Complicated Pregnancies
One Patient's Experience with TTS
Anna Garcia was 38 when she became pregnant with twins. A pregnancy involving two or more fetuses is automatically classified as "high risk,' so she was referred by her private obstetrician, Dr. Miguel Fernandez, to see Rodney A. McLaren, MD, Director of Maternal-Fetal Medicine at Virginia Hospital Center.
A sonogram performed by Dr. McLaren revealed that Garcia's twins had developed twin-to-twin transfusion syndrome (TTTS), a progressive disorder that affects up to 15% of identical twins. In TTTS, blood passes disproportionately from one baby to another through connecting blood vessels in their shared placenta. The cardiovascular system of one twin becomes overloaded by an excessive amount of blood, while the other twin suffers from diminished blood supply.
Diagnosing TTTS requires special sonographic skills, as other conditions may mimic twin-to-twin transfusion. Ultrasound findings that indicate TTTS may include a large volume of amniotic fluid in one twin and decreased or absence of fluid in the other, evidence of heart failure in one or both twins, and differing growth rates.
The prognosis is generally poor, especially when the condition develops at a premature gestational age and when one fetus develops heart failure, as with one of Garcia's twins. In the absence of treatment, up to 100% of fetuses suffering from TTTS will die. Even with treatment, a large number do not survive.
Fortunately, early treatment of TTTS with a procedure known as amnioreduction can prevent complications. The procedure involves inserting a needle into the uterus and removing a large volume of amniotic fluid. The procedure is repeated as often as necessary to maintain a normal volume of amniotic fluid. Although it's not known exactly how amnioreduction improves the health of twins, it doubles the TTTS survival rate. Garcia's boys were born at 36 weeks in late 2002 and both are fine.
In addition to fetal disorders such as TTTS, maternal-fetal medicine specialists like Dr. McLaren are uniquely trained to care for patients whose pregnancies are complicated by a pre-existing medical problem and those who develop complications related to the pregnancy. Specialization in the field requires a four-year OB/GYN residency, plus three years of training in maternal and fetal medicine