No. Pregnancy is not a time for dieting and you would have to diet in order to not gain weight during the nine months you are pregnant...
Can I maintain my current weight while pregnant?
No.
Pregnancy is not a time for dieting and you would
have to diet in order to not gain weight during the
nine months you are pregnant. This is a time for
revamping your eating habits if they aren't already
the best they can be. Read Pregnancy and weight
loss.
As far as how much weight you will put on, expect to
gain the average 20-30 pounds (just over two stone)
by the end of your pregnancy, most of which you will
gain in the last two trimesters.
Here’s what those extra stones consist of: About seven of these pounds are the foetus, the enlarged uterus accounts for another two pounds and the placenta and amniotic fluid contribute about one pound each.
About four to eight pounds consists of extra blood
and extra-cellular fluid, plus about four pounds of
body fat. Please remember that these are general
figures, and may vary from person to person.
The way you eat during pregnancy may have a greater
effect on the health of the baby you're bringing
into the world than almost anything else you do.
Pregnancy is not a time to try and lose weight,
especially on the silly ‘super-low fat’ diets that
are thankfully being re-examined. For example, the
long chain omega-3 fat DHA, found in cold water fish
like salmon, is a big part of your baby's developing
brain.
Pregnancy is a time to eat more healthily and better
than you ever have in your life. The results will be
well worth it, and you can work on getting your body
back to where you want it after your baby is born.

