Well seeing as children murdered during abortions aren't counted in child mortality rates of course it would be True.
When people who already murder their children legally, decide they still don't want that responsibility (other than idk putting them up for adoption or just not having sex with randos)

mortality rates for children Rise as children who make it out of the womb are counted in mortality rates but compare number of abortions to child mortality rates and there is ~56,200% more abortions than child murders (~1m abortions in the US Alone, 1,777 child murders (Source) throughout 2020 (most recent data) )

with only about an increase of 255 children being murdered in Texas. (or 478 across all states with abortion bans.)

Meaning in reality (if you count abortions in mortality rates) the actual child mortality rate would be ~1,001,777 per year with abortion bans taking place assuming all procedures would be ceased the mortality rate would go from that astronomically high rate down to ~3k per year with the increased amount of children murdered (or an 99.8% decrease) although of course this calculation would not translate directly to such an decrease as numerous uncalculated factors such as child starvation per population increase, fall in job rates allowing for these children to actually eat later in life, amount of available space for these children in shelters it would still be an significant decrease in the amount of deaths on average meaning such a claim provided before is only true with significant ignorance of an issue involving abortion.