Department of Psychology, 1040Åbo Akademi University, Turku, Finland.
Evol Psychol. 2021 Oct;19(4):14747049211046162. doi: 10.1177/14747049211046162.
To test the hypothesis that infant night waking is an adaptation to increase interbirth intervals (IBIs) (i.e., the time between a mother's consecutive births) by exhausting the mother, we made an initial attempt at investigating whether maternal sleep disturbance is associated with longer IBIs. We also explored whether postpartum depression symptoms mediated the association between maternal sleep disturbance and IBI length. We used retrospective self-reports from 729 mothers living in Finland. We conducted structural regressions separately for the mother's two first children at two different age intervals (0-1 and 1-3 years). Infant night waking was associated with maternal sleep disturbance (β = .78-.84) and maternal sleep disturbance was associated with postpartum depression symptoms (β = .69-.81). Postpartum depression symptoms were also associated with longer IBIs for the first child (β = .23-.28). This result supports the notion that postpartum depression in and of itself could be viewed as adaptive for the offspring's fitness, and not just as an unintentional byproduct of the mother's sleep disturbance. Contrary to our prediction, maternal sleep disturbance was, however, associated with shorter IBIs for the first child (β = -.22 to -.30) when including postpartum depression symptoms in the model. We discuss the potential role of social support as an explanation for this unexpected result.
为了验证婴儿夜间醒来是一种通过使母亲疲惫来延长产间间隔（即母亲连续分娩之间的时间）的适应机制的假设，我们首次尝试调查母亲睡眠障碍是否与更长的产间间隔有关。我们还探讨了产后抑郁症状是否在母亲睡眠障碍与产间间隔长度之间起中介作用。我们使用了来自芬兰的 729 名母亲的回顾性自我报告。我们分别对母亲的头两个孩子在两个不同的年龄间隔（0-1 岁和 1-3 岁）进行结构回归。婴儿夜间醒来与母亲睡眠障碍（β=0.78-0.84）有关，而母亲睡眠障碍与产后抑郁症状（β=0.69-0.81）有关。产后抑郁症状也与第一个孩子的产间间隔较长有关（β=0.23-0.28）。这一结果支持了这样一种观点，即产后抑郁本身可以被视为对后代适应性的一种看法，而不仅仅是母亲睡眠障碍的无意副产品。与我们的预测相反，当将产后抑郁症状纳入模型时，母亲睡眠障碍与第一个孩子的产间间隔较短（β=-0.22 至-0.30）有关。我们讨论了社会支持作为对这一意外结果的解释的潜在作用。
