trimester

1.trimester of pregnancy, first

妊娠头三个月

2.trimester of pregnancy, second

妊娠中三个月

3.trimester of pregnancy, third

妊娠末三个月

4.the first trimester of pregnancy.

妊娠头三个月

5.The skull is opened in this third trimester stillborn fetus to reveal hydranencephaly.

此处打开颅骨来自一个7-9月死胎儿，以显示积水性无脑畸形。