Although some women say they feel more forgetful or spaced out when they are expecting a baby (which is sometimes referred to as ‘pregnancy brain’) I’m not aware of any scientific evidence that says a woman’s brain is directly affected by pregnancy.
We know that many expectant women have a desire to eat or drink certain things and can experience cravings for certain foods but there’s no scientific research to prove that this is a result of pregnancy.
Of course when a woman is pregnant she does experience high levels of certain hormones such as oestrogen and progesterone, and these hormones can sometimes affect her moods. But these are also pre-menstrual hormones that tend to affect women before their period. The levels are raised for longer period (throughout pregnancy) when a woman is pregnant.
Despite some women feeling forgetful, perhaps due to being distracted and thinking about the new baby, women are often highly effective during pregnancy. On top of this they are usually happy, an emotion that releases positive hormones such as endorphin. So I don’t see being pregnant as having a negative effect on a woman’s brain and emotions.