Neurodevelopmental outcome in twin anemia-polycythemia sequence after laser surgery for twin-twin transfusion syndrome

OBJECTIVE

To evaluate the long-term neurodevelopmental outcome in children who developed twin anemia-polycythemia sequence (TAPS) after fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS).

METHODS

Neurological, motor and cognitive development was assessed in a consecutive cohort of TTTS survivors treated with laser surgery between 2004 and 2011 and complicated by post-laser TAPS. Primary outcome was neurodevelopmental impairment, a composite outcome including any of the following: cerebral palsy, bilateral deafness, blindness, severe motor and/or cognitive developmental delay (>2 SD below the mean). A risk analysis on cognitive outcome was performed.

RESULTS

During the study period, 33/306 (11%) monochorionic twin pairs developed TAPS after laser surgery for TTTS. Survival was 53/66 (80%). Long-term outcome was assessed in 47/53 (89%) children. The incidence of neurodevelopmental impairment was 4/47 (9%), occurring in one donor (1/20; 5%) and three recipients (3/27; 11%) (P=0.63). Mild-to-moderate cognitive delay, i.e. scores below 85, was detected in 8/47 (17%) children. Risk factors for low cognitive scores were low gestational age at birth (P=0.02) and low birth weight (P<0.01). The lowest cognitive scores were detected in the subgroup of TAPS survivors treated with intrauterine transfusion (median score, 82.5).

CONCLUSIONS

Neurodevelopmental impairment and cognitive delay were found in almost one in five children surviving post-laser TAPS. Better treatment and, ideally, prevention of this complication after laser treatment for TTTS is urgently needed.

Laser surgery as a management option for twin anemia-polycythemia sequence

OBJECTIVE

To evaluate the effectiveness of laser treatment for antenatally detected twin anemia-polycythemia sequence (TAPS) compared with intrauterine transfusion or expectant management.

METHODS

All monochorionic twin pregnancies with TAPS managed between 2005 and 2013 in two European fetal therapy centers were evaluated. The outcomes of TAPS cases treated primarily with laser surgery were compared with the outcomes of cases managed expectantly or treated with intrauterine transfusion.

RESULTS

In this retrospective study 52 cases of TAPS were detected antenatally and were managed with either laser surgery (n=8; 15%) or intrauterine blood transfusion (n=17; 33%) or expectantly (n=27; 52%). Perinatal survival in the laser group was 94% (15/16) vs 85% (29/34) in the intrauterine-transfusion group and 83% (45/54) in the expectant-management group (P=0.30). The rates of severe neonatal morbidity in liveborn neonates in the laser, intrauterine-transfusion and expectant-management groups were 7% (1/15), 38% (12/32) and 24% (12/50), respectively (P=0.17). There was a significant reduction in respiratory distress syndrome in cases treated by laser. No severe postnatal hematological complications were detected in the laser group compared with 72% (23/32) in the intrauterine-transfusion group and 52% (26/50) in the expectant-management group (P<0.01). Median time between diagnosis and birth was 11 weeks in the laser group compared to 5 weeks after intrauterine transfusion and 8 weeks after expectant management (P<0.01). After injection of colored dye no residual anastomoses were found in the laser group.

CONCLUSIONS

Laser surgery for TAPS appears to improve perinatal outcome by prolonging pregnancy and reducing respiratory distress syndrome. Larger, adequately controlled studies are needed to reach firm conclusions on the optimal management of TAPS.

Termination of pregnancy for maternal indications at the limits of fetal viability: a retrospective cohort study in the Dutch tertiary care centres

OBJECTIVE

Maternal morbidity, either pregnancy related or pre-existent, can become life threatening and of such severity as to warrant termination of pregnancy (TOP). In this situation, chances of fetal survival are usually poor, either because of low gestational age and/or because of the fetal effects of the maternal condition. Examples include severe growth restriction in pre-eclampsia and intrauterine infection due to the very early preterm prelabour rupture of membranes. There are very few reports on the prevalence of TOP for maternal indication at the limits of fetal viability. We investigated the prevalence of and indications for TOP on maternal indication in the 10 tertiary care centres in the Netherlands during the past decade.

STUDY DESIGN

We conducted a retrospective review of the medical records of all women who underwent TOP for maternal indications between 22 and 27 completed weeks of gestation in all 10 tertiary care centres from 2000 to 2009.

RESULTS

During the study period, there were 1 929 470 deliveries; 163 052 (8.4%) of these took place in one of the 10 tertiary care centres and 177 pregnancies were terminated for severe maternal disease, 131 for hypertensive disorders, 29 for intrauterine infection and 17 for other reasons. The mean gestational age at TOP was 171 days (24(3/7))±10 days. No maternal deaths were recorded. The overall perinatal mortality was 99.4%.

CONCLUSIONS

Over a 10-year period, TOP for maternal indications was performed in 1 in 1000 deliveries in the 10 Dutch tertiary care centres. Hypertensive disorders comprised three-quarters of the cases.

Perinatal outcome after selective feticide in monochorionic twin pregnancies

OBJECTIVE

To evaluate the incidence and risk factors of adverse perinatal outcome in complicated monochorionic twin pregnancies treated with selective feticide.

METHODS

This was a retrospective analysis of prospectively collected data from a consecutive, national cohort. All monochorionic twin pregnancies treated with selective feticide at Leiden University Medical Center between June 2000 and November 2011 were included. Obstetric and neonatal data were recorded. The primary outcome measure was adverse perinatal outcome, including fetal or neonatal demise or severe neonatal morbidity.

RESULTS

Data on perinatal outcome were obtained in all cases (n = 131). Overall perinatal survival rate was 67.2% (88/131). Median gestational age at delivery was 34 (interquartile range, 23-38) weeks. Neonatal mortality and morbidity rate in liveborn children was 4.3% (4/92) and 12.0 % (11/92), respectively. Severe cerebral injury was detected in three children. The overall incidence of adverse perinatal outcome was 41.2% (54/131). Median gestational age at occurrence of preterm prelabor rupture of membranes (PPROM) was 19.0 weeks and 32.0 weeks in cases with and without adverse perinatal outcome, respectively (P = 0.017). Liveborn children with adverse perinatal outcome were born at a lower median gestational age (29.0 weeks) than were children without adverse perinatal outcome (38.0 weeks) (P < 0.001).

CONCLUSIONS

The risk of adverse perinatal outcome after selective feticide is high and associated with low gestational age at occurrence of PPROM and low gestational age at delivery. Long-term follow-up to assess neurodevelopmental outcome in survivors is required.

Severe cerebral injury in a recipient with twin anemia-polycythemia sequence

Twin anemia-polycythemia sequence (TAPS) results from slow intertwin blood transfusion through minuscule placental vascular anastomoses and is characterized by large intertwin hemoglobin differences in the absence of amniotic fluid discordance. The optimal management of TAPS is not clear. We report a case of TAPS detected antenatally by Doppler ultrasound examination at 15 + 6 weeks' gestation. After counseling, the parents opted for expectant management. Regular Doppler measurements were performed and these remained fairly stable. An emergency Cesarean section was performed at 34 + 5 weeks following signs of fetal distress. The donor twin was severely anemic while the recipient twin had severe polycythemia-hyperviscosity syndrome. On day 1, the recipient developed respiratory insufficiency and subclinical status epilepticus. Magnetic resonance imaging showed a total loss of gray-white matter differentiation as a sign of severe diffuse cerebral ischemia and bilateral intra- and extra-axial hemorrhages. There was almost complete lack of arterial and venous cerebral blood flow. On day 3 intensive care treatment was withdrawn in view of the severity of the brain injury. This case report demonstrates that TAPS may lead to severe cerebral injury and fatal outcome in the recipient twin, and highlights the importance of antenatal Doppler ultrasound monitoring and choice of management.

Association of innate immune activation with latent Epstein-Barr virus in active MS lesions

OBJECTIVE

To determine whether the activation of innate immune responses, which can be elicited by pathogenic and endogenous triggers, is associated with the presence of Epstein-Barr virus (EBV) infection in the multiple sclerosis (MS) brain.

METHODS

White matter postmortem MS (n = 10) and control tissue (n = 11) was analyzed for the expression of the proinflammatory cytokine interferon α (IFNα) by immunohistochemistry and for EBV by using the highly sensitive method of EBV-encoded RNA (EBER) in situ hybridization.

RESULTS

We detected overexpression of IFNα in active areas of white matter MS lesions but not in inactive MS lesions, normal-appearing white matter, or normal brains. The presence of IFNα in macrophages and microglia (expressing human leukocyte antigen class II) is suggestive of local production as part of an acute inflammatory process. Interestingly, EBERs were also specifically detected in areas where IFNα was overexpressed in these preselected active MS lesions. EBER+ cells were also found in CNS lymphoma and stroke cases, but were absent in other control brains. We next addressed a potential mechanism, e.g., the role of EBERs in eliciting IFNα production, and transfected EBERs into human embryonic kidney (HEK) cells. We used HEK cells that stably expressed Toll-like receptor-3, which recognizes double-stranded RNAs, associated with many viral infections. EBERs elicited IFNα production in vitro.

CONCLUSION

These findings suggest that latent EBV infection may contribute to the inflammatory milieu in active MS lesions by activating innate immune responses, e.g., IFNα production. Unraveling the underlying mechanisms may help in uncovering causal pathways and developing better treatment strategies for MS and other neuroinflammatory diseases.

Prophylaxis with low-dose low-molecular-weight heparin during pregnancy and postpartum: is it effective?

BACKGROUND

The optimal approach for venous thrombosis (VTE) prophylaxis during pregnancy and postpartum in women with an increased risk of VTE is not established.

OBJECTIVES

To evaluate the effectiveness, represented as the incidence of pregnancy-related VTE, and safety, represented as incidence of postpartum hemorrhage (PPH), of a protocol recommending prophylaxis with low-dose low-molecular-weight heparin (LMWH) in women at intermediate to high risk of VTE.

PATIENTS/METHODS

In this retrospective cohort study, we analyzed 34 women (44 pregnancies) with intermediate risk of VTE who received low-dose LMWH for 6 weeks postpartum and 57 women (82 pregnancies) with high risk of VTE who received low-dose LMWH during pregnancy and for 6 weeks postpartum. Pregnancy-related VTE was defined as VTE during pregnancy or ≤ 3 months postpartum. PPH was defined as blood loss >500 mL and severe PPH as blood loss > 1000 mL.

RESULTS

The incidence of pregnancy-related VTE was 5.5% (95% CI, 2.4-12.3) despite prophylaxis with low-dose LMWH. All events occurred in women at high risk, with a postpartum incidence of 7.0% (95% CI, 2.9-16.7) and antepartum incidence of 1.8% (95% CI, 0.4-9.2). The risk of PPH was 21.6% (95% CI, 14.3-31.3) and severe PPH 9.1% (95% CI, 4.7-16.9), which was not different in women who started LMWH postpartum and those who used LMWH during pregnancy.

CONCLUSIONS

Although prophylaxis with low-dose LMWH during pregnancy and postpartum proved to be safe, the risk of pregnancy-related VTE is considerable in women with a high risk of VTE. VTE prophylaxis with low-dose LMWH may not be sufficiently effective in these women.

Is routine TORCH screening and urine CMV culture warranted in small for gestational age neonates?

BACKGROUND

congenital infections are associated with a wide variety of clinical symptoms, including small for gestational age (SGA).

AIMS

to determine the co-occurrence of SGA and congenital TORCH infections, as diagnosed by TORCH serologic tests and/or cytomegalovirus (CMV) urine culture.

STUDY DESIGN

we performed a retrospective study of all neonates admitted to our neonatal intensive care unit from January 2004 to February 2010 in whom SGA was diagnosed and TORCH serologic tests and/or CMV urine cultures were performed.

RESULTS

TORCH serologic tests (in neonatal or maternal serum) and/or a CMV urine culture were performed in 112 neonates with SGA. None of the neonates tested positive for Toxoplasma gondii, Rubella, and Herpes simplex virus. Positive CMV urine culture was detected in 2% (2/112) of neonates, but their CMV IgM titers were negative.

CONCLUSIONS

the co-occurrence of TORCH congenital infection in infants with SGA is rare. Routine TORCH screening in neonates with isolated SGA does not seem warranted and should be limited to CMV urine cultures.

GFAP in health and disease

Glial fibrillary acidic protein (GFAP) is the main intermediate filament protein in mature astrocytes, but also an important component of the cytoskeleton in astrocytes during development. Major recent developments in astrocyte biology and the discovery of novel intermediate filament functions enticed the interest in the function of GFAP. The discovery of various GFAP splice variants gave an additional boost to explore this protein in more detail. The structural role of GFAP in astrocytes has been widely accepted for a long time, but over the years, GFAP has been shown to be involved in astrocyte functions, which are important during regeneration, synaptic plasticity and reactive gliosis. Moreover, different subpopulations of astrocytes have been identified, which are likely to have distinctive tasks in brain physiology and pathology, and which are not only classified by their spatial and temporal appearance, but also by their specific expression of intermediate filaments, including distinct GFAP isoforms. The presence of these isoforms enhances the complexity of the astrocyte cytoskeleton and is likely to underlie subtype specific functions. In this review we discuss the versatility of the GFAP cytoskeletal network from gene to function with a focus on astrocytes during human brain development, aging and disease.

Hematological characteristics in neonates with twin anemia-polycythemia sequence (TAPS)

OBJECTIVE

To evaluate the neonatal hematological features of monochorionic twins with twin anemia-polycythemia sequence (TAPS) and to determine the additional diagnostic value of reticulocyte count measurement.

METHODS

A cohort of consecutive monochorionic twins with TAPS (n = 19) was included in the study and each twin pair was compared with two monochorionic twin pairs (n = 38) unaffected by TAPS or twin-twin transfusion syndrome (TTTS), matched for gestational age at birth. We measured full blood counts on day 1 and determined the incidence of anemia, polycythemia, reticulocytosis and thrombocytopenia.

RESULTS

Median inter-twin hemoglobin (Hb) difference in monochorionic twins with and without TAPS was 13.7 g/dL and 2.4 g/dL, respectively (p < 0.01). Median inter-twin reticulocyte count ratio in twins with and without TAPS was 3.1 and 1.0, respectively (p < 0.01). Thrombocytopenia (platelet count < 150 x 10(9)/L) occurred more often in the TAPS group than in the control group, 45% (17/38) versus 11% (11/38), respectively (p < 0.01). In the TAPS group, mean platelet count was significantly lower in recipients than in donors, 133 x 10(9)/L versus 218 x 10(9)/L, respectively (p < 0.01).

CONCLUSIONS

TAPS twins have a large inter-twin Hb difference in combination with a large inter-twin reticulocyte count ratio. Recipients are more often thrombocytopenic than donors, probably due to polycythemia.

Expression patterns of glial fibrillary acidic protein (GFAP)-delta in epilepsy-associated lesional pathologies

AIMS

Glial fibrillary acidic protein (GFAP)-delta is a novel isoform that differs in its C-terminal sequence from other GFAP isoforms. Previous studies suggest restriction of expression to the subpial layer, subventricular zone and the subgranular zone astrocytes, with an absence in pathological conditions causing reactive gliosis. GFAP-delta is speculated to have roles in regulation of astrocyte size and motility and a subpopulation of GFAP-delta-positive glia may be multipotent stem cells. The aim of this study was to investigate its expression in common causes of lesion-related refractory epilepsy.

METHODS

Hippocampal sclerosis (HS), focal cortical dysplasia (FCD) type IIB, cortical tuberous sclerosis (TSC) lesions, gangliogliomas, grey matter heterotopias and hemimegalencephaly from a wide age range of patients using both surgical and post mortem tissue specimens were studied.

RESULTS

GFAP-delta expression was observed in CA4 and CA1 astrocytes in HS with less frequent labelling in the granule cell layer, even where granule cell dispersion was present. No significant labelling was noted in the subiculum in HS cases or in any subfields in non-HS epilepsy cases. Balloon cells in FCDIIB and hemimegalencephaly, giant cells in TSC and the astrocytic component of gangliogliomas showed immunoreactivity, colocalizing with conventional GFAP. No neuronal expression for GFAP-delta was seen in any of the pathologies. Quantitative analysis in 10 FCDIIB and five TSC cases revealed greater numbers of GFAP-delta-positive balloon cells than conventional GFAP. There was no GFAP-delta expression within nodular heterotopia.

CONCLUSIONS

GFAP-delta expression patterns in HS overall appears to mirror regional reactive gliosis. It is a useful marker for the demonstration of balloon cells in FCD and TSC, which may be relevant to their abnormal size and localization. The lack of GFAP-delta within heterotopia supports their composition from cells destined for deeper cortical layers.

Fetal cardiac output in monochorionic twins

OBJECTIVES

To compare fetal cardiac output (CO) in donor and recipient twins of twin-twin transfusion syndrome (TTTS) pregnancies after laser therapy with that of monochorionic twins without TTTS and normal singletons.

METHODS

In a longitudinal, prospective study, we sonographically assessed fetal CO in donors (n = 10) and recipients (n = 10) with TTTS after fetoscopic laser therapy, in monochorionic twins without TTTS (n = 20) and in normal singleton pregnancies (n = 20). The fetal CO of TTTS twins was determined 1 day and 1 week after laser treatment, and from then on every 2-4 weeks until birth. Twins without TTTS were examined biweekly until birth. Singletons were examined twice, with an 8-week interval, at different gestational ages between 17 and 35 weeks.

RESULTS

Absolute CO increased exponentially with advancing gestational age (P < 0.0001), and was significantly related to fetal weight in all groups (P < 0.0001). The median CO/kg in donors after laser therapy, recipients after laser therapy and non-TTTS monochorionic twins was significantly higher than that in singletons (all P < 0.001). Median CO/kg in donors after laser therapy, recipients after laser therapy, and non-TTTS monochorionic twins was not significantly different between groups.

CONCLUSIONS

Monochorionic twins with TTTS have higher CO after laser therapy than normal singletons.

Multiple roles of LMP1 in Epstein-Barr virus induced immune escape

The life cycle of Epstein-Barr virus (EBV) is intriguing in that the virus resides within the immune system and utilizes distinct latency expression programs to establish a persistent infection yet escaping elimination. To achieve this EBV has hijacked cellular signaling pathways to its own benefit, but deregulated viral gene expression can turn into oncogenesis. EBV like many other persistent herpes viruses has evolved ingenious tricks to evade the immune system in part by mimicking host gene function(s). Latent membrane protein 1 (LMP1) mimics CD40 signaling as part of its "normal" biological function and when deregulated, functions as a viral oncogene. LMP1 also affects cell-cell contact, cytokine and chemokine production, Ag presentation and is secreted in the extracellular milieu via immunogenic exosomes. Thus, besides its well-known growth promoting properties LMP1 modulates immune responses. Herein we discuss current knowledge regarding the role of LMP1 in immune evasion of EBV and how this strategy for establishment of persistence contributes to immune escape of EBV+ tumors.

The effect of fetoscopic laser therapy on fetal cardiac size in twin-twin transfusion syndrome

OBJECTIVES

To evaluate the influence of fetoscopic laser therapy on fetal cardiac size in monochorionic twins complicated by twin-twin transfusion syndrome (TTTS).

METHODS

In a longitudinal, prospective study, we assessed fetal cardiac size sonographically in monochorionic diamniotic twins with TTTS treated by laser therapy and in monochorionic twins without TTTS. The fetal cardiothoracic ratio (cardiac circumference divided by thoracic circumference) of TTTS twins was determined within 24 h before, 12-24 h after and 1 week after laser treatment, and from then on every 2-4 weeks until birth. TTTS twins were classified into Quintero Stages 1-2 (n = 18) and Stages 3-4 (n = 16), and measurements were compared with biweekly measurements of non-TTTS monochorionic twins matched for gestational age (n = 38). Cardiomegaly was defined as a cardiothoracic ratio above the 97.5th percentile.

RESULTS

Before laser treatment, cardiomegaly was observed in 44% (8/18) and 50% (8/16) of recipients in Quintero Stages 1-2 and Stages 3-4, respectively. Cardiomegaly occurred in none of the donors before treatment. After laser treatment, cardiomegaly was observed in 76% (13/17) and 50% (7/14) of recipients in Stages 1-2 and Stages 3-4, respectively, and in 17% (3/18) and 13% (2/15) of donors in Stages 1-2 and Stages 3-4, respectively. Cardiomegaly was present in 18% (7/38) and 8% (2/25) of non-TTTS monochorionic twins and singletons. After laser therapy, the cardiothoracic ratio of recipients in Stages 1-2 and Stages 3-4 was not significantly changed (P = 0.34 and P = 0.67, respectively). The cardiothoracic ratio of donors in Stages 1-2 and Stages 3-4 was increased compared with that before laser therapy (P = 0.0002 and P = 0.005, respectively). Cardiothoracic ratios of non-TTTS monochorionic twins were not significantly different from our reference range in singletons throughout gestation, and were smaller than those in both recipients and donors after laser therapy.

CONCLUSIONS

TTTS recipients show cardiomegaly before as well as after fetoscopic laser therapy for TTTS. Donors develop cardiomegaly only after laser treatment. Our findings emphasize the significant effect of TTTS and fetoscopic laser therapy on the fetal heart of both recipient and donor twins.

Twin-to-twin transfusion syndrome after 26 weeks of gestation: is there a role for fetoscopic laser surgery?

OBJECTIVE

To compare fetoscopic laser surgery with amniodrainage in the treatment of twin-to-twin transfusion syndrome (TTTS) diagnosed after 26 weeks of gestation.

DESIGN

A retrospective cohort study.

SETTING

Leiden University Medical Centre, a tertiary referral hospital for fetal therapy.

POPULATION

Between January 1991 and February 2006, 21 TTTS cases were diagnosed and treated after 26 weeks of gestation.

METHODS

Treatment of TTTS consisted of either amniodrainage or fetoscopic laser coagulation of vascular anastomoses.

MAIN OUTCOME MEASURES

PRIMARY OUTCOME

adverse outcome (intrauterine or neonatal death, major neonatal morbidity and/or severe cerebral injury). Secondary outcome: gestational age at birth.

RESULTS

Eleven TTTS cases were treated with amniodrainage and ten with laser surgery. Median gestational age at birth in the amniodrainage group and in the laser surgery group was 29 and 31 weeks, respectively (P = 0.17) All infants were born alive. Major neonatal morbidity occurred more often in the amniodrainage group than in the laser surgery group, 27% (6/22) and 0% (0/20), respectively (P = 0.02). Severe cerebral injury in the amniodrainage group and in the laser surgery group occurred in 23% (5/22) and 15% (3/20) of infants, respectively (P = 0.70). Neonatal mortality in the amniodrainage group and in the laser surgery group was 14% (3/22) and 0% (0/20), respectively (P = 0.23). Overall adverse outcome was 36% (8/22) in the amniodrainage group and 15% (3/20) in the laser surgery group (P = 0.17).

CONCLUSION

In TTTS diagnosed after 26 weeks of gestation, amniodrainage and laser surgery both result in 100% survival. However, infants born after laser surgery have less major neonatal morbidity.

Residual Anastomoses After Fetoscopic Laser Surgery in Twin-to-Twin Transfusion Syndrome: Frequency, Associated Risks and Outcome

Fetoscopic laser coagulation of placental vascular anastomoses is considered to be the treatment of choice in severe twin-to-twin transfusion syndrome. The aim of fetoscopic laser surgery is to separate completely the inter-twin placental circulation. Incomplete laser coagulation may result in residual vascular anastomoses. The incidence and clinical implications of residual anastomoses in twin-to-twin transfusion syndrome treated with fetoscopic laser surgery has not yet been studied. We examined all placentas treated with fetoscopic laser surgery and delivered at our center between June 2002 and December 2005 with vascular injection using colored dyes. Presence of residual anastomoses was studied in association with adverse outcome and inter-twin hemoglobin difference at birth. Adverse outcome was defined as fetal demise, neonatal death or severe cerebral injury. The relation between residual anastomoses and placental localization (anterior or posterior uterine wall) was evaluated. A total of 52 laser-treated placentas were studied. Residual anastomoses were detected in 33% (17/52) of placentas. Adverse outcome was similar in the groups with and without residual anastomoses, 18% (6/34) and 29% (20/70), respectively (p=0.23). Large inter-twin hemoglobin differences (>5g/dL) were found in 65% (11/17) of cases with residual anastomoses and 20% (7/35) of cases without residual anastomoses (p<0.01). Anterior placental localization was not associated with a more frequent presence of residual anastomoses. In conclusion, residual anastomoses at our institution are seen in one-third of monochorionic placentas treated with fetoscopic laser surgery. Although residual anastomoses in our study were not associated with adverse outcome, they were often associated with neonatal hematological complications.

Assessment of Feto-fetal Transfusion Flow Through Placental Arterio-venous Anastomoses in a Unique Case of Twin-to-Twin Transfusion Syndrome

In vivo measurements of blood flow through arterio-venous anastomoses in monochorionic twin placentas have recently been attempted with Doppler ultrasound, but the accuracy is questionable. We present a case of twin-to-twin transfusion syndrome treated with fetoscopic laser surgery. The ex-recipient subsequently became severely anaemic and was treated with an intrauterine blood transfusion at 29 weeks' gestation. After birth, a placental injection study identified residual unidirectional arterio-venous anastomoses from the ex-recipient to the ex-donor without arterio-venous anastomoses in the opposite direction. Prospective measurements of decreasing haemoglobin levels between the intrauterine transfusion and birth allowed us to assess the net blood flow through the anastomoses as 27.9mL/24h. This finding may also explain the inaccuracy of Doppler flow measurements, as such low flow velocities cannot possibly be detected with current Doppler techniques.

Fetoscopic laser surgery in 100 pregnancies with severe twin-to-twin transfusion syndrome in the Netherlands

OBJECTIVE

In this prospective cohort study, we evaluated the initial results of fetoscopic laser surgery for severe second trimester twin-to-twin transfusion syndrome (TTTS) treated at our centre.

METHOD

A total of 100 consecutive pregnancies with severe second trimester TTTS treated at our centre with selective fetoscopic laser coagulation of vascular anastomoses on the placental surface between August 2000 and November 2004 were included in the study. Perinatal survival was analysed in relation to Quintero stage.

RESULTS

Median gestational age was 20 weeks at fetoscopy (range: 16-26) and 33 weeks at delivery (range: 18-40). Perinatal survival rate was 70% (139/200). The treatment resulted in at least one survivor at the age of 4 weeks in 81% of pregnancies. Perinatal survival was significantly higher when treatment was performed in the early Quintero stages (95% in stage 1, 76% in stage 2, 70% in stage 3, 50% in stage 4) (p = 0.02).

CONCLUSION

Results of fetoscopic laser surgery for TTTS in our centre are similar to those in specialised centres in other countries. Diagnosis and treatment in the early Quintero stages resulted in significantly higher perinatal survival.

Twin Anemia–Polycythemia Sequence in Two Monochorionic Twin Pairs Without Oligo-Polyhydramnios Sequence

Placental vascular anastomoses in monochorionic twins may lead to acute or chronic inter-twin transfusion. We report an uncommon form of chronic inter-twin transfusion, referred to as twin anemia-polycythemia sequence (TAPS), with severe anemia in one twin and polycythemia in the other, without the characteristically associated twin oligo-polyhydramnios sequence (TOPS) seen in the classical twin-to-twin transfusion syndrome (TTTS). The clinical course and placental characteristics of two pairs of monochorionic twins with TAPS born at, respectively, 33 and 34 weeks' gestation were reviewed. Serial fetal ultrasound examinations revealed no signs of TOPS. At birth, both donor twins were severely anemic requiring blood transfusion and both recipients were polycythemic, one requiring partial volume exchange transfusions. Inter-twin difference in reticulocyte counts was extremely high, suggesting a chronic form of inter-twin blood transfusion. Placental injection studies revealed a preponderance of very small (<1mm) arterio-venous anastomoses in one direction. In conclusion, chronic inter-twin transfusion may lead to an uncommon form of inter-twin transfusion, named TAPS, not associated with TOPS, resulting in severe fetal or neonatal hematological complications. We hypothesize that TAPS is mediated through minuscule unidirectional anastomoses. TAPS can be diagnosed antenatally with Doppler studies and postnatally by hemoglobin and reticulocyte measurements.

Single-assay combination of Epstein-Barr Virus (EBV) EBNA1- and viral capsid antigen-p18-derived synthetic peptides for measuring anti-EBV immunoglobulin G (IgG) and IgA antibody levels in sera from nasopharyngeal carcinoma patients: options for field screening

Assessment of immunoglobulin A (IgA) antibody responses to various Epstein-Barr virus (EBV) antigen complexes, usually involving multiple serological assays, is important for the early diagnosis of nasopharyngeal carcinoma (NPC). Through combination of two synthetic peptides representing immunodominant epitopes of EBNA1 and viral capsid antigen (VCA)-p18 we developed a one-step sandwich enzyme-linked immunosorbent assay (ELISA) for the specific detection of EBV reactive IgG and IgA antibodies in NPC patients (EBV IgG/IgA ELISA). Sera were obtained from healthy donors (n = 367), non-NPC head and neck cancer patients (n = 43), and biopsy-proven NPC patients (n = 296) of Indonesian and Chinese origin. Higher values of optical density at 450 nm for EBV IgG were observed in NPC patients compared to the healthy EBV carriers, but the large overlap limits its use for NPC diagnosis. Using either EBNA1 or VCA-p18 peptides alone IgA ELISA correctly identified 88.5% and 79.8% of Indonesian NPC patients, with specificities of 80.1% and 70.9%, whereas combined single-well coating with both peptides yielded sensitivity and specificity values of 90.1 and 85.4%, respectively. The positive and negative predictive values (PPV and NPV, respectively) for the combined EBNA1 plus VCA EBV IgA ELISA were 78.7% and 93.9%, respectively. In the Indonesia panel, the level of EBV IgA reactivity was not associated with NPC tumor size, lymph node involvement, and metastasis stage, sex, and age group. In the China panel the sensitivity/specificity values were 86.2/92.0% (EBNA1 IgA) and 84.1/90.3% (VCA-p18 IgA) for single-peptide assays and 95.1/90.6% for the combined VCA plus EBNA1 IgA ELISA, with a PPV and an NPV for the combined EBV IgA ELISA of 95.6 and 89.3%, respectively. Virtually all NPC patients had abnormal anti-EBV IgG diversity patterns as determined by immunoblot analysis. On the other hand, healthy EBV carriers with positive EBV IgA ELISA result showed normal IgG diversity patterns. By using EBV IgG immunoblot diversity as confirmation assay for EBV IgA ELISA-positive samples, the sensitivity and specificity for NPC diagnosis increased to 98% and 99.2%, respectively, in the Indonesian NPC samples. The use of these combined methods for seroepidemiological screening studies is proposed.

Amnioinfusion to facilitate external cephalic version after initial failure

OBJECTIVE

To evaluate the effectiveness of antepartum transabdominal amnioinfusion to facilitate external cephalic version after initial failure.

METHODS

Women with a structurally normal fetus in breech lie at term, with a failed external cephalic version and an amniotic fluid index (AFI) less than 15 cm, were asked to participate in our study. After tocolysis with indomethacin, a transabdominal amnioinfusion was performed with an 18G spinal needle. Lactated Ringers solution was infused until the AFI reached 15 cm, with a maximum of 1 L. External cephalic version was performed directly afterward.

RESULTS

Seven women participated in the study. The gestational age of the women was between 36(+4) and 38(+3) weeks, and three women were primiparous. The AFI ranged from 4 cm to 13 cm. A median amount of 1,000 mL Ringers solution (range 700-1,000 mL) was infused per procedure. The repeat external cephalic versions after amnioinfusion were not successful in any of the patients.

CONCLUSION

In our experience, amnioinfusion does not facilitate external cephalic version.

Timely diagnosis of twin-to-twin transfusion syndrome in monochorionic twin pregnancies by biweekly sonography combined with patient instruction to report onset of symptoms

OBJECTIVES

To assess the value of serial ultrasound examinations together with patient instructions to report the onset of symptoms in achieving timely detection of twin-to-twin transfusion syndrome (TTTS) in a cohort of monochorionic diamniotic twin pregnancies, and to evaluate sonographic TTTS predictors.

METHODS

Timely detection of TTTS was defined as diagnosis before severe complications of TTTS occurred, such as preterm prelabor rupture of membranes, very preterm delivery (24-32 weeks of pregnancy), fetal hydrops, or intrauterine fetal death. During a 2-year period, a prospective series of 23 monochorionic twin pregnancies was monitored from the first trimester until delivery. At least every 2 weeks we performed ultrasound and Doppler measurements (nuchal translucency thickness, presence of membrane folding, estimated fetal weight, deepest vertical pocket, bladder filling, and Doppler waveforms of the umbilical artery, ductus venosus and umbilical vein). Measurements of TTTS cases were compared with those of non-TTTS cases matched for gestational age. Furthermore, patients were informed about the symptoms caused by TTTS, and instructed to consult us immediately in case of rapidly increasing abdominal size or premature contractions.

RESULTS

In all four TTTS cases, the diagnosis was timely. At the time of diagnosis, one case was at Quintero Stage 1, two at Quintero Stage 2, and one at Quintero Stage 3. Two of the TTTS cases became apparent after the patients' feeling of rapidly increasing girth. The identification of TTTS predictors was successful with respect to one parameter: isolated polyhydramnios in one sac, without oligohydramnios in the other, preceded the ultimate diagnosis of TTTS in two of the four TTTS cases. All other ultrasound measurements of TTTS cases, prior to the diagnosis of TTTS, were within the range of measurements of non-TTTS cases.

CONCLUSION

Biweekly ultrasound examinations, with special attention to the amniotic fluid compartments of both fetuses, combined with detailed patient instructions to report the onset of symptoms resulted in timely diagnosis of all TTTS cases and appears to be a safe program for monitoring monochorionic twin pregnancies.