Which condition can cause sinusoidal patterns in fetal monitoring?

The correct choice is severe fetal anemia, as this condition is directly associated with the development of sinusoidal patterns in fetal heart rate monitoring. Sinusoidal patterns are characterized by a smooth, undulating pattern with a regular frequency of oscillations, which can often be seen as a sign of fetal distress.

Severe fetal anemia typically results from conditions like Rh isoimmunization or fetal hemorrhage, leading to insufficient oxygen supply to the fetus. The resultant metabolic acidosis generates the sinusoidal rhythm. This pattern indicates that the fetus may be experiencing significant stress and requires immediate medical assessment and intervention.

In contrast, severe dehydration, fetal tachycardia, and maternal fever are less likely to produce sinusoidal patterns. Severe dehydration affects maternal blood volume and can lead to fetal hypoxia and other complications, but it does not create sinusoidal patterns. Fetal tachycardia may indicate an increased heart rate but does not typically manifest as a sinusoidal waveform. Maternal fever can impact fetal heart rate but usually results in other patterns, such as variability changes rather than sinusoidal ones.

Understanding the connection between severe fetal anemia and sinusoidal patterns is crucial for effective fetal monitoring and timely intervention in high-risk pregnancies.