Thanks for the query.
Some amount of giddiness is common in pregnancy
That can occur due to hypoglycemia
You have to improve the food intake to avoid this. If you are not able to eat larger quantities take smaller quantity food more frequently.
can cause drowsiness
To avoid this you can take the tablet at bed time or use it vaginally.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429