Patient's question:
Medical Description: During a color Doppler ultrasound examination at 20 weeks of pregnancy, a fetal body echo was observed in the uterus. Fetal position: Left occiput anterior. Biparietal diameter: 6.8 cm. Femur length: 4.9 cm. Fetal heart rate: 147 bpm. Regular fetal movement: Present. Placental position: Anterior wall. Placental grade: Grade 1. Amniotic fluid depth: 5.1 cm. A 1.20.9 cm anechoic area was observed in the fetal posterior fossa, suggesting possible posterior fossa effusion.Possible Treatment History and Effect: A color Doppler ultrasound examination result from August 13, 2010.
Desired Help: What tests should I undergo? What precautions should I take? Can the child be kept? Thank you.
Doctor's answer:
Hello, generally the cisterna magna is less than 7 mm in early pregnancy and less than 10 mm in late pregnancy. If the fetal cisterna magna is significantly widened, it is necessary to consider whether there is underdevelopment of the vermis of the cerebellum, which can be classified into complete and incomplete types. The former is easier to detect earlier, while the latter is more difficult. The time it takes is uncertain, and in some cases, it may only be discovered after birth.We recommend that such cases undergo MRI to determine whether there is underdevelopment of the fetal cerebellar vermis. We suggest that such cases undergo MRI, with the purpose of determining whether there is underdevelopment of the fetal cerebellar vermis. Additionally, ultrasound dynamic observation is necessary, as a single examination showing similar findings is not sufficient for diagnosis or classification, especially when the data is at the critical threshold.
If there is isolated posterior fossa cisterna expansion without other abnormalities, the prognosis is generally favorable.