Sinusoidal rhythm caused by fetal hemorrhage during fetoscopy

Area of Science:

• Perinatology
• Fetal Medicine
• Maternal-Fetal Medicine

Background:

• The sinusoidal fetal heart rate pattern is a complex sign with varied associations, including fetal anemia, hypoxia, and medication effects.
• Its presence does not invariably predict a poor fetal outcome.

Observation:

• Fetoscopy was performed for prenatal diagnosis in a patient with thalassemia trait.
• Following trocar insertion, fetal blood was aspirated, indicating feto-maternal hemorrhage (5.7 ml).
• A sinusoidal fetal heart rate pattern emerged two minutes after the hemorrhage and persisted for over ten minutes.

Findings:

• The sinusoidal pattern resolved within two hours, with the fetal heart rate returning to normal.
• The pregnancy proceeded without complications.
• A healthy infant was delivered at 38 weeks' gestation.

Implications:

• This case suggests that a transient sinusoidal fetal heart rate pattern following iatrogenic fetal hemorrhage may not indicate impending fetal demise.
• It highlights the importance of considering the clinical context and potential causes, such as hemodynamic disturbance or acidosis, when interpreting this pattern.
• Further research into the management and significance of sinusoidal fetal heart rate patterns in specific obstetric scenarios is warranted.