Pregnancy is the most crucial phase of a woman's life and a happy one too - if everything's fine and without complications. However, the presence of the following signs is a serious cause of concern and need to be brought to the doctor's notice immediately:

• If the mother is suffering from high blood pressure, diabetes, kidney and heart diseases, tuberculosis, or any other chronic illness.

• If the mother is malnourished, suffering from serve anemia or osteomalacia (due to the deficiency of vitamin D and calcium).

• If the previous pregnancy had resulted in an abortion, still or premature birth of physically or mentally retarded body.

• If there was excessive bleeding, toxemia or any infections during the previous pregnancy.

• If the mother's age is less than 18 years or more than 35 years.

• If the mother is obese or underweight.

• If the mother is suffering from AIDS, Hepatitis B or syphilis or other sexually transmitted or infectious diseases.

• If the mother is drug addict, smoker, alcoholic, or epileptic.

• If the mother's blood group is Rh negative and the father's is Rh positive.
  

If you doubt the presence of any of the above you must surely consult the doctor. Its better to take precautions at the early stages so as to prevent complications in the final stages of pregnancy.