred just before or after the cotwin's death may have contributed to the decrease in volume overload in the recipient twin, leading to a prompt amelioration of the critical hemodynamic indices. The early death of the donor twin may thus have played a significant role in improving the status of the recipient twin in this case of twin-twin transfusion syndrome.

Placental vascular anastomoses visualized during fetoscopic laser surgery in severe mid-trimester twin-twin transfusion syndrome

The aim of this study was to describe the type and number of placental vascular anastomoses identified during fetoscopic laser coagulation in severe mid-trimester twin-twin transfusion syndrome (TTS). In 126 patients with severe TTS, undergoing fetoscopic laser coagulation between 16 and 25 weeks of gestation, the different types of placental anastomoses [arterio-venous (AV), arterio-arterial (AA) and veno-venous (VV)] were counted. In cases of AV anastomoses their direction was identified and four groups were defined: in group 1 there were only anastomoses shunting from donor to recipient. Group 2 consisted of placentae with more anastomoses shunting from donor to recipient than in the opposite direction, group 3 showed an equal number in both directions and in group 4 there were more anastomoses shunting from recipient to donor than in the opposite direction. In 9 cases (7 per cent) the anastomoses could not be clearly identified due to impaired visualization, leaving 117 cases for analysis. The median number of anastomoses found was 5 with a range from 1-14. In all cases AV anastomoses from donor to recipient were present, 36 cases (31 per cent) had also AA anastomoses and 14 cases (12 per cent) showed VV anastomoses. Regarding the direction of AV anastomoses, the results were as follows: there were 35 cases (30 per cent) in group 1, 52 cases (44 per cent) in group 2, 14 cases (12 per cent) in group 3 and 16 cases (14 per cent) in group 4. In 54 (46 per cent) placentae there was at least one thin anastomosis whose type was unclassifiable. There were no placentae showing AV anastomoses only from the recipient to the donor fetus. This study demonstrates that AV anastomoses are the prerequisite for the development of TTS in monochorionic placentae. The majority (74 per cent) of cases showed a higher number of AV anastomoses from donor to recipient than in the opposite direction. In approximately one third of placentae there are also AA anastomoses and the overall number of anastomoses seen and coagulated during fetoscopy is higher than reported in postnatal studies.

Intrauterine rescue transfusion in monochorionic multiple pregnancies with recent single intrauterine death

To assess the role of fetal blood sampling and intrauterine transfusion in monochorionic (MC) multiple pregnancy complicated by single intrauterine death (IUD), we reviewed ten cases over a 4-year period in a tertiary referral centre which underwent fetal blood sampling within 24 h of death of its MC co-twin. Intrauterine rescue transfusion was performed in all seven anaemic fetuses (hematocrit; Hct < 30%) to raise the fetal Hct to > or = 40%. The rationale was to prevent death and/or brain injury. Two fetuses, which were severely acidaemic at blood sampling, died in utero within 24 h of the procedure. In two cases, the surviving twins manifested abnormal sonographic findings of the fetal brain 2-5 weeks later and underwent late termination. In two cases, the pregnancies continued uneventfully until delivery at 35 and 40 weeks' gestation with good neonatal outcome. In one case the co-twin delivered 1 week later at 29 weeks but died within 12 h. Fetuses without anaemia were not transfused and had normal clinical outcomes. We suggest that intrauterine rescue transfusion before the development of severe acidaemia in anaemic surviving MC co-twins may prevent fetal death, but does not necessarily prevent brain injury. Until its role becomes clearer, we recommend that its use be restricted to situations in which the parents and the local jurisdiction allow late termination as an option if brain injury subsequently manifests on ultrasound.

Endoscopic laser coagulation of placental anastomoses in 200 pregnancies with severe mid-trimester twin-to-twin transfusion syndrome

OBJECTIVE

To investigate perinatal outcome after endoscopic laser coagulation of the placental vascular anastomoses in severe mid trimester twin-to-twin transfusion syndrome (TTTS).

STUDY DESIGN

In a prospective study between January 1995 and September 1999, we performed laser therapy in 200 consecutive pregnancies with TTTS between 16 and 25 weeks of gestation. We compared outcome of the first group of 73 pregnancies whose outcome has been reported previously in a study comparing laser surgery and serial amniodrainages [Am J Obstet Gynecol 1999;180:717-24], with the following group of 127 patients.

RESULTS

The overall survival rate increased from 61% (89/146) in group 1 to 68% (172/254) in group 2. The percentage of pregnancies with survival of both fetuses was 42% (31/73) in group 1 and increased to 54% (69/127) in group 2 (P=0.142). The survival rate for at least one fetus was 81% (103/127) in group 2. The median gestational age at delivery of liveborn babies was 33.7 weeks in group 1 and 34.4 weeks in group 2 with a median interval of 13 weeks between the intervention and delivery.

CONCLUSION

This study of a large population of pregnancies with severe second trimester twin-to-twin transfusion syndrome confirms the improvements of outcome after laser therapy as compared to serial amniodrainages reported previously. Furthermore, it shows a trend towards an increase in survival rates with growing experience in this technique, most likely attributable to a more selective identification and efficient coagulation of the placental vascular anastomoses.

Current experience with fetoscopy and the Eurofoetus registry for fetoscopic procedures

Fetoscopy has consolidated its position in fetal medicine, thanks to a combination of insight into the pathophysiology of selected conditions that are amenable to fetal surgery and the technical innovations in endoscopic equipment. In clinical practice, two types of fetoscopy can be discerned: Obstetrical Endoscopy and Endoscopic Fetal Surgery. The first involves surgical interventions on the placenta, umbilical cord and fetal membranes. Nd:YAG laser coagulation of placental vessels in case of feto-fetal transfusion syndrome and cord occlusion in monochorionic pregnancy are the most typical procedures. The second type addresses some rare fetal conditions requiring in utero surgery; most experience has been gathered with congenital diaphragmatic hernia. Endoscopic fetal surgery has a different historical and experimental background than obstetrical endoscopy, but they both share technical aspects as well as potential side effects. In this review, we aimed at bringing together currently available experience. We suggest that future developments of fetal endoscopic operations will involve a mixture of concepts from both fetoscopy types to reduce maternal invasiveness and complications, eventually improving acceptance by parents and doctors. We encourage the registration of all experience in a yet available open registry for prospective data collection, supported by the European Commission, with as primary target the assessment of maternal and fetal safety.

Thermocoagulation for selective reduction of conjoined twins at 12 weeks of gestation

Conjoined twins occur rarely. Most of the prenatally diagnosed cases are terminated either because of extensive organ sharing or because of the presence of major structural abnormalities. We present a case of omphalopagus conjoined twins diagnosed at 10 weeks of gestation with selective reduction performed at 12 weeks. The twins were conjoined at the umbilicus with vascular communication demonstrated at the conjunction. Twin A was normal but twin B was growth restricted and hydropic. Thermocoagulation of twin B was performed at 12 weeks by passing an insulated electric wire through a 18-gauge needle placed close to the fetal heart. Reassessment at 15 weeks showed that twin A was growing normally with a small dead twin B attached at its umbilicus. Twin B was subsequently sloughed off from this attachment and could be seen lying free in the amniotic cavity at 17 weeks. Twin A was delivered at term and was healthy. A small scar could be seen just above the umbilical cord insertion. This case represents the first antenatal example of selective reduction of conjoined twins by thermocoagulation.