Reproductive Quiz #6, Twinning and Twin-Twin Transfusion Syndrome  

1. A 28-year-old woman at 24 weeks of gestation with a monochorionic diamniotic twin pregnancy is found to have one fetus that is significantly larger with a polyhydramniotic sac and another fetus that is smaller with an oligohydramniotic sac on ultrasound. Which of the following best describes the pathology affecting this pregnancy?,"Radio",1,"Twin-twin transfusion syndrome (TTTS) occurs in monochorionic diamniotic twin pregnancies due to unbalanced blood flow through vascular connections in the shared placenta. This leads to one twin (the donor) becoming anemic and growth-restricted with oligohydramnios, while the other twin (the recipient) becomes polycythemic and overnourished, leading to polyhydramnios. The discrepancy in fluid volumes within their respective amniotic sacs is a hallmark of TTTS.","A. Dichorionic diamniotic twinning",0,0,"B. Monochorionic monoamniotic twinning",0,0,"C. Twin-twin transfusion syndrome",1,1,"D. Twin reversed arterial perfusion syndrome",0,0,"E. Sirenomelia",0,0

Question 1 of 5

2. Which of the following is a characteristic finding in the donor twin in a case of twin-twin transfusion syndrome?,"Radio",1,"In twin-twin transfusion syndrome, the donor twin transfuses blood to the recipient twin through placental vascular connections, leading to anemia in the donor twin. The donor twin is typically the smaller twin with oligohydramnios due to reduced blood volume, which leads to decreased urine production and amniotic fluid volume.","A. Polycythemia",0,0,"B. Polyhydramnios",0,0,"C. Anemia",1,1,"D. Increased urinary output",0,0,"E. Cardiomegaly",0,0

Question 2 of 5

3. A pregnant woman with a known monochorionic diamniotic twin pregnancy presents for a routine ultrasound. The ultrasound technician notes that one twin appears to have a significantly larger bladder than the other. This finding is most suggestive of which of the following conditions?,"Radio",1,"A significantly larger bladder in one twin compared to the other in the setting of a monochorionic diamniotic twin pregnancy suggests twin-twin transfusion syndrome (TTTS). The recipient twin often has an enlarged bladder due to increased blood volume and consequently increased urine output, which contributes to polyhydramnios. This finding, along with disparities in amniotic fluid volumes and fetal sizes, helps in diagnosing TTTS.","A. Twin anemia-polycythemia sequence",0,0,"B. Twin-twin transfusion syndrome",1,1,"C. Congenital urinary tract obstruction",0,0,"D. Sirenomelia",0,0,"E. Twin reversed arterial perfusion syndrome",0,0

Question 3 of 5

4. During a prenatal visit, a 32-year-old woman is found to have a dichorionic diamniotic twin pregnancy. Which of the following best describes the origin of this type of twinning?,"Radio",1,"Dichorionic diamniotic twinning occurs when two separate eggs are fertilized by two separate sperm, resulting in the development of two genetically distinct embryos, each with its own placenta (dichorionic) and amniotic sac (diamniotic). This is the most common type of twinning and occurs in all fraternal (non-identical) twins.","A. Fertilization of two different eggs by two different sperm",1,1,"B. Fertilization of one egg by one sperm, followed by early splitting of the embryo",0,0,"C. Fertilization of one egg by two different sperm",0,0,"D. Late splitting of a monochorionic embryo",0,0,"E. Fertilization of two different eggs by one sperm",0,0

Question 4 of 5

5. Which of the following fetal outcomes is most commonly associated with untreated severe twin-twin transfusion syndrome?,"Radio",1,"Untreated severe twin-twin transfusion syndrome (TTTS) has a high risk of perinatal mortality for both twins. The imbalance in blood flow can lead to heart failure in the recipient twin due to volume overload, and severe anemia in the donor twin, which can result in intrauterine growth restriction (IUGR) or death. Without intervention, the mortality rate for both twins can exceed 80%. Early detection and treatment options such as laser ablation of placental anastomoses can significantly improve outcomes.","A. Both twins survive without intervention",0,0,"B. The donor twin survives, while the recipient twin experiences heart failure",0,0,"C. The recipient twin survives, while the donor twin experiences severe growth restriction",0,0,"D. High risk of perinatal mortality for both twins",1,1,"E. Both twins develop normally without any complications",0,0

Question 5 of 5


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