The psychological resilience of an expectant father may influence the course of pregnancy and the mother’s health, according to a new study by U.S. researchers. In legally married couples, men’s internal resources—optimism, a sense of control over life, and social support—are associated with lower levels of inflammation in pregnant women and, consequently, with longer gestation. The study was published in Biopsychosocial Science and Medicine (BSM).

Preterm birth remains one of the key public health challenges, as it increases the risk of chronic diseases and developmental disorders in children later in life. One factor contributing to preterm birth is elevated systemic inflammation in the mother’s body. Until now, most research has focused on negative factors—stress, poverty, and adverse living conditions—while potential protective psychological mechanisms have received far less attention.

The research team analyzed data from the Community Child Health Network project, which followed families from socially vulnerable regions of the United States. The sample included 217 couples expecting a child. The researchers assessed so-called “psychological resilience resources” in expectant parents: optimism, self-esteem, perceived life control, and level of social support. In mothers, levels of C-reactive protein—a marker of inflammation—were additionally measured during the second and third trimesters.

The results revealed an unexpected pattern. Higher levels of psychological resilience in fathers were associated with lower levels of inflammation in mothers, which in turn predicted a longer duration of pregnancy. Notably, this effect was observed only in married couples. Among cohabiting but unmarried partners, as well as parents not living together, no such association was found.

Interestingly, the mothers’ own psychological resources in this model were not directly linked to either inflammation or pregnancy outcomes. According to the researchers, this does not mean these resources are unimportant; rather, they likely influence health through other pathways that were not examined in this study.