Eugenics is the practice of arranging reproduction within a human population to increase the occurrence of heritable characteristics regarded as desirable. Setting aside who gets to decide which human traits are desirable and undesirable, we simply don’t know enough about the genetic basis for things like industriousness, fidelity, thrift, honesty and countless other human behaviors to pursue a selective breeding program to enhance the frequency of those qualities in humans.
Eugenics fell into bad odor when it was used as a justification for forced sterilization and killing. People may decide to breed selectively, believing their children will possess qualities they desire, but even if that met the threshold for eugenics, it isn’t coercive. People marry within their racial and religious communities all the time, and nobody accuses them of practicing eugenics.
Kate Cox is the Texas woman who sought an elective abortion when she discovered the fetus she was carrying had trisomy 18, an invariably fatal chromosome abnormality. Her physician recommended an abortion, because attempting to carry the fetus to term might result in her being unable to get pregnant again. For this, she has been accused of practicing eugenics.
If anything, the state of Texas is practicing eugenics by forcing her to carry the pregnancy to term. Most fetal aneuploidies are the consequence of maternal chromosome mis-segregation. By denying her an abortion, Texas is trying to coerce Kate Cox into forced sterilization, thereby selectively preventing her from having future aneuploid pregnancies, such as a Down Syndrome child.
Beyond that, aborting a fetus with trisomy 18 is not eugenics. Zero humans with trisomy 18 reach reproductive age, so abortion is redundant as a eugenic measure in this case.
Indeed, an estimated 70%-75% of all human conceptions fail to survive to birth. That number includes both embryos that are reabsorbed before anyone knows conception has occurred as well as miscarriages that happen later in the pregnancy. So God is the greatest abortionist and eugenicist of all time.