Curiously, in some rare cases and under certain very specific circumstances it is more than just a thought experiment (the paper you have linked also briefly mentions it), although it is thought of as a special case of euthanasia rather than an unusual kind of abortion.

The Dutch euthanasia laws require people to ask for euthanasia themselves (voluntary euthanasia), and it is legal for people of 12 years and older. In the Netherlands, euthanasia remains technically illegal for patients under the age of 12.

[...]

In 2005 a review study was undertaken of all 22 reported cases between 1997 and 2004.[7] All cases concerned newborns with spina bifida and hydrocephalus. In all cases, at least 2 doctors were consulted outside the medical team. In 17 of 22 cases, a multidisciplinary spina bifida team was consulted. All parents consented to the termination of life; in 4 cases they explicitly requested it. The mean time between reporting of the case and the decision concerning prosecution was 5.3 months. None of the cases led to prosecution. The study concluded that all cases of active termination of life reported were found to be in accordance with good practice.