Evolution resulted in human females having the potential to become pregnant at any time of the year: a superior survival trait. And God, or Mother Nature, has been lavish in provisions to make it easy for women to get pregnant. But it’s been left to the woman to figure out how to not get pregnant or how to get un-pregnant.
At the beginning of an average young woman's fertile years, she has about one million immature oocytes (eggs). Every lunar month, one or two eggs mature and are made available for fertilization, except for when the woman is pregnant and for a period of time after a birth. And the average woman remains fertile until menopause, about 30 years later. Doing the math, 13 (lunar months) times 30 (years) would total 390 eggs potentially available for fertilization.
Of course life doesn't always go smoothly, and most couples use contraception, so the actual number of eggs presented is less. But compare that with average number of children women actually produce – not quite two. Technically, only two or three eggs are required. So what happens to all the other eggs? One way, or the other, they all die. But that's all right, that's the way it's supposed to work.
Since, on average, there will only be two or three "lucky" eggs, why shouldn't the woman who possesses them get to decide which ones they will be? Certainly makes more sense than having a group of politicians making medical and financial decisions for her.
John H. Terrell