THC has no abnormal effects on baby's development.Its a good news
The effects of THC on your pregnancy are similar to that of tobacco smoking. Reduced oxygen and nutrition to your baby via the placenta may occur and result in reduced growth and development of your baby during pregnancy.
So we can expect baby to be small .
No need to worry overall.Just quit smoking for sake of baby's well being.
Take healthy diet,stay happy and calm down for sake of baby's health.