ANDERSON – It’s tempting at a time like this to offer a crash course in biology to the Indiana General Assembly. These lawmakers, the vast majority of them men, are about to wade into what until now has been a conversation between a woman and her physician. Perhaps we should tell these guys a bit more about how pregnancy works.

Do they know, for example, that a woman can never really be one week pregnant?

Physicians track a pregnancy from the first day of the woman’s most recent period, which means that in that first week, a woman’s body is not yet ready to become pregnant. It does not have an egg in position to be fertilized.

That point comes in week two when ovulation begins and a sperm can find its way to an egg waiting in a woman’s fallopian tube. If a sperm manages to penetrate the layers of an egg, the result will be a new cell called a zygote. This process can take up to 24 hours.

The zygote then divides into two cells, which divide into four cells, which divide into more and more cells as the zygote becomes a blastocyst and moves down the fallopian tube before entering the uterus three to four days after fertilization.

Pregnancy really begins, though, when the blastocyst implants in the uterine lining and forms an embryo. That can happen anywhere between eight and 18 days after fertilization, but it usually takes about 14 days. Researchers estimate at least 40% of all fertilized eggs never reach this stage.

So life doesn’t really begin at fertilization. For many fertilized eggs, it doesn’t happen at all, and for others it takes weeks. Around the end of the 10th week, the embryo becomes a fetus. By this point, the fetus has a profile with well-defined eyes, mouth and ears.

Under current Indiana law, abortions are legal up to the point of fetal viability.

That is the stage in development when a fetus can survive on its own outside the mother’s womb. The Supreme Court majority in Roe vs. Wade decided this was the point when the rights of an unborn child could legally trump those of an expectant mother.

Until that point, the court said, the decision about whether to move ahead with a pregnancy should rest exclusively with the woman and her physician.

Medical experts place this mark at 22 weeks of development. They warn, though, that many babies born at this stage won’t survive, and for those who do, the risk of permanent disability is high.

Still, some say 22 weeks is too long to wait. They might draw the line as early as six weeks, the point at which a cluster of cells that will eventually form a heart begins to send out electrical signals that can be detected by ultrasound.

This milestone comes at about the time when a woman might learn she’s pregnant. It’s the milestone abortion opponents refer to as the “fetal heartbeat.” Scientists will tell you that heartbeat is generated by the ultrasound machine itself. You won’t hear an actual heartbeat for a few more weeks.

There are lots of reasons a woman might seek to end a pregnancy. Most are intensely personal. Some are heartbreaking. None is really the business of politicians.

The legislation now pending in the Indiana Senate would outlaw nearly all abortions, leaving exceptions only for cases of rape or incest or to save the life of the mother. Some pro-life advocates would go further. They’d eliminate the exceptions for rape and incest, even in the case of a 10-year-old girl.

Every Hoosier has a right to be born, they say. Even those Hoosiers who remain a disorganized group of cells just forming in the womb. 

Hawes is a columnist for CNHI.