How frequently does OCP use cause an early abortion?
At this point, no one knows. There are many factors which influence the answer to this question and it is possible that as technology improves, an accurate estimate will be made. One of the determining factors is how often OCP use allows ovulation to occur. If the rate of ovulation is documented to be substantially higher than the pregnancy rate, then one could start to make an estimate of the frequency of abortion in women who take the OCP. Measuring a woman’s ability to ovulate is difficult. Researchers measure ovulation rates in women who are taking the pill by using several parameters including: 1) Ultrasound measurements of the ovary, specifically the size of the largest (dominant) follicle (which contains the egg or oocyte), and 2) hormonal assays of progesterone and estradiol levels. Until now, many researchers have arbitrarily accepted that a pregnancy has occurred when the progesterone levels reaches a certain height, but it is possible that OCP use depresses the ovary’s abili
