by Carol A Westbrook

The Supreme Court is poised to make another landmark decision this year, when it determines if it will uphold a Texas Federal court’s ruling that invalidates the FDA’s (U.S. Food and Drug Administration’s) updated labeling of the abortion pill mifepristone (pronounced mi-ˈfe-pri’-stōn) , brand name Mifeprex (Fig 1). Not only will this ruling have a significant impact on abortions in the US, it will also determine whether the Supreme Court (Fig 2) has the power to modify or nullify an FDA ruling. But before we delve any further into this debate, let’s review the action of this drug on the biology of the female reproductive system.

In the early part of a woman’s monthly cycle, her levels of the hormone progesterone rise, and this causes the lining of the uterus to thicken and increases its blood supply, converting it into a state that can support a fetus. After unprotected sex, sperm are deposited in the vagina, and they begin to travel up the fallopian tubes; at the same time, an egg is released from the ovary and travels down the fallopian tube. (Fig 3) When sperm and egg unite, conception occurs. Interestingly, the date of conception does not mark the start of the pregnancy; pregnancy is actually counted from the beginning of a woman’s monthly cycle, two weeks prior to conception. The total length of a pregnancy is usually 40 weeks, or 9 months. Read more »