<unk>  use during pregnancy can be discovered by asking the mother, but sometimes women will not admit to having used drugs. Mothers may lie for fear of prosecution or having their children taken away, but even when they are willing to tell the truth, their memories may not be very accurate. Determining the purity of the drug they have taken also may not be possible. More reliable methods for detecting<unk><unk>  involve testing the newborn's hair or meconium (the infant's earliest stool). Hair analysis, however, can give false positives for<unk><unk> , and a newborn may not have enough hair to test. The newborn's urine can be tested for<unk>  and metabolites, but it must be collected as soon as possible after birth. It is not known how long after<unk>  the markers will still show up in a newborn's urine. The mother's urine can also be tested for drugs, but it cannot detect drugs used too far in the past or determine how much or how often the drugs were used. Tests cannot generally detect<unk>  use over a week prior to sample collection. Mothers are more honest about<unk>  use when their urine is also tested, but many users still deny it. Both maternal and neonatal urine tests can give false negatives.
Prenatal cocaine exposure
Maternal hypothyroidism
Y chromosome microdeletion
Chromosomal fragile site
Child-on-child sexual abuse
Chromosome 2q deletion
Haploinsufficiency of A20
Prenatal testosterone transfer