Having a problem in a past pregnancy does not necessarily mean  it will happen again but you may need special attention or care during your next pregnancy. That's why it's important to review  your obstetric history (if you have been pregnant before) with your doctor.

Many women are worried that if they have had a miscarriage before, they will have trouble having a healthy pregnancy. This is not necessarily true. One in five women who become pregnant are known to have a miscarriage at some point, and there are probably many miscarriages which are never detected. Most of these women go on to have normal pregnancies the next time around.

There may be a correctable reason for a prior miscarriage such as having had poor blood glucose control or having been exposed to a potentially harmful medication during your prior pregnancy (e.g. an oral diabetes medication, an anti-cholesterol drug like Zocor or blood-pressure drug like an ACE inhibitor).


Your doctor will ask what medications you are taking, including over the counter (bought without a prescription) ones such as aspirin, antihistamines, diet pills, etc. Some can be harmful to your fetus and should be avoided around the time of conception.

Other medications which should absolutely be avoided during pregnancy. If you are taking them, your doctor may suggest you stop and/or choose an alternative medicine that is less harmful.

Some Medications to Avoid

  • Accutane [Isotretinoin a Vitamin A derivative] - for acne
  • ACE inhibitor [e.g. lisinopril, captopril] - for high blood pressure or to protect your kidneys
  • Zocor, Lipitor - for high cholesterol
  • Coumadin - a blood thinner

Environmental Exposures

Some substances found in the environment or in your work place may make it more difficult for you to get pregnant, or increase your risk for miscarriage or a problem pregnancy. If you know of a "toxic" substance (chemicals, radiation, radioactive substances, toxic fumes) where you work, take extra care to avoid it. Unfortunately, however, the effects of most chemicals in our environment are unknown.

Women who are planning a pregnancy and are exposed to radiation in the work place should ask for monthly readings that show how much radiation they have been exposed to. The amount of radiation in a chest X-ray is not sufficient to harm a pregnancy but radiation used to treat disease such as cancer is usually at much higher doses and may be harmful. Ask your doctor or a genetic counselor about this before getting pregnant.


Infections can harm both the mother and the baby, and sometimes can cause serious birth defects. Some may be prevented with vaccination prior to pregnancy.

Even if you were immunized (vaccinated) as a child, you may not be immune now. Take a blood test to check if you are immune. If you are vaccinated before pregnancy you should probably wait about 3 months to conceive.


  • Tetanus-diptheria booster [every 10 years]
  • Measles, mumps, rubella [once if not immune]
  • Varicella [chicken pox]
  • Hepatitis B vaccine*
  • Influenza vaccine*
  • Pneumococcal vaccine*

* as needed based on risk factors

Other infections that may be harmful to pregnancy are those passed on by sexual contact, sexually transmitted diseases [STDs]. These can affect your ability to become pregnant or can harm your baby once you conceive. Some common STDs are chlamydia, gonorrhea, genital herpes, human immunodeficiency virus [HIV].