title: Exposure to specific herbal products during pregnancy and the risk of low birth weight.
abstract: BACKGROUND
  Despite the fact that herbal products (HP) are used frequently during gestation worldwide, studies indicate that they may not be free of danger for fetuses. Evidence about the safety of HP use during pregnancy and their impact on pregnancy outcomes is currently lacking.
  
  
  OBJECTIVE
  To quantify the association between HP use during the last 2 trimesters of pregnancy (≥15 weeks of gestation [WG]) and more specifically, between use of chamomile (Anthemis nobilis), flax (Linum usitatissimum), peppermint (M. balsamea), or green tea (Camellia sinensis) (alone or in combination with other HPs) and the risk of low birth weight (LBW).
  
  
  METHODS
  We evaluated data from the Quebec Pregnancy Registry, which was created by the linkage of 3 administrative databases in Quebec, and a self-administered questionnaire mailed to subjects. Participants 8505 women were randomly selected from the registry. Overall, 38.5% of women (n = 3273) returned their questionnaires, and 3183 were included in the study (8 were excluded because of missing values on birth weight or giving birth to twins or triplets). Outcome measures We performed a case-control analysis. Cases were defined as women who delivered a newborn <2500g and controls as women who delivered a newborn ≥2500g. Multivariate logistic regression models were used to analyze data.
  
  
  RESULTS
  Amongst the selected 3183 participants, 424 (13.32%) were cases. After adjusting for potential confounders, no statistically significant associations were found between the use of any HP during the last 2 trimesters of pregnancy and the risk of LBW, or between the use of flax, chamomile, peppermint, or green tea (alone or in combination with other HPs) during the last 2 trimesters of pregnancy and the risk of LBW.
  
  
  CONCLUSIONS
  HP use during the last 2 trimesters of pregnancy and more specifically, use of flax, chamomile, peppermint, or green tea alone or in combination with other HPs did not significantly increase the risk of LBW.
authors.affiliation: Ste-Justine Research Center, Montreal.
authors.forename: Krystel
authors.initials: K
authors.lastname: Moussally
authors.forename: Anick
authors.initials: A
authors.lastname: Berard
mesh_terms: D000328:Adult; D028244:Camellia / Q000009:adverse effects; D016022:Case-Control Studies; D031167:Chamaemelum / Q000009:adverse effects; D005260:Female; D019597:Flax / Q000009:adverse effects; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D036142:Mentha piperita / Q000009:adverse effects; D028321:Plant Preparations / Q000009:adverse effects; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011792:Quebec / Q000453:epidemiology; D012042:Registries; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D028321:Plant Preparations