Beginning of Essay
Although birth control has been practiced since ancient times, the first organized efforts developed during the 19th century as population increased dramatically because of improved medical care, nutrition, and sanitation. However, birth control met with resistanc ....

Middle of Essay
.... of menstruation and ovulation that can be identified by keeping a careful record of the dates of menstruation. A second assumption is that ovulation occurs 14 days before the onset of the next menstruation. The rhythm method is the most commonly used of the natural methods. To be used successfully a record should be kept for at least six menstrual cycles. The fertile period is then defined by a set of rules for example: The length of the shortest cycle less 18 days marking the start of the fertile period and the length of the longest cycle less 11 days marking the end of the fertile period. This is the only birth control method that has receiv ....