Which condition can lead to fetal cardiac conduction issues?

Congenital heart block is a specific condition that directly affects the fetal cardiac conduction system. It is often associated with autoimmune conditions in the mother, particularly those that produce anti-Ro/SSA and anti-La/SSB antibodies. These antibodies can cross the placenta and impact the fetus, leading to disruptions in the normal electrical conduction pathways of the heart.

In congenital heart block, the electrical signals that coordinate the heartbeat can be affected, resulting in bradycardia (slow heart rate) or even complete heart block. This condition is not typical for the other options provided, as oligohydramnios, gestational diabetes, and preterm labor do not primarily target the cardiac conduction pathways in the same way. While they can have significant implications for fetal health, they are not directly linked to causing conduction issues within the heart itself like congenital heart block.