Exercise during pregnancy has been linked to better foetal heart health and nervous system development, according to new research.
This means women who continue to cycle while pregnant could be benefiting their unborn babies as well as themselves.
However, a team from the Kansas City University used stationary cycling rather than road cycling to achieve their findings among a panel of expectant mums.
And while the anecdotal evidence is that many cyclists continue to ride their bikes well into the final months of pregnancy, the Royal College of Obstetricians and Gynaecologists puts it in the same category as sports like skiing, because of the potential for falls.
RCOG official guidance on the matter is as follows: “Women are cautioned about the potential for loss of balance and foetal trauma if they participate in horseback riding, downhill skiing, ice hockey, gymnastics and cycling during pregnancy”
But a forum on the CTC’s website contains several examples of women who defied this guidance and said they achieved benefits from road cycling during pregnancy, some even continuing to go out on club runs.
The Kansas City University researchers wanted to see if maternal exercise had cardiovascular benefits for the foetus, according to a story on the BBC website.
The scientists used a non-invasive device to measure the magnetic fields produced by the electrical activity of maternal and foetal heart rates.
The women studied were aged between 20 and 35 and were checked between the 36th and 38th weeks of pregnancy.
They were classed as exercisers if they did moderate intensity aerobic exercise such as moderate to vigorous walking, stationary bicycling and running for at least 30 minutes, three times per week. Most were doing more.
The researchers then compared them with pregnant women who did not exercise regularly.
Dr Linda May, who led the study, said: "Foetal breathing movement and the nervous system were more mature in babies exposed to exercise."
She said more research was needed, but the study showed babies of women who exercised had a more mature respiratory system, suggesting they would fare better after birth.
A spokesperson from the Royal College of Obstetricians and Gynaecologists rold road.cc: “Light-to-moderate exercise is beneficial to women during pregnancy. The findings from this new research are interesting but more research needs to be done as this was a small study. Pregnant women should consult their midwives and doctors on the types of exercise to do when pregnant and how much. ”