Pregnancy is a time when women need to be prepared mentally and physically to meet the challenges of childbirth and the transitions to parenthood. However, this needs to be within the realms of safe practice. The study on which this book is based is derived from the author's work as a midwife with a special interest in exercise. The main aims of the study were to investigate the effects of undertaking a regular exercise programme during and following pregnancy on psychological well being, pregnancy and birth outcomes. Data were collected at three time points during and following pregnancy using a variety of outcome measures and were analysed using appropriate statistical testing. Conclusions were drawn indicating that women who participated in regular physical activity tended to have protection against reduction of psychological well being as measured by a variety of psychological constructs.