previous pregnancies 中文意思是什麼

previous pregnancies 解釋

The researchers also confirmed previous findings that an earlier maternal age was somewhat protective against breast cancer. those whose first pregnancies occurred when they were 19 or younger had about a 10 percent reduced risk of breast cancer, while those who waited until they were 35 or older to have their first child faced 20 times the average breast cancer risk

那些首次懷孕發生在19歲或更小的時候的女性，其患這種疾病的危險要少10而那些直到35歲或更大年紀才有第一個孩子的女性將面臨著是平常女性20倍的患病危險。
Previous studies looking at this topic may have failed to identify a link because they focused on women at least 6 weeks after their last menstrual period. by contrast, most miscarriages occur earlier in pregnancy, usually within three weeks of conception. in the study reported in the proceedings of the national academy of sciences early edition, levels of the stress hormone cortisol levels were measured in the urine during the first 3 weeks of 22 pregnancies

此前就這一課題進行的多次研究之所以未能成功確認兩者之間的聯系，其原因或許在於研究人員總是將注意力放在那些停經已達6周之久的孕婦身上，但大部分流產都發生在妊娠的最初階段，通常是在懷孕開始后的3周內。