Just for argument/clarification I looked up causes for cerebral palsy. This is from the Mayo Clinic's website...
Cerebral palsy is caused by an abnormality or disruption in brain development, usually before a child is born. In many cases, the exact trigger of this abnormality isn't known. Factors that may lead to problems with brain development include:
- Random mutations in genes that control brain development.
- Maternal infections that affect the developing fetus.
- Fetal stroke, a disruption of blood supply to the developing brain.
- Lack of oxygen to the brain (asphyxia) related to difficult labor or delivery. This is rarely a cause.
- Infant infections that cause inflammation in or around the brain.
- Traumatic head injury to an infant from a motor vehicle accident or fall.
So none of those really fall in line with smoking. Maybe the lack of oxygen thing, but it says that's rare, and I would think you'd have to be smoking an insane amount to even get to that point.
Smoking while preggers usually causes low birth weight (which can cause many other problems), premature births, which kinda goes hand in hand with that first symptom, heart problems, lung problems, greater susceptibility to cancer, and yes even low IQ and behavioral and learning problems.
As CP is technically not a disease or genetic condition, and rather a sort of injury brought on, usually congenital, I guess it's technically possible smoking could be the trigger. But I haven't seen any links to that yet in the few pages I have looked up.