Women with tetralogy of Fallot have an increased risk of pregnancy loss and their offspring have an increased risk of birth defects. Researchers from Minnesota assessed the clinical, haemodynamic and obstetric data of 72 women with tetralogy of Fallot. 43 women had a total of 112 pregnancies (range 1 - 5 pregnancies), of which 82 pregnancies were successful. In 8 women, tetralogy of Fallot remained untreated at the time their pregnancy was successful. The report states that adverse maternal outcomes (although rare) may be associated with left ventricular dysfunction, severe pulmonary hypertension or right atrial dysfunction. Such women may benefit from surgery performed, if possible, before pregnancy. Unoperated tetralogy of Fallot and morphological abnormalities of the pulmonary artery are independent contributory factors to low birthweight infants of such mothers. The rate of spontaneous abortion in women with Fallot syndrome is significantly higher (24%) than in the general population (10%). Congenital malformations including congenital heart defects and gastrointestinal defects occur in 6% of newborns, i.e. 2 times more often than in the general population.