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Re: velamentous cord ins From: James S Smeltzer MD (gaperina@mindspring.com) Mon Mar 1 09:59:10 1999 Messages sorted by: [ date ][ thread ][ subject ][ author ] Next message: James S Smeltzer MD: "Re: intrauterine TV." Patty, Your excellent follow-up of your case confirmed the work of others regarding twin transfusion syndrome and cord insertion problems. Severe twin transfusion syndrome is often associated with an abnormal cord insertion of the donor. Abnormal cord insertion is more frequent with monozygotic twins where it can herald twin transfusion problems, and dizygotic as well where it obviously does not. Nice case. See: Title Placental pathophysiology of the twin oligohydramnios-polyhydramnios sequence and the twin-twin transfusion syndrome. Author Bruner JP; Anderson TL; Rosemond RL Address Department of Obstetrics and Gynaecology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2529, USA. joe.bruner@mcmail.vanderbilt.edu Source Placenta, 19(1):81-6 1998 Jan Abstract Currently accepted sonographic criteria for antenatal diagnosis of twin-twin transfusion (TTT) syndrome include a monochorionic placenta with same-sex twins, marked growth discordance, and oligohydramnios of the growth-retarded twin with coexistent polyhydramnios of the larger twin. Our previous report of nine women fulfilling these criteria, examined using sequential funipuncture of both fetuses, demonstrated inter-twin blood transfusion in only four cases (44 per cent). It was proposed that traditional sonographic criteria actually describe a heterogeneous group of disorders more appropriately described as the twin oligohydramnios-polydramnios sequence (TOPS). True TTT is a subset of this population, the antenatal diagnosis of which requires specific demonstration of transfusion from one fetus (donor) to the other (recipient). In this report, antenatal placental evaluation has been correlated using duplex pulsed-wave Doppler analysis of arterial blood flow velocity with postpartum gross and histopathologic evaluation of the placenta, with special attention to microvasculature. There was a higher incidence of resistance to blood flow, abnormal umbilical cord insertion, and diminished placental microvasculature associated with oligohydramnic growth-retarded (donor) twins when compared with polyhydramnic (recipient) twins. Based on these observations, it is proposed that TTT and TOPS represent asymmetric placental insufficiency resulting from aberrant placentation. Language Eng Unique Identifier 98142788 Title The biology of the twinning process: how placentation influences outcome. Author Benirschke K Address Department of Pathology, University of California, San Diego 92103-8321, USA. Source Semin Perinatol, 19(5):342-50 1995 Oct Abstract Placentation of twins has important bearing on the fetal development and neonatal outcome. Because of limitation in space of the endometrial cavity, twin placentas frequently collide during their expansion. This may restrict their growth and also lead to a somewhat increased rate of placenta previa. Moreover, abnormal cord insertions such as marginal and velamentous cords are much more frequent in multiple gestation. Absence of one umbilical artery is also much more frequent in twins. The best prognosis is had when two independent placentas develop, the dichorionic separate organs. Fusion of two separate placentas does not lead to vascular anastomoses in human twins, whereas it often does in other species (marmoset, cattle). Blood vessel fusion occurs only in monochorionic twins, all of which are "identical" (monozygotic). Large anastomoses (usually artery-to-artery) allow blood to shift rapidly from one to the other. Thus, when one twins dies, the survivor may quickly exsanguinate into the dead twin, leading to hypotension and occasionally to cerebral palsy. Arteriovenous anastomoses are the basis for the twin transfusion syndrome. This results in severe prematurity and gross discordance of all sorts of physical parameters. Knowing this type of vascular shunts helped develop the prenatal laser obliteration with salvage of the twins. The worst prognosis occurs with the rarest type of placentation in twin, in which both reside in the same cavity. This is the monoamnionic-monochorionic twin placentation. By moving about, the twins often entangle their umbilical cords and some 40% to 50% may die in utero. Language Eng Unique Identifier 96418237 Title Velamentous cord insertion in monochorionic twin gestation. An added risk factor. Author Machin GA Address Department of Genetics, Permanente Medical Group, Oakland, California 94611-5693, USA. Geoffrey.Machin@ncal.kaiperm.org Source J Reprod Med, 42(12):785-9 1997 Dec Abstract OBJECTIVE: To study the effects of umbilical cord insertion combinations on outcomes in monochorionic (MC) twin placentas. STUDY DESIGN: Sixty consecutive MC placentas were analyzed by cord insertion patterns with regard to growth discordance, placental parenchymal sharing, types and patterns of intertwin vascular anastomoses, perinatal mortality and frequency of fetofetal transfusion. Cord insertions were classified as central/eccentric (CEN) or velamentous/marginal (VEL). RESULTS: Forty-five percent of the twins had VEL insertions. The CEN/VEL combination was found in 53% of pairs. The CEN/VEL group had the highest rates of growth discordance > 20%, unequal placental parenchymal sharing, uncompensated anastomoses and perinatal demise. CONCLUSION: VEL cord insertion and the CEN/VEL combination are indicators of high-risk subgroups within MC twins. VEL cord insertions can be diagnosed by ultrasound, identifying these high-risk groups. Language Eng Unique Identifier 98100246 Title Color Doppler ultrasonography in the identification of communicating vessels in twin-twin transfusion syndrome and acardiac twins. Author Hecher K; Ville Y; Nicolaides KH Address Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London, England. Source J Ultrasound Med, 14(1):37-40 1995 Jan Abstract This study evaluates the role of color Doppler ultrasonography in the identification of the communicating placental vessels in pregnancies with twin-twin transfusion syndrome and acardiac twins. In 18 pregnancies with twin-twin transfusion syndrome and two with an acardiac twin, color Doppler studies of the placental vasculature were performed before fetoscopy for laser coagulation of the communicating vessels. In six cases of twin-twin transfusion syndrome the placental attachment of the intertwin membrane could be visualized. Pulsatile arterial blood flow was observed from the donor to the recipient twin that disappeared after laser therapy. In both cases of acardiac twins, one communicating vessel with pulsatile and another vessel with nonpulsatile blood flow in the opposite direction could be identified. Color Doppler imaging is unlikely to play a major role in assisting endoscopic laser separation of chorioangiopagus in patients with acute polyhydramnios, but it may prove to be useful in the early identification of pregnancies at risk of developing twin-twin transfusion syndrome. Language Eng Unique Identifier 95222695 Title Ultrasonography and Doppler studies in twin-to-twin transfusion syndrome. Author Ishimatsu J; Yoshimura O; Manabe A; Matsuzaki T; Tanabe R; Hamada T Address Department of Obstetrics and Gynecology, Kurume University School of Medicine, Fukuoka, Japan. Source Asia Oceania J Obstet Gynaecol, 18(4):325-31 1992 Dec Abstract In 40 twin pregnancies, the evaluation of hemodynamics by ultrasound was performed during the period January 1986 through September 1991. The blood flow velocities' waveforms in the umbilical artery, umbilical vein and tricuspid valve, and the total cardiac dimension, were obtained by ultrasonography in conjunction with 3.5 MHz pulsed Doppler ultrasound. Six patients with twin pregnancies were identified as having twin-to-twin transfusion syndrome (TTS), on the basis of like-sex twins with monochorionic diamniotic placentation, vascular anastomosis in the placenta, and umbilical cord venous blood hemoglobin difference exceeding 5 g/dl at delivery. No distinctive findings for TTS were revealed by the measurement of umbilical artery blood flow velocity waveforms. However, cardiomegaly in 5 recipient fetuses and tricuspid regurgitation and biphasic umbilical vein waveforms in 3 recipient fetuses constituted characteristic features of TTS. Ultrasonography and a Doppler study might be beneficial in diagnosing TTS and evaluating the hemodynamics in a recipient fetus. Language Eng Unique Identifier 93151771 Jim Smeltzer MD At 07:03 PM 2/25/1999 -0600, you wrote: >Pat, don't beat yourself up about this one. Turn the negative out of it to >a positive learning experience. You will probably check for cord insertion >on all low lying placentas from now on.... no reason to do this on high or >fundal placentas. >Good luck and positive scanning!!!! > >Clay Stewart > >patricia carris wrote: > >> Looking for some discussion on velamentous cord insertions. >> I had been scanning my friend and neighbor since 14 wks. twin gest >> single post placenta thin membrane, both males. Size discrepancy >> appeared early on. Watched closely for signs of twin-twin transfusion. >> no signs. Subjectively less fluid (but adequate) for smaller baby, size >> discrepancy consistent at approx 30-32% over serial >> scans. Last scan on fri showed basically no growth in AC/efw, size >> difference at 40%. She was induced that nite at 36wks. >> Babies came sat am vaginally. >> baby a 4lb 4oz (I got 4lb 2 oz on the scan)(still in intermed nursery) >> baby b 6lb 14oz (was right on the money with him)(at home) >> >> Baby a turned out to have a velamentous insertion. We do not routinely >> scan for placental cord insert. Unfortunately our "high risk referral >> lab" (for the state of NM!!) only has 1 machine out of 4 with color >> doppler. >> >> Just curious if others have standard protocol for placental cord ins. >> In hindsight, I feel the concern over t-tts led me to over look the >> a cord problem. >> Patty >> > Next message: James S Smeltzer MD: "Re: intrauterine TV."

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