Hello I understand your concern. The known effects of methamphetamine on the fetus are quite a few. Premature delivery, detachment of the placenta, low birth weight, heart and brain abnormalities to name just a few. There is also a small number of studies that show behavioral abnormalities such as impaired attention in children whose mothers were meth users during pregnancy. The first four months of pregnancy are very important in the development of the fetus, however it cannot be said for sure how much damage has been done. I understand that it is quite common to not be aware of a pregnancy until the fourth month and if the meth use is stopped and not picked up again until the end of pregnancy and after that, the chances that the baby will be taken away from the mother are very low. It is never too late to turn a new page. Wishing you all the best