Little is known about human fathers’ physiology near infants’ births. This may represent a period during which paternal psychobiological axes are sensitive to fathers’ new experiences of interacting with their newborns and that can provide insights on how individual differences in fathers’ biology relate to post-partum parenting. Drawing on a sample of men in South Bend, IN (U.S.), we report results from a longitudinal study of fathers’ oxytocin, cortisol, and testosterone (N = 211) responses to their first holding of their infants on the day of birth and men's reported caregiving and father-infant bonding at 2–4 months post-partum (N = 114). First-time fathers’ oxytocin was higher following first holding of their newborns, compared to their pre-holding levels. Contrasting with prior results, fathers’ percentage change in oxytocin did not differ based on skin-to-skin or standard holding. Drawing on psychobiological frameworks, we modeled the interactions for oxytocin reactivity with testosterone and cortisol reactivity, respectively, in predicting father-infant outcomes months later. We found significant cross-over interactions for (oxytocin × testosterone) in predicting fathers’ later post-partum involvement and bonding. Specifically, we found that fathers whose testosterone declined during holding reported greater post-partum play if their oxytocin increased, compared to fathers who experienced increases in both hormones. We also observed a similar non-significant interaction for (oxytocin × cortisol) in predicting fathers’ post-partum play. Fathers whose testosterone declined during holding also reported less involvement in direct caregiving and lower father-infant bonding if their oxytocin decreased but greater direct care and bonding if their testosterone increased and oxytocin decreased. The results inform our understanding of the developmental time course of men's physiological responsiveness to father-infant interaction and its relevance to later fathering behavior and family relationships.

中文翻译：

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父亲对第一次抱新生儿的催产素反应：与睾酮反应的相互作用以预测后来的养育行为和父婴关系

关于人类父亲在婴儿出生时的生理机能知之甚少。这可能代表了父亲心理生物学轴对父亲与新生儿互动的新体验敏感的时期，并且可以提供关于父亲生物学的个体差异如何与产后育儿相关的见解。我们以印第安纳州南本德的男性样本为样本，报告了一项纵向研究的结果，该研究是对父亲 在出生当天第一次抱婴儿时的催产素、皮质醇和睾酮 ( N = 211) 的反应，以及男性在产后 2-4 个月报告的护理和父婴关系（N = 114)。第一次做父亲的人在第一次抱新生儿后的催产素水平高于抱婴儿前的水平。与之前的结果相比，父亲在催产素方面的百分比变化并没有因皮肤接触或标准持有而不同。利用心理生物学框架，我们分别模拟了催产素反应性与睾酮和皮质醇反应性的相互作用，以预测几个月后的父婴结局。我们发现（催产素 × 睾酮）在预测父亲后期的产后参与和结合方面存在显着的交叉相互作用。具体来说，我们发现，与两种激素都增加的父亲相比，如果他们的催产素增加，睾丸激素下降的父亲报告说产后玩耍会更多。我们还观察到（催产素 × 皮质醇）在预测父亲的产后游戏时存在类似的非显着相互作用。睾丸激素下降的父亲也报告说，如果他们的催产素减少，他们对直接照料的参与较少，并且父婴关系降低，但如果他们的睾丸激素增加而催产素减少，则直接照料和亲子关系会增加。这些结果使我们了解了男性对父婴互动的生理反应的发育时间过程及其与后来的父亲行为和家庭关系的相关性。睾丸激素下降的父亲也报告说，如果他们的催产素减少，他们对直接照料的参与较少，并且父婴关系降低，但如果他们的睾丸激素增加而催产素减少，则直接照料和亲子关系会增加。这些结果使我们了解了男性对父婴互动的生理反应的发育时间过程及其与后来的父亲行为和家庭关系的相关性。睾丸激素下降的父亲也报告说，如果他们的催产素减少，他们对直接照料的参与较少，并且父婴关系降低，但如果他们的睾丸激素增加而催产素减少，则直接照料和亲子关系会增加。这些结果使我们了解了男性对父婴互动的生理反应的发育时间过程及其与后来的父亲行为和家庭关系的相关性。