The aforementioned recommendations are intended for women who do not have any additional risk factors for adverse maternal or perinatal outcome. A number of medical or obstetric conditions may lead the obstetrician to recommend modifications of these principles.

The following conditions should be considered contraindications to exercise during pregnancy:

• Pregnancy-induced hypertension
• Preterm rupture of membranes
• Preterm labor during the prior or current pregnancy or both
• Persistent second or third trimester bleeding
• Intrauterine growth retardation

In addition, women with certain other medical or obstetric conditions, including chronic hypertension or active thyroid, cardiac, vascular or pulmonary disease, should be evaluated carefully in order to determine whether an exercise program is appropriate.