Skeletal Growth Arrest Lines in Fetal Remains: Histopathology and Correlative Placental Pathology.

INTRODUCTION: Skeletal growth arrest lines (GAL) are transverse lines of metaphyseal radiodensity accompanying episodic severe physiological stress. They are poorly described in fetal remains. MATERIALS AND METHODS: We searched our autopsy practice for instances of fetal GAL in post mortem radiology, and correlated them with long bone histology and placental pathology. We describe the appearance, distribution, and pathology of GAL in a cohort of fetal autopsies, and compare the placental pathology accompanying GAL to the placental pathology of asymmetrical growth restriction (AGR) in the same time period. RESULTS: In 2108 consecutive fetal post mortems, we found 20 cases with GAL. About 16 were in singletons with AGR. In these 16, the distribution of placental pathologies was similar to a contemporaneous cohort of 113 cases with AGR. Of the remaining 4, two twins out of 9 sets of monochorionic twins with AGR demonstrated GAL. One case of GAL had symmetrical growth restriction with cytomegalovirus infection, and one case had no AGR and an old, unexplained retroplacental hemorrhage. On histology, GAL are characterized by a region of mineralized chondroid, which is variably incorporated into irregular trabecular bone. DISCUSSION: GALs accompany a variety of placental pathologies and twin-twin transfusion, suggesting episodic disease progression.

Fetal surgery is not associated with increased inflammatory placental pathology.

OBJECTIVE: Fetal surgery has improved neonatal outcomes; however, it is unknown if the intervention contributes to the developmental of inflammatory pathologies in the placenta. Here, an association between fetal surgery and placental pathology was examined. METHOD: This case-control study compared pregnancies with fetal surgery (n = 22), pregnancies with an indication for fetal surgery but without an intervention being done (n = 13), and gestational-age and fetus-number matched controls (n = 36). Data on maternal, infant, and placental outcomes were abstracted. Additionally, immunohistochemistry identified expression of lymphoid and myeloid cells in the placenta on a subset of cases. Comparisons were performed using Kruskal-Wallis or Pearson's chi-squared tests. RESULTS: Maternal characteristics were comparable between groups. Most fetal interventions were for diaphragmatic hernia, spina bifida, or twin-to-twin transfusion syndrome. Fetuses who were operated on before birth were more likely to be born preterm (p = 0.02). There was no increase in the rate of observed placental pathologies or immune cell infiltration in fetal surgery cases compared to controls. CONCLUSION: The data suggest that fetal surgery is not associated with increased inflammatory or morphologic pathology in the placenta. This observation supports the growing field of fetal surgery.

Chimerism involving a RB1 pathogenic variant in monochorionic dizygotic twins with twin-twin transfusion syndrome.

We report the first case of blood chimerism involving a pathogenic RB1 variant in naturally conceived monochorionic-dizygotic twins (MC/DZ) with the twin-twin-transfusion syndrome (TTTS), presumably caused by the exchange of stem-cells. Twin A developed bilateral retinoblastoma at 7 months of age. Initial genetic testing identified a de novo RB1 pathogenic variant, with a 20% allelic ratio in both twins' blood. Subsequent genotyping of blood and skin confirmed dizygosity, with the affected twin harboring the RB1 pathogenic variant in skin and blood, and the unaffected twin carrying the variant only in blood.

The mystery of monozygotic twinning II: What can monozygotic twinning tell us about Amyoplasia from a review of the various mechanisms and types of monozygotic twinning?

Monozygotic (MZ) twins ("identical twins") are essentially unique to human beings. Why and how they arise is not known. This article reviews the possible different types of MZ twinning recognized in the previous article on twins and arthrogryposis. There appear to be at least three subgroups of MZ twinning: spontaneous, familial, and those related to artificial reproductive technologies. Each is likely to have different etiologies and different secondary findings. Spontaneous MZ twinning may relate to "overripe ova." Amyoplasia, a specific nongenetic form of arthrogryposis, appears to occur in spontaneous MZ twinning and may be related to twin-twin transfusion.

Monochorionic Triplet Pregnancies With Twin Reversed Arterial Perfusion and Acardiac Triplet: Report of Two Cases and Literature Review.

TRAP pregnancies involving monochorionic triplets are extremely rare, calculated to be 1 in 4.5 million. We report two cases of monochorionic triplet pregnancies with an acardiac triplet. In one case, the mother was a 33-year-old G2P1 who underwent dilation and evacuation at 20 weeks due to poor prognosis. The other case involved a 21-year-old G1P0 mother presenting in advanced preterm labor at 21 weeks who elected expectant management. Seventeen cases of monochorionic triplets with TRAP were identified in the literature. Invasive intervention was performed in 10 cases; 9 cases resulted in the survival of the nonacardiac twins and 1 case resulted in the survival of 1 fetus. Our two cases had common sonographic features which included polyhydramnios of all fetuses. Placental features shared between both cases included being large for gestational age and velamentous insertion of the acardiac twin. The acardiac twins in both of our cases were hydropic and demonstrated developed pelvis and lower extremities. One had an omphalocele. Most case reports in the literature review demonstrate similar findings. Two cases of monochorionic triplets with TRAP and acardiac twin are herein described. Successful treatment by invasive interventions have been described in this condition, highlighting the importance of early diagnosis.

Outcome of twin-twin transfusion syndrome according to Quintero stage of disease: systematic review and meta-analysis.

OBJECTIVES: To report the outcome of pregnancies complicated by twin-twin transfusion syndrome (TTTS) according to Quintero stage. METHODS: MEDLINE, EMBASE and CINAHL databases were searched for studies reporting the outcome of pregnancies complicated by TTTS stratified according to Quintero stage (I-V). The primary outcome was fetal survival rate according to Quintero stage. Secondary outcomes were gestational age at birth, preterm birth (PTB) before 34, 32 and 28 weeks' gestation and neonatal morbidity. Outcomes are reported according to the different management options (expectant management, laser therapy or amnioreduction) for pregnancies with Stage-I TTTS. Only cases treated with laser therapy were considered for those with Stages-II-IV TTTS and only cases managed expectantly were considered for those with Stage-V TTTS. Random-effects head-to-head meta-analysis was used to analyze the extracted data. RESULTS: Twenty-six studies (2699 twin pregnancies) were included. Overall, 610 (22.6%) pregnancies were diagnosed with Quintero stage-I TTTS, 692 (25.6%) were Stage II, 1146 (42.5%) were Stage III, 247 (9.2%) were Stage IV and four (0.1%) were Stage V. Survival of at least one twin occurred in 86.9% (95% CI, 84.0-89.7%) (456/552) of pregnancies with Stage-I, in 85% (95% CI, 79.1-90.1%) (514/590) of those with Stage-II, in 81.5% (95% CI, 76.6-86.0%) (875/1040) of those with Stage-III, in 82.8% (95% CI, 73.6-90.4%) (172/205) of those with Stage-IV and in 54.6% (95% CI, 24.8-82.6%) (5/9) of those with Stage-V TTTS. The rate of a pregnancy with no survivor was 11.8% (95% CI, 8.4-15.8%) (69/564) in those with Stage-I, 15.0% (95% CI, 9.9-20.9%) (76/590) in those with Stage-II, 18.6% (95% CI, 14.2-23.4%) (165/1040) in those with Stage-III, 17.2% (95% CI, 9.6-26.4%) (33/205) in those with Stage-IV and in 45.4% (95% CI, 17.4-75.2%) (4/9) in those with Stage-V TTTS. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS. Overall, the incidence of PTB and neonatal morbidity increased as the severity of TTTS increased, but data on these two outcomes were limited by the small sample size of the included studies. When stratifying the analysis of pregnancies with Stage-I TTTS according to the type of intervention, the rate of fetal survival of at least one twin was 84.9% (95% CI, 70.4-95.1%) (94/112) in cases managed expectantly, 86.7% (95% CI, 82.6-90.4%) (249/285) in those undergoing laser therapy and 92.2% (95% CI, 84.2-97.6%) (56/60) in those after amnioreduction, while the rate of double survival was 67.9% (95% CI, 57.0-77.9%) (73/108), 69.7% (95% CI, 61.6-77.1%) (203/285) and 80.8% (95% CI, 62.0-94.2%) (49/60), respectively. CONCLUSIONS: Overall survival in monochorionic diamniotic pregnancies affected by TTTS is higher for earlier Quintero stages (I and II), but fetal survival rates are moderately high even in those with Stage-III or -IV TTTS when treated with laser therapy. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS treated with laser and expectant management, respectively. In pregnancies affected by Stage-I TTTS, amnioreduction was associated with slightly higher survival compared with laser therapy and expectant management, although these findings may be confirmed only by future head-to-head randomized trials. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Resultado del síndrome de transfusión feto-fetal según el estadio de Quintero de la enfermedad: revisión sistemática y metaanálisis OBJETIVOS: Informar sobre el resultado de los embarazos complicados por el síndrome de transfusión feto-fetal (TTTS, por sus siglas en inglés) según el estadio de Quintero. MÉTODOS: Se hicieron búsquedas en las bases de datos de MEDLINE, EMBASE y CINAHL de estudios que hubieran informado sobre el resultado de embarazos complicados por TTTS, estratificados según el estadio de Quintero (I-V). El resultado primario fue la tasa de supervivencia fetal según el estadio de Quintero. Los resultados secundarios fueron la edad gestacional al nacer, el parto pretérmino (PPT) antes de las 34, 32 y 28 semanas de gestación y la morbilidad neonatal. Los resultados se reportan de acuerdo con las diferentes opciones de tratamiento (expectante, terapia de láser o amniorreducción) para los embarazos con TTTS en Estadio I. Sólo se consideraron los casos tratados con terapia de láser para aquellos con TTTS de las Etapas II-IV y sólo se consideraron los casos tratados de manera expectante para aquellos con TTTS de la Etapa V. Para analizar los datos extraídos se utilizó un metaanálisis directo de efectos aleatorios. RESULTADOS: Se incluyeron veintiséis estudios (2699 embarazos de gemelos). En total, 610 (22,6%) embarazos fueron diagnosticados con TTTS de Estadio I de Quintero, 692 (25,6%) de Estadio II, 1146 (42,5%) de Estadio III, 247 (9,2%) de Estadio IV y cuatro (0,1%) de Estadio V. La supervivencia de al menos un gemelo se produjo en el 86,9% (IC 95%, 84,0-89,7%) (456/552) de los embarazos en Estadio I, en el 85% (IC 95%, 79,1-90,1%) (514/590) de aquellos en Estadio II, en el 81,5% (IC 95%, 76,6-86,0%) (875/1040) de aquellos en Estadio-III, en el 82,8% (IC 95%, 73,6-90,4%) (172/205) de aquellos en Estadio-IV y en el 54,6% (IC 95%, 24,8-82,6%) (5/9) de aquellos en Estadio-V de TTTS. La tasa de embarazos sin supervivientes fue del 11,8% (IC 95%, 8,4-15,8%) (69/564) de aquellos en Estadio-I, 15,0% (IC 95%, 9,9-20,9%) (76/590) de aquellos en Estadio-II, 18,6% (IC 95%, 14,2-23,4%) (165/1040) de aquellos en Estadio-III, 17,2% (IC 95%, 9,6-26,4%) (33/205) de aquellos en Estadio-IV y en el 45,4% (IC 95%, 17,4-75,2%) (4/9) de aquellos en Estadio-V de TTTS. La edad gestacional al nacer fue similar en los embarazos con TTTS en los Estadios I-III, y disminuyó gradualmente en aquellos con TTTS en los Estadios IV y V. En general, la incidencia de PPT y la morbilidad neonatal aumentaron a medida que se incrementó la gravedad del TTTS, pero los datos sobre estos dos resultados se vieron limitados por el pequeño tamaño de la muestra de los estudios incluidos. Al estratificar el análisis de los embarazos con TTTS en Estadio I según el tipo de tratamiento, la tasa de supervivencia fetal de al menos un gemelo fue del 84,9% (IC 95%, 70,4-95,1%) (94/112) en los casos tratados de forma expectante, del 86,7% (IC 95%, 82,6-90.4%) (249/285) en los sometidos a terapia láser y del 92,2% (IC 95%, 84,2-97,6%) (56/60) en los sometidos a amniorreducción, mientras que la tasa de supervivencia doble fue del 67,9% (IC 95%, 57,0-77,9%) (73/108), del 69,7% (IC 95%, 61,6-77,1%) (203/285) y del 80,8% (IC 95%, 62,0-94,2%) (49/60), respectivamente. CONCLUSIONES: La supervivencia en general en los embarazos biamnióticos monocoriónicos afectados por TTTS es mayor en los estadios tempranos de Quintero (I y II), pero las tasas de supervivencia fetal son moderadamente altas incluso en aquellos con TTTS en estadios III o IV cuando se tratan con terapia láser. La edad gestacional al nacer fue similar en los embarazos con TTTS en los Estadios I-III, y disminuyó gradualmente en aquellos con TTTS en los Estadios IV y V tratados con láser y tratamiento expectante, respectivamente. En los embarazos afectados por TTTS en Estadio I, la amniorreducción estuvo asociada con una supervivencia ligeramente mayor en comparación con la terapia de láser y el tratamiento expectante, aunque estos hallazgos solo pueden confirmarse mediante futuros estudios aleatorizados directos. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Morphology, intrafetal vascular pattern, and umbilical artery Doppler indices of acardiac twins.

BACKGROUND: Twin reversed arterial perfusion (TRAP) sequence consists of acardiac twin (A) paradoxically perfused by pump twin (P) through an umbilical artery (UA). We proposed characterization of acardiac twins with intrafetal vascular pattern (IVP), and assessed its correlation with morphology and UA Doppler indices. METHODS: We prospectively evaluated 21 cases of TRAP sequence. Morphology (acardia vs hemicardia) and IVP (simple vs complex) of acardiac twins were characterized with ultrasound and color Doppler. Twins weight ratio (A/P Wt) and UA Doppler indices of acardiac and pump twins including (1) difference of systolic/diastolic ratio (UA ∆S/D), (2) difference of resistance index (UA ∆RI), and (3) ratio of pulsatility index (UA PI A/P) were calculated. RESULTS: The median (min, max) gestational age at diagnosis was 18 (11, 27) weeks. Acardia (n = 14) were associated with simple IVP (n = 16) (P < .05). After exclusion of acardia with complex IVP (n = 1), the A/P Wt, UA ∆S/D, UA ∆RI, and UA PI A/P of acardia with simple IVP (n = 13), hemicardia with simple IVP (n = 3), and hemicardia with complex IVP (n = 4) were not significantly different (P > .05). CONCLUSIONS: Most of acardiac twins were acardia with simple IVP. Morphology and IVP of acardiac twins were not associated with UA Doppler indices.

Effect of Chorionicity on Umbilical Cord Blood Acid-Base Analysis of the Second Twin.

Our objective was to determine whether chorionicity affects umbilical cord blood acid-base parameters of the second twin. This was a retrospective cohort of twin pregnancies delivered at ≥23 weeks of gestation at a tertiary hospital from 2010 to 2016. Patients were included if arterial and venous umbilical cord gas results were available for both newborns and chorionicity was confirmed histologically. Exclusion criteria included intrauterine fetal demise of either twin prior to labor, major fetal anomalies, monoamnionicity, uncertain chronicity and twin-to-twin transfusion syndrome. The primary outcome evaluated was the umbilical artery (UA) pH of the second twin. A total of 593 dichorionic (DC) and 86 monochorionic (MC) twin pregnancies were included. No difference in UA pH was observed between MC and DC twins. Among vaginal deliveries (n = 97), the UA pH of the first twin was higher than the second twin (7.26 vs. 7.24; p = .01). Twin-to-twin delivery interval (TTDI) ≥20 min was associated with a higher UA pH in the first twin compared to the second twin (7.25 vs. 7.16, respectively; p = .006). Multivariable logistic regression was used to predict arterial pH < 7.20 for the second twin; the most predictive factors were arterial pH < 7.20 for the first twin, chronic hypertension and prolonged TTDI. Chorionicity was not associated with any acid-base parameter of umbilical cord blood in either the first or second twin. No differences in neonatal outcomes were observed based on chorionicity or birth order. Populations with a lower cesarean delivery rate may yield different findings.

Cardiac Anomalies in Liveborn and Stillborn Monochorionic Twins.

BACKGROUND: Cardiovascular anomalies are more common in monochorionic twins, especially with twin-twin transfusion, compared to other twin types and to singletons. Because previous studies are based on fetal and neonatal echocardiography, more information is needed to study prevalence of cardiac anomalies in twin miscarriages, stillbirths, and children after the immediate neonatal period. METHODS: With specific attention to cardiac anomalies, we reviewed the medical records of 335 selected liveborn twin pairs from the Marshfield Clinic Twin Cohort (enriched for twin-twin transfusion) and all twins (175 pairs) identified in the Wisconsin Stillbirth Service Program cohort of late miscarriages and stillbirths. RESULTS: Structural cardiac defects occurred in 12% of liveborn monochorionic twin infants and 7.5% of stillborn infants with twin-twin transfusion compared to only 2% of liveborn dizygotic twins and no stillborn dizygotic infants. The most common cardiac lesion in liveborn twins was ventricular septal defect, which was usually isolated and discordant, preferentially affecting the smaller twin in monochorionic pairs. Among stillborn and miscarried monochorionic twins, the most common cardiac lesion was acardia. CONCLUSIONS: Monochorionic twins, particularly those with TTT, are at increased risk for a spectrum of structural cardiac malformations which we suggest may be related to asymmetry of the inner cell mass resulting in a smaller poorly perfused twin. In severe cases, limited cardiac and circulatory development in the affected twin leads to acardia. In less severe cases, the smaller infant has deficient septal growth that sometimes results in ventricular septal defect.

Characteristics of referred patients with twin-twin transfusion syndrome who did not undergo fetal therapy.

INTRODUCTION: Abundant research has reported twin-twin transfusion syndrome (TTTS) outcomes following fetal therapy. Our research describes TTTS patients who did not undergo fetal therapy. METHODS: Records from TTTS pregnancies evaluated at 16 to 26 gestational weeks were reviewed between January 2006 and March 2017. The study population comprised subjects who did not undergo fetal therapy. Based on initial consultation, patients were grouped as nonsurgical vs surgical candidates. TTTS progression and perinatal outcomes were assessed. RESULTS: Of 734 TTTS patients evaluated, 68 (9.3%) did not undergo intervention. Of these, 62% were nonsurgical candidates and 38% were surgical candidates. Nonsurgical candidates were ineligible for treatment because of fetal demise or maternal factors (placental abruption, severe membrane separation, and preterm labor). Of surgical candidates, 11 underwent expectant management, eight elected pregnancy termination, and seven planned fetal intervention but had a complication before the procedure. TTTS progression occurred in 10 (15.2%) of 66 cases. Neonatal survival in 64 cases was as follows: in 41 (64%), no survivors; in 11 (17.2%), one survivor; and in 12 (18.8%), two survivors. CONCLUSION: Nine percent of referred TTTS patients did not undergo fetal therapy, with many ineligible because of morbidity between referral and consultation. Studies of TTTS should acknowledge this subgroup and circumstances leading to lack of treatment.

Significance of placental cord insertion site in twin pregnancy.

OBJECTIVE: To investigate the association between abnormal cord insertion and the development of twin-specific complications, including birth-weight discordance, selective fetal growth restriction (sFGR) and twin-to-twin transfusion syndrome (TTTS). METHODS: This was a single center retrospective cohort study of twin pregnancies. Abnormal cord insertion was defined as either marginal (umbilical cord attachment site less than 2 cm to the nearest margin of the placental disc) or velamentous (cord attached to the membrane before reaching the placental disc with clear evidence of vessels traversing the membranes to connect with the placental disc), as described in placental pathology reports. Twins with major structural or chromosomal abnormalities and monochorionic monoamniotic twins were not included in the study. Information on the pregnancies, ultrasound findings, prenatal investigations and interventions was obtained from the electronic ultrasound database, while data on placental histopathological findings, pregnancy outcome, mode of delivery, birth weight, gestational age at delivery and admission to the neonatal intensive care unit were obtained from maternity records. Categorical variables were compared using the chi-square or Fisher's exact test, while continuous variables were compared using the Student's t-test, ANOVA for multiple comparisons and the Kruskal-Wallis test. RESULTS: Of the 497 twin pregnancies included in the analysis, 351 (70.6%) were dichorionic and 146 (29.4%) were monochorionic. The incidence of birth-weight discordance of 25% or more was significantly higher in pregnancies with velamentous and those with marginal cord insertions compared to those with normal cord insertion (24.0%, 15.3% vs 7.6%, P < 0.001 and P = 0.020, respectively). In pregnancies with birth-weight discordance of 25% or more, the smaller twins had significantly higher prevalence of velamentous (13.8%) and marginal (34.2%) cord insertions compared with the larger twins (1.8% and 18.5%, respectively, P < 0.001). The smaller twins of the monochorionic diamniotic pregnancies showed an even higher prevalence of velamentous (29.5%) and marginal (40.9%) cord insertions compared with the larger twins (2.3% and 31.5%, respectively, P < 0.001). Compared with the normal cord insertion group, only velamentous insertion was associated significantly with the risk of sFGR (odds ratio (OR), 9.24 (95% CI, 2.05-58.84), P < 0.001) and birth-weight discordance of 20% or more (OR, 4.34 (95% CI, 1.36-14.61), P = 0.007) and 25% or more (OR, 6.81 (95% CI, 1.67-34.12), P = 0.003) in monochorionic twin pregnancies. There was no significant association between velamentous cord insertion and TTTS (P = 0.591), or between marginal cord insertion and the development of sFGR (P = 0.233), birth-weight discordance of 25% or more (P = 0.114) or TTTS (P = 0.487). Subgroup analysis of dichorionic twins showed that abnormal cord insertion was not associated with the risk of birth-weight discordance (P = 0.999), sFGR (P = 0.308), composite neonatal adverse outcome (P = 0.637) or intrauterine death (P = 0.349). CONCLUSION: Monochorionic twins with velamentous cord insertion are at increased risk of birth-weight discordance and sFGR. Sonographic delineation of placental cord insertion could be of value in the antenatal stratification of twin pregnancies. Prospective studies are required to assess the value and predictive accuracy of this potential screening marker. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

[Rare forms of feto-fetal transfusion in a clinical practice]. / Vzácné formy feto-fetální transfuze v klinické praxi.

OBJECTIVE: To analyze monochorionic twin pregnancies with twin anemia polycythemia sequence (TAPS) and acute peripartal twin to twin syndrome (aTTTS), to compare their prenatal management and perinatal outcome. METHODS: Retrospective analysis of monochorionic biamniotic twin pregnancies without signs of chronic TTTS within a period 10/2010 to 10/2013. Further selection of cases with haemoglobin difference in neonates greater than 50 g/l was made, type of feto-fetal haemorrhage was determined and their prenatal and postnatal characteristics were described. RESULTS: Based on the criteria described above we selected four cases out of 55 monochorionic pregnancies. One case of prenatally diagnosed spontaneous TAPS which fulfilled all the diagnostic criteria with typical angioarchitecture inclusive, one case of spontaneous TAPS diagnosed postnatally, a case of postlaser TAPS with a spontaneous resolution and one unusual case of feto-fetal haemorrhage which does not fully meet criteria of TAPS or aTTTS. All the pregnancies were delivered by caesarean section. All the anaemic neonates required blood transfusion postpartum and two of the polycythemic neonates needed partial exsanguination. CONCLUSION: Rare forms of feto-fetal transfusion syndrome form a heterogenous group and it may be difficult to distinguish between TAPS and aTTTS in certain cases. A recommendation for a management of TAPS cases was published in recent literature. However, correct interpretation of dopplerometric measurments belongs to the hands of experienced ultrasonographers in perinatal centers.

[Clinical outcome and placenta characteristics of spontaneous twin anemia-polycythemia sequence].

Objective: To investigate the clinical outcome and placental characteristics of spontaneous twin anemia-polycythemia sequence (sTAPS). Methods: Twelve cases with sTAPS delivered in Peking University Third Hospital from May 2013 to August 2016. The data of ultrasound characteristics, gestational age at delivery, and 1 minute Apgar score were analyzed, retrospectively. Placental superficial vascular anastomoses, placental territory discordance and the ratio of umbilical cords insertion distance to the longest placental diameter were also analyzed. Results: (1) Only 1 case of sTAPS was diagnosed prenatally, the others were diagnosed postnatally because the fetal middle cerebral artery(MCA) doppler was not measured regularly. Five cases were complicated with selective intrauterine growth restriction (sIUGR). The median gestational age at delivery was 32.8 weeks (31-37 weeks) . The pregnancies were terminated because 3 cases were sIUGR type Ⅰ, 1 case was sIUGR type Ⅱ, 1 case was sIUGR type Ⅲ, 2 cases were fetal distress, 2 cases were severe pre-eclampsia, 2 cases were premature rupture of membrane, 1 case was fetal hydrops with abnormal doppler waveforms of ductus venouses. (2) When 5 sIUGR cases were excluded, there was no difference between the twins in birth weight [1 797 g (940-2 620 g) , 1 648 g (980-2 500 g) ; P=0.688]. The hemoglobin (Hb) level in all donor was significantly lower than recipient (P=0.000) and the inter-twin Hb difference was 147.6 g/L (84.0-216.0 g/L). While the reticulocyte percentage in donor was significantly higher than recipient (P=0.013) and reticulocyte percentage ratio was 3.60 (1.04-7.50). Five donor newborns had neonatal asphyxia, including 1 severe asphyxia, while no asphyxia happened in the recipient twins. (3) Arterio-arterial (A-A) anastomoses, veno-venous (V-V) anastomoses, arterio-venous (A-V) anastomoses were found in 3, 1 and 11 placentas, respectively. The total number of anastomoses was 2 (1-5) and the total diameter was 1.1 mm (0.4-2.1 mm), including 0 (0-1) A-A anastomoses with 0.2 mm (0.0-0.9 mm) in diameter and 2 (0-5) A-V anastomoses with 0.7 mm (0.0-2.1 mm) in diameter. The placental territory discordance was 0.17 (0.02-0.40) and the ratio of umbilical cords insertion to the longest placental diameter was 0.82 (0.34-0.99). Conclusions: The pathogenesis of sTAPS might result from slow and chronic blood transfusion from donor to recipient through a few minuscule vascular anastomoses in the placenta. In all monochorionic twins, especially sIUGR cases, MCA doppler should be monitored closely in the second and third trimester, in order to diagnose and manage sTAPS in time.

Fetal Intra-Peritoneal Transfusion for the Management of Very Early Spontaneous Twin Anemia-Polycythemia Sequence in an Obese Patient With a Whole Anterior Placenta.

Twin anemia-polycythemia sequence (TAPS) is a rare condition in monochorionic twin pregnancies. Small intertwin placental vascular communications allow transfusion, which results in a hemoglobin difference in the twins in the absence of oligohydramnios or polyhydramnios. We report here a case of TAPS diagnosed at 17 weeks' gestation in an obese patient (BMI 42) with a whole anterior placenta. The only possible treatment at this stage of pregnancy was intra-uterine transfusion (IUT), which was repeated weekly until photocoagulation of placental anastomoses was feasible. Fetoscopic laser surgery is the only curative treatment, but is challenging in TAPS because of the absence of polyhydramnios and the presence of minuscule anastomoses. An anterior placenta and high BMI can make the procedure even more challenging. This case report demonstrates that very early and rapidly progressing TAPS with technically complicated conditions (elevated BMI and anterior placenta) can be successfully managed with IUT until laser procedure is achievable.

Decreased Total Placental Mass Found in Twin-Twin Transfusion Syndrome Gestations with Selective Growth Restriction.

INTRODUCTION: We examined placental weight characteristics associated with donor selective intrauterine growth restriction (SIUGR) among patients with twin-twin transfusion syndrome (TTTS) who underwent laser surgery. MATERIALS AND METHODS: Fresh placental specimens were studied. Pregnancies with higher-order multiples, fetal demise, or disrupted or nonsubmitted placental specimens were excluded. Placental characteristics prospectively collected included total placental weight, individual placental weight, and placental share. Data were compared between pregnancies with SIUGR (TTTS + SIUGR group) and those without SIUGR (TTTS-only group). RESULTS: Of 369 consecutive patients who underwent laser surgery for TTTS, 155 (42%) met inclusion criteria: 91 with TTTS + SIUGR and 64 with TTTS-only. Compared to the TTTS-only group, patients in the TTTS + SIUGR group had a lower total placental weight (608 ± 163 vs. 687 ± 224 g, p = 0.012), with a lower donor individual placental weight (237 ± 91 vs. 291 ± 124 g, p = 0.002), but no apparent difference in the individual placental weight of recipient twins (371 ± 109 vs. 396 ± 133 g, p = 0.211). Donor placental share was smaller in those pregnancies affected by SIUGR (38.7 ± 9.6 vs. 42.3 ± 9.8%, p = 0.029). DISCUSSION: TTTS patients with SIUGR had a lower total placental weight and a lower donor individual placental weight compared to those without SIUGR. These findings suggest that differences in donor individual placental weights for SIUGR gestations may not solely be related to differences in placental share.

Twin-Twin Transfusion Syndrome in Cases with Suspected Close Proximity of Umbilical Cord Insertions.

We encountered 3 cases of twin-twin transfusion syndrome (TTTS), in which preoperative ultrasonography revealed that the cord insertion sites of the twins were close. Two cases were successfully treated with fetoscopic laser photocoagulation (FLP); however, the third case could not be treated surgically because fetoscopy revealed that the cord insertions formed a V-shaped joint above the placenta and that all chorionic vessels of the placental surface were shared by the twins. No residual anastomoses were detected on placental examination in the 2 cases treated with FLP. Our experiences indicate that the feasibility of FLP could be evaluated using fetoscopy, not just ultrasonography, in cases of TTTS accompanied by proximate umbilical cord insertion.

Twin Reversed Arterial Perfusion Sequence (TRAPS): An Illustrative Series of 13 Cases.

Twin reversed-arterial-perfusion sequence (TRAPS) is a rare and severe complication of monochorionic twin pregnancies. It usually occurs in the setting of monochorionic placentation, when the heart of a normal appearing twin serves as the pump for one or more dysmorphic twins whose head, thoracic organs, and upper extremities do not fully develop or do not develop at all and thus lack cardiac activity. Anomalous vascular placental architecture causes a shift in arterial flow towards the acardiac twin(s). The exact physiopathologic mechanisms that lead to this devastating phenomenon are not well known. We reviewed the maternal history and the surgical pathology reports of the fetuses and placentas of 13 different cases of TRAPS that were collected in a 23-year study period at a single institution. Herein we summarize the characteristic findings and illustrate specific mechanical feto-placental circulation issues that appear to be instrumental in the development of TRAPS.

[Effect on maternal blood dilution of fetoscopic laser occlusion of chorioangiopagous vessels in treating twin to twin transfusion syndrome].

OBJECTIVE: To evaluate the effect on maternal blood dilution of fetoscopic laser occlusion of chorioangiopagous vessels (FLOC) in treating twin to twin transfusion syndrome (TTTS). METHODS: The clinical data of 71 cases of TTTS who had FLOC in Peking University Third Hospital were reviewed. Fluid intake, blood pressure, heart rate, red blood cell count, hemoglobin and hematocrit in perioperative 24 hours were analyzed. RESULTS: (1) According to the Quintero staging, 9 cases were stage Ⅰ, 24 were stage Ⅱ, 28 were stage Ⅲ and 10 cases were stage Ⅳ. (2) The average operation time of FLOC was (64.0±16.3) minutes. One case had placental abruption after the procedure; one had placental vessel rupture and 6 women refused to take blood counting. These 8 cases were excluded and 63 cases were included in the study. (3) The perioperative bleeding volume was 3 (1, 5) ml, and the volume of fluid intake, urine, amniotic fluid drainage and net fluid intake in the perioperative 24 hours was 2 050 ml(1 530 ml, 3 700 ml), 2 300 ml (1 100 ml, 3 500 ml), 1 900 ml (1 400 ml, 2 700 ml) and -1 760 ml (-100 ml, -3 350 ml), respectively. There was no significant difference between maternal blood pressure or heart rate preoperatively and postoperatively. (4) The maternal red blood cell count [(3.47±0.36)×10(12)/L versus (3.01± 0.37)×10(12)/L, P=0.000], hemoglobin [(107.8±12.1) g/L versus (95.1±11.2) g/L, P=0.000] and hematocrit [0.313(0.238, 0.387) versus 0.276(0.213, 0.800), P=0.000] decreased significantly 24 hours after FLOC. (5) The postoperative hematocrit decreased more in the group which the amniotic fluid drainage volume was 2 000-3 000 ml than that in the group which the amniotic fluid drainage volume was 1 000-1 999 ml. CONCLUSIONS: The blood dilution can not be ignored after the FLOC in TTTS patients. The more the amniodrainage volume during the FLOC, the more the maternal blood dilution would be. It might result from amniodrainage during the FLOC, improved maternal-placenta circulation and tocolytics used after FLOC. More attention should be take about maternal cardiac function and complications related with anemia after FLOC.

[TWIN-TO-TWIN TRANSFUSION SYNDROME: THE POSSIBILITY OF LATENT FLOW (CASE REPORT)].

The early diagnosis of the Twin-To-Twin transfusion syndrome (TTTS) carries benefits of the better survivor for the fetus-donor; but at the same time there are obvious practical impediments to diagnose the condition earlier in the course of a pregnancy. That's why this particular problem in practical medicine requires in depth investigation to clarify casual factors, and specify tactical approach to the prospective patients which in turn will lead to prevention of the fetal death and damage and improvement of fetal survivor in any form of TTTS. The TTTS is one of the complications of a monochorionic pregnancy leading to fetal distress and certain developmental abnormalities as well as worse prognosis for the survival for the affected twin. Previous scientific researches established two major forms of TTTS: chronic - which develops over period of time during the course of the pregnancy and acute - which can develop during the labor itself. This scientific article represents description and analysis of the clinical case of the monozygotic (identical) twin pregnancy characterized by antenatal asphyxia of one of the fetuses at the full-term with unclear clinical etiology but with all morphological characteristics specific for TTTS for monochorionic diamniotic pregnancy. Analyzing the data from this clinical case we have decided that there are latent forms of TTTS which can manifest in the third trimester of the pregnancy.