Effect of prenatally administered hypericum (St John’s wort) on growth and physical maturation of mouse offspring

Objective: Our purpose was to determine whether prenatal exposure to the herb hypericum (St John’s wort) affects long-term growth and physical maturation of mouse offspring. Study Design: Forty CD-1 mice were randomly assigned to receive daily doses of either 180 mg/kg per day hypericum (n = 20) or a placebo (n = 20) for 2 weeks before conception and throughout gestation. Perinatal outcomes, growth, and physical milestones of the offspring were compared in a blinded manner. Variables were compared by analysis of variance or by χ2 testing. Results: The gestational ages at delivery and litter sizes did not differ between the hypericum-exposed and the placebo-exposed offspring. The body weight, body length, and head circumference measurements from postnatal day 3 through adulthood increased in a manner that was indistinguishable between the two groups of offspring, regardless of gender. No differences in reaching physical milestones (teeth eruptions, eye opening, external genitalia) were noted between the 2 groups. The reproductive capability, perinatal outcomes, and growth and development of the second-generation offspring were unaffected by hypericum exposure. Conclusion: Maternal administration of hypericum before and throughout gestation did not affect long-term growth and physical maturation of exposed mouse offspring. (Am J Obstet Gynecol 2001;184:191-5.)