extension of fetal head

例句：

1. 1. The doctor performed anemergency surgery to save the baby'slife.
   医生进行了紧急手术，挽救了婴儿的生命。
2. 2. Thefetal extension was causing severediscomfort for the mother.
   胎儿头部的延伸给母亲带来了严重的不适。
3. 3. The fetal expansion is a common cause of miscarriage.
   胎儿扩张是常见的流产原因之一。