The Fetal Treatment Program
HASBRO CHILDREN'S HOSPITAL - WOMEN & INFANTS' HOSPITAL OF RHODE ISLAND
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Intrauterine growth retardation: is said of a fetus who does not grow as fast as he should, often because not enough nutrients or not enough blood (and oxygen) arrive to him, or because the fetus has to 'work' harder than usual. In twin-to-twin transfusion, it is often seen in the donor twin, who has to pump blood to himself and to the recipient twin. Intrauterine growth retardation can be seen by ultrasound, when the fetus appears smaller than expected for a given gestational age. At birth, this will lead to a baby who is 'small for gestational age.' Monoamniotic twins: identical twins who not only share a common placenta, but a common amniotic space as well. This is a much rarer situation than identical twins who each have their own amniotic sac (so-called monochorionic, diamniotic twins). Monochorionic twins: identical twins who share a common placenta. In addition, they can either have their own amniotic sac (they are then called monochorionic, diamniotic twins) or share a common amniotic sac (which is much less common, and is called a monochorionic, monamniotic twin pregnancy). Nuchal fold: the skin fold in the back of the neck. Measuring its thickness can be used to decide whether there is edema, in which case that fold will be thicker. Oligohydramnios: there should always be a sufficient amount of amniotic fluid around the fetus, to allow him to develop and move around. When there is too little fluid, it is called oligohydramnios. Anhydramnios refers to a situation where there is virtually no fluid left. Polyhydramnios: too much amniotic fluid. Although the fetus can now freely move around, polyhydramnios can represent a danger because of an increased risk of premature rupture of the membranes (PPROM). It can also cause too much pressure on the umbilical cord. Polyhydramnios is often noted because the mother's abdomen is much larger than expected for the time of pregnancy. Preterm Premature Rupture Of Membranes (PPROM): around the time of labor, the membranes rupture (or are ruptured by the obstetrician, if labor has to be induced). If membranes rupture before the fetus has reached term, it is called preterm premature rupture. This will often lead to the onset of labor, causing the baby to be born prematurely. Pulsatile flow: blood flow in arteries is pulsatile: it is fastest with each heartbeat, and slows down a little in between beats. In contrast, blood flow in a vein is generally uniform: always at the same speed. In severe TTTS, the fetus may be so stressed that flow in the umbilical vein becomes pulsatile. This can be seen with a doppler ultrasound examination of the vein. Randomized Controlled Trial (RCT): A clinical research trial set up to evaluate a new form of treatment or a new drug, by comparing it to an existing one (the control group). In this, the most scientifically correct form of research, patients agree to be "randomized," or assigned to one or the other form of treatment in a random fashion: neither the patient nor the treating physician can choose to which group the patient will belong. Thus, any possible bias is eliminated. In the case of Twin-to-twin Transfusion Syndrome, a randomized controlled trial is currently in progress. Our Fetal Treatment Center participates in the first such trial, sponsored by Eurofoetus Tricuspid regurgitation: the tricuspid valve is the heart valve between the right atrium and the right ventricles (two of the heart chambers). Valves keep the blood flowing in one direction only (from the veins into the atrium, from the atrium into the ventricle, and from the ventricle into the arteries. If the heart is stressed and enlarged, the tricuscpid valve may be stretched too, and may not close properly anymore: blood can then be seen to leak backward, or regurgitate. This is best seen with doppler ultrasound.
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