>>1302401Baby is not in vagina, and there is a barrier separating the vagina from the uterus (the cervix). During pregnancy it grows a true, full seal (the "water" that breaks at the start of labor) and outside of pregnancy it's an incredibly small passage (<0.1mm diameter).
Also, yes, water will enter the vagina during submersion, to some extent, and yes it can cause issues (usually yeast infections) Water will also intrude up the urethra a short distance in both males and females as well.