Study Reveals Substance Use Among One in Ten Pregnant Women

In this new nationwide study, researchers assessed the prevalence of substance use among approximately 2000 pregnant women in Denmark through the analysis of urine samples and self-reported questionnaires.

The results showed that one in ten pregnant women uses one or more substances.

-The encouraging aspect of our findings is that we did not observe the high hidden numbers suggested by our pilot study. The current method of identifying substance use among pregnant women, that be self-reporting, appears to be adequate, except for alcohol intake and cannabis use. That almost all confirmed positive urine samples were due to nicotine use was not surprising, but still concerning, says Nete Lundager Rausgaard, medical doctor and PhD student at the University of Southern Denmark.

Identification and Support in Maternity Care

Substance use during pregnancy poses risks to both the pregnant woman and the fetus. These risks include malformations, miscarriage, premature birth, and cognitive challenges for the child. The severity of the risk depends on the type of substance used, the timing during pregnancy, the quantity consumed, and the duration of use.

Therefore, it is crucial to identify pregnant women using substances to provide them with help and support. Key figures in this effort are the woman's doctor and midwife, who frequently interact with the pregnant woman and routinely ask about substance use, including alcohol and nicotine.

In Denmark, pregnant women with problematic substance use can be referred to the regional Family Outpatient Clinic (Familieambulatoriet), where interdisciplinary healthcare professionals provide 'extended maternity care' that focuses on the pregnant woman, her partner, and the developing child.

-We cannot rule out the possibility that the pregnant women who participated in the project self-reported their substance use differently than they did to their healthcare professionals. Additionally, since the project was anonymous, we were unable to offer support to those who had positive urine samples or self-reported substance use, explains Nete Lundager Rausgaard.

Are Current Identification Methods Sufficient?

Pregnant women were invited to participate in the project during routine scans, and 88% agreed. They completed a self-reported questionnaire and provided a urine sample, which was initially screened with a urine dipstick and subsequently confirmed by laboratory analysis.

The study revealed that approximately 11% of the pregnant women had confirmed positive urine samples for substance use, with nicotine being the most prevalent substance identified.

Researchers compared the urine sample results with the self-reported data and found a high correlation between what the pregnant women self-reported and what was confirmed in their urine samples.

-It appears that many pregnant women inform us when they use one of the substances we screened for, particularly nicotine," says Nete Lundager Rausgaard

Researchers observed that alcohol intake and cannabis use were not self-reported to the same extent. They have speculated that pregnant women might perceive low alcohol intake as unproblematic.

-On the other hand, some women self-reported recent alcohol intake that was not identified by the urine dipsticks, likely because the intake was below the identification threshold. This indicates that we need to be more thorough in questioning pregnant women about their alcohol intake," explains Nete Lundager Rausgaard.

False Positives in Urine Dipstick Results

Researchers were surprised by the high number of false-positive results from the urine dipsticks. This means the urine dipsticks indicated substance use, but confirmatory analysis revealed that this was not the case.

-Only 44% of the positive results from the urine dipsticks were confirmed by laboratory analysis, explains Nete Lundager Rausgaard.

Therefore, it is essential to question the reliability of these urine dipsticks and always send urine samples with positive dipstick results for confirmatory analysis.

The project has produced results that are now being applied in clinical settings. Notably, it has already prompted local changes in the choice of analysis methods.