In the 1960s, the U.S. Food and Drug Administration approved a contraceptive that allowed women to plan desired pregnancies and prevent unwanted pregnancies. Oral hormonal contraception ('the pill') uses synthetic hormones similar in structure to progesterone and/or estradiol. What is the pill's mechanism of action? Imagine that four different contraceptives are under development. One blocks ovulation, one blocks fertilization, one blocks cleavage, and one blocks implantation. In the United States, which contraceptive is likely to be the least controversial to bring to market? Why?

Video transcript

Welcome back. Here's our next question. It says. The birth control pill functions primarily by. Well let's recall from our content video that the birth control pill consists of progesterone or a combination of progesterone and estrogen. This action inhibits the release the secretion of FSH and LH follicle stimulating hormone and lutin izing hormone which are necessary for ovulation. So it blocks ovulation, thereby preventing pregnancy. So that's answer. C preventing ovulation. When we look at our other answer choices, we have Choice A blocking cleavage. That would be the actual splitting of the early embryo and multiplying and growing. But that is not how it acts. So not our answer. Choice Choice B says blocking fertilization, preventing the sperm from eating the egg. Um But that is not the case. In fact, if a breakthrough ovulation occurs it can be fertilized so that's not the mechanism. And then finally, Choice D blocking implantation. Um There's a theoretical thought it might thin the lining and prevent implantation. But in when you have pregnancies occur despite being on the pill, it seems that uh the zygote can still implant if ovulation if a breakthrough ovulation does occur despite being on the pill. So that's not its primary function. So Choice D. Is not our answer. So again, the birth control pill functions primarily by choice c preventing ovulation. See you in the next video