Twin-to-twin transfusion syndrome (TTTS), also known as feto-fetal transfusion syndrome (FFTS), twin oligohydramnios-polyhydramnios sequence (TOPS) and stuck twin syndrome, is a complication of monochorionic multiple pregnancies (the most common form of identical twin pregnancy) in which there is disproportionate blood supply between the fetuses. This leads to unequal levels of amniotic fluid between each fetus and usually leads to death of the undersupplied twin and, without treatment, usually death or a range of birth defects or disabilities for a surviving twin, such as underdeveloped, damaged or missing limbs, digits or organs (including the brain), especially cerebral palsy.The condition occurs when the vein–artery connections within the fetuses shared placenta allow the blood flow between each fetus to become progressively imbalanced. It usually develops between week 16 and 25 of pregnancy, during peak placental growth. The cause of the developmental effects on a surviving fetus may include necrotic embolisms from a dead fetus, low blood volume due to pooling in the dead fetus or velamentous cord insertion (insertion of the umbilical cord into the chorioamniotic membranes).The primary treatment of TTTS is fetoscopy and laser ablation of the interconnecting blood vessels to cut off the exchange of blood between the fetuses. This treatment is associated with an 85% survival rate of at least one fetus. Other treatments include periodic removal of amniotic fluid (serial amniocentesis), which is associated with a 66% survival rate of at least one fetus. Without treatment, there is an almost 100% mortality rate of one or all fetuses.
Chemical colitis is a type of colitis, an inflammation of the large intestine or colon, caused by the introduction of harsh chemicals to the colon by an enema or other procedure. Chemical colitis can resemble ulcerative colitis, infectious colitis and pseudomembranous colitis endoscopically.Prior to 1950, hydrogen peroxide enemas were commonly used for certain conditions. This practice will often result in chemical colitis.Soap enemas may also cause chemical colitis. Harsh chemicals, such as compounds used to clean colonoscopes, are sometimes accidentally introduced into the colon during colonoscopy or other procedures. This can also lead to chemical colitis.Chemical colitis may trigger a flare of ulcerative colitis or Crohns colitis. Symptoms of colitis are assessed using the Simple Clinical Colitis Activity Index. == References ==