Objectives

Infant testosterone (T) surges early in life. This period (known as mini puberty) is crucial to development. Little is known as to what the ultimate function of mini puberty might be. We predicted that parents with putative endocrine signatures of challenging environments (elevated levels of maternal cortisol and paternal T) may be related to elevated levels of infant T. In turn, these endocrine relationships are hypothesized to influence infant growth.

Methods

In a U.S. sample (n = 225 families) of first-time parents and their infants, we measured infant length and weight at three occasions—birth, 3 months old, and 10 months old. We conducted salivary assays of infants for T, mothers for cortisol, and paternal T during the early postnatal period.

Results

We utilized latent growth curve modeling to explore changes in length and weight as predicted by infant T. Infant T predicted the slope of length gains across the study period. Maternal cortisol and paternal T (positively correlated with one another) were positively related to infant T. Neither maternal cortisol nor paternal T predicted the slope of length gains. In an exploratory model, temperament was not related to neuroendocrine measures. Gains in weight—unlike length—were not related to infant T.

Conclusions

The ultimate function of mini puberty in infant growth is nuanced. In addition—at a time of rapid hormone changes across mothers, fathers, and infants—our results suggest that a tripartite neuroendocrine relationship is conceivable. Discussion surrounds the potential role of mini puberty and the numerous limitations of the study.

中文翻译：

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母体皮质醇和父体睾酮与通过迷你青春期的婴儿生长相关

目标

婴儿睾酮 (T) 在生命早期激增。这个时期（称为迷你青春期）对发育至关重要。人们对迷你青春期的最终功能知之甚少。我们预测，具有挑战性环境的假定内分泌特征（母体皮质醇和父方 T 水平升高）的父母可能与婴儿 T 水平升高有关。反过来，假设这些内分泌关系会影响婴儿的生长。

方法

在美国首次为人父母及其婴儿的样本（n = 225 个家庭）中，我们在出生、3 个月大和 10 个月大的三种情况下测量了婴儿的身长和体重。我们在产后早期对婴儿的 T、母亲的皮质醇和父亲的 T 进行了唾液检测。

结果

我们利用潜在生长曲线模型来探索婴儿 T 预测的身长和体重变化。婴儿 T 预测了整个研究期间身长增加的斜率。母体皮质醇和父体 T（彼此呈正相关）与婴儿 T 呈正相关。母体皮质醇和父体 T 均不能预测长度增加的斜率。在探索性模型中，气质与神经内分泌指标无关。体重增加——与身长不同——与婴儿 T 无关。

结论

迷你青春期在婴儿成长中的最终功能是微妙的。此外——在母亲、父亲和婴儿之间激素快速变化的时期——我们的结果表明三方神经内分泌关系是可以想象的。讨论围绕迷你青春期的潜在作用和研究的众多局限性展开。