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At least 73 records · Page 4Linked to original sources
PubMed2004

Modeling a hydropic recipient twin in twin-twin transfusion syndrome.

We developed a mathematical model of twin-twin transfusion syndrome (TTTS) that includes a hydropic recipient twin, adding interstitial and intracellular fluid compartments, fetal congestive cardiac failure, and the dynamics of renin-angiotensin system (RAS) mediators to our previous TTTS model. Ten differential equations for each twin, coupled by the net fetofetal transfusion of blood and blood components, i.e., colloids, osmoles, and RAS mediators, describe the development of fetal arterial and venous blood volumes, blood osmolality and colloid osmotic pressure (COP), interstitial fluid volume and COP, intracellular fluid volume, amniotic fluid volume and osmolality, and RAS mediator concentration. We included varying placental anastomoses, placental sharing, and amnionicity. The 20 differential equations were solved numerically from 0 to 40 wk with a 0.6-s time step. Consistent with clinical experience, model predictions are as follows. Unidirectional arteriovenous anastomoses and arteriovenous anastomoses inadequately compensated by oppositely directed anastomoses cause severe TTTS that includes a hydropic recipient. Adequately compensated arteriovenous anastomoses simulated TTTS without hydrops. The probability that oppositely directed anastomoses prevent onset of a hydropic recipient after TTTS onset, i.e., the largest interval between onset of TTTS and onset of hydrops in the recipient, was best for a venovenous anastomosis, closely followed by an arterioarterial and finally an oppositely directed arteriovenous anastomosis. Hydropic recipients have decreased amniotic fluid volume. Unequal placental sharing and amnionicity modify hydrops onset. In conclusion, our model simulates a sequence of events that results in a hydropic recipient twin in severe TTTS. The model may allow an assessment of the efficacy of current therapeutic interventions for TTTS cases that include a hydropic recipient twin.

Adult↗
PubMed1988

Twin-twin transfusion syndrome: the surgical removal of one twin as a treatment option.

The twin-twin transfusion syndrome, associated with acute polyhydramnios in the 18th to 28th week of gestation, has a high perinatal mortality rate. Patients managed without intervention have essentially a 100% mortality rate for the involved twins. Different methods of intervention have been described, including therapeutic amniocentesis, selective feticide, and placental vessel puncture. In this case report we describe selective removal of one twin at 21 weeks of gestation by hysterotomy in a patient with the twin-twin transfusion syndrome.

Abortion, Eugenic↗
PubMed2006

Peripheral skin necrosis in the recipient of monochorionic twins complicated by twin-twin transfusion syndrome.

Twin-twin transfusion syndrome (TTTS) complicates approximately 15% of monochorionic, diamniotic twin pregnancies and if untreated carries a high perinatal loss rate of between 80% and 100%, depending on the stage. The underlying pathology in TTTS appears to be an imbalanced intertwin perfusion difference, secondary to functional unidirectional arteriovenous anastomoses within a monochorionic placenta. We report two cases of monochorionic twin pregnancy complicated by TTTS, in which the pregnancies were treated by serial aggressive amnioreduction. However, the recipient twin in each pregnancy developed 'ischemic damage' to a lower limb.

Adult↗
PubMed1997

Conversational patterns of two-year-old twins in mother-twin-twin triads.

This study investigated the general nature of conversational interaction in mother-twin-twin triads. Four sets of firstborn twins (2;3) were videotaped during 15 minutes of free play with their mothers. Analyses revealed that triadic conversations were approximately five times longer, and elicited more turns from all speakers, than dyadic conversations between mother and a single twin. Twins also responded as often to comments and requests made to another person as to those directed to themselves, but responded more often to questions directly to them than to others, indicating reliable monitoring of language not addressed to them. These results largely parallel those reported for mother-infant-sibling triads and indicate the unique effects of triadic exchanges are not due to the relative linguistic levels of the child partners.

Child, Preschool↗
PubMed1991

Neutropenia in donor (anemic) twins involved in the twin-twin transfusion syndrome.

Neutropenia is common in neonates with sepsis and in those born to women with pregnancy-induced hypertension. Neutropenia has not previously been described, however, as a result of the twin-twin transfusion syndrome. We observed neutropenia of 4 to 8 days' duration in each of five "donor" (anemic) twins affected with the twin-twin transfusion syndrome. No evidence of infection was observed. Like neutropenia of pregnancy-induced hypertension, no left shift was seen. Neutrophil kinetic studies were performed on one of the neutropenic patients. Assessment of the marginal, storage, proliferative, and progenitor cell pools indicated that neutropenia resulted from diminished neutrophil production.

Anemia↗
PubMed2006

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.

Adult↗
PubMed1990

In utero resolution of hydrops fetalis following the death of one twin in twin-twin transfusion.

A case of massive hydramnios involving a twin-twin transfusion syndrome is presented with death of the larger twin and the development of hydrops fetalis in the surviving smaller twin. The amniotic fluid volume of the surviving twin became normal and the hydrops fetalis resolved spontaneously in utero. Concomitant with the resolution of the hydrops fetalis, the umbilical cord systolic to diastolic ratio improved. At the time of delivery, the hydrops had resolved. The liveborn infant died 11 days later secondary to pulmonary hypertension and cardiorespiratory failure. Although the fetal status improved in utero, the pulmonary hypertension postdelivery resulted in neonatal death.

Adult↗
PubMedDate not supplied

Unusual cardiac malformations in conjoined twins: thoracopagus twins with conjoined pentalogy of Cantrell and an omphalopagus twin with atretic ventricles.

Two unrelated cases of conjoined twins were found to have cardiac malformations that apparently have not been reported previously. In one case, thoracopagus twins had an extensive thoracoabdominal wall defect that resulted in ectopia cordis of a conjoined heart along with evisceration of the shared liver and intestine along with one spleen. These malformations, accompanied by defects in the sternum, diaphragm, and supraumbilical abdominal wall, constitute a conjoined pentalogy of Cantrell. In the second case, the heart of one of omphalopagus twins consisted of a solid ventricular mass with only a minute aortic cavity but no atrioventricular communication-an ineffective heart that could develop only in a conjoined or chorioangiopagus twin. In both cases, a common atrium lay in the primitive (embryologic) position caudal to the ventricles.

Abdomen↗
PubMedDate not supplied

Monochorionic twins and twin-twin transfusion syndrome: the protective role of arterio-arterial anastomoses.

Unidirectional arterio-venous (AV) anastomoses often result in twin-twin transfusion syndrome (TTTS). Additional oppositely directed anastomoses may compensate for the circulatory imbalance and either prevent, delay the onset, or moderate the severity of TTTS. Intuitively, higher pressure gradient, oppositely-directed AV anastomoses (indicated as VA) would be expected to compensate better for TTTS than lower pressure gradient arterio-arterial (AA) anastomoses. However, clinical evidence suggests AA anastomoses compensate more efficaciously, because virtually all non-TTTS monochorionic twin placentas have AAs (84 per cent), contrary to TTTS placentas, where only 30 per cent have an AA. We sought to explain this observation by comparing the capabilities of various size VA and AA anastomoses to compensate for the effects of the primary AV. As study design we used a previously developed mathematical computer model of TTTS to determine ranges of anastomotic vascular resistances which cause varying fetal and amniotic fluid discordances. Anastomotic resistances were related with the radii of their feeding vessels, using fractal geometry modelling to mimic the placental vascular tree, and various assumptions regarding arterial blood flow. The results were as follows. An AA anastomosis of equal size as the feeding artery of an AV or VA has a significantly smaller resistance. The primary AV anastomosis may be compensated by both VA as well as AA anastomoses. However, VA transfusion adequately compensates AV flow only for a small range of VA to AV vascular radius ratios. In contrast, AA transfusion compensates the AV flow for a much wider range of AA to AV vascular radius ratios. In conclusion, the wider range of AA than VA radii for adequate compensation of the AV explains the finding that an AA protects more frequently than a VA of similar size against the manifestations of TTTS. These results may possibly allow future risk stratification of monochorionic twins by non-invasive sonographic assessment of the size and type of anastomoses.

Adult↗
PubMed2001

Amniotic fluid and hemodynamic model in monochorionic twin pregnancies and twin-twin transfusion syndrome.

We developed a mathematical model of monochorionic twin pregnancies and twin-twin transfusion syndrome (TTTS), combining both fetal fluid dynamics and fetoplacental growth and circulation alterations and assuming that transplacental fluid flow from mother to fetus accounts for normal fetal and amniotic fluid volumes. Ten coupled differential equations, describing fetal total body and amniotic fluid volumes, their osmolalities, and fetal blood colloid osmotic pressure, for both donor and recipient twins, were solved numerically. Amniotic flows are controlled by fetal plasma osmolality and hydrostatic and colloid osmotic pressures. We included varying placental anastomoses and placental sharing of the circulations. Consistent with clinical experience, model predictions are: fetofetal transfusion from unidirectional arteriovenous anastomoses cause oligo-polyhydramnios, a normal size recipient but hypovolemic donor; compensating oppositely directed deep and superficial anastomoses moderate discordant development; and anhydramnios results from mild and severe TTTS, where milder forms may even present earlier in gestation than severe TTTS. Unequal placental circulatory sharing may exacerbate discordant development. In conclusion, our model simulates a wide variety of realistic manifestations of amniotic fluid volume and fetal growth in TTTS related to placental angioarchitecture. The model may allow an assessment of the efficacy of current therapeutic interventions for TTTS.

Amniotic Fluid↗
PubMed2006

The role of laser surgery in dissecting the etiology of absent or reverse end-diastolic velocity in the umbilical artery of the donor twin in twin-twin transfusion syndrome.

OBJECTIVE: This study was undertaken to gain insight on the cause of absent or reverse end-diastolic velocity (AREDV) in the umbilical artery (UA) of the donor twin by analysis of individual placental mass and vascular anastomoses in patients with twin-twin transfusion syndrome (TTTS) treated with laser. STUDY DESIGN: TTTS patients who successfully underwent selective laser photocoagulation of communicating vessels (SLPCV), 16 and 26 weeks' gestation, with both twins born alive and complete Doppler and placental data were considered eligible for the study. Doppler examination of the UA was performed before and 24 hours after SLPCV. Abnormal UA Doppler findings were defined as persistent AREDV. Pre- and post-SLPCV UA Doppler results yielded the following 4 groups: (1) normal-normal; (2) normal-abnormal; (3) abnormal-normal; and (4) abnormal-abnormal. The types of vascular anastomoses were categorized during surgery. Individual placental territory (IPT) was defined as individual placental weight divided by total placental weight x 100. RESULTS: There were 132 cases in group 1 and no patients in group 2. AREDV resolved in 78% (28/36) of patients (group 3) and remained unchanged in 22% (8/36) (group 4). The mean IPT-donor in group 4 was significantly smaller than in group 1 (P = .015). Patients with preoperative AREDV (groups 3 and 4) were more likely to have artery-to-artery anastomoses (P = .002). However, AREDV resolved in 57% (16/28) patients without artery-to-artery anastomoses. CONCLUSION: Preoperative AREDV may result from a small IPT, placental vascular anastomoses, or both. AREDV resulting from a small IPT may have a similar cause to that of singletons, and may be inferred by lack of postoperative resolution. Resolution of AREDV after SLPCV implies the presence of an adequate IPT and removal of donor hypotension.

Blood Flow Velocity↗
PubMed1999

Twin-to-twin transfusion syndrome: a case report. Antepartum prediction of underlying placental vascular pattern in monochorionic twin pregnancies may be possible.

A case of twin-to-twin transfusion syndrome is described. Comparing data of serial antepartum ultrasonography with a haemodynamic model suggests the possibility of predicting the underlying placental vascular anatomy. It is suggested that serial ultrasonography, including full biometry, pulsatility indices of the umbilical arteries, foetal echocardiography, assessment of amniotic fluid indices and foetal bladder filling could serve as ultrasound parameters for pattern recognition of the underlying placental vascular anomaly. Biometry should be plotted serially in a difference/average plot. Future application of such intensive ultrasound monitoring in monochorionic twins, as soon as monochorionicity is established, may distinguish those monochorionic twins who may benefit from treatment from those whom it would be better only to observe.

Adult↗
PubMed2005

Successful selective termination at 17 weeks' gestation in monochorionic monoamniotic twin pregnancy affected by twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome.

OBJECTIVES: To report a successful selective feticide in a complicated monochorionic monoamniotic (MCMA) pregnancy. METHODS: A case of MCMA pregnancy with severe twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome was diagnosed at 16 weeks' gestation. A complete ultrasound and fetoscopic surveillance was performed, ruling out cord entanglement and, thus, precluding the necessity of transecting the cord. RESULTS: The selective feticide was successfully performed by bipolar coagulation of the umbilical cord of the abnormal fetus under ultrasound guidance. The survivor twin developed normally during the rest of the pregnancy and was born at term. At 6 months of age, the infant was healthy. CONCLUSION: Selective feticide in complicated monoamniotic pregnancies can be safely performed. Cord entanglement can be confidently excluded by both ultrasound and fetoscopy, thus making the systematic transection of the umbilical cord unnecessary.

Adult↗
PubMed2000

Anesthesia for fetoscopic fetal surgery: twin reverse arterial perfusion sequence and twin-twin transfusions syndrome.

IMPLICATIONS: Twin reversed arterial perfusion sequence and twin-twin transfusion syndrome can be managed by fetoscopic fetal surgery. It is important to consider the fetal, uteroplacental, and maternal issues when choosing an anesthetic technique. We report on three patients with differing anesthetic issues using fetoscopic surgery for umbilical cord coagulation.

Adult↗
PubMed1996

Fetal death of one twin in a monochorionic pregnancy with twin-twin transfusion syndrome.

BACKGROUND: Twin-twin transfusion syndrome (TTTS) occurs in 5-30% of all monochorionic pregnancies. The mortality and morbidity rates are high and therapeutic options limited. CASE: TTTS in a monochorionic twin pregnancy was initially diagnosed by differences in amniotic fluid volume at 26 weeks. No signs of atrioventricular valve insufficiency or nonimmune hydrops fetalis were present in the recipient. Despite this, the recipient died in utero, whereupon the condition of the donor improved markedly. After spontaneous delivery at 30 weeks' gestation, coarctation of the umbilical cord at its insertion was observed in the recipient, probably secondary to severe torsion. CONCLUSION: Unexpected obstetric events may occur in already-complicated pregnancies that are not related to a specific condition, its diagnosis or its therapy.

Adult↗
PubMed1993

Twin-twin transfusion with abrupt onset of microcephaly in the surviving recipient following spontaneous death of the donor twin.

We describe a case in which twin-twin transfusion with fetal death of the donor at 23 weeks was complicated by suspected intracranial embolic insult of the surviving recipient twin. Dynamic transient intracranial ultrasonographic findings were noted with complete resolution by 28 weeks. Subsequent severe microcephaly of the survivor with no further growth of any of the cranial parameters beyond 25 weeks was thought to be a result of this very unusual pathophysiologic mechanism.

Adult↗
PubMed2000

Pulmonary stenosis in recipient twins in twin-to-twin transfusion syndrome: report on 3 cases and review of literature.

This report describes 3 cases of pulmonary stenosis in the recipient twin in twin-twin transfusion syndrome. Fetal echocardiography showed cardiomegaly, tricuspid valve regurgitation, and increased reverse flow in the inferior vena cava, as signs of congestive heart failure in all 3 cases. We diagnosed 2 cases of pulmonary stenosis by fetal echocardiography prenatally and confirmed our findings in all 3 cases postnatally. Two cases underwent postnatal balloon valvuloplasty to release the pulmonary valvular stenosis in neonatal period. The third one died soon after delivery and autopsy showed a slightly thickened pulmonary valve. One of the cases was diagnosed in the early second trimester (20 weeks of pregnancy), the earliest detection of fetal pulmonary stenosis reported in literature. The presence of high peak velocity of the pulmonary artery at 20 weeks of pregnancy preceded the development of pulmonary stenosis in this case. This supports the hypothesis that alterations in fetal hemodynamics may result in structural cardiac abnormality.

Adult↗