Twin–Twin Transfusion Syndrome.The case Definition problem
Before the use of ultrasound, TTTS was diagnosed by a 20% discordance in the weights and at least 5 g/dl difference in the hemoglobin concentration at birth of two twins of the same sex.3 These criteria were left aside because they were not always possible to demonstrate antenatally by ultrasound and because it is frequent in diamniotic twins as much as in monochorionic twins. Besides, these were used for surviving twins but not in cases of double- or single-fetal demise, which were more possibly affected by severe TTTS.
With the development of ultrasound, new antenatal findings were correlated to adverse outcome. The polyhydramnios/oligohydramnios sequence has been found to be the condition with one of the highest mortalities in obstetrics, with 90% mortality without treatment. Recently, growth discordance with abnormal umbilical Doppler has been considered a new indication for laser photocoagulation of anastomoses on the chorionic plate.
There are cases that led to anemia of one twin and polycythemia of the other, outside the polyhydramnios/oligohydramnios sequence. These scenarios suggest that the presence of vascular communications are variable in number and type, producing pathophysiologically different problems, and that the TTTS is a complex situation in which fetal growth, fetal volemia, amniotic fluid discordance, and anemia are conjugated to produce a specific condition.
Mortality and morbidity may be related to these complications in different ways. Comprehension of the mechanisms leading to complications and death is important to plan diagnostic and treatment strategies. With the use of Doppler and highresolution two-dimensional (2D) imaging, new data on fetal anemia, hypervolemia, and fetal diuresis have been identified. TTTS is now defined on ultrasound as oligohydramnios and polyhydramnios in the donor and recipient, respectively. The demonstration of the effectiveness of laser photocoagulation in these cases has largely oriented the investigation of the anastomoses on the pathophysiology of this condition.
The mechanisms by which TTTS may produce death and sequealae are multiple. The study of these complications, as well as the possibility of treating them independently, will increase the chances of survival and the global rate of success of the different treatment modalities. TTTS may lead to fetal demise in utero through cardiac overload or severe intrauterine growth restriction. It may lead to extreme preterm delivery because of the effect of polyhydraminios on the cervix that mimics cervical incompetence, may produce extreme premature fetuses, and may provoke vascular disruptive consequences.
the twin anemia-polycythemia sequence TAPS is mentioned here, before it got a name. My Admin squad tend towards saying "This is Old", which it may be, however I find it to be both comprehensive & highly accurate. would you perhaps have a suggestion as to which of the current practitioners would be best to attempt the Gaseous Environment option mentioned, in an effort to improve the currently Terrible survival numbers that Anterior Placentation cases currently have? I have supported mothers in Monochorionic pregnancy since December of 2010, this being after losing my sons to TTTS earlier that year,after the experts at that time, Ham Min Lee & his Crack Team, told me & my wife at the time that Anterior Placentation was "Impossible" to work on. So, we were sent back to San Jose on a program of Serial Amnioreduction, which commenced on our Stage Three case in 23/4. Of course it didn't work, with Morgan Mark Aaron, our Recipient, expiring on or about 25/5 with 26/2 being the latest. Our Donor, Brian Raymond Lee, was in Nominal shape until 30/0 on 9/29/2010, when non reassuring NST data brought about his Emergent delivery via CS. He was impossible to oxygenate due to Pulmonary Hypoplasia, secondary to Anhydramnios in week 22. After 38 hours, he followed his brother.
ReplyDeleteThis, I suspect, is what defines a Mission of sorts. My family desperately needed accurate information that was not at all forthcoming. After communicating with the Principal of the International Twin To Twin Transfusion Syndrome Foundation, it became Abundantly Clear that our definitions of Progress & Advancement concerning diagnosis & treatment of TTTS varied radically. Thus, the years 2011 until 2019 have been spent in study of the various aspects of Monochorionicity, with at least two hours a day spent in this backwater area of maternal fetal medicine, in which the "average" diagnosis of TTTS, & mom's care team therein, are quite often Fraught with errors, often Lethal ones. Thank you for this site, it is truly unique.