Analyse einer Studie zur möglichen Teratogenität chinesischer Arzneidrogen und ihrer Entgegnung von TCM-Seite

A Chinese study conducted at 23 Chinese hospitals postulated an association between “peri-conceptional” exposure to TCM medicines and an increased rate of teratogenicity (Peng et al. 2023). This exposure refers to a period from up to six months before conception until the end of early pregnancy and examines the intake of TCM medicines without or with additional Western medicines compared to no intake of medicines at all. The study was later withdrawn by the publishing journal. Nevertheless, an evaluation of the study is worthwhile with a view to avoiding misinterpretations.

The evaluation comes to the conclusion that the data collection with regard to Chinese medicines taken is clearly inadequate and the study presentation shows distinct transparency deficiencies, particularly with regard to the description of group baseline characteristics and the number of women taking TCM medication exclusively. The research question of the study is based on a flawed design because it mixes the intake of medication before pregnancy—for which an influence on teratogenicity is implausible—with the intake during early pregnancy as well as mixing the exclusive intake of TCM medicines with the intake of TCM medicines with additional Western medication. In addition, the study is based on very small numbers of teratogenicity cases attributed to TCM. There were 10 cases, two of which are to be disregarded due to pre-conceptual intake and one with mixed TCM/Western medication; in one further case TCM medication is unclear. The study does not provide adequate evidence for a valid statement about a possible teratogenicity risk attributable to TCM medication. However, the absence of a teratogenicity risk cannot be inferred either. It remains striking that among the 6 cases of teratogenicity in which TCM medication is known, there are 4 cases involving the compound medicine Pudilan.

In November 2023, several authors from various Chinese-influenced TCM institutions from the USA and Australia published a response questioning the Peng study (Liu et al. 2023). This response is also analysed to clarify whether its arguments are accurate.

The analysis shows that the authors enumerate shortcomings in the teratogenicity study, but remain superficial in their criticism and fail to uncover significant structural deficiencies in the study design. At the same time, they document a dubious concept of safety in Chinese medicine by referring to a short passage in the “Yellow Emperor’s Inner Classic” (Huang Di Nei Jing, published in the 1st century BCE), the application of which to the risk of teratogenicity is highly questionable. Medical ethical principles demand that a well-founded suspicion of a teratogenic risk should be taken seriously, even if the risk has not (yet) been strictly scientifically proven. Concerning pregnancy risks of Chinese medicine, there are still many unanswered questions, particularly with regard to the overall lack of human data.