The popular belief that pregnancy addles women's brains is a myth, a comprehensive study suggests.

    Mothers claim to have suffered 'baby brain' or 'preg head', characterised by lapses in memory or logical thinking.

    But researchers who tracked 2,500 women over ten years found no difference between their brainpower before and during their pregnancies.

    In fact, the scientists believe, pregnancy and motherhood could actually improve women's mental abilities - and the improvement may be permanent.

    Previous studies have claimed that pregnant women's brains decline in size and that they consistently perform worse than other women on tests for memory and verbal skills.

    They have suggested that the difference could be as great as comparing the mental ability of someone aged 20 with someone aged 60.

    But Professor Helen Christensen, of the Australian National University in Canberra, said her study is superior to previous research because it compares the same women before and during pregnancy.

    'Women often report problems with memory and reasoning after they become pregnant,' she said. 'But the latest findings from our decade-long study, the most in-depth to look at this issue, has proven they do not.'

    The researchers studied 2,500 women aged from 20 to 24, first in 1999 and then again in 2004 and 2008.

    'We found that women who were pregnant during the second or third batch of interviews performed the same on tests of logic and memory as they did before, and there was no difference between the pregnant women and the controls,' she said.

    'It really leaves the question open as to why women think they have poor memories, when the best evidence we have is that they don't.

    'Perhaps women notice minor lapses in mental ability and then attribute it to being pregnant because that is the most significant thing in their mind at the time.

    'Or sleep deprivation could mask the positive cognitive effects.'

   一項大規模研究表明，“懷孕會影響女性智力”的普遍觀點其實并不正確。

    很多媽媽稱她們在懷孕期間有“嬰兒腦”或“懷孕腦”現象，主要表現為健忘和反應遲鈍等。

    但研究人員對2500名女性進行的一項為期十年的跟蹤調查發現，女性的智力水平在懷孕前和懷孕期間沒什么差別。

    研究人員認為，女性懷孕當媽媽以后的智力水平反而比以往有所提高——而且這種提高可能是長期的。

    此前的研究認為，女性懷孕后大腦會變小，相應地，她們在記憶力和語言能力方面的測試不如其他女性。

    這一差別與20歲和60歲人群之間的智力差異差不多。

    但位于堪培拉的澳洲國立大學的海倫•克里斯坦森教授稱，她的研究超越了此前的研究，因為她的研究對比的是同一女性在懷孕前和懷孕期間的智力水平。

    她說：“女性在懷孕后常稱自己的記憶力和邏輯思考能力出現退化。但我們的這項長達10年的最新研究證明事實并非如此，這是目前有關這一課題最深入的一項研究。”

    研究人員對2500名年齡在20歲至24歲之間的女性進行了研究，首批研究于1999年進行，另外兩批分別于2004年和2008年進行。

    海倫說：“我們發現在第二或第三批訪問期間懷孕的女性在邏輯和記憶力測試中的表現與懷孕前差不多，而且懷孕女性與控制小組的女性在測試中的表現也沒什么差別。”

    “這就留下了一個疑問，為什么女性覺得自己懷孕后記憶力變差了，而我們掌握的最有力的證據則表明事實并非如此？”

    “可能女性注意到自己的智力水平稍有下降，就將其歸于懷孕所致，因為那段時期她們的注意力都集中在‘懷孕’這件事上了。”

    “或者睡眠不足可能也會掩蓋積極的認知效果。”