单词trimester
n.: 妊娠的三月期（医学上将妊娠期分为三期，每一期为三个月）
网络: 三学期制；三个学期；怀孕第三期
妊娠的三月期（医学上将妊娠期分为三期，每一期为三个月）:
a period of three months during the time when a woman is pregnant
三月期
(约)三个月;(一年三学期制的)学期
复数：trimesters
In each case, fetuses seem most vulnerable to these drugs in the first trimester of pregnancy, sometimes just a few weeks after conception.
一般说来，怀孕头三个月甚至是只怀孕几周的胎儿似乎最容易受这些药物的侵害。
With that said, a woman will begin taking on some additional weight during the first trimester of the pregnancy stages.
也就是说，在这第一个三月期里，准妈妈们的体重会有所增加。
She wore the air-monitoring backpack in 1999 when she was in the third trimester of her pregnancy with her oldest child, Patience.
在1999年当她怀着她三个月大的孩子时，那是他最大的孩子佩兴斯，她穿上了空气检测背包。
As the third trimester begins in week 26, the grooves deepen and the brain begins to look more like that of a newborn.
怀孕第7个月，也就是差不多在26周的时候，这些沟槽越来越深，婴儿的大脑就开始成形了。
The final or third trimester of the pregnancy stages is one in which the child, already fully differentiated, grows and takes on weight.
最后的三月期是已成形的婴儿生长，增加体重的时期。
The use of any painkiller during the second trimester more than doubled the risk of the condition in a boy baby.
在这段时间使用任何一种止痛药将使得宝宝的风险增加1倍。
A woman experiences nausea ( "morning sickness" ) mostly in the last trimester of pregnancy.
在妊娠后三个月，孕妇通常有作呕（“晨起呕吐”）的症状。
Mothers completed questionnaires within a few months after delivery regarding alcohol use during the first trimester.
这些孩子的妈妈们在产后几个月内完成了有关“怀孕最初三个月是否有过饮酒经历”的调查问卷。
Case Study: A woman in the first trimester of a pregnancy aborted her fetus before dying from rhubarb poisoning herself.
案例：一个怀胎三个月的女人先是堕了胎，而后因为吃大黄花叶自己也中毒身亡。
Since the first trimester is such a vulnerable period for the embryo, many doctors also advise against coloring your hair during that time.
因为前三个月胚胎很容易受到伤害，许多医生都建议你在那段时间里不要染头发。