Various studies pointed towards a relationship between chronic diseases such as asthma and allergy and environmental risk factors, which are one aspect of the so-called Exposome. These environmental risk factors include also the intake of drugs. One critical step in human development is the prenatal period, in which exposures might have critical impact on the child's health outcome. Thereby, the health effects of drugs taken during gestation are discussed controversially with regard to newborns' disease risk. Due to this, the drug intake of pregnant women in the third trimester was monitored by questionnaire, in addition to biomonitoring using a local birth cohort study, allowing correlations of drug exposure with disease risk. Therefore, 622 urine samples were analyzed by an untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) urine screening and the results were compared to self-administered questionnaires. In total, 48% (n = 296) reported an intake of pharmaceuticals, with analgesics as the most frequent reported drug class in addition to dietary supplements. 182 times compounds were detected by urine screening, with analgesics (42%; n = 66) as the predominantly drug class. A comparison of reported and detected drug intake was performed for three different time spans between completion of the questionnaires and urine sampling. Even if the level of accordance was low in general, similar percentages (~25%, ~19%, and ~ 20%) were found for all groups. This study illustrates that a comprehensive evaluation of drug intake is neither achieved by questionnaires nor by biomonitoring alone. Instead, a combination of both monitoring methods, providing complementary information, should be considered.