Anecdote alert!
I know the midwife who delivered the first grandchild of the founder of Hell's Angels. The pregnant daughter of the founder of Hell's Angels smoked marijuana every day of the pregnancy until she told the midwife. The midwife told her to stop, around the 7th month of the pregnancy and put her on high doses of vitamin C for the duration of the pregnancy to detox. After the baby was born, the newborn was sweating, which is rare, and is a sign of detoxing.
Years ago Mothering Magazine did an article on this; many mothers reported their babies born of a pregnancy during which the mother was smoking pot had "very clear blue eyes" - I have no idea what that may mean.
Over these many years, I have known many women who smoked marijuana during pregnancy. I am sure the marijuana may have helped the emesis gravidarum that many women have in the early pregnancy. I do not know of any problems with the babies at the time I knew these moms.
I never smoked marijuana during pregnancy.