A review of the literature concerning sport during pregnancy is presented. The mother's heart rate, arterial blood pressure, systolic ejection fraction and cardiac output undergo the same changes during exercise in the pregnant and non-pregnant patient. The increase in the fetal heart rate during maternal physical exercise does not adversely affect the fetal outcome. The uterine blood flow is diminished during exercise. The respiratory rate increases equally in pregnant and non-pregnant women. The maternal response to effort is also modified by weight gain during pregnancy, by changes in the musculo-skeletal system, and by maternal temperature control during exercise. Weight gain, uterine contractility, duration of pregnancy, labour and neo-natal conditions are not altered by sport during pregnancy. Contra-indications to sport during pregnancy include threatened premature labour, and conditions associated with an increased risk of prematurity. A previous history of fetal growth retardation, acute fetal distress, or the presence of diabetes or arterial hypertension is a contra-indication to sport during pregnancy. The advice which should be given to a pregnant woman wishing to continue her sporting activities during pregnancy is outlined.