It's every mother's nightmare to have a child taken away by Child Protective Services (CPS), but that's exactly what can happen. In some states, smoking pot while pregnant is treated as child abuse, so THC testing during pregnancy has been used to screen expectant mothers.
Legal Status
Marijuana has been decriminalized in most states in some way, such as for medicinal use. In these states, even though you can't be punished for marijuana use, it's not necessarily the case if you're pregnant.
For example, Colorado legalized pot for recreational use in 2012, but state law considers it differently while pregnant. If a newborn tests positive for a schedule I or II controlled substance, it's considered child abuse. Although marijuana is legal in Colorado, it's still a schedule I controlled substance according to the federal government.
In 2001, the case of Ferguson v. City of Charleston was decided by the Supreme Court. This clarified that expectant mothers had a reasonable right to privacy when attending pre-natal checkups. While this doesn't exclude THC testing during pregnancy, it does mean that pregnant mothers can seek medical attention without fear of being prosecuted.
Many people contrast the situation with smoking tobacco while pregnant, which is harmful but not illegal.
Is Marijuana Harmful while Pregnant?
The truth is that no one knows for sure. What is known is that THC passes from the mother to the fetus through the placenta. Some studies have found no statistical link between THC and birth defects, while others have indicated various risks and long-term effects.
The general consensus is to avoid marijuana while pregnant, even though it may be less dangerous than tobacco or alcohol.
Drug Testing while Pregnant
Given the supreme court's ruling, any positive results for THC are likely to result in a recommendation to not use marijuana while pregnant or breast feeding. If you continue, however, they may initiate steps to get CPS involved. Despite the Supreme Court ruling, there are various ways they can initiate this process.
Note that they can also test the infant after birth, and this may have consequences depending on state law.
Passing a THC Drug Test while Pregnant
The best way to pass a drug test while pregnant is to stop as soon as you learn you're expecting. Unless you've been a heavy user, the metabolites should leave your system in a couple of weeks. For the heaviest users, it might take a month or more.
A detox drink would usually get you through a drug test, but most drinks recommend against using them while pregnant. Even though they contain all-natural ingredients that are well tolerated in adults, it's not known how they might affect a developing fetus.
Taking a hair or a saliva drug test is a little easier while pregnant, because you don't need to ingest anything. For example, if you were to use a detox mouthwash, you could (and should) spit it out after use.
If a hair sample needs to be given for THC testing during pregnancy, you can use special hair shampoos and treatments before a test. As these are applied directly to the hair, it can't harm your baby.