According to the more dominant interpretations of the doctrine or dogma of the Catholic Church, birth control is not completely forbidden. For as long as the method chosen does not impede, block, or alter natural human physiological processes, then the chosen form of birth control is perfectly acceptable. This means that things like condoms, the pill, herbal tinctures, and vasectomies are all out the window for the average, devout Catholic couple.
However, while the afore-cited methods effectively removes all of the more conventional (and some of the more unusual) forms of birth control that are publicly known, it does not eliminate something known as natural family planning or NFP. Incidentally, NFP techniques are officially supported by the Catholic Church, so there is technically no violation of dogma by using them. This, of course, is only the general consensus and may be challenged, depending on interpretation of the appropriate scriptures and teachings.
One trait that all NFP birth control tactics use is observation of the female. Working on the assumption that the male is generally fertile at all times and, thus, nothing can be done about that, NFP focuses...