To reach a stage in labor when a large segment of the fetal scalp is visible at the vaginal orifice.Used of a fetus or the head of a fetus.是什么意思_To reach a stage in labor when a large segment of the fetal scalp is visible at the vaginal orifice.Used of a fetus or the head of a fetus.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句