What is the standard for fetal biparietal diameter suitable for vaginal delivery? Fetal biparietal diameter refers to the length of the upper and lower diameter of the fetal head and is one of the indicators for evaluating fetal growth and development. During pregnancy examinations, doctors will measure the fetal biparietal diameter to determine whether the fetal size is normal and whether it is suitable for vaginal delivery. So, what is the standard for fetal biparietal diameter suitable for vaginal delivery? This article will start from four