Pain in the Ass

An bill making its way through the Ohio legislature has attracted a lot of attention lately for proposing that abortions be outlawed after a fetal heartbeat can be detected - which occurs about 6 or 7 weeks after conception.  This law - HB 125 - is not only in direct defiance of Roe v. Wade (which mandates that abortion rights not be violated prior to viability, currently defined at 24 weeks of gestation), but was also recently the subject of a court case in which a pregnant woman was given a ultrasound in the courtroom when her 9-week-old fetus was called to "testify."

Similarly, many states require that a pregnant woman have an ultrasound and listen to her fetus' heartbeat prior to obtaining an abortion.  These ridiculous bills are founded on the sappily sweet "Touched by an Angel" sentiment that a beating heart on an ultrasound could never cause anything but joy and reverence.  Naturally, however, lots of organisms have circulatory organs just as complex as the heart tube found in the 7-week fetus:  the cattle and pigs we don't hesitate to slaughter for meat, for example.  Maybe McDonald's patrons should be legally required to listen to a bovine heartbeat before deciding whether to order a McRib.

As does a major myocardial infarction, fatass

What worries those of a slightly more scientific, less sentimental nature is the issue of embryonic brain development and fetal pain.  After all, no brain, no pain.  The fetal pain argument has recently led five US states (Kansas, Nebraska, Indiana, Oklahoma, and Idaho) to ban abortions after 20 weeks of gestation - once again, in direct opposition to Roe v. Wade.  Now, since I just finished writing a paper on fetal cortical development for my Developmental Biology course, I'll try to reproduce the gist of the argument here to dispel any and all concerns for fetal pain in abortion.

The cerebral cortex, the portion of the brain necessary for thought, language, and pain sensation, begins forming around 8 weeks post conception, when the anterior and posterior regions of the dorsal telencephalon start secreting signals to pattern the cortical layout.  From this point, cortical progenitor cells in the subventricular zone begin differentiating into glial cells and neurons, and neurons begin the process of migrating upward to the cortical plate.  Once they have reached their destination, they will undergo myelination and form synapses with other neurons, in a process which will continue throughout development and even after birth.

http://www.humpath.com/spip.php?article5287&id_document=4056

The brain of a 22-week-old human fetus

According to the Guttmacher Institute, 88% of abortions occur prior to 12 weeks of gestation.  At 12 weeks after conception, the regions of the cortex have been specified, but neuronal migration is just beginning, and will not be completed for at least another month.  The neuronal circuits that are needed for sensory perception will not form until much later, 24 weeks at the earliest.

Neurons beginning their migration

Neurobiologists are and have been in agreement that a fetus cannot feel pain prior to 24 weeks of gestation, since the circuits needed for sensation are simply not present before that time (seriously, no brain, no pain).  Less than 2% of abortions occur after 20 weeks of gestation, and abortions are performed after the 24-week mark only in the most dire of situations.  So, an aborted fetus can not and will not feel pain.  Questions answered?  Problems solved?  If only.