Lustermans H, Beijers R, de Weerth C
Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Nijmegen, the Netherlands.
Department of Social Development, Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands.
Psychophysiology. 2025 Sep;62(9):e70150. doi: 10.1111/psyp.70150.
Milk glucocorticoids (MGCs) in human milk may play a pivotal role in the health and development of children. Though MGCs might be increased by maternal stress, prior research yielded conflicting findings. The aim of this preregistered study is to examine the impact of maternal stress on MGCs. Mothers from the low-risk SMILEY cohort participated 6-8 weeks postpartum. During a naturalistic study, mothers (n = 110) reported their current global affective state three times a day (morning n = 96, afternoon n = 98, evening n = 97) and simultaneously collected milk samples (morning n = 89, afternoon n = 93, evening n = 88). During an experimental study in the lab, mothers (n = 80) were exposed to the Trier Social Stress Test or a control task and collected a milk sample 15 min thereafter. Global affect reactivity was measured using visual analogue scales and cortisol reactivity with salivary sampling. Mothers reported on mental health symptoms during the last week(s) using questionnaires. Outcomes were milk cortisol and cortisone, and the cortisol-to-cortisone ratio (cc-ratio). In the naturalistic study, global affect was unrelated to MGCs and cc-ratio. In the experimental study, the stress condition significantly increased MGCs and cc-ratio, compared to the control condition. Moreover, irrespective of group, heightened salivary cortisol reactivity was associated with increased MGCs and cc-ratio, while heightened global affect reactivity was related to increased milk cortisone only in mothers with fewer mental health symptoms. These findings show a causal effect of maternal stressor exposure on MGCs, though replication studies are warranted. Links between MGCs and self-reported global affect remain unclear, requiring future research.
人乳中的乳糖皮质激素（MGCs）可能对儿童的健康和发育起着关键作用。尽管母亲的压力可能会使MGCs增加，但先前的研究结果相互矛盾。这项预先注册研究的目的是检验母亲压力对MGCs的影响。来自低风险SMILEY队列的母亲在产后6 - 8周参与研究。在一项自然主义研究中，母亲们（n = 110）每天报告三次她们当前的整体情感状态（早上n = 96，下午n = 98，晚上n = 97），并同时采集乳汁样本（早上n = 89，下午n = 93，晚上n = 88）。在实验室的一项实验研究中，母亲们（n = 80）接受了特里尔社会压力测试或一项对照任务，并在15分钟后采集一份乳汁样本。使用视觉模拟量表测量整体情感反应性，通过唾液采样测量皮质醇反应性。母亲们使用问卷报告过去一周的心理健康症状。结果指标为乳汁皮质醇和可的松，以及皮质醇与可的松的比率（cc比率）。在自然主义研究中，整体情感与MGCs和cc比率无关。在实验研究中，与对照条件相比，压力条件显著增加了MGCs和cc比率。此外，无论组别如何，唾液皮质醇反应性增强与MGCs和cc比率增加相关，而仅在心理健康症状较少的母亲中，整体情感反应性增强与乳汁可的松增加有关。这些发现表明母亲暴露于压力源对MGCs有因果效应，不过仍需要重复研究。MGCs与自我报告的整体情感之间的联系仍不明确，需要未来进一步研究。
