Brief Answer:
not entirely sure of the question

Detailed Answer:
but beecause it is very closely defined, I can probably give close to all the information there is on the topic.
The first laboratory studies on this began in the 1990's. It doesn't seem likley there could be any prior to that time. Anywhere.
Then, the question of what do you test to determine drug exposure. HAIR of the newborn is the longest lasting and most sensitive way to test for drug exposure. The really interesing thing is that NON-identical twins have different amounts of drug in their hair (?!/) BUT alcohol doesn't stick inside of hair. Alcohol related compounds can be found in the STOOL of the newborn BUT, this testing is not ready for prime time. All of the compounds can be there from things other than alcohol (infection, other alcohol like compounds, etc.)

wow, this seems to be a THING in XXXXXXX area with estimates being double the rate most other places (1 in five versus more like 1 in ten or less).
This got to be a big deal about 2010.

then, you might wonder how long the test will still be positive for. It is about the same as with the mom BUT different materials hold the drugs longer. Hair will tell exposure for certainly anytime in the last month prior to delivery. Stool will be for over a week. Urine is generally clean after a week for most drugs of abuse same as the mom... and genrally the mom is a better source for the urine to test. A lot of marijuana use, and it will stay in the urine for over a month.

I hope this answers the question. It was interesting.

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Brief Answer:
cats.. trees, drug positve infants.. social services.

Detailed Answer:
You know certain things by the mathematical distribution of the possible.....
You know cats can get down from trees because you rarely see cat skeletons in trees.
You know they don't pull the licenses of doctors who have mistresses because you can find some doctors.
You know they cannot take every infant that tests positive for drugs in XXXXXXX because a very large percentage of the schools would be filled by foster-kids; higher percentage than any one single minority group by comparison.

http://www.avvo.com/legal-guides/ugc/the-consequences-of-drug-use--abuse-in-virginia-abuse-and-neglect-cases

It will be a pain; you will be under investigation either if in treatment or if not in treatment and drugs are found on testing. And treatment is probalby your best option for a number of reasons.

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Brief Answer:
tricky

Detailed Answer:
first, that is not going to be a very major issue by itself since it is not a very serious drug and there is a very very large number of people who use it. It is doubtful they will remove a child from a home JUST for that. But they might visit.
Then... depends on the amount of marijuana smoked. ONE use of marijuana stays inthe mother for about a week and that is about the same for the cord blood; probably LESS. HOWEVER, in heavy users marijuana may be detectable for a bit over a month in urine. Cord blood.....
"positive hair test results were confirmed in placenta/fetal tissues in 10 cases out of 60 for cannabis... " 1 in six of probably fairly regular users. Blood is generally NOT as good as urine for detection.
So, if heavy user, it is going to be detected. If used within 1 week of testing very likely to be detected. If over a week and NOT a heavy user (using most days) then probably NOT detectable.

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Brief Answer:
best of luck

Detailed Answer:
you're very welcome.
counseling is a good idea (although to be entirely honest, there is marginal data for marginal risks associated to the developing baby from marijuana use... not very major problems). the ones that are worrisome are school success in much later life but there are so many other possible explainations on that.

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