Herbal Medicines Used During the First Trimester and Major Congenital Malformations–an Analysis of Data From a Pregnancy Cohort Study

Abstract

P-364 Introduction: Major congenital malformations place a considerable burden on the affected child, the family and society. Use of herbal medicine during pregnancy is gaining popularity worldwide. Any kind of medicine used during pregnancy might have a harmful impact, so such practice has raised concerns. Aim: To explore the relationship between use of herbal medicines by pregnant women during the first trimester of pregnancy and risk of major congenital malformation in live born infants. Methods: This was a cross-sectional analysis of data from a prospective pregnancy cohort which was established in 1984–1987. To assemble the cohort, each pregnant woman of 26 or more weeks of gestation who came to the Taipei Municipal Maternal and Child Hospital in Taiwan for prenatal care was enrolled and interviewed using structured questionnaires. Detailed information, including herbal medicines used during different periods of pregnancy, was obtained. Past medical history, current obstetric data, and medicines used during pregnancy were abstracted from medical records. Data on birth weight, gestational duration, and characteristics of live born infants were gathered from the Taiwan national birth registration. Congenital malformation information was obtained from multiple sources: from the newborn examination record during 1984–1987; from the national death registration for the period during 1984–2003; and from the National Health Insurance for critical illness and injury registration data during 1996–2000 in Taiwan. Multiple logistic regression was used to estimate the odds ratio of major congenital malformation by herbal medicines used during the first trimester. Results: A total of 14,551 live births were analyzed. After adjustment for confounding factors, taking Huanglian during the first trimester of pregnancy was found to be associated with increased risk of congenital malformations of the nervous system (adj. odds ratio 8.62, 95% CI 2.54 to 29.24). An-Tai-Yin was associated with increased risk of congenital malformations of musculoskeletal and connective tissues (adj. odds ratio 1.61, 95% CI 1.10 to 2.36) and eye (adj. odds ratio 7.30, 95% CI 1.47 to 36.18). Conclusion: We found evidence for a link between the use of specific herbal medicines during the first trimester of pregnancy and increased risks of specific groups of congenital malformations. We could not investigate whether the adverse effects related to direct toxicity of herbal medicines, from misuse or contamination, or from uncontrolled confounding. Nonetheless, we would advise caution regarding use of herbal medicine during pregnancy, and suggest further investigation of these findings.