
This is not entirely true: if the water is properly chlorinated (such as public swimming pools), it is impossible containing dangerous germs.
Yes it is true, however, that chlorine can cause a deterioration of the protective vaginal flora, which in turn returns to the pregnant more vulnerable to infections, especially during the last three or four weeks before delivery. So in this period, you must perform periodic inspections and consult your doctor if present flow, burning or itching.
During pregnancy there is no objection against the pits, whether covered or outdoors. They are also excellent places to get fit before the imminent arrival of childbirth.