I have experience with a family of 5 girls whose Mother was/is a crack addict. The oldest is now 16 years and the degree of addiction has gone from the Mother attempting to taper her drug use to not having concern about the impending birth at all. The oldest child, now attending school with average and above average grades and working a part-time job, appears to be normal except for her unusually quick and violent temper. All the girls do well in school, the younger two however, likely most affected by uncurtailed drug use, are extremely hyper and often are difficult to focus on things which require long sitting and concentration. There were also symptoms of noticeable tremors in these girls when they were born. None of the girls required any specific detoxification. The girls are thriving well considering their living situation. They are accomodated by relatives periodically but for the most part have remained in the home. There is an older daughter born before the Mothers' decline, who is 23 and assits with their care a great deal. In a stable environment these children can thrive. Many have emotional problems as they get older, however, I don't know of any studies which might indicate how much of these problems are due to their relationship, or lack of, with their parents and how much may be related to the drug use. Your patience and watchful eye can help curb these problems. Best of luck.
If the mom had been using cocaine during the pregnancy, particularly at the time of birth, this would likely have been evident at birth. In fact, babies can be born displaying withdrawal effects because of the influence of the cocaine. Children who have been damaged due to cocaine often do not thrive physically in their early years, they have unstable mood patterns, they do not progress cognitively at a normal rate, may display learning problems and behavioral difficulties, etc. In other words, the impact can be evident in one or several of the developmental processes.