RESUMO
PURPOSE: The objective of this study was to explore whether maternal nausea in pregnancy, a potential surrogate marker of endogenous estrogen levels, was associated with age at attaining pubertal milestones in sons and daughters. MATERIALS AND METHODS: The study included a total of 14,612 boys and girls born in 2000-2003, from the Danish National Birth Cohort. Information on nausea was reported by mothers during pregnancy in telephone interviews scheduled around gestational week 12 and 30. Their children were invited every six months from 11 years of age until 18 years of full maturation to provide information on current pubertal status. Pubertal milestones included pubic hair, axillary hair and acne for both sexes, besides genital development, voice break and first ejaculation for boys, and breast development and menarche for girls. Mean monthly differences in age at attaining several pubertal milestones for boys and girls were estimated according to duration of nausea in the first trimester (0, 1-6, 7-11, 12 weeks). Further, we explored whether duration of nausea in the first two trimesters (0, 1-8, 9-15 or 16-28 weeks) and severity (measured by co-existence of vomiting and weight loss) were associated with pubertal timing. RESULTS: Neither maternal nausea in the first trimester nor duration or severity of nausea in the first two trimesters were associated with pubertal timing. CONCLUSION: Our study does not support the hypothesis that nausea in pregnancy - as a surrogate marker of endogenous estrogen levels - is associated with age at attaining pubertal milestones in children.