PRENATAL AND CHILDHOOD EXPOSURES AND AGE AT MENARCHE

暴露于化学物质对发育中的胎儿和儿童造成的危害正日益受到关注。 主要检查的发育终点是不良妊娠结局，以及对神经行为发育的一些考虑。 关于正常的月经功能以及它是如何在青春期开始的知之甚少。在这项试点研究中，我们建议检查性发育的措施，即初潮年龄，其关系到产前暴露于化学物质，包括烟草烟雾，酒精和咖啡因（TAC）。 主动吸烟是怀孕期间已知的生殖危害，也与不孕症和激素排泄水平的改变有关。产前酒精暴露与胎儿生长迟缓和后代神经功能缺损有关。 许多研究表明酒精对成年人的内分泌系统有影响，并且有证据表明它可能影响性成熟。 咖啡因的已知作用提出了改变激素分布的合理机制，并报告了与延迟受孕时间的关联。 因此，这三种接触都可能通过对产前激素环境或发育中的神经系统的作用影响性发育。 拟议的试点研究将利用20世纪60年代初确定的大量怀孕数据库。 本研究的受试者将是1000名女儿，这些女儿在童年和青春期都受到了跟踪，在青春期确定了月经初潮的年龄。前瞻性地收集了大量关于产前暴露以及潜在混杂因素的数据。 一些重要的暴露和儿童期的条件也被前瞻性地确定，包括父母吸烟，儿童期的行为和成长。 有了这些数据，我们建议检查是否在子宫内暴露于TAC或儿童期暴露于父母吸烟与月经初潮年龄的扰动。初潮年龄早与乳腺癌风险增加有关，因此初潮年龄的改变可能会对儿童和妇女的健康产生其他不利影响。 这些数据将有助于设计与生命早期接触有关的生殖过程和生长发育的进一步研究。

Hazards posed to the developing fetus and child by exposure to chemical substances are receiving increasing attention. The developmental endpoints examined primarily have been adverse pregnancy outcomes, as well as some consideration of neurobehavioral development. Little is known about normal menstrual function and how it is initiated during adolescence. In this pilot study we propose to examine a measure of sexual development, namely, age at menarche, and its relationship to prenatal exposure to chemical substances including, tobacco smoke, alcohol and caffeine (TAC). Active smoking is a known reproductive hazard during pregnancy and has also been associated with infertility and alterations in hormone excretion levels. Prenatal alcohol exposure is associated with fetal growth retardation and neurologic impairment in offspring. Numerous studies have shown effects of alcohol on the endocrine system of adults and there is suggestive evidence it may effect sexual maturation. Known actions of caffeine present plausible mechanisms for alteration of hormonal profiles and an association with delayed time to conception has been reported. Thus all three exposures may possibly affect sexual development via actions on the prenatal hormonal milieu or the developing nervous system. The proposed pilot study would make use of a large data base of pregnancies ascertained in the early 1960's. Subjects of this study will be the 1000 daughters followed through childhood and adolescence, at which time age at menarche was ascertained. Extensive data was collected prospectively on prenatal exposures, as well as on potential confounders. A number of important exposures and conditions of childhood were also ascertained prospectively, including parental cigarette smoking, childhood behaviors, and growth. With these data we propose to examine whether in utero exposure to TAC or childhood exposure to parental smoking are related to perturbations in age at menarche. Early age at menarche has been associated with an increased risk of breast cancer, thus alteration in menarcheal age may serve as a sentinel of other adverse effects on children's and women's health. Such data will be valuable in designing further studies of the reproductive process and growth and development in relation to early life exposures.