Need to Know!

Question 1

What is TORCH syndrome?

Answer 1

TORCH Syndrome refers to infection of a developing fetus or newborn by any of a group of infectious agents. “TORCH” is an acronym meaning (T)oxoplasmosis, (O)ther Agents, (R)ubella (also known as German Measles), (C)ytomegalovirus, and (H)erpes Simplex.
OTHER agents include HIV, syphilis and varicella
Spreads through the blood system to the foetus, their immune system won’t be able to fight it off
Causes their organs to not develop properly

Question 2

Describe the TRAP sequence

Answer 2

Foetus that does not have a cardiac pump but continues to grow
Must be at least one art-art and one venous-venous placental anastomosis
Arterial blood flows in retrograde from one twin (pump twin) to the affected acardiac twin therefore cardiac flow is reversed in the acardiac twin
Poorly oxygenated, nutrient depleted blood goes directly into the acardiac twin instead of the placenta
Acardiac anecphalus is the most common type with well-developed pelvis and lower limbs but no head
Diagnosis should be considered when there is a monochorionic twin gestation with a foetus that continues to grow despite the lack of cardiac activity
Shunting of blood to the acardiac twin increases the demands on the pump twin which can lead to heart failure and polyhydramnios
Continued growth of the acardiac twin can result in increased intrauterine volume, leading to preterm delivery
Blood that exits the acardiac twin is further deoxygenated and circulates back to the pump twin via the venous-venous anastomosis. Double used blood can cause hypoxia, IUGR, high output cardiac failure
Treatments:
Cord occlusion
Intrafetal ablation using laser coagulation

Question 3

Describe TTTS

Answer 3

Caused by a net transfer of blood from a donor foetus to the recipient foetus through unbalanced unidirectional AV placental anastomoses
The presence of a one-way AV connection without the presence of other connections that can compensate from the unidirectional flow
Results from deep unidirectional AV channels with a paucity of superficial bidrectional channels
Leads to an imbalance in amniotic fluid caused by polyuria in the recipient who has a presistently full bladder and is hypervolemic
Polyhydramnios
Oligohydramnios
Diagnosis is based on a weight discrepancy of >20% and polyhydramnios in the larger twin, and oligohydramnios in the smaller twin
One twin is the donor, and the other is the recipient
Donor has blood shunted AWAY from it, causing anaemia, hypovolaemia, IUGR and oligohydramnios
The recipient has hypervolemia, cardiac overload, polyhydramnios and hydrops
As TTTS worsens, the recipient develops cardiomegaly with decreased cardiac function, ultimately leading to hydrops
Donor has a persistent empty bladder and is often stuck against the uterine wall as a result of severe oligohydrmanios
Donor can be growth restricted secondary to placental insufficiency with increased resistence in the umbilical arterial Doppler