Tetrahydrocanabis (THC) and Concomitant Illicit Drug Consumption during Pregnancy
With the increasing number of states where Tetrahydrocanabis (THC) medical or recreational use is legal, consumption of this drug during pregnancy is expected to increase. It is unknown what other drugs are used concomitantly by pregnant woman. We aim to report pregnant woman’s drug use habits when consuming THC.
Our study looks at maternal-newborn dyads with positive urine-meconium THC drug screenings at our institution between January 2006 and December 2010. Data is from an urban non-profit teaching hospital with a high volume delivery center that averaged 5,000 births a year during the study period. Screenings for both mothers and newborns were done per Arizona state’s guidelines: history of previous or current substance use by mother and/or significant others living in the home, history of substance-exposed newborn, non-compliance, signs of neonatal abstinence syndrome, birth weight <5th percentile, along with other specific criteria. Maternal UDS and newborn UDS and MDS results for marijuana (THC), amphetamines, cocaine, and opioids were available. We found mother-baby pairs in which either mother or baby had a positive THC (both urine and meconium were counted). We converted screening reports into mother-baby pair entries in Microsoft Excel, and assigned each a pair number for anonymity. Each entry listed both mother and baby’s positivity status for each of the 4 screened substances (urine was listed separately from meconium for the baby). Our combined analysis looked at every pair in our study. Our split analysis looked separately at maternal screening data for all entries with THC positive mothers and newborn screening data for all entries with THC positive babies.
We found that 26.1% of mother-baby dyads with positive THC tests were positive for another illicit drug(s). The most common drug was opioids (11.6%) followed by amphetamines (10.8%) and cocaine (6.5%). When the data was reviewed separately in THC positive mothers versus THC positive babies, the most common illicit drug picked up on maternal urine drug screening was opioids (16.3%) versus amphetamines in newborn urine/meconium screenings (8.8%). There was concomitant maternal and newborn THC positivity in 22.4% of dyads; majority of THC exposure was picked up in only one party (77.6%) – infants more than mothers (42.4% vs. 35.2%).
This study reveals a significant concomitant use of THC with other illicit drugs during pregnancy in our population. Looking at mother-baby dyads allows us to infer undetected drugs on the maternal urine drug screening test. THC use can be a marker for use of other drugs by pregnant women that may be eliminated faster from the mother or baby’s systems. It is important to probe for other illicit drug use in pregnant women who consume THC. In order to not miss THC exposures, it is crucial to do complete screening of both mother and infant (particularly meconium in infants).