Pregnancy and exercise go very well together, also in recreational and elite athletes

Mireille van Poppel is part of an IOC expert group on exercise and pregnancy, and recently the first paper out of this group found it's way into the BJSM.

Guidelines on physical activity or exercise and pregnancy encourage pregnant women to continue or adopt an active lifestyle during and following pregnancy. Systematic reviews of pregnancy-related guidelines on physical activity found similarities between recommendations from different countries, but noted that the guidelines differed in focus. Importantly, the focus of most previous guidelines has been on healthy pregnant women in the general population, in whom there is almost always a decline in physical activity during pregnancy. Yet there are enthusiastic exercisers and elite athletes who often meet and exceed general exercise recommendations for pregnant women, but there are no exercise guidelines specifically for these women. 

The IOC and most National Sports Federations encourage women to participate in all Olympic sport disciplines. The IOC promotes high-level performance, and it is also strongly committed to promoting lifelong health among athletes — not just during their competitive sporting careers. With an increasing number of elite female athletes competing well into their thirties, many may wish to become pregnant, and some also want to continue to compete after childbirth. With this background, the IOC assembled an international expert committee to review the literature on physical activity and exercise (1) during pregnancy and (2) after childbirth, using rigorous systematic review and search criteria.

The full paper can be found here (open access)

Kari Bø, Raul Artal, Ruben Barakat, Wendy Brown, Gregory A L Davies, Michael Dooley, Kelly R Evenson, Lene A H Haakstad, Karin Henriksson-Larsen, Bengt Kayser, Tarja I Kinnunen, Michelle F Mottola, Ingrid Nygaard, Mireille van Poppel, Britt Stuge, Karim M Khan. Exercise and pregnancy in recreational and elite athletes: 2016 evidence summary from the IOC expert group meeting, Lausanne. Part 1—exercise in women planning pregnancy and those who are pregnant. Br J Sports Med 2016;50:571-589 doi:10.1136/bjsports-2016-096218