In one study, use of birth control pills led to a higher risk of premenopausal breast cancer in women who took the pill for four or more years before having a baby.
一项研究显示，在生育前使用口服避孕药达10年或以上，可导致绝经前乳腺癌风险增加。
We enrolled for NCT classes: four or five couples sitting round on bean bags, all questing for the perfect birth.
我们加入了NCT课程：4 -5对夫妻坐在豆子袋上，围在一堂，提些如何顺产的问题。
They were assessed for symptoms of depression and anxiety twice during their pregnancy and four times after giving birth, at 8 weeks, 8 months, 21 months and 33 months.
这些女性大部分在怀孕期间产生2次抑郁和焦虑的症状，而在生产之后产生了4次症状，分别在生产的8个星期、8个月、21个月以及33个月之后。
After being abandoned by their mothers shortly after birth, the four play fight, nipping and teasing each other, and cuddling up for a Shared nap when they are worn out.
这四个出生不久就被它们的各自的母亲遗弃的小动物相互戏耍打闹，玩累了变抱成一团小睡一会儿。
The four laeding causes accounting for 68. 5 % of . 127 perinatal deaths were malformation, complications of the cord, preterm, and obstructed labour or birth trauma.
围产儿死亡的前四位死因依次为先天畸形、脐带因素、早产、难产与产伤，累计占全部围产儿死亡的68．5％。
The four laeding causes accounting for 68. 5 % of . 127 perinatal deaths were malformation, complications of the cord, preterm, and obstructed labour or birth trauma.
围产儿死亡的前四位死因依次为先天畸形、脐带因素、早产、难产与产伤，累计占全部围产儿死亡的68．5％。
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